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DonH
01-29-2014, 01:23 AM
First Person that can tell me why majority believe some sort of magical gain can be had by using a 4th-order band pass design on this forum in this day and age....

READY GO!

bbeljefe
01-29-2014, 01:37 AM
Some sort of magical gain?

So you're asserting that there are more than one sorts of magic?

DonH
01-29-2014, 01:40 AM
Some sort of magical gain?

So you're asserting that there are more than one sorts of magic?

Oh yes my Friend, whether it be black magic or white magic or a new form of magic that is plain out MAGICAL

Slo_Ride
01-29-2014, 01:42 AM
First Person that can tell me why majority believe some sort of magical gain can be had by using a 4th-order band pass design on this forum in this day and age....

READY GO!

so do you not believe in magic or fourth orders?

jeffdachef
01-29-2014, 01:47 AM
might as well throw the T line and 6th order into the fray as well.... lol

DonH
01-29-2014, 01:49 AM
so do you not believe in magic or fourth orders?

magic no, 4th order (ported and bandpass), yes I believe in them. they are great in certain applications BUT for some reason ive read many posts where some users think they will be louder simply because it is a 4th order bandpass... Most have no clue that why not save the enclosure size while gaining the extra output and run a 4th order ported enclosure... most if not all amps have a LPF correct? a 4th order banpass simply does the same but does so acoustically and normally at about a -24db/octave slope compared to a electronically filtered LPF (like on most amps) -12db/octave slope.

Slo_Ride
01-29-2014, 01:49 AM
i dont really mess with bandpass unless its prefab and has neons inside. adds deebeez ya know.

DonH
01-29-2014, 01:56 AM
might as well throw the T line and 6th order into the fray as well.... lol

well now now there. you cant throw in a t-line as well. sheesh, 6th order is ok, but not a t-line. not talking quarter wavelength loudspeaker design here

Nutdawg651
01-29-2014, 02:17 AM
ill tell you why lol they think it looks cool , and because its such an intricate design they believe theyll gain 10dbs and blow everyone out the water lmao....can i get my design now?

DonH
01-29-2014, 02:20 AM
ill tell you why lol they think it looks cool , and because its such an intricate design they believe theyll gain 10dbs and blow everyone out the water lmao....can i get my design now?

ask politely?

Slo_Ride
01-29-2014, 02:27 AM
i won. but i forfeit because i design and build my own boxes.

brian84corvette
01-29-2014, 02:30 AM
because they saw a youtube video of a viechle that LOOKS like its loud using a 4th order design box
not actually seeing one in person
or sitting in a viechle demoing with a 4th order box
or even having a friend with a properly functioning LOUD 4th order box in their viechle
nope

they just saw a youtube video of someone looking like their crap is loud on a awfull cell phone video 4th order
lols me

slammedincouch
01-29-2014, 02:34 AM
Opens up portal to another dimension filled with unicorns, leprechauns, and other mystical creatures. We can't see it because it happens in the sealed chamber(s)...

slammedincouch
01-29-2014, 02:36 AM
These people also come and dance in the box as well- help with some frequencies
http://youtu.be/rQ4ss7tq0AQ

jeffdachef
01-29-2014, 02:37 AM
well now now there. you cant throw in a t-line as well. sheesh, 6th order is ok, but not a t-line. not talking quarter wavelength loudspeaker design here

but but but... t-line is the current forum boner! 4th order was soo last year!

Slo_Ride
01-29-2014, 02:41 AM
These people also come and dance in the box as well- help with some frequencies
http://youtu.be/rQ4ss7tq0AQ

"call me a fly cause i'm on some ****". lol

Nutdawg651
01-29-2014, 02:47 AM
lmao not sayin it like that but please lol sorry i come off as a **** sometimes i cant emphasize jokes like i want to on this cpu

Slo_Ride
01-29-2014, 02:50 AM
i must of missed something.

Slo_Ride
01-29-2014, 02:53 AM
lmao not sayin it like that but please lol sorry i come off as a **** sometimes i cant emphasize jokes like i want to on this cpu

you're good man.

