1. u loose when u go from 4v deck to a 2v deck
2. sound deadening does not guarantee u gain in spl (matter of fact u might loose spl)

thank u for your time.

[img]graemlins/bow.gif[/img]

all my questions have been answered! :D

1. In most cases
2. Agreed

thank u for your time.

common chamber vs shared chamber??? I am designing a CRX box in my golf (hatchbach) about 6.1 cuft including port. I have always used a shared chamber. Would it be better to use seperate chambers? are there any benefits

your crx box is too big, dont go over 5.25 cubes. try box commong and separate, i have never tried common chamber for a crx box but it just might work.

A single chamber design will be fine. Are you building a wall? What year is your CRX? I used to compete with a CRX and might be able to help you out.

I'm building a "Crx Box" it just the name for the box (port facing back & sub facing up ...I didn't know this untill a couple days ago) I am putting it in a vw golf hatchback. So if you have any tips on hatch backs i'm all ears

small box works better than a big if it's a crx style box. my boxes are only 2.25 cubes each (two boxes in the hatch of the jeep). only make the box big enough to tune it properly, nothing bigger

told you :D :D

Box size "should" be dictated by woofer parameters, not some arbitrary size that fits the space or a whim.

shouldnt box size fit the car and have shape and form that performs best in a given vehicle????

my ihuman parameters tell me to whip out a 3.5 cube box for each sub so i did. then i put them both into a 4.75cube box and it was over a 3db gain on the meter.

[ April 13, 2004, 05:45 PM: Message edited by: Tinted ]

Is there anywhere on the net that i can read up SPL information, that can help explain some physics. I was also wondering if a sharesd chamber is better than seperate chambers for 2 woofers (ported, of course)

MATTX u have to try both, there is no 'forsure' way to tell which one is better.

Not surprising to me... which is why I don't quite understand why you'd disagree that larger boxes are better for SPL ?

A larger box, generally speaking, will lower the Q of the system. You will probably loose accuracy and maybe screw up group delay, but it will reach full excursion with less power.....

Maybe it's not an issue for alot of you guys, cause ya have 20+ batteries and 20KW of juice... [img]graemlins/headbang.gif[/img]

not sure what u are saying there.

i said that i went from a big box to smaller and smaller and gained every time. thus i disagree with the big box theory in a lower class. look at all the street class boxes, they are pretty small comparing to what u would expect them to be.

Whe box should fit the woofer's needs, not the vehicles. Often a compromise needs to be made on both sides.

Every enclosure design program I have seen "recommends" a maximally flat Butterworth response which as you found is not necessarily the best box for SPL. Glad you came up with a box that worked though.

i dont want ppl to get me wrong. im not saying that a big box is always bad. not at all. MATTX asked about a crx style box for a hatch back vehicle, that's what i was talking about this whole time. in other applications a big box probaby is better.

Bottom line with spl.. put the specs, theory's and everything on hold.. and just rely on trial and error "does this work, or not work"..

putting a speaker in a smaller box also creates a peak at the point of rolloff
which would explain the gain
alot of box progams do not show this to the degree that leap does

I agree Chris.
It's "basicly" all trial and error.. SPL is not a book, nor a forumla, and never will it be! Yes there are things that help, and some physics, and acoustics of course does apply, to a certain degree. But noone can go out and tell someone what will be ABSOLUTE loudest in every application, with every speaker, or every box design!
I have figured out that it comes down to a few simple things in this SPL Sport. That is:

1.) Money- ewithout money you cannot purchase the material's/equip you need.

2.) Time - You need hours/days, weeks/months to perfect any system, or box designs that work best for your application.

3.) DEDICATION - i Hightlight this because that's why a lot of poeple will fail, or give up in SPL. It's becasue they don't search for the help, don't "MAKE" the time, and don't have the heart in it like some of us do!


This statement is of course bias because it is coming straight form the mouth of a Guy who has spent more time in the shop then at his workplace and home combined!

Some people may think this SPL is a Joke, or anyone can make a vehcile loud all it takes is MONEY, Let me tell you i just laugh and say "meet me in the lanes" It actualy gets me frustrated when people say this and i hope i meet them in the lanes!!


