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RangerDangerV2
07-04-2013, 09:13 AM
There seems to be a lot of misinformation regarding 4th orders these days... So maybe this thread will help to get rid of some of that. Simply ask a question, and I, or anyone else who has knowledge of 4th orders for that matter will answer it. Please keep it strictly about 4th orders. Ask away!

RangerDangerV2
07-04-2013, 02:00 PM
http://i1161.photobucket.com/albums/q513/bumpin101/P1250006_zps597ec033.jpg (http://s1161.photobucket.com/user/bumpin101/media/P1250006_zps597ec033.jpg.html)
http://i1161.photobucket.com/albums/q513/bumpin101/P1250007_zps0b266d5a.jpg (http://s1161.photobucket.com/user/bumpin101/media/P1250007_zps0b266d5a.jpg.html)
http://i1161.photobucket.com/albums/q513/bumpin101/P1250008_zps5c880986.jpg (http://s1161.photobucket.com/user/bumpin101/media/P1250008_zps5c880986.jpg.html)
http://i1161.photobucket.com/albums/q513/bumpin101/P1250009_zps04ea19c7.jpg (http://s1161.photobucket.com/user/bumpin101/media/P1250009_zps04ea19c7.jpg.html)
heres the beginning of my current 4th order. I will be making a 12" aero, that is what the ring is for. here is the Fc of my rear chamber. Measured with the vehicle sealed and the loading wall off. Its just about right where I want it to be.
http://i1161.photobucket.com/albums/q513/bumpin101/datscap_zps6fe93bbb.png (http://s1161.photobucket.com/user/bumpin101/media/datscap_zps6fe93bbb.png.html)

5.3bowtie
07-04-2013, 02:20 PM
I will be the first to ask.......Always heard 4th orders, or bandpass boxes in general, had a certain frequency range in the "middle" that would be "dead" with the subs playing fequencies on each side of the "dead zone". Is this true?

Nice looking box btw.

RangerDangerV2
07-04-2013, 02:23 PM
I will be the first to ask.......Always heard 4th orders, or bandpass boxes in general, had a certain frequency range in the "middle" that would be "dead" with the subs playing fequencies on each side of the "dead zone". Is this true?

Nice looking box btw.
entirely false, actually, its sort of the opposite of that. they will play a bandwidth, but will roll off above and below that bandwidth, however it is a gradual roll off because of the sealed side of the enlcosure.

5.3bowtie
07-04-2013, 02:49 PM
Ah ok, so how large of a bandwidth can it hold? Is this dependant uppon drivers, box, both? How does the size of the ported section relative to the size of the sealed section determin box characteristics?

Sorry for all the newb questions, never had or built or played with a 4th order before......

Buck
07-04-2013, 02:52 PM
One thing I see a lot of in people's build thread is using a really stiff, high Fs woofer (i.e. like DD's) in a 4th and using a small sealed portion, creating a very high Fc/Qtc and they get no lows out of it.

Garcia915
07-04-2013, 03:02 PM
Can u guys list a few subs that are 4th order friendly? Do type r's do we'll in 4th orders?

Buck
07-04-2013, 03:09 PM
You want to look for a high Qts and a low Fs, and a higher Vas generally.

Type r's are 4th order friendly.

vetkilr
07-04-2013, 04:01 PM
DC level 3's and 4's work great. PSI level 1's and 2's work as well. Depending on power you can get them minus a spider to make them more efficient. Seen two 12" psi level one's with only 1 spider sound really loud on a BC2000d.

RangerDangerV2
07-05-2013, 12:26 AM
Ah ok, so how large of a bandwidth can it hold? Is this dependant uppon drivers, box, both? How does the size of the ported section relative to the size of the sealed section determin box characteristics?
very dependent on the rear chamber, woofers, and ratio. Typically, a larger ratio of sealed to ported will have a smaller passband, but a higher spl. But, if you want to get your low end back, you can throw more power at your woofers. That has worked for me quite well, if your woofers can handle it.
Sorry for all the newb questions, never had or built or played with a 4th order before......
questions are a great thing! thats why I made this thread!

One thing I see a lot of in people's build thread is using a really stiff, high Fs woofer (i.e. like DD's) in a 4th and using a small sealed portion, creating a very high Fc/Qtc and they get no lows out of it.
Most of the people that I have met/seen that do that, are using very large ratios (above 5:1) and are strictly doing it for spl burps.

Can u guys list a few subs that are 4th order friendly? Do type r's do we'll in 4th orders?
type rs would be great, soft suspension and low fs, otherwise, The sa series is another favorite.

You want to look for a high Qts and a low Fs, and a higher Vas generally.

Type r's are 4th order friendly.
yup yup. I would like to swap out the sa's for r's just for an experiment, but the r's wouldnt fit in my flush mount lol

5.3bowtie
07-05-2013, 10:10 AM
When you say a 5:1 ratio, does that mean the sealed portion or the vented portion is larger?

RangerDangerV2
07-05-2013, 10:23 AM
When you say a 5:1 ratio, does that mean the sealed portion or the vented portion is larger?

the vented side, which is referred to as the front chamber, is the larger portion. and it is always either the same size, or larger than the sealed portion, which is referred to as the rear chamber. so 5:1 = Front:rear

TaylorFade
07-05-2013, 12:02 PM
You could start by explaining the fact that the term "4th order" is a bit of a misnomer since a regular ol' ported box is also a 4th order. Lol.

RangerDangerV2
07-05-2013, 12:09 PM
You could start by explaining the fact that the term "4th order" is a bit of a misnomer since a regular ol' ported box is also a 4th order. Lol.

I thought about just filling up the first post with everything that I know, but thats no fun, and too much information at once is hard for some people to comprehend. so please, take it away if you wish.

---------- Post added at 12:09 PM ---------- Previous post was at 12:09 PM ----------

I suppose we could start using the term "4th order BP"

TaylorFade
07-05-2013, 01:25 PM
I thought about just filling up the first post with everything that I know, but thats no fun, and too much information at once is hard for some people to comprehend. so please, take it away if you wish.

---------- Post added at 12:09 PM ---------- Previous post was at 12:09 PM ----------

I suppose we could start using the term "4th order BP"

Or single reflex bandpass. But that could include a series tuned "6th" order and quasi 8th too, I suppose.

Anyway... why don't you go into detail about how you arrived at the graph and the tuning for the box you posted for those who don't know. And why we tune to sealed resonance.

And how one might arrive at tuning without a "Woofer Tester."

How ratios affect bandwidth.

How to figure port area. And how tuning or other factors affect said area.

How the size of the sealed chamber affects response.

RangerDangerV2
07-05-2013, 01:50 PM
Or single reflex bandpass. But that could include a series tuned "6th" order and quasi 8th too, I suppose.

Anyway... why don't you go into detail about how you arrived at the graph and the tuning for the box you posted for those who don't know. And why we tune to sealed resonance.
I purchased a DATS (first I did some math but I will delve into that later) placed my enclosure in the tahoe, vehicle sealed, loading wall off of the enclosure. Then I ran an impedence sweep, which showed me at what frequency my imp. peaked at. That is called the Fc or sealed resonance.
And how one might arrive at tuning without a "Woofer Tester."
the equation is (Vas/Vb)+1, then sqrt that number, and multiply by the fs of the woofer. when I did this I got an Fc of 45.5 hz, real world with the dats was 45.09. quite close if you ask me, so I would have no problem trusting the equation.
How ratios affect bandwidth.
to put it in simple terms, large ratio= smaller passband smaller ratio=larger passband. but I have found that is not always the case. many more factors that have control over your bandwidth than just the ratio
How to figure port area. And how tuning or other factors affect said area.
im a test and find out type of guy, but I usually start off with 1/2 port area to cone are (my enclosure uses a single 12" aero, because I have 2 12s) I prefer to go bigger, because shrinking down is easy. But some people have luck with 1/3 port to cone area. I have had good luck with 1/2 though. But many things come into play here such as goals, woofers, vehicle, etc. just like any other enclosure.
How the size of the sealed chamber affects response.
more simple terms, typically, large rear= lots of low end, but lacks on the higher end from what I have seen, and the opposite applies for smaller rear ends. But I am a fan of my Fc being in the 45-48hz range for daily.