Jroo
01-29-2014, 10:46 AM
no real magic to a 4th order. When done right, they should have the same response curve as that sub in sealed box, but should be louder doing it. Nothing more, nothing less. Ive seen people claim all sorts of crazy stuff with a 4th order, but you hear the same stuff with t lines, 6th orders, ported. You name the enclosure and we can find somebody that says they did 150 db from one 8" on 2000 watts with a flat response curve from what ever box they are in love with.

bbeljefe
01-29-2014, 11:19 AM
No real magic.

There. Fixtit. ;-)

Fourth orders do not have the same response curve as sealed boxes. They have a passband which causes them to roll off both above and below tuning. And they roll off at a steeper rate (slope) than sealed enclosures. The benefit that goes with that negative is acoustical gain at and around tuning. This is why they make good burp boxes and home theater LFE boxes and it's why they don't make good all around music boxes. Ditto for 6th and 8th orders, although the latter can have a much wider bandwidth and still be above flat.

As for transmission lines, they're great for all around music boxes because they're more efficient than conventional ported enclosures and they have exceptional low end extension. To date, the only negative I've been able to find with respect to lines is their size. Being, on average, three times the size of a conventional ported box and owing to the fact that they're one long tube... they present a huge challenge in design even in vehicles where space isn't an issue.

DonH
01-29-2014, 07:49 PM
There. Fixtit. ;-)

Fourth orders do not have the same response curve as sealed boxes. They have a passband which causes them to roll off both above and below tuning. And they roll off at a steeper rate (slope) than sealed enclosures. The benefit that goes with that negative is acoustical gain at and around tuning. This is why they make good burp boxes and home theater LFE boxes and it's why they don't make good all around music boxes. Ditto for 6th and 8th orders, although the latter can have a much wider bandwidth and still be above flat.

As for transmission lines, they're great for all around music boxes because they're more efficient than conventional ported enclosures and they have exceptional low end extension. To date, the only negative I've been able to find with respect to lines is their size. Being, on average, three times the size of a conventional ported box and owing to the fact that they're one long tube... they present a huge challenge in design even in vehicles where space isn't an issue.

1. Very true indeed upstairs there :) BUT why design one? we have digital crossovers in our headunits, and onboard amplifiers that do what a 4th order BANDPASS does acoustically as apposed to electronically.

2. Second portion also so true, BUT they are huge due to Quarter Wave... gotta love quarter wave ;) I should post a few pics of my tapped horns :o

RangerDangerV2
01-29-2014, 08:13 PM
oh... I dont know... 2 12s, less than 1k, burping 147's sealed on the dash in a tahoe. only a week or so testing. oh, and played music 1db flat from 25-60hz. 145s on the dash musical sealed as well, as stated in sig.

bbeljefe
01-30-2014, 12:02 AM
1. Very true indeed upstairs there :) BUT why design one? we have digital crossovers in our headunits, and onboard amplifiers that do what a 4th order BANDPASS does acoustically as apposed to electronically.

2. Second portion also so true, BUT they are huge due to Quarter Wave... gotta love quarter wave ;) I should post a few pics of my tapped horns :o

Crossovers don't provide the acoustical gains a 4th order box does and that's the reason why most people want them. As for transmission lines, I wasn't asserting the reason, I was just pointing out that they are large. But... it could also be argued that wave t-lines are rather small, owing to the fact they they're only a wavelength long. ;-)

And dude... post up the pics man. Everyone here likes to drool over wooden boxes that make noise. :-)

Here are a few I've done. Some old, some new one not yet finished...

https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-prn2/t31/1410857_1419030651666560_1206450193_o.jpg

https://scontent-a.xx.fbcdn.net/hphotos-prn2/1485953_1419030744999884_926599038_o.jpg

https://scontent-a.xx.fbcdn.net/hphotos-prn1/t31/861101_1419030854999873_2139312248_o.jpg

https://scontent-a.xx.fbcdn.net/hphotos-prn1/1622421_1434861513416807_238578072_o.jpg

https://scontent-b.xx.fbcdn.net/hphotos-prn1/t31/1522535_1434862183416740_1727230456_o.jpg

snoopysnooper
01-30-2014, 12:05 AM
may i please have a free design???

hispls
01-30-2014, 12:23 AM
oh... I dont know... 2 12s, less than 1k, burping 147's sealed on the dash in a tahoe. only a week or so testing. oh, and played music 1db flat from 25-60hz. 145s on the dash musical sealed as well, as stated in sig.

