Does anyone know anything about designing a bandpass box. I have a pair of 12 w6s in a ported box w 2 6 inch areo ports tuned to 44 hz and a jl 1000/1. I can do 143.4 db at a 48-50 hz tone. Im trying to get in the uper 140s without reaching the 2500-4000 watt amplifier range. Any help on design principals or general advise on how to get louder would be greatly appreciated.

4th order won't help your score, 6th might but a different ported box or different drivers will help the most. You aren't exactly using drivers made for output...

You can download winISD alpha version to help you view bandpass boxes, how they'll model, and what size and tune of chambers may be best for you. I think the 6th order bandpass is what you'd look for for more SPL.

But I have to question why you'd put W6s in a fart box? They were JL's sound quality drivers. You're kinda doing them a disservice for not using the SQ they were born with.

The reason I want to put them in a fart box is because the 12 w6s is what i have right at the moment. My plans are to run L7s or CVXs. My objective is to get as loud as possible using what I have at the moment.

Fair enough.

Do you guys have any sugestions on woofers or amps? I am going to compete in usaci trunk 0-1000 the rest of this season and I plan to compete next season in 0-1000 using a memphis 4kw if my cash is right.

redesign your ported box and move things around

resin and mat the inside sand and buff the resin afterward

Im on my third box with the subs up port back. When I get my enclosure near perfect then I will resin the inside. Im thinking about sealing the trunk from the cabin and running the subs foward but Im afraid that not having a loading area might hurt spl.

It shouldn't. After you seal off the trunk the subs will have less area to pressurize, and you won't have the cancellation effects that you get by facing the subs forward but not sealing off the trunk (the reason those setups aren't as loud as facing towards the rear).

It shouldn't. After you seal off the trunk the subs will have less area to pressurize, and you won't have the cancellation effects that you get by facing the subs forward but not sealing off the trunk (the reason those setups aren't as loud as facing towards the rear).

not always true try both I have seen the same car get louder having subs forward port driver and box to the taillights non sealed

<!--quoteo(post=529055:date=Jun 14 2009, 05:41 PM:name=KU40)--><div class='quotetop'>QUOTE (KU40 @ Jun 14 2009, 05:41 PM) <a href="index.php?act=findpost&pid=529055"><{POST_SNAPBACK}></a></div><div class='quotemain'><!--quotec-->It shouldn't. After you seal off the trunk the subs will have less area to pressurize, and you won't have the cancellation effects that you get by facing the subs forward but not sealing off the trunk (the reason those setups aren't as loud as facing towards the rear).<!--QuoteEnd--></div><!--QuoteEEnd-->

not always true try both I have seen the same car get louder having subs forward port driver and box to the taillights non sealed

I tried a different enclosure with woofers firing out and port firing back and with my seat unbolted and out of the vehicle I managed to do 147.2 @ 68hz and 146.2 @ 68hz with seat down and in vehicle. I gained about 3 db by changing enclosures and raising 24hz in tone. All measuments done on term lab. Im extremely happy with the score but always tring to improve with my current equipment. What should be my next move to gain a few more decibles and still stay within usaci rules. Any sugestions on box tuning or equipment would be greatly appreciated.

<!--quoteo(post=529055:date=Jun 14 2009, 05:41 PM:name=KU40)--><div class='quotetop'>QUOTE (KU40 @ Jun 14 2009, 05:41 PM) <a href="index.php?act=findpost&pid=529055"><{POST_SNAPBACK}></a></div><div class='quotemain'><!--quotec-->It shouldn't. After you seal off the trunk the subs will have less area to pressurize, and you won't have the cancellation effects that you get by facing the subs forward but not sealing off the trunk (the reason those setups aren't as loud as facing towards the rear).<!--QuoteEnd--></div><!--QuoteEEnd-->

not always true try both I have seen the same car get louder having subs forward port driver and box to the taillights non sealed

I tried a different enclosure with woofers firing out and port firing back and with my seat unbolted and out of the vehicle I managed to do 147.2 @ 68hz and 146.2 @ 68hz with seat down and in vehicle. I gained about 3 db by changing enclosures and raising 24hz in tone. All measuments done on term lab. Im extremely happy with the score but always tring to improve with my current equipment. What should be my next move to gain a few more decibles and still stay within usaci rules. Any sugestions on box tuning or equipment would be greatly appreciated.

Sounds like your doin ok at 146+. I had 3 JL12W6 in a 4th order bandpass. The great thing about the bandpass is how efficient you can get them but at the same token you lose your frequency range the more efficient it gets. Mine was in an extra cab pickup with no rear seat and the box was pretty monsterous for 3 12's, 12+ cubic feet most of it in the ported chamber, the larger the ported chamber in comparison to the driver side the more efficient it is (to a point) so they take up alot of room if spl is what your going for. I was able to get 148+ out if it but had it tuned to low I think for great spl numbers that number was hit at 37hz. I love bandpass boxes but the downside is/or was in my case a bad case of trunkitice, windows down the thing pounded alot hard than up. Not sure if that helps you at all.

FM

what car are you trying to achieve this in ?

what car are you trying to achieve this in ?

2000 grand prix 4 door.

If You Don't Want Them Whenever You Get A More SPL Oriented Driver Or Drivers, I'd Like One Of Them For My SQ Car.

I'd Look Around For Better Than Kicker Products, Though. (Like The Brands On This Forum, For Example.)

Edited July 4, 200916 yr by BigCProductions99

what is the size of your ported enclosure??

I'd make it bigger...bigger means more efficiency and more of a peak around tuning.

That was what I thought too initialy but the second box i tried was about 6 cubic feet and had three 6 inch areo ports and only did a 138 dbs in the floor using the term lab meter. The next box was about 5 cubes and had two 6 inch areo ports in it and I got a 143.6 dbs. The box i have now is only about 3 cubes and only has two 4 inch areos and has me in the mid 147 db range on the same meter. What Ive been told is that if you have alot of port and airspace, you better have some powah. Honestly I dont have much of that at this moment. For me its been the smaller the box the better the spl.