I give out respect to those who have done up there own stuff take pride in it. There's nothing better than that! Take pride in what you do, no matter what people tell you!!!

And SPL is a " "Sport" in my mind, not a game!

Livin Loud

I agree Chris.
It's "basicly" all trial and error.. SPL is not a book, nor a forumla, and never will it be! Yes there are things that help, and some physics, and acoustics of course does apply, to a certain degree. But noone can go out and tell someone what will be ABSOLUTE loudest in every application, with every speaker, or every box design!
I have figured out that it comes down to a few simple things in this SPL Sport. That is:

1.) Money- ewithout money you cannot purchase the material's/equip you need.

2.) Time - You need hours/days, weeks/months to perfect any system, or box designs that work best for your application.

3.) DEDICATION - i Hightlight this because that's why a lot of poeple will fail, or give up in SPL. It's becasue they don't search for the help, don't "MAKE" the time, and don't have the heart in it like some of us do!


This statement is of course bias because it is coming straight form the mouth of a Guy who has spent more time in the shop then at his workplace and home combined!

Some people may think this SPL is a Joke, or anyone can make a vehcile loud all it takes is MONEY, Let me tell you i just laugh and say "meet me in the lanes" It actualy gets me frustrated when people say this and i hope i meet them in the lanes!!


I give out respect to those who have done up there own stuff take pride in it. There's nothing better than that! Take pride in what you do, no matter what people tell you!!!

And SPL is a " "Sport" in my mind, not a game!

Livin Loud </font>[/QUOTE][img]graemlins/thumb.gif[/img] [img]graemlins/thumb.gif[/img] [img]graemlins/thumb.gif[/img]

X

I agree...people can argue physics and all that..basically all goes out the window when you are doing SPL :cool:

regarding your box in vw golf... ill letcha know very soon. personally i dont think keeping a small crx box in the hatcha rea of a golf will work, because in most vehicles you need about 6-10inches space from rear of vehicle to the box. then agian there is barely enoguh room for 10's so i will be trying it. but my suggestion it to try two seperate chambers, sub up with a slot port right beside it. then the other box build exactly the same and turn it 180 degrees so both ports are in middle. if you have access to a mic, then try facing port all certain ways with sub in this format leave box dimensions like 16x16x18"width" and that way you can lie the box down facing backwards as well to see what kind of gains but still, good luck.


"all aside, leave it to the lanes" [img]graemlins/thumb.gif[/img]

See, the thing that everyone is forgetting here is that SPL is for ninnies ;) [img]tongue.gif[/img]

Who was Team BS made up of? Weren't they all a bunch of German physicists and acoustic engineers? Makes ya wonder if science can't be used?

or was it 16 Treo Subs and 64 dei 1100d amps...yah i would say 64000 watts of rms power did help the nerds?

how about those superior sound guys, they pretty much smashed Team BS score with only 1 sub and 8 amps i think. They sure dont look like they got any physicists major backround.

My kats breath smells like kat food

really????????? i beleive that's about 153 on the new termlab? SWEET! i'ma Get one!

Livin Loud

No they are not so instead they cheat.

X

oh god.. here we go.. :rolleyes:

tell us how they cheated

whenever someone is loud.. they must have cheated.. its just how it is..

My dogs breath smells like dog food. [img]tongue.gif[/img]

seriously? mine too!

I once heard putting a two way valve in the firewall the opens up once you burp helps your score but is illegal that is one way to cheat. Or its the same as just cutting a hole in the floor up underneath the dash and covering it with speaker grill cloth or the vehicles carpet

If you tune your box properly to your vechicle you should loose SPL by having an opening into your car's chamber.

i think u actually gain. and yes most of the time a two way valve helps, but it's highly illegal

i agree with the trial and error. we tried and tried to build me a box for my 1251's and we were only gainin little by little. one day i found a FUSION* box sittin in the shop. i threw my subs in it and boom! huge difference.
and i find that if i move my box even an inch it makes a world of difference. go by instinct. :rolleyes: TRIAL AND ERROR IS THE DEFINATION OF SPL.

You do generaly gain SPL but not at the same frequency that you have your system tuned to. So you loose SPL at your original frequency but gain SPL at a new frequency is what I meant to say.

i gain at the same frequency. try it. u will gain at every frequency.