I am not the best at explaining things, because I cant really put them into simple terms very well. hopefully everyone understands this. Also, I am no 4th order master, I dont have all of the answers, but I do know a good amount, mostly from testing, and educating myself. So please, if anyone else has some things that they would like to add, feel free to do so, I could always use some more information!

Buck
07-05-2013, 02:30 PM
more simple terms, typically, large rear= lots of low end, but lacks on the higher end from what I have seen, and the opposite applies for smaller rear ends. But I am a fan of my Fc being in the 45-48hz range for daily.



I'm right there with you.

RangerDangerV2
07-05-2013, 02:35 PM
I'm right there with you.

like I said too... lots is woofer dependent as well. Thats why the sa series is my favorite. they are kind of a middle category woofer. they can work well in almost anything, and they really shine in the 4th orders. plus they dont need a large rear chamber at all.

---------- Post added at 02:35 PM ---------- Previous post was at 02:34 PM ----------

but yeah, thats why I said "typically" lol power is a factor as well

Buck
07-05-2013, 02:44 PM
Power is a big factor especially when trying to mix lows with high power, trying to balance the lower Fc with mechanical handling. Low Fs woofers really make that easy, like the RE XXX.

RangerDangerV2
07-06-2013, 01:43 AM
Power is a big factor especially when trying to mix lows with high power, trying to balance the lower Fc with mechanical handling. Low Fs woofers really make that easy, like the RE XXX.

fur sure lol

Buck
07-06-2013, 02:07 AM
I've always thought home theater 4th order were interesting. It's where you do something like 3:1 ratio, except your larger section is the sealed one and the smaller one is the ported. Gotta get those 10 hz lows.

SounDrive
07-06-2013, 02:10 AM
This thread makes me want to grab a pair of AA Havocs

RangerDangerV2
07-06-2013, 02:19 AM
This thread makes me want to grab a pair of AA Havocs

get some sa's yo. cheap, and they can get stupid. at least mine do... lol

Buck
07-06-2013, 02:21 AM
The end plan in my explorer is 8 sa-15's in a 4th order wall :sneaky:

RangerDangerV2
07-06-2013, 02:22 AM
I've always thought home theater 4th order were interesting. It's where you do something like 3:1 ratio, except your larger section is the sealed one and the smaller one is the ported. Gotta get those 10 hz lows.

id just get that fan that can play down to 1hz... you may not be able to hear it, but you can def feel 1hz @120 db lol

RangerDangerV2
07-06-2013, 02:23 AM
The end plan in my explorer is 8 sa-15's in a 4th order wall :sneaky:

one of my buddies is doing 12 12s in a 4th, and another guy I know just did 8 15s in a 4th on 4 ns1s.

Buck
07-06-2013, 02:23 AM
Fi IB3 is where it's at. I say some video where this dude was shaking his old house with 4 18's mounted in a wall, like literally in one of his walls on his house. His ceiling fan was shaking up and down like in an earthquake playin like 5 hz or something stupid.

SounDrive
07-06-2013, 02:34 AM
The end plan in my explorer is 8 sa-15's in a 4th order wall :sneaky:

Before or after you completely destroy the thing from flex? lol

Buck
07-06-2013, 02:39 AM
Before or after you completely destroy the thing from flex? lol

I'll build the wall when the hatch is unrepairable.

SounDrive
07-06-2013, 02:42 AM
I'll build the wall when the hatch is unrepairable.

If you wake up with a destroyed hatch one day.... it wasn't me

Buck
07-06-2013, 02:44 AM
If you wake up with a destroyed hatch one day.... it wasn't me

Yes it was.

RangerDangerV2
07-07-2013, 06:18 PM
I got the port made, and I got it in, just for temp yesterday so my buddies could here it. I still have a lot of work to do, but its coming together... should be an easy 50, but sealed will be a different story. so heres some pics.
http://i1161.photobucket.com/albums/q513/bumpin101/IMG292_zps6ef0bcb5.jpg (http://s1161.photobucket.com/user/bumpin101/media/IMG292_zps6ef0bcb5.jpg.html)
http://i1161.photobucket.com/albums/q513/bumpin101/IMG293_zps0801a98d.jpg (http://s1161.photobucket.com/user/bumpin101/media/IMG293_zps0801a98d.jpg.html)
http://i1161.photobucket.com/albums/q513/bumpin101/IMG294_zps72ba76ee.jpg (http://s1161.photobucket.com/user/bumpin101/media/IMG294_zps72ba76ee.jpg.html)
http://i1161.photobucket.com/albums/q513/bumpin101/IMG295_zps39e1e894.jpg (http://s1161.photobucket.com/user/bumpin101/media/IMG295_zps39e1e894.jpg.html)
dat port area... it plays music quite well, which is to be expected, but it does some nazzty burps fur sure. I have lots of testing to do.... lol. plus I still have to finish the port!

RangerDangerV2
07-07-2013, 10:56 PM
nobody else wants to share their 4th order builds?!?! come on people!

RangerDangerV2
07-09-2013, 12:19 PM
I got my first set of numbers today, this is drop in, no testing, no deadner etc. Im wired to 3 ohms, rising to about 6 or 7 ohms. No clamp numbers because I cant find my clamp. I know it is well under 1000 watts though. I want to say that its about 6-700 watts, but like I said, no clamp, so im not going to say anything. But its not too bad for music, vehicle sealed, meter is at the MWSPL location song is juicebox.
http://i1161.photobucket.com/albums/q513/bumpin101/musicsealed_zpsad13f8eb.png (http://s1161.photobucket.com/user/bumpin101/media/musicsealed_zpsad13f8eb.png.html)

RangerDangerV2
07-09-2013, 12:21 PM
and if you didnt know, this is in a tahoe. not quite under the window line because I havent dropped down the false floor, but its only like .75" over

RangerDangerV2
07-09-2013, 12:26 PM
feel free to ask questions people!

vetkilr
07-09-2013, 01:10 PM
FloridaSPL - View Single Post - 2 DC Level 4 12's on a 3500 in a Blowthru - 2011 Malibu (http://www.floridaspl.com/forums/showpost.php?p=440152&postcount=44)

---------- Post added at 01:09 PM ---------- Previous post was at 01:09 PM ----------

FloridaSPL - View Single Post - 2 DC Level 4 12's on a 3500 in a Blowthru - 2011 Malibu (http://www.floridaspl.com/forums/showpost.php?p=440209&postcount=47)

---------- Post added at 01:10 PM ---------- Previous post was at 01:09 PM ----------

FloridaSPL - View Single Post - 2 DC Level 4 12's on a 3500 in a Blowthru - 2011 Malibu (http://www.floridaspl.com/forums/showpost.php?p=440268&postcount=54)

RangerDangerV2
07-09-2013, 01:16 PM
FloridaSPL - View Single Post - 2 DC Level 4 12's on a 3500 in a Blowthru - 2011 Malibu (http://www.floridaspl.com/forums/showpost.php?p=440152&postcount=44)

---------- Post added at 01:09 PM ---------- Previous post was at 01:09 PM ----------

FloridaSPL - View Single Post - 2 DC Level 4 12's on a 3500 in a Blowthru - 2011 Malibu (http://www.floridaspl.com/forums/showpost.php?p=440209&postcount=47)

---------- Post added at 01:10 PM ---------- Previous post was at 01:09 PM ----------

FloridaSPL - View Single Post - 2 DC Level 4 12's on a 3500 in a Blowthru - 2011 Malibu (http://www.floridaspl.com/forums/showpost.php?p=440268&postcount=54)
beautiful build! if I was a daily guy I would love to have something so clean, but sadly, im always cutting, gluing and taping lol

RangerDangerV2
07-09-2013, 04:47 PM
http://i1161.photobucket.com/albums/q513/bumpin101/IMG296_zpsa2c1dbcc.jpg (http://s1161.photobucket.com/user/bumpin101/media/IMG296_zpsa2c1dbcc.jpg.html)
whoops... 4th order FTW!