What amp? Let's have a look at the RTA graph of that.

TaylorFade
01-30-2014, 08:26 AM
So, let's see...

You're asserting that a bandpass is no more efficient/offers no gain over a standard ported box?

And bbeljefe says that they have a steeper rolloff than sealed?

Interesting.

Jroo
01-30-2014, 09:08 AM
I know some of you guys are box gurus, but I am hearing some things that I never heard before. The rolloff and passband are all a fuction of the 4th design? I have seen several 4th order graphs that are literally the same response curve as that same sub sealed, only louder throughout the entire range. The rolloff on the upper and lower end were basically identical, again the only difference being the 4th was lounder. On the flip side, I have seen some nasty I guess you call them burp boxes that have huge peaks and drop like rocks on the low and high end. In both cases, isnt that just a function of the design? So I can have a very musical 4th if I have the correct sized sealed section, ported section, port tuning, and port size.

I also want to say that my response is a way to get educated not argue. Again, I have heard some things that were explained much differently than I heard before.

raptor727
01-30-2014, 09:27 AM
Can I haz a design?!? Need to get those monsta deebeez yo.

RangerDangerV2
01-30-2014, 11:28 AM
What amp? Let's have a look at the RTA graph of that.

saz3500 wired to 2, rising to 12. I never got a screenshot of the sine sweeps. But if you dont believe me, I really dont care.

pro-rabbit
01-30-2014, 12:12 PM
No one has mentioned the idea behind tuning the bandpass for spl yet? I find that interesting. Of course if they did, they would likely not understand how that applies to a daily setup or how the volumes of each chamber can drastically alter the response curve.

MarkAm
01-31-2014, 01:18 PM
Hey slo, can I have your reward since you forfeit? lol
I'm still stuck trying to convert inches into ft^3. lol

T3mpest
02-20-2014, 02:20 PM
Actual correct answer, hopefully it entitles me to a box design..

It's because when people are willing to do a 4th order bandpass they realize they need to give up SPACE..

When people talk about ported boxes and def sealed they are always looking to save space. Sure that 15 works GREAT in 3cubes net.. It's tuned low, go ahead and use skimpy port area....

As soon as you start talking 4th and 6th order you start hearing about how ungodly big they need to be. Part of that is the extra displacements offered by the sealed or other ported section, but MOST of it is because people are finally willing to give subwoofers the space they deserve.

Instead of trying to cram a 15 into 3 cubes they start using large port volumes and huge ports onto the ported section of the 4th order. Sure they are only fitting 2 15's in a 4th order compared to the 4 ported subs they could cram in there.. However, they are also playing flat down to 15hz with authority because they finally built something that was effecient.

People see youtube vids of a guy with 4 15's in a 4th order using 30 cubes of space and it's moving air like a freaking industrial fan off of 6k.. Then they wonder why their 4 18's in only 16 cubes tuned at 35hz with a skimpy port on 20k can't do the same thing.. HENCE.. MAGIC!

Hoffmans Iron laws rearing their head once again, but when it comes to 4th orders, priorities change.

NO1B4ME
02-21-2014, 09:49 PM
I want a bandapss box for my new 2014 Honda Accord. I have 2 JL 10W6v3's in a dual sealed enclosure and the bass is staying in the trunk :(. I want a bandpass box to port through the ski hole. What do you guys think? These subs only need .63 cft3 of airspace.

drbizerk
03-17-2014, 10:45 AM
....and the winner is..... T3mpest!!!