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View Full Version : *PICS* 6.6 cuft 33hz 140sq.in. of port for (2) 15's getting 3300rms



SHiZNiLTi
05-19-2007, 05:32 PM
37x19x29, 6.6cuft, 140 sq.in. of port area, 33hz for a couple of inverted 15's getting around 3300rms from a RF Power t30001BD...

Hey guys I'm about to go to home depot and pick up some wood to make this box, but I just wanted some opinions before I start.

I drew on my old 7 cuft box which was made for a 18" BTL so you can get the idea of what the deisgn will look like.

The 15" subs will be inverted mounted on top and the 8" wide port will be firing to the rear passenger side wall in the corner of the cargo area.

http://img368.imageshack.us/img368/1102/des1ay6.jpg

http://img368.imageshack.us/img368/7615/des4tt2.jpg

http://img368.imageshack.us/img368/4366/des2ee6.jpg

http://img368.imageshack.us/img368/1540/des3nf6.jpg

Please let me know what you think about this port being so big, the subs are rated at 1500rms for daily and I'm going to be giving them just a tad more then that.

If I reduce the port width to 7" instead of 8" I drop to 30hz tuning, but then get up to 7cuft. If I reduce the port to 6" width I drop to 28hz and get up to 7.4 cuft.

This is for loud daily driving.

Opinions please?

bdawson72
05-19-2007, 05:33 PM
Oh geez RD

bdawson72
05-19-2007, 05:33 PM
Or is it atomic

iamamp3pimp
05-19-2007, 05:54 PM
good luck homes.


IM me if u need

iamamp3pimp
05-19-2007, 05:54 PM
oh


neither btw

jadon087
05-19-2007, 05:57 PM
Its American Bass right?

Calikid
05-19-2007, 06:00 PM
damm shiznilti, u change subs faster then i change my underwear.

jadon087
05-19-2007, 06:02 PM
Those subs in the pics arent AB's I dont think. They have the atomic/rd bottom, top place, and that guard around the spiders. But i would actually tune to like 32-34hz personally.

Um, Yeah i think it is AB http://www.caraudio.com/forum/showthread.php?t=232157&page=2

tommyk90
05-19-2007, 06:04 PM
That's an asston of port for a daily driver and a pair of 15's.

I would only do about 100 square inches of port MAX for a daily driver. 75-80 is a more comfortable number IMO.

jadon087
05-19-2007, 06:10 PM
Wow it is. Does look exactly like the atomics

no doubt Atomic/Rd/Ab all look the exact same

SHiZNiLTi
05-19-2007, 06:10 PM
LOL, I should have never posted the sub in above pics. That sub isnt going to be used in this setup, it's just there as a reference 15, but it's a prototype for Atomic/American bass. It has 4" voicecoil with a super strong motor and takes 4krms, also weighs like 70+lbs.

Anyways back to topic...

Tommy if i reduce the port area to 100sq.in. that would mean making the port narrower to 6" instead of 8" which would also effect tuning and make it at 28hz which is way to low I want to stay at 33-34hz where im at now.

And why do u say max you would do is 100sq.in. of port. What effects will I see from having 140 compared to 100?

SHiZNiLTi
05-19-2007, 06:17 PM
whats going in it? MT's? :)
:D nothing too special, but it will be loud!

Any more opinions on how subs will be effected and sound different with more then the needed amount of port area?

Or is 140sq.in. of port cool for these 15's in just under 7cuft?

SHiZNiLTi
05-19-2007, 06:38 PM
Anyone have any more input on this Im about to make the cuts?

Calikid
05-19-2007, 06:38 PM
Good Luck!!!!!!!!!!!

this should wang.

azbass
05-19-2007, 06:40 PM
Good Luck

skadude016
05-19-2007, 06:42 PM
Anyone have any more input on this Im about to make the cuts?

I really dont think it will make a big difference. I have my box for my 15 at 4.5 cubes with 115 sq inches of port and for daily driving i enjoy it. I doubt 40 extra sq inches will be a big deal

skadude016
05-19-2007, 06:42 PM
if anything more port area should be louder :)

SHiZNiLTi
05-19-2007, 06:42 PM
Good Luck


Good Luck
Thx!

BTW in teh pics the line drew out of the port is the outter wall of it not the inner wall of the port. It looks bigger then it really is.

What does increasing (more) port area do anyways, I still have a hard time understaing it.

Calikid
05-19-2007, 06:43 PM
vids when its done please.

azbass
05-19-2007, 06:44 PM
vids when its done please.

Calikid
05-19-2007, 06:46 PM
^^^ BaStArd!!

tommyk90
05-19-2007, 06:52 PM
LOL, I should have never posted the sub in above pics. That sub isnt going to be used in this setup, it's just there as a reference 15, but it's a prototype for Atomic/American bass. It has 4" voicecoil with a super strong motor and takes 4krms, also weighs like 70+lbs.