Buck
07-09-2013, 08:18 PM
http://i1161.photobucket.com/albums/q513/bumpin101/IMG296_zpsa2c1dbcc.jpg (http://s1161.photobucket.com/user/bumpin101/media/IMG296_zpsa2c1dbcc.jpg.html)
whoops... 4th order FTW!

http://images.wikia.com/adventuretimewithfinnandjake/images/f/f0/And_its_gone_original.jpg

RangerDangerV2
07-09-2013, 08:21 PM
http://images.wikia.com/adventuretimewithfinnandjake/images/f/f0/And_its_gone_original.jpg

I need to shorten my port, to cause a resonance spike, I will gain quite a bit im sure, I may shrink down the front too. this tahoe is hard to get loud in with such little cone area and power, but its doing okay, its a burp box, that im playing music with, I just cant find any tones lol

Buck
07-09-2013, 08:23 PM
What's your rear Fc?

RangerDangerV2
07-09-2013, 08:25 PM
What's your rear Fc?

45, and im not going smaller, I will throw the surrounds if I do. and yes, I know tune to the Fc is what you SHOULD do, which I did to begin with, but, if you tune above the Fc, it will cause a resonance spike. which I need for a burp situation.

Buck
07-09-2013, 08:30 PM
45, and im not going smaller, I will throw the surrounds if I do. and yes, I know tune to the Fc is what you SHOULD do, which I did to begin with, but, if you tune above the Fc, it will cause a resonance spike. which I need for a burp situation.

I was jc. Just getting the picture. You can't beat testing.

Buck
07-09-2013, 08:33 PM
Did you try testing rear firing?

RangerDangerV2
07-09-2013, 08:34 PM
I was jc. Just getting the picture. You can't beat testing.
true that. I need to beat a 148.7 on under 1k clamped. thats the record held by n8skow ; I might get it, but I doubt it. I hope to come close though. still lots of work to do, this is only the second day of testing, so far I have gained 8db since yesterday lol

RangerDangerV2
07-09-2013, 08:36 PM
Did you try testing rear firing?

yup, gained me over 1db

---------- Post added at 08:36 PM ---------- Previous post was at 08:35 PM ----------

which I expected
lol

Buck
07-09-2013, 08:36 PM
yup, gained me over 1db

---------- Post added at 08:36 PM ---------- Previous post was at 08:35 PM ----------

which I expected
lol

Ya, that's right lol.

RangerDangerV2
07-09-2013, 08:39 PM
Ya, that's right lol.

i figured why not test port forward lol, never know what could happen. All in all, I am learning a lot, this being my first actual 4th order build. if I could burp a 146 or 147 I would be quite happy, its nice that im louder sealed than outlaw though, by almost 2 db! lol

RangerDangerV2
07-09-2013, 08:44 PM
and the sucky part is, ive been testing music all day, because I cant find any 0db tones lol, im sure burps will gain me too

Buck
07-09-2013, 09:04 PM
i figured why not test port forward lol, never know what could happen. All in all, I am learning a lot, this being my first actual 4th order build. if I could burp a 146 or 147 I would be quite happy, its nice that im louder sealed than outlaw though, by almost 2 db! lol

That's a very significant difference.

RangerDangerV2
07-09-2013, 09:06 PM
That's a very significant difference.

from what I have seen, its pretty common for that to happen with small cone area/large cabin setups. which makes sense.

RangerDangerV2
07-10-2013, 10:46 AM
http://i1161.photobucket.com/albums/q513/bumpin101/1445_zpsb07dd6bd.png (http://s1161.photobucket.com/user/bumpin101/media/1445_zpsb07dd6bd.png.html)
making progress. only thing I did, was to actually set my gain with my scope instead of guessing. but this score is vehicle sealed, wired to 2.6, probably rising into the 5 or 6 ohms range, so that should give me around 600-800 watts. not too bad, but no where near where I want to be. peaking looooow too. which I like.

RangerDangerV2
07-10-2013, 11:35 AM
I used the dats to find my rise, and I rise from 2.3 ohms, to 8.93 ohms at 32hz. so 3500/8.93 is 391.9 watts....

mazdakid
07-10-2013, 12:03 PM
You need to bolt your box down so you dont get so much box rise.

RangerDangerV2
07-10-2013, 01:20 PM
You need to bolt your box down so you dont get so much box rise.

LOL! the dats is off I believe, but a 4th order typically has a lot of rise.

RangerDangerV2
07-10-2013, 05:08 PM
test test test test lol lots of variables with 4th orders.

vetkilr
07-10-2013, 09:19 PM
LOL! the dats is off I believe, but a 4th order typically has a lot of rise.

Yep mine wired to .5 and rises almost to 5 ohms.

RangerDangerV2
07-10-2013, 09:58 PM
Yep mine wired to .5 and rises almost to 5 ohms.

yeah... so im doing a 144.5, sealed, on 397 watts or so... no big deal lol

Buck
07-10-2013, 11:08 PM
yeah... so im doing a 144.5, sealed, on 397 watts or so... no big deal lol

What frequency? Isn't it low?

I compliment your db achievement.

RangerDangerV2
07-10-2013, 11:11 PM
What frequency? Isn't it low?

I compliment your db achievement.

32hz lol pretty low to me

---------- Post added at 11:11 PM ---------- Previous post was at 11:10 PM ----------

and thanks!

RangerDangerV2
07-11-2013, 10:40 AM
http://i1161.photobucket.com/albums/q513/bumpin101/14518_zpsf0efb934.png (http://s1161.photobucket.com/user/bumpin101/media/14518_zpsf0efb934.png.html)
best so far, not bad for less than 500 watts :cool:

n8skow
07-11-2013, 11:12 AM
That should be close to a 148 on 1k, turned it up yet?
:cool:




best so far, not bad for less than 500 watts :cool:

RangerDangerV2
07-11-2013, 11:43 AM
That should be close to a 148 on 1k, turned it up yet?
:cool:

I could wire to .5... but im enjoying 2 ohms lol. Id try for the b1 record, but the b2 record is quieter lol.

RangerDangerV2
07-11-2013, 07:59 PM
tested more today... couldnt get more than the 145.18, morning it averages 144.5ish, midday and night after its been in the sun all day it meters about a 141.5. really amazing how much the temp of the vehicle matters. but ive got some plans, so hopefully Ill see that 150 by sunday.

RangerDangerV2
07-11-2013, 08:02 PM
some other cool stuff, does a 160.2 in the port, and 134.xx 1 ft outside the window, not too shabby I would say. both those are at 33hz.

noble brown
07-11-2013, 09:58 PM
I wish I could understand half of what you cats are saying, but I'm learning. I am thinking of building a fourth for a pair of type r's. So I throw some numbers in a program I found on the net and I have some questions. First shouldn't the volume need to be larger then with a ported? The program o only allowed for calculations for one speaker at a time so do I just double the volumes for two? Is a db gain of two or three audibly noticeable, if so how much. For an everyday driver I wanna be able to get the lows nicely (listen to rap) but I also wanna gain as much as I can too. Currently I'm tuned to 32hz and I like it but wondering if it's practical to sacrifice a bit of the low end for some gain. I guess I'm curious how low rap on average gets
. Isn't low 30's rare? also is the functional output of a given port the same regardless of shape as long as the volume is the same?

