mandos

Dude, you don't know how to calculate the fact that a box has 2 pieces of wood taken from each dimension. You made dimensions for a 3 sided box, not 6. How can you even attempt to blast anyone.

I explained everything in terms everyone can understand. You tried making a point using horribly flawed math that someone in 3rd grade could do better.

Don't claim it's because you weren't using a calculator, that won't help you remember there's 6 sides to a box, not 3.

Did it not even cross your mind that when you have a divider in one direction, maybe you should take a bit more away from that dimension than the others?

And btw, I am a tech/sales/r&d guy. eD sponsored this board before I worked here. I troubleshoot installs every day.

And did you miss the part where I mentioned that 2 subs in a common chamber can be modeled as 1 sub, because in the circuit...they are.

Unless, as you mentioned, someone decided stereo subs in a common chamber made sense, in which case, they have a lot to learn about car audio because stereo w/ a sub doesn't make sense no matter how the boxes are configured.

Oh, and please, explain how any cancellation would be different w/ two subs firing differently in a common chamber vs. 2 separate boxes. If they're poorly spec'd enough to be noticably off, then they will be no matter how they're configured.

Oh yeah, and like I said before...if you're buying subs from a manufacturer that are so horridly spec'd that 2 in one box sounds radically different than 2 in separate boxes, well...you just got ripped of.

Oh, and I already mentioned that subs have tolerances...no, ours probably won't spec out at IDENTICAL impedances, but they're made within a certain TOLERANCE of one number. If they're too far off, guess what, they don't end up in a customers hand.

Now please, try to make ridiculous claims about others....but seriously...check your own facts before you try anything.

I'm pretty sure no one will ever believe a word you say simply based on the fact that you think boxes have 3 sides.

trialsindude

1SXETC
WOW dude, 2 subs one chamber is all good, get over it. Like Mandos said unless the subs are seriously out of wack and then it will make a difference , if you are USING the same exact sub sharing a chamber is fine.

Next time I see this one guy I know I should tell him he should put those DD 9900 subs in a individual box since he has 2 of them. I guess good thing he knows what he is doing thats why he holds the amateur record for hitting 165db.

1SXETC

no. because ORIGINALLY the point i was making WAS ABOUT EXTERIOR DIMENSIONS (14" high to fit under hatch cover). i left the thread for a while (cuz i was at work!) and when i came back it was about interior volume. I simply forgot to subtract the 1.5 ( .75 x2) in my rush to calculate volume.

"And did you miss the part where I mentioned that 2 subs in a common chamber can be modeled as 1 sub, because in the circuit...they are."
---ONLY if they are bridged. and just because they ACT as one sub doesn't mean that each sub now has increased q volume specs!

eg. say a 10" driver's optimum air space is 1 cu ft. so you put it in a 1 cu ft enclosure. if you have 2 subs, EACH SUBS spec volume is STILL 1 cu ft. putting them in a shared chamber 2 cu ft box does not CHANGE THEIR Q specs... they are still optimizd for a 1 cu ft enclosure. 2 cu ft is TOO MUCH volume for each sub. ie. they will play lower but won't handle as much power.

bottom line. 2 subs in a single chamber 3 cu ft box are both using 3 cu ft of air space. NOT 1.5 each. YOu cannot divide AIR like you can an electrical circuit. THIS IS WHY DUAL CHAMBER BOXES ARE BUILT!!! DO YOU THINK ITS JUST FOR THE FUN OF IT?!!!

if you have 2 subs that are rated 1cu ft optimum sealed