Anyways back to topic...

Tommy if i reduce the port area to 100sq.in. that would mean making the port narrower to 6" instead of 8" which would also effect tuning and make it at 28hz which is way to low I want to stay at 33-34hz where im at now.

And why do u say max you would do is 100sq.in. of port. What effects will I see from having 140 compared to 100?

Having that much port area will decrease power handling, especially in a box of that size.

It MAY be louder, but it's not worth it. No sense in having a port that large if you aren't going to benefit from it.

Every box that i've built for 15's had between 35 and 45 square inches of port per sub, both daily driver and SPL boxes.

TypeRBass
05-19-2007, 06:53 PM
i'll agree when tommy says thats a lot of port...i have 84 sq inches of port per 2 15's in my box...you'll have almost double that amount. eh.

Decipha
05-19-2007, 06:54 PM
i have 130sq in of port on my 2 xxx 15s.. got them powered off an orion 2500d at a half and i loves it

SHiZNiLTi
05-19-2007, 07:00 PM
Having that much port area will decrease power handling, especially in a box of that size.

It MAY be louder, but it's not worth it. No sense in having a port that large if you aren't going to benefit from it.

Every box that i've built for 15's had between 35 and 45 square inches of port per sub, both daily driver and SPL boxes.

Thats exactly what I'm not looking for :( I'm worried that I'll be pushing the limit of the woofers allready and I want to make sure they aren't going to get over powered with my T30001bd. But on the other hand I do want it as loud as it can be.

Should I completely redesign this box? What should I do?

tommyk90
05-19-2007, 07:04 PM
Thats exactly what I'm not looking for :( I'm worried that I'll be pushing the limit of the woofers allready and I want to make sure they aren't going to get over powered with my T30001bd. But on the other hand I do want it as loud as it can be.

Should I completely redesign this box? What should I do?

Here's a possible solution.

Build the port as you want to right now, the big one.

Then build a variety of port plugs with different port areas.

See which one you like the best. :)

bdawson72
05-19-2007, 07:06 PM
ahhhhhhhhhh

SHiZNiLTi
05-19-2007, 09:28 PM
Every box that i've built for 15's had between 35 and 45 square inches of port per sub, both daily driver and SPL boxes.


i'll agree when tommy says thats a lot of port...i have 84 sq inches of port per 2 15's in my box...you'll have almost double that amount. eh.

Dont you guys run aero ports? With those I've heard you dont need to use as much port area.

97cavy
05-19-2007, 09:34 PM
I have 4 15''s (soundstream t4's) in 11 cubes with 200sq'' of port and it works GREAT. Bassraces a 147 with less then 700 watts per sub

Calikid
05-19-2007, 09:35 PM
done already???

tommyk90
05-19-2007, 10:19 PM
Dont you guys run aero ports? With those I've heard you dont need to use as much port area.

You don't NEED as much port area with aeros because of the flare, but both myself and joe have built slot ported enclosures.

Wheter I run aeros or make a slot port, I usually end up with the same amount of port area.

SHiZNiLTi
05-20-2007, 01:21 AM
Ok so scratch that 1st idea of using 140sq.in. of port side firing and subs up being inverted, here is the new design that I came up with that will give me more room and work alot better for the setup I have in mind....

7 cuft tuned at 35hz with 85sq,in. of port...

The box is 37" wide x 24" deep x 19" tall which is 8 cuft before port.

The port is 15" wide x 5" tall x 19" long and is 1 cuft in size.

So 8cuft - 1cuft for the port = 7 cuft at 35hz with the above dimensions right?

http://img368.imageshack.us/img368/603/boxtn2.jpg

Can somebody double check my dimensions please and make sure the port is correct and the tuning is what it's supposed to be at.

Thanks a bunch and let me know what you think about 85sq.in. of port.

inapontiac
05-20-2007, 01:22 AM
beautiful.

Blove1991
05-20-2007, 01:37 AM
Dont forgot sub displacement and bracing and all that

SHiZNiLTi
05-20-2007, 01:41 AM
Dont forgot sub displacement and bracing and all that
Ya, subs are inverted, really no bracing just double baffle and posisbly a dowel from left to right.

Lil_KB
05-20-2007, 02:27 AM
Ya, subs are inverted, really no bracing just double baffle and posisbly a dowel from left to right.

2 15s...3k+ rms...and a big *** box...means don't half *** on bracing. i've learned that lesson before. i'd put at least one length of all-thread from left to right and top to bottom.

TheFiverMan
05-20-2007, 02:32 AM
u selling the BTL?

iamamp3pimp
05-20-2007, 04:57 AM
i like the original box better.

tommyk90
05-20-2007, 10:42 AM
We did a box like that in my buddies jimmy for 2 MT 15's. It throws down the lows like no other, and sounds awesome, but it doesn't meter too well.