RangerDangerV2
07-11-2013, 10:13 PM
I wish I could understand half of what you cats are saying, but I'm learning. I am thinking of building a fourth for a pair of type r's. So I throw some numbers in a program I found on the net and I have some questions. First shouldn't the volume need to be larger then with a ported? The program o only allowed for calculations for one speaker at a time so do I just double the volumes for two? Is a db gain of two or three audibly noticeable, if so how much. For an everyday driver I wanna be able to get the lows nicely (listen to rap) but I also wanna gain as much as I can too. Currently I'm tuned to 32hz and I like it but wondering if it's practical to sacrifice a bit of the low end for some gain. I guess I'm curious how low rap on average gets
. Isn't low 30's rare? also is the functional output of a given port the same regardless of shape as long as the volume is the same?

forget the program. do the equation to find the Fc of your rear chamber, then multiply that by the ratio that you wish to achieve. a 3db gain is very noticeable. depending on the design of the 4th order, you can dig very low, and be very loud on little power, like my enclosure. and some port shapes are louder than others, but that depends on the application. I would go with a slot port, very easy to do

noble brown
07-11-2013, 10:21 PM
What ratio would you recommend for my application. I will do the math and figure it out. Will I have to go large then my 4.2cu ported I have now to get the gain I'm looking for or will that depend on what I come up with on my math

RangerDangerV2
07-11-2013, 10:24 PM
What ratio would you recommend for my application. I will do the math and figure it out. Will I have to go large then my 4.2cu ported I have now to get the gain I'm looking for or will that depend on what I come up with on my math

id go with the standard 2:1, and yes it will probably be a tad larger than your enclosure now, gain is really dependent upon design, but some people see a 6+ db gain. but put it this way, I used to run 4 12s in a ported enclosure, and I was doing 145.1 on about 2k, now, im running 2 sa12s, and doing a 145.1 on about 400 watts. lol

SounDrive
07-11-2013, 10:31 PM
id go with the standard 2:1, and yes it will probably be a tad larger than your enclosure now, gain is really dependent upon design, but some people see a 6+ db gain. but put it this way, I used to run 4 12s in a ported enclosure, and I was doing 145.1 on about 2k, now, im running 2 sa12s, and doing a 145.1 on about 400 watts. lol

This post has me wanting to do a 4th order trunk build... even though my rear deck opening makes my trunk into a 6th order of sorts already lol

RangerDangerV2
07-11-2013, 10:35 PM
This post has me wanting to do a 4th order trunk build... even though my rear deck opening makes my trunk into a 6th order of sorts already lol

do it man! my numbers dont lie lol! 4th orders can do some magical things

SounDrive
07-11-2013, 10:44 PM
do it man! my numbers dont lie lol! 4th orders can do some magical things

I may throw some ideas around, I've got about 8 cubes to work with (before any displacements) and this would be about the only way to do a cabin firing build in my car due to the rear deck being so short. Now that I think of it, I may be able to squeeze a little more volume with the front chamber sliding under the rear deck.

Can you think of any higher powered woofers that work well in a 4th order? More likely than not it'll be 2 12s or 1 15 on around 4k - although I'm really not sure how rise effects a 4th order bandpass compared to a regular ported enclosure

RangerDangerV2
07-11-2013, 10:55 PM
I may throw some ideas around, I've got about 8 cubes to work with (before any displacements) and this would be about the only way to do a cabin firing build in my car due to the rear deck being so short. Now that I think of it, I may be able to squeeze a little more volume with the front chamber sliding under the rear deck.

Can you think of any higher powered woofers that work well in a 4th order? More likely than not it'll be 2 12s or 1 15 on around 4k - although I'm really not sure how rise effects a 4th order bandpass compared to a regular ported enclosure

rise is really dependent on ratio... large ratio like mine, equals lots of rise. but rise is actually efficiency. I rise from 2.3 ohms to 8.8 at 33hz. now, if you were to do a 1:1 or a 2:1 you would have less rise. but honestly, id go zv3s, or even sas if you have a 4k amp, because you will never see 4k out of it.

SounDrive
07-11-2013, 11:23 PM
rise is really dependent on ratio... large ratio like mine, equals lots of rise. but rise is actually efficiency. I rise from 2.3 ohms to 8.8 at 33hz. now, if you were to do a 1:1 or a 2:1 you would have less rise. but honestly, id go zv3s, or even sas if you have a 4k amp, because you will never see 4k out of it.

Yeah, when competing a huge ratio would be better because of rise for me (MECA is classified by cone area + fuse rating, could run a tiny fuse with that kind of rise) but I'm not too concerned with competing right now. I'm just tired of being limited to a trunk build and want to switch it up and possibly get louder. Most of my listening is music at full tilt for long periods of time while driving lol

2 Zv3 10s with a huge ratio on a ton of power would absolutely rape everyone else in the trunk class

RangerDangerV2
07-11-2013, 11:25 PM
Yeah, when competing a huge ratio would be better because of rise for me (MECA is classified by cone area + fuse rating, could run a tiny fuse with that kind of rise) but I'm not too concerned with competing right now. I'm just tired of being limited to a trunk build and want to switch it up and possibly get louder. Most of my listening is music at full tilt for long periods of time while driving lol

2 Zv3 10s with a huge ratio on a ton of power would absolutely rape everyone else in the trunk class

its not as easy as I make it look lol. 4th orders take a good amount of work in both design and build to make them do work. I designed mine at least 20 times until I was happy

SounDrive
07-11-2013, 11:30 PM
its not as easy as I make it look lol. 4th orders take a good amount of work in both design and build to make them do work. I designed mine at least 20 times until I was happy

Yeah I get that as well. A musical box isn't going to perform as well as a burp box either lol

I'm just adding this to the list of things to do.... There's plenty of things in front of it... like ultracaps :) and upgrading my rear suspension before it blows out

RangerDangerV2
07-11-2013, 11:32 PM
Yeah I get that as well. A musical box isn't going to perform as well as a burp box either lol

I'm just adding this to the list of things to do.... There's plenty of things in front of it... like ultracaps :) and upgrading my rear suspension before it blows out

my "burp" box plays flat within 2db from 25-60hz lol if thats not flat then I dont know what is

SounDrive
07-11-2013, 11:38 PM
my "burp" box plays flat within 2db from 25-60hz lol if thats not flat then I dont know what is

I'm jealous... lol

RangerDangerV2
07-11-2013, 11:43 PM
I'm jealous... lol

the power of the 4th order! lol

anubis
07-12-2013, 11:41 AM
more simple terms, typically, large rear= lots of low end, but lacks on the higher end from what I have seen, and the opposite applies for smaller rear ends. But I am a fan of my Fc being in the 45-48hz range for daily.

I am not the best at explaining things, because I cant really put them into simple terms very well. hopefully everyone understands this. Also, I am no 4th order master, I dont have all of the answers, but I do know a good amount, mostly from testing, and educating myself. So please, if anyone else has some things that they would like to add, feel free to do so, I could always use some more information!

What is Vb?

Buck
07-12-2013, 12:23 PM
Yeah I get that as well. A musical box isn't going to perform as well as a burp box either lol

I'm just adding this to the list of things to do.... There's plenty of things in front of it... like ultracaps :) and upgrading my rear suspension before it blows out

Getting that spoiler under control lol.

SounDrive
07-12-2013, 12:38 PM
Getting that spoiler under control lol.

I'd remove it but it would be a PITA to get everything looking right... (And I would have to install and wire a third brake light)

Maybe I'll just jb weld it to the trunk. Lol

Buck
07-12-2013, 12:50 PM
What is Vb?

Box volume.

noble brown
07-12-2013, 04:10 PM
so im starting to turn some numbers... Vb, where do i pull this number from. specs for my type r's is pretty conservative and also im assuming I would use sealed specs, right? and is the correct units to use for Vas liters?

Buck
07-12-2013, 05:12 PM
so im starting to turn some numbers... Vb, where do i pull this number from. specs for my type r's is pretty conservative and also im assuming I would use sealed specs, right? and is the correct units to use for Vas liters?

Vb can vary drastically depending on your goals and the woofer. All of the t/s parameters basically determine box size as far as maximum goes. This is ported box size.

Most 10's it's about 1 cube.
Most 12's it's about 1.5-2.5 cubes.
Most 15's it's bout 3-5 cubes
Most 18's it's 5-8 cubes.

---------- Post added at 04:12 PM ---------- Previous post was at 04:12 PM ----------

For the type r's you can do 2-2.5 tuned all over the place depending on what you want.

RangerDangerV2
07-12-2013, 05:58 PM
Vb can vary drastically depending on your goals and the woofer. All of the t/s parameters basically determine box size as far as maximum goes. This is ported box size.

