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I am going to start designing what I hope to be the ultimate SPL box.

I have no details yet, but want a lot of suggestions. All I know so far is that I want a removable port. Anything else I am pretty much open to.

If anybody has any suggestions, let me hear them.

 
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how much are you willing to give up, and what division do you wanna compete in

 
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I'm street A

How much am I willing to give up in terms of what? money? Shouldn't cost too much to build, maybe < $100cdn at the absolute most if i go all out

I'm not gonna carpet it, it's gotta be all go and no show

 
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No i think lud means how much of your trunk are you willing to give up. Most strickly SPL boxes are huge with huge slot ports.

 
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not only that, are you willing to go up form street A to another division. also, you willing to give up your back seat (if you have a 2 door)?

if you want ultimate spl, id reccomend you upgrade to SS 1-2

Street A = car off, no walls, only one battery, box cant leave trunk

SS 1-2 = much much less limitations. more batteries, car on, walls, etc...

 
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ooh, i know, buy another car!

 
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I'm gonna stay in Street A... I have my reasons why

I don't care how much trunk space I use up, it's gonna be a competition only box, I will have a differnet box for daily use.

and I'm not buying another car lease:

 
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the most successful box ive ever seen in a civic for street A was upfiring, and sat in the trunk.

about 5 ish cubes ported with an 8" port approx 4x12 or so, reducing the porth length killed his spl.

he hit 150 dB on an old audiocontrol with a single 12.

good luck. my single tempest in 5 cubes ported to 48 Hz with a 5 inch port and 600 rms hit 136.

 
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basially what you want to do is take up as much airspace as you can, and tune decently high, make your port removeable at first so you can test diff frequencies

 
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keep the port away from the cone, or at least allow the vibrations to travel the box before exiting the port.

resin the inside of the box for that extra tenth of a db

you can try adding a loading panel just behind the vent pole of the woofer

brace, brace, brace, brace, brace

weve had luck over here rounding all the edges inside with moulding, its supposed to aid wave propagation or something. i dunno. it helped us though

usually the target port area is 75% Sd, but this is just a general rule to go off of. its possible itll work better either way.

tune to the cars resonant frequency to get that extra bit of help from cabin gain.

 
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What do you mena by loading panel?

The edges will be rounded, especially where the air will be exiting the port. I hope to have my first draft finished shortly and I will post a pic here.

 
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a loading panel is anything the woofer has to reflect sounds off of.

for example, when you rearfire your box, no matter what, the back of the car becomes a giant loading panel. its usually not as effective when teh box is pushed up agasint hte back seats versus when the box is like 5 inches away from the back because the waves have time to disperse before bouncing off.

the general rule of thumb is 5-7" for 15" drivers, 4-6 inches for 12" drivers, and 3-6 inches for 10" drivers.

It is also critical for home theater drivers. for example, my tempest box sits 3 or 4 inches above the ground, and sounds like poop. my neighbor built a box that loaded a touch over 5 inches, and its freaking LOUD and clean in his house.

the same can be taken advantage of in a car. people ask me all the time if my subwofoers are in a bandpass box. I tell them they are plane loaded off the bottom board at a distance of 7 or 7.5 inches:



not only effective, but looks damn good, too!

so by placing a beam of wood directly behind the woofer, you do two things:

#1 brace the box
#2 create reflections that can potentially increase the metered output.

I know you asked for hte time and I basically told you how to build a halfassed watch, but hopefully it helped.

 
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Hmmmmmmmmmmmmmm I think you may be on to sometihng here

Do you have any more pics so that I can steal.. errr BORROW your idea?

 
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not my idea, im just capitalizing on it!

its actually a poor example, because in my car, the loading panel is in FRONT of hte woofers. and for the purposes of my suggestion to you, it was placing the loading panel IN the box

feel free to IM me anytime, ive only got like 60 meg of pictures of this stuff, itd be easier, since i only have 4 meg of upload space.

 
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Sure, do you use MSN at all?

 
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If you do, add me, my e-mail is rollz2low_420@hotmail.com

 
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The first draft is done, here are the pics:


A drawing with the top and front planes removed


Same thing but with the side plane removed as well


A design for a removable port, no particular tuning frequency yet


Top and front planes


Top and front with port mounted to give you an idea of how it will look


Totally assembled with port installed


Same thing but another angle, just to give you an idea of how it will look


The fixed part of the removable port system. You can see how the port will slide in and meet up nice and flush. The corner as well as the top and bottom are rounded to remove airflow out of the port.

Pics can be found at my cardomain site here:

http://www.cardomain.com/memberpage/563904/4

As well as all the other pics of my car, let me know what you think.

 
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Feel free to provide feedback of course

 
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the port tuning might be a bitch to calculate on pper with a round port like that
youd have to do it with a multimeter

 
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? How would I calculate tuning with a multimeter?

I just bought one today (a multimeter)

I could quite easily calculate the volume of the rounded section and just add it to the volume of each port.