Unless you aren't concerned about how it meters. :)

iamamp3pimp
05-20-2007, 11:31 AM
looks like he just wants a daily ground pounde..

rpfuror
05-20-2007, 11:51 AM
Ok..

That design without the bracing and double baffle is:
Net Volume: 6.97 cu/ft
Tuning Freq: 35.15 Hz

With the 45s and double baffle it is:
Net Volume: 6.32 cu/ft
Tuning Freq: 36.90 Hz

If you want the same freq and bracing you will need to do this:

Vent Length: 23.00 inches

which will give you ~ this:

Net Volume: 6.08 cu/ft
Tuning Freq: 35.07 Hz
Port Area: 85.00 sq/in

(I designed something very similar;))

SHiZNiLTi
05-20-2007, 05:15 PM
http://img368.imageshack.us/img368/603/boxtn2.jpg

Thanks rpfuror!

If I made a 8 cuft box as shown above without the square port how many 4" aeros would you use? I want to stay around 35hz tuning.

If I did (6) 4inch ports at 17inch long that would be 75 sqin of port area and 35-36hz.

Think I can get away with only using (4) 4 inchers?

And tommy, Im not so much wanting killer lows, I want more SPL output from it.

These are the 4inch ports im looking at...

http://www.partsexpress.com/images/268-350m.jpg

tommyk90
05-20-2007, 06:33 PM
http://img368.imageshack.us/img368/603/boxtn2.jpg

Thanks rpfuror!

If I made a 8 cuft box as shown above without the square port how many 4" aeros would you use? I want to stay around 35hz tuning.

If I did (6) 4inch ports at 17inch long that would be 75 sqin of port area and 35-36hz.

Think I can get away with only using (4) 4 inchers?

And tommy, Im not so much wanting killer lows, I want more SPL output from it.

These are the 4inch ports im looking at...

http://www.partsexpress.com/images/268-350m.jpg

I would do a minimum of 6 4" ports. In fact, I would rather that you do 8 of them, and just plug 2 of them to play around with tuning and whatnot.

Another thing to be concerned about is the height of the box. That's the problem we ran into with my teammates box. Its the right size (a little too large I think), but its really tall and blocks off airflow from the rear-firing ports.

It sounds killer, but doesn't meter well.

Side firing the ports may be the best way to go if you need the box to be that tall.

SHiZNiLTi
05-20-2007, 07:44 PM
I would do a minimum of 6 4" ports. In fact, I would rather that you do 8 of them, and just plug 2 of them to play around with tuning and whatnot.

Another thing to be concerned about is the height of the box. That's the problem we ran into with my teammates box. Its the right size (a little too large I think), but its really tall and blocks off airflow from the rear-firing ports.

It sounds killer, but doesn't meter well.

Side firing the ports may be the best way to go if you need the box to be that tall.
Hmm interesting. I don't think the height of a box will be the issue because it's going int he back of my blazer and the box's 19" height is the same as my rear seats.

I'm definatly considering (8) 4" ports, check this out...

With (8) 17" long ports all open I'd be at 42hz with 100sq.in. of port.

With plugging (2) of the ports I'd be at 35hz with 75sq.in. of port.

God D*mn, (8) flared precision ports will cost me $127.25 shipped!!!

Any have any hookups on good ports?

What do you guys think about using ports?

tommyk90
05-20-2007, 08:07 PM
Hmm interesting. I don't think the height of a box will be the issue because it's going int he back of my blazer and the box's 19" height is the same as my rear seats.

I'm definatly considering (8) 4" ports, check this out...

With (8) 17" long ports all open I'd be at 42hz with 100sq.in. of port.

With plugging (2) of the ports I'd be at 35hz with 75sq.in. of port.

God D*mn, (8) flared precision ports will cost me $127.25 shipped!!!

Any have any hookups on good ports?

What do you guys think about using ports?

Oh, ok. Thats considerably shorter than my teammates box. I think his is at least 6-7" higher than the rear seat. You shouldn't have a problem with that box height.

Yeah, aeroports can get a little pricey, but the benefits you can from them can be really noticeable, especially in an SPL-geared setup.

Playing with teh port length can greatly affect performance. For instance, in my single 10" setup (which I know isn't like most people's, but bear with me), I took 5" off the port length.

Now the funny thing is that my note stayed the same, but I lost 1.8 dB!!

The ability to change tuning and port area on a whim is a very nice feature to have, if you are willing to pay for it.

15nissen
05-21-2007, 08:10 PM
aeros FTW. When your sick of this box, just relocate them to the next box. etc, etc. its a solid investment in my eyes.:)

Zeuslicious
05-22-2007, 01:56 AM
Any updates?

tapout
05-22-2007, 01:58 AM
Any updates?

forrealz