Most 10's it's about 1 cube.
Most 12's it's about 1.5-2.5 cubes.
Most 15's it's bout 3-5 cubes
Most 18's it's 5-8 cubes.

---------- Post added at 04:12 PM ---------- Previous post was at 04:12 PM ----------

For the type r's you can do 2-2.5 tuned all over the place depending on what you want.

for two of them I would suggest that, but with single spider suspension and such a low Fs already, that will get very sloppy on the low end. Too low of an Fc is terrible from my tests, lowest I would go is about 40. anything lower got really sloppy on almost anything. but to each his own. never tested with type r's

Buck
07-12-2013, 05:59 PM
for two of them I would suggest that, but with single spider suspension and such a low Fs already, that will get very sloppy on the low end. Too low of an Fc is terrible from my tests, lowest I would go is about 40. anything lower got really sloppy on almost anything. but to each his own. never tested with type r's

Those were ported specs.

RangerDangerV2
07-12-2013, 06:01 PM
Those were ported specs.

oh, sorry :blackeye: lol

---------- Post added at 06:01 PM ---------- Previous post was at 06:00 PM ----------

this thread was SUPPOSED to be for 4th orders... I got confused lol

Buck
07-12-2013, 06:45 PM
I'm sorry :(

So those are sa-12's you are running? What's the specs of the box now?

RangerDangerV2
07-12-2013, 06:48 PM
I'm sorry :(

So those are sa-12's you are running? What's the specs of the box now?
yes, sa12s, rear chamber is 2 cubes. thats all im giving out lol

RangerDangerV2
07-12-2013, 06:52 PM
http://i1161.photobucket.com/albums/q513/bumpin101/4thordercap_zps7b04f4b4.png (http://s1161.photobucket.com/user/bumpin101/media/4thordercap_zps7b04f4b4.png.html)
heres the innards though lol

Buck
07-12-2013, 06:53 PM
Yes, that's what I've used on them as well.

RangerDangerV2
07-12-2013, 06:58 PM
Yes, that's what I've used on them as well.

id go smaller, but the tahoe peaks so low, theres not point to it. and if one were to go smaller, the woofers would be getting beat on fur sure... I doubt the surrounds would hold up lol. but 1-1.2 is optimal.

Buck
07-12-2013, 07:01 PM
There is a certain trust or faith you have to have with people when it comes to mechanical failure. I say that because you have to assume people will test the limits of that box, so it's fair to give a little over-excursion room, as in more cone control. So I think long and hard about the size of my chambers.

If you know what I mean :naughty:

RangerDangerV2
07-12-2013, 07:03 PM
There is a certain trust or faith you have to have with people when it comes to mechanical failure. I say that because you have to assume people will test the limits of that box, so it's fair to give a little over-excursion room, as in more cone control. So I think long and hard about the size of my chambers.

If you know what I mean :naughty:

******, the way I like it.

Buck
07-12-2013, 07:03 PM
One guy was running almost 8 cubes with 4 12's to achieve the Fc he wanted. I understand that, but for most I wouldn't feel comfortable doing that even if the numbers did match up. If it was my box, wouldn't be a second thought about it because I know how to spot problems. That's why bandpasses are fun. Trying to get the best performance while trying not to mechanically destroy your woofer. Maybe that's the name of the game.

RangerDangerV2
07-12-2013, 07:06 PM
One guy was running almost 8 cubes with 4 12's to achieve the Fc he wanted. I understand that, but for most I wouldn't feel comfortable doing that even if the numbers did match up. If it was my box, wouldn't be a second thought about it because I know how to spot problems. That's why bandpasses are fun. Trying to get the best performance while trying not to mechanically destroy your woofer. Maybe that's the name of the game.

one thing I learned, small rear chamber=more port larger rear=less port. Im as small as I want to go rear chamber wise, but I still only have like .25" of excursion, now, since I have a large ratio, the woofers arent pressurizing the enclosure as I wish they were, thats why im chopping the port down. That will give me a higher tuning, and more excursion at my peak.

Buck
07-12-2013, 07:10 PM
one thing I learned, small rear chamber=more port larger rear=less port. Im as small as I want to go rear chamber wise, but I still only have like .25" of excursion, now, since I have a large ratio, the woofers arent pressurizing the enclosure as I wish they were, thats why im chopping the port down. That will give me a higher tuning, and more excursion at my peak.

smaller chamber = higher Fc. The higher you tune, the higher your vent mach is given same power and port area. So it makes sense why your port velocity would increase when you shrink the rear chamber based on that logic.

noble brown
07-12-2013, 11:15 PM
ok so vas:46/Vb:2.2=20.9 + 1 = 21.9, sqrt = 4.6 x Fs:27 = 126, which should be my Fc of my rear chamber right? it seems really high. am i messing something up?

RangerDangerV2
07-12-2013, 11:17 PM
ok so vas:46/Vb:2.2=20.9 + 1 = 21.9, sqrt = 4.6 x Fs:27 = 126, which should be my Fc of my rear chamber right? it seems really high. am i messing something up?

vb needs to be in liters. you have to convert it from cu ft.

noble brown
07-12-2013, 11:19 PM
specs claim the 46 is in liters. a missprint?

RangerDangerV2
07-12-2013, 11:21 PM
specs claim the 46 is in liters. a missprint?

vas is in liters. you need your Vb to be in liters as well.

noble brown
07-12-2013, 11:22 PM
wouldnt that give me an even larger number, 46 cuft is 1302 liters

---------- Post added at 11:21 PM ---------- Previous post was at 11:21 PM ----------

oh ok

---------- Post added at 11:22 PM ---------- Previous post was at 11:21 PM ----------

duh

noble brown
07-12-2013, 11:26 PM
ok so Fs of rear is 35hz. i multiply this by my desired ratio... whats my next step

Oraclem19
07-12-2013, 11:32 PM
its not as easy as I make it look lol. 4th orders take a good amount of work in both design and build to make them do work. I designed mine at least 20 times until I was happy
curious to build one of these, from what you say(some of the time) it is simple calculate rear chamber tune, multiply ratio for front chamber, port front chamber.
Yet with all the redesign, what is there to adjust so many times? ratio, port volume, and port size?
Just looking to get enough information to not put $800 into wood redesigning this many times. Possibly how to find what Fb to tune front chamber to and how that(as well as Fc) translate to the response range?

Not sure if you have a preferred program or if there is one. Used to use Bassbox until my license expired. Possible in Hornresp?
Not exactly trying to rule 4th orders, just trying to get Q requirements for a good 4th order woofer, and be able to make 35-55 flat(ish) response boxes. Anything on that is just a bonus.

RangerDangerV2
07-12-2013, 11:41 PM
curious to build one of these, from what you say(some of the time) it is simple calculate rear chamber tune, multiply ratio for front chamber, port front chamber.
Yet with all the redesign, what is there to adjust so many times? ratio, port volume, and port size?
Just looking to get enough information to not put $800 into wood redesigning this many times. Possibly how to find what Fb to tune front chamber to and how that(as well as Fc) translate to the response range?

Not sure if you have a preferred program or if there is one. Used to use Bassbox until my license expired. Possible in Hornresp?
Not exactly trying to rule 4th orders, just trying to get Q requirements for a good 4th order woofer, and be able to make 35-55 flat(ish) response boxes. Anything on that is just a bonus.

have you ever tested at all for spl? what I am trying to accomplish is very difficult, and so far I am succeeding. I am not building your everyday 4th order. The smallest changes with my enclosure can make huge differences. if you want a simple 4th order, then build a simple 4th order. I dont use programs, I use my mind. honestly, what you need to do, is pick a woofer, run the numbers, and see if it will model well in a 4th, I dont have a long list that I keep for 4th order friendly woofers.

Oraclem19
07-13-2013, 12:32 AM
have you ever tested at all for spl? what I am trying to accomplish is very difficult, and so far I am succeeding. I am not building your everyday 4th order. The smallest changes with my enclosure can make huge differences. if you want a simple 4th order, then build a simple 4th order. I dont use programs, I use my mind. honestly, what you need to do, is pick a woofer, run the numbers, and see if it will model well in a 4th, I dont have a long list that I keep for 4th order friendly woofers.
Was simply wondering if it had a certain Q it likes. Like every tranmission and horns and a few other complex styles as I consider this a complex design.

Why not have your design style be an everyday design? 25hz-60hz with 2 db difference sounds pretty **** musically ideal in a daily box to me.

What numbers am I running? I only know how to calculate a Fc, and multiply it by a ratio chosen at random between 1:1 and 4:1 depending on... desired box rise(?)

Does this modeling consist of a calculation to determine spl at a certain hz, watt, and box resonance? Would love to not need a program for that.

You started this thread to ask "any" questions about 4th orders. Just trying to get enough info here so I don't need to make 20 boxes, test 10 woofers, and find someone who will loan me a TermLab 100 times to find a box that performs in the correct frequency range with the flatness I desire.

RangerDangerV2
07-13-2013, 12:39 AM
Was simply wondering if it had a certain Q it likes. Like every tranmission and horns and a few other complex styles as I consider this a complex design.

Why not have your design style be an everyday design? 25hz-60hz with 2 db difference sounds pretty **** musically ideal in a daily box to me.

What numbers am I running? I only know how to calculate a Fc, and multiply it by a ratio chosen at random between 1:1 and 4:1 depending on... desired box rise(?)

Does this modeling consist of a calculation to determine spl at a certain hz, watt, and box resonance? Would love to not need a program for that.

You started this thread to ask "any" questions about 4th orders. Just trying to get enough info here so I don't need to make 20 boxes, test 10 woofers, and find someone who will loan me a TermLab 100 times to find a box that performs in the correct frequency range with the flatness I desire.

My design is a burp design, the goal is 150 with less than 500 watts, which im getting close to. it just happens to be very musical. Model the Fc for a given woofer, if it needs a stupidly large rear chamber, then it is not optimal, second off, if you would take the time to read, a ratio is not chosen at "random." second, any program that gives you spl calculations is going to be wrong. unless it can factor in cabin gain, tempurature, barometric pressure, electrical inductance to the coils, and efficiency of the amplifier. this is why i dont use them. If you follow the guidelines that I have layed out for a 4th order, it will have a very transient response and get loud. If you are reading this in a voice that makes me look like a jerk, then read it again. Im not very good at typing politely, so if you need help, I can help you more via PM's

Oraclem19
07-13-2013, 12:45 AM
My design is a burp design, the goal is 150 with less than 500 watts, which im getting close to. it just happens to be very musical. Model the Fc for a given woofer, if it needs a stupidly large rear chamber, then it is not optimal, second off, if you would take the time to read, a ratio is not chosen at "random." second, any program that gives you spl calculations is going to be wrong. unless it can factor in cabin gain, tempurature, barometric pressure, electrical inductance to the coils, and efficiency of the amplifier. this is why i dont use them. If you follow the guidelines that I have layed out for a 4th order, it will have a very transient response and get loud. If you are reading this in a voice that makes me look like a jerk, then read it again. Im not very good at typing politely, so if you need help, I can help you more via PM's

Much better with first post how-tos, although I did read the whole thread a few times on occasions, My memory didn't quite serve me as I'm mixing them up with a few other ratios for horns. PMing away.

mlstrass
07-13-2013, 02:21 AM
You won't need to build/test 20 times for a daily set up. Use a decent program and go from there as those numbers will not translate perfectly to real world application.

I just did a 4th in a Suburban with 8 15's. Port opening/tuning in the program was WAY diff then what worked best in vehicle. So that is the part you normally want to be able to play with to dial it in. So if possible design it so loading wall/port can be adjusted until your happy, then make it permanent.

One I just did is a demo set up: 57.5 @ 30Hz and 60.3 @ 40Hz, so perfect for most Decaf music. Does dropp off again at 50Hz and loading wall alone wouldn't correct that but guy is happy with it.

RangerDangerV2
07-13-2013, 09:29 AM
You won't need to build/test 20 times for a daily set up. Use a decent program and go from there as those numbers will not translate perfectly to real world application.

I just did a 4th in a Suburban with 8 15's. Port opening/tuning in the program was WAY diff then what worked best in vehicle. So that is the part you normally want to be able to play with to dial it in. So if possible design it so loading wall/port can be adjusted until your happy, then make it permanent.

One I just did is a demo set up: 57.5 @ 30Hz and 60.3 @ 40Hz, so perfect for most Decaf music. Does dropp off again at 50Hz and loading wall alone wouldn't correct that but guy is happy with it.
we need pics yo. ill see if boland will give me some pics of his new build too, going to be easy 57's

Buck
07-13-2013, 12:25 PM
x2 pics.

RangerDangerV2
07-13-2013, 12:30 PM
doing 146.9's wired to .7, rising to 3ohms at about 12.5-13v. I dont have a clamp, but I know Im drawing 65.5Vac lol. but my guess is that its either at 1k, or very close + or - a 100 watts or so

RangerDangerV2
07-13-2013, 01:25 PM
So ive been playing music, mostly higher stuff because I cut my port down, and the front chamber wont pick up the lows like it did before. and wired to .7 its averaging a 145.xx on music, which is pretty good for about 1k, but it feels like 150s on music. very very intense.

2kyukon
07-13-2013, 06:50 PM
anyone wanna charge to design me a 4th for 4 18s in a blowthrough? pm me if so

Buck
07-13-2013, 07:27 PM
Mr. Danger, what do you think about front chamber tuning frequency? I see a lot of mid to high 40's tuning, even 50, 51. What are you tuned at now?

RangerDangerV2
07-14-2013, 12:32 AM
Mr. Danger, what do you think about front chamber tuning frequency? I see a lot of mid to high 40's tuning, even 50, 51. What are you tuned at now?

I was tuned to Fc, which is perfect for daily music/ and even some spl. makes it very flat. but I cut down my port and tuned my front to 54, which makes it peak right at 41hz, which is the resonant frequency of the tahoe. so its all application dependent really.

Beatin'
07-14-2013, 01:42 PM
on the subject of building 4th's, isn't easier to build the sealed box first, then build the front chamber as a "sleeve" that slips over the sealed box? The you screw a plank of mdf on the bottom end of the sleeve that the rear of the sealed box is showing through to keep the sealed box from slipping out. You can have bolts screwed in on the sides of the sleeve so the sealed box won't go all the way forward if the entire system is sitting on its side. The small open edges on the back end of the box between the sleeve and sealed box can be stuffed with some foam or rubber to prevent air leaks.

This way you can get to the subs quicker for whatever reason, or take it apart faster and put it in a different vehicle.

RangerDangerV2
07-14-2013, 04:29 PM
on the subject of building 4th's, isn't easier to build the sealed box first, then build the front chamber as a "sleeve" that slips over the sealed box? The you screw a plank of mdf on the bottom end of the sleeve that the rear of the sealed box is showing through to keep the sealed box from slipping out. You can have bolts screwed in on the sides of the sleeve so the sealed box won't go all the way forward if the entire system is sitting on its side. The small open edges on the back end of the box between the sleeve and sealed box can be stuffed with some foam or rubber to prevent air leaks.

This way you can get to the subs quicker for whatever reason, or take it apart faster and put it in a different vehicle.

my front baffle is removeable... I thought about that idea, but decided against it. I wouldnt do it.

RangerDangerV2
07-15-2013, 06:29 PM
gah, toasted my 3500. blew a few output fets. oh well, at least I can fix it myself. just got to wait on my fets and drivers to get here, and I might mod it to do 5k@1. but well see if I feel like pulling the board or not

jdawg90
07-16-2013, 12:47 PM
I take it Vb is box volume? Is that sealed or ported? I plugged that number in the formula you gave for Fc with the specs and reccomended ported box specs for the sa-12 v1 and v2 and got around 100 both times. For the sealed box volume I got closer to 200.

The formula is Fc=sqrt[(Vas/Vb)+1]*Fs correct?

RangerDangerV2
07-16-2013, 12:54 PM
I take it Vb is box volume? Is that sealed or ported? I plugged that number in the formula you gave for Fc with the specs and reccomended ported box specs for the sa-12 v1 and v2 and got around 100 both times. For the sealed box volume I got closer to 200.

The formula is Fc=sqrt[(Vas/Vb)+1]*Fs correct?
100 or 200 what? sa12 for example. vas=21.21, fs is 33.7. now, take 21.21/28.3168(1 cu ft in ltrs) this will give you .75 if you round it. now, add 1, and you get 1.75. then sqrt that and you get 1.33, then multiply that by the fs, so 33.7*1.33 and you get 44.821. that is your Fc.

shauncox26
07-16-2013, 02:44 PM
Hey guys newb on the 4 ths. Going to try on with my obsidian 12 s. So the larger chamber should be the ported one.

RangerDangerV2
07-16-2013, 02:52 PM
Hey guys newb on the 4 ths. Going to try on with my obsidian 12 s. So the larger chamber should be the ported one.

yes.... did you read the first page? I would start there

shauncox26
07-16-2013, 03:05 PM
Yes i did. Ok oas fs is 33 and the vas is 34.4 vb is 1.5 ft2 or 42.4752 lts. I came up with 44.3982 for my fc. So i tune my ported chamber to around 44 hz correct. So much to take in.

RangerDangerV2
07-16-2013, 03:10 PM
Yes i did. Ok oas fs is 33 and the vas is 34.4 vb is 1.5 ft2 or 42.4752 lts. I came up with 44.3982 for my fc. So i tune my ported chamber to around 44 hz correct. So much to take in.

yup, youre on the right track

shauncox26
07-16-2013, 03:25 PM
So i was thinking 1:3 was a good starting point. Ill post pics once i start.

Buck
07-16-2013, 06:21 PM
I may try 1:2 first.

jdawg90
07-16-2013, 07:17 PM
100 or 200 what? sa12 for example. vas=21.21, fs is 33.7. now, take 21.21/28.3168(1 cu ft in ltrs) this will give you .75 if you round it. now, add 1, and you get 1.75. then sqrt that and you get 1.33, then multiply that by the fs, so 33.7*1.33 and you get 44.821. that is your Fc.

I didn't pay attention to units... I'm getting the right answer now.

What's the difference in using a passband ripple (S) of .5, .6, and .7 when designing a box?

Beatin'
07-17-2013, 12:13 AM
what!? The ported chamber has to be the bigger one? WinISD shows too much peak and group delay.

RangerDangerV2
07-17-2013, 08:10 AM
I may try 1:2 first.
I would disagree, its easier to shrink down than gain more space.

what!? The ported chamber has to be the bigger one? WinISD shows too much peak and group delay.

forget winisd, it is highly innacurate.

RangerDangerV2
07-17-2013, 08:16 AM
I have been getting quite a few pms lately, and it seems that all of you think that you need winisd to design a 4th order.... well, you dont. take the steps that have been explained, build it, test it, enjoy it.

RangerDangerV2
07-17-2013, 01:26 PM
people.... if you pm me asking for advice, then listen to what I have to say. dont keep asking me about modeling programs, because they are useless. Ive had to tell about 10 people that in the past 2 days, and nobody is listening. If you pm me, and dont listen to my advice, then I will not respond back.

jdawg90
07-18-2013, 09:53 PM
How does a high ratio effect the frequency spectrum the sub plays at ? Does it simply shrink it with the peak being the higher? In your pm you said if you want to hit the lows go with a larger FC. What exactly do you mean by that? A sub with a higher FC (I'd think it'd be the opposite, that's why I'm kinda confused)?

thatguy12
07-18-2013, 11:25 PM
and the sucky part is, ive been testing music all day, because I cant find any 0db tones lol, im sure burps will gain me too

Not sure if someone said this yet. You can create your own 0db tones on audacity for any length of time in any format; lose less, mp3 or wav. Sorry if was answered within next pages.

RangerDangerV2
07-19-2013, 12:30 AM
Not sure if someone said this yet. You can create your own 0db tones on audacity for any length of time in any format; lose less, mp3 or wav. Sorry if was answered within next pages.

already have everything I need. thanks though

gumby688
07-19-2013, 10:34 AM
Ok I am picking up a pair of Sundown z v.3 18's. How do they preform in a 4th order or would I be better off with something else? Will be running approximately 4k to them in a explorer sport 2 door. I have a space of about 48 wide 25 height and 30 depth so right at 20cuft. am trying to stay in cargo area behind rear seats until I can talk my wife into letting me build a wall.

RangerDangerV2
07-19-2013, 10:46 AM
Ok I am picking up a pair of Sundown z v.3 18's. How do they preform in a 4th order or would I be better off with something else? Will be running approximately 4k to them in a explorer sport 2 door. I have a space of about 48 wide 25 height and 30 depth so right at 20cuft. am trying to stay in cargo area behind rear seats until I can talk my wife into letting me build a wall.

read the first few pages, run some numbers and see lol

IonRL205
07-19-2013, 10:55 AM
Ok I am picking up a pair of Sundown z v.3 18's. How do they preform in a 4th order or would I be better off with something else? Will be running approximately 4k to them in a explorer sport 2 door. I have a space of about 48 wide 25 height and 30 depth so right at 20cuft. am trying to stay in cargo area behind rear seats until I can talk my wife into letting me build a wall.

A friend has two Zv3 18s on a SAZ4500 in a 4th order and he does a 154/155ish

gumby688
07-19-2013, 11:16 AM
A friend has two Zv3 18s on a SAZ4500 in a 4th order and he does a 154/155ish
Any idea what ratio he is using?

IonRL205
07-19-2013, 11:26 AM
Any idea what ratio he is using?

No idea, not sure if he knows either lol

he bought the car from the guy on youtube a21bravo. You could ask him what the ratio was

Nut Hair Trick
07-19-2013, 11:40 AM
I'm thinking about getting 2 SA12's and I ran some numbers for my vehicle. I have 4.52 cubic feet available which is 127.99 l.
So, 27.66 l / 127.99= .21611......+1= 1.21611, square root of that =1.102, x the Fs of the woofer (32.97) comes to an FC of 36.3.
Where do I go from here?

P.S. I got the t/s parameters from what PWK extracted from the sub

RangerDangerV2
07-19-2013, 11:42 AM
I'm thinking about getting 2 SA12's and I ran some numbers for my vehicle. I have 4.52 cubic feet available which is 127.99 l.
So, 27.66 l / 127.99= .21611......+1= 1.21611, square root of that =1.102, x the Fs of the woofer (32.97) comes to an FC of 36.3.
Where do I go from here?

P.S. I got the t/s parameters from what PWK extracted from the sub

too low of an Fc IMO. get it to around 45-50

Nut Hair Trick
07-19-2013, 11:43 AM
Should I have used the whole available space on the equation or broke down the box to a 2:1 ratio, and used the liters from the 1 for the equation?

---------- Post added at 10:43 AM ---------- Previous post was at 10:43 AM ----------

I used total available space

RangerDangerV2
07-19-2013, 11:44 AM
I'm thinking about getting 2 SA12's and I ran some numbers for my vehicle. I have 4.52 cubic feet available which is 127.99 l.
So, 27.66 l / 127.99= .21611......+1= 1.21611, square root of that =1.102, x the Fs of the woofer (32.97) comes to an FC of 36.3.
Where do I go from here?

P.S. I got the t/s parameters from what PWK extracted from the sub

and you are doing that wrong it seems. you divide the vas by the sealed chamber volume, not total volume that you have. but ill make this easy for you. give each of the sa12s 1 cu ft sealed. that is the best for them.

Nut Hair Trick
07-19-2013, 11:46 AM
Awesome, thanks. Makes sense

OldManBass
07-19-2013, 11:51 AM
Would Fi SSDs be good in a 4th order?

RangerDangerV2
07-19-2013, 11:54 AM
Would Fi SSDs be good in a 4th order?

run the numbers and see...

Nut Hair Trick
07-19-2013, 12:28 PM
A true 2:1 ratio of my available space of 127.99 would be 42.66l (1.5 cuft) and gives me an FC of 42.32
If I used 2cuft for the 2 sa12s or 56.63l for the sealed chamber, I get an Fc of 40.22.

The smaller Sealed chamber gave me a higher Fc. I tried it again with both volumes using the T/s parameters on SSA's site and I got much lower FC's 39.6 (42.66l or 1.5 cuft) and 37.155 (56.63l or 2 cuft). I can not access the sundown site because it asks me for a password. The only T/s parameters I can trust right now is that of what Pete extracted. I know this may sound dumb, but would the T/s parameters that I have access to change due to me using (2) D4 Sa12's?

RangerDangerV2
07-19-2013, 01:20 PM
A true 2:1 ratio of my available space of 127.99 would be 42.66l (1.5 cuft) and gives me an FC of 42.32
If I used 2cuft for the 2 sa12s or 56.63l for the sealed chamber, I get an Fc of 40.22.

The smaller Sealed chamber gave me a higher Fc. I tried it again with both volumes using the T/s parameters on SSA's site and I got much lower FC's 39.6 (42.66l or 1.5 cuft) and 37.155 (56.63l or 2 cuft). I can not access the sundown site because it asks me for a password. The only T/s parameters I can trust right now is that of what Pete extracted. I know this may sound dumb, but would the T/s parameters that I have access to change due to me using (2) D4 Sa12's?

youre doing something wrong here, you cant use the whole volume of the rear chamber in the equation, because you have two woofers, so you need to use 1/2 of it. makes sense? so, with my tsp's for my sa12, which yours should be close, if you use a 1 cu ft rear chamber per woofer, that will give you an Fc of 44.57hz. Now, since it seems that you want to do a 2:1 ratio, you will need a rear chamber of 2 cu ft, and a front chamber of 4 cu ft, from what I can understand, you have 4.5 cu ft of GROSS volume. so in essence, you dont have room for a 2:1.

Nut Hair Trick
07-19-2013, 01:49 PM
youre doing something wrong here, you cant use the whole volume of the rear chamber in the equation, because you have two woofers, so you need to use 1/2 of it. makes sense? so, with my tsp's for my sa12, which yours should be close, if you use a 1 cu ft rear chamber per woofer, that will give you an Fc of 44.57hz. Now, since it seems that you want to do a 2:1 ratio, you will need a rear chamber of 2 cu ft, and a front chamber of 4 cu ft, from what I can understand, you have 4.5 cu ft of GROSS volume. so in essence, you dont have room for a 2:1.

Understood, thanks

Nut Hair Trick
07-19-2013, 02:00 PM
Now I have an Fc of 46.3 using 1cuft in volume for each sub for a total of 2 cubes sealed. that will leave me with 2.5 for vent area but that doesnt account for the baffle for each sub as well as .14 displacement for each sub. This is going to be a trunk build with the 2 sealed chambers facing each other with the vented chamber being in the middle porting through the arm rest. The 2 compartment areas (sealed and ported) just might be **** close to being even, unless I were to reduce the size of the sealed compartments.

RangerDangerV2
07-19-2013, 02:11 PM
Now I have an Fc of 46.3 using 1cuft in volume for each sub for a total of 2 cubes sealed. that will leave me with 2.5 for vent area but that doesnt account for the baffle for each sub as well as .14 displacement for each sub. This is going to be a trunk build with the 2 sealed chambers facing each other with the vented chamber being in the middle porting through the arm rest. The 2 compartment areas (sealed and ported) just might be **** close to being even, unless I were to reduce the size of the sealed compartments.

a word of advice, more ratio>cone area. so if you have to drop it down to 2 10s, or 2 8s to allow a larger ratio, then do it. this is talking spl wise of course though.

Nut Hair Trick
07-19-2013, 02:43 PM
a word of advice, more ratio>cone area. so if you have to drop it down to 2 10s, or 2 8s to allow a larger ratio, then do it. this is talking spl wise of course though.
Sounds good, and I do see what you are saying in order to have an efficient 4th order band pass. But, i dont even have to go with a 4th order just for the sake of doing so. I do know with my space available, I have enough room for say (4) 8's, (3)10's, (2) 12's, or (1) 15 for a basic ported enclosure.
My goals are certainly more musically oriented with a flat response from mid 20's to low 60's or even high 50's,with a little SPL. I have mids that can drop to the low 50's so I say high 60's for overlap. It is nice to run the numbers to see what a 4th order can do and learn about them. I could just as easily construct a ported box, waveguide, or tapered t-line to achieve my goals. Thanks for your help.

hispls
07-22-2013, 08:49 AM
tested more today... couldnt get more than the 145.18, morning it averages 144.5ish, midday and night after its been in the sun all day it meters about a 141.5. really amazing how much the temp of the vehicle matters. but ive got some plans, so hopefully Ill see that 150 by sunday.

So did you find that 150?

RangerDangerV2
07-22-2013, 09:56 AM
So did you find that 150?
nope. was doing 47s, on 1k. but now im out of car audio. more time testing and I could have.

Beatin'
11-15-2013, 12:59 AM
I suppose it is possible to do an IB setup and add a front chamber so you can have a huge rear "chamber/trunk" that allows the sub to dig down low. What are the cons to this type of 4th order bandpass?

SounDrive
11-15-2013, 01:01 AM
I suppose it is possible to do an IB setup and add a front chamber so you can have a huge rear "chamber/trunk" that allows the sub to dig down low. What are the cons to this type of 4th order bandpass?

Double post

SounDrive
11-15-2013, 01:03 AM
IB does not equal 4th order bandpass

That's called a ported box

Beatin'
11-15-2013, 01:11 AM
IB does not equal 4th order bandpass

That's called a ported box

the trunk would be sealed off from the front chamber and cabin. Therefore, giving the rear of the subs the same cubic feet of volume as the trunk would have. The front chamber that is firing into the cabin and sealed off from the trunk would be tuned low to give you horrific low end extension at the cost of upper end bass.

That would be a 4th order bandpass that uses the trunk as the rear chamber. My question is, what are the side effects of having a rear chamber that big?

SounDrive
11-15-2013, 01:27 AM
the trunk would be sealed off from the front chamber and cabin. Therefore, giving the rear of the subs the same cubic feet of volume as the trunk would have. The front chamber that is firing into the cabin and sealed off from the trunk would be tuned low to give you horrific low end extension at the cost of upper end bass.

That would be a 4th order bandpass that uses the trunk as the rear chamber. My question is, what are the side effects of having a rear chamber that big?

You're not understanding here... You literally just described a ported box with the port firing forward and subs firing into the trunk.

vetkilr
11-15-2013, 08:28 AM
Here's me new box:
http://i1259.photobucket.com/albums/ii542/vetkilr01/sneakpeak_zpsa3baf91a.jpg (http://s1259.photobucket.com/user/vetkilr01/media/sneakpeak_zpsa3baf91a.jpg.html)

soloXgt
12-12-2013, 06:15 PM
4th order peeps opinions....i've got a 10" 2004 XXX layin around (I can recone to whatever if i wish) and a 12" Eclipse TI collecting dust. As far as a daily driver, without giving a **** about numbers, just lows and loud (while retaining sq) what are my best options for a 4th order build??. Power isn't an issue, but want to limit this to a 10 or 12 (again, either can be reconed if necessary)

Beatin'
01-02-2014, 01:12 AM
can you put polyfill in the ported chamber of a bandpass to make it appear bigger to the woofer?

SounDrive
01-02-2014, 02:10 AM
can you put polyfill in the ported chamber of a bandpass to make it appear bigger to the woofer?

Yes.. There's a thread on MAF somewhere with specific information about 4th orders and polyfil but I'd have to search to find it

NO1B4ME
02-13-2014, 02:11 PM
Ranger awesome thread. I am looking to build a 4th order for 2 JL 10W6v3's and only use 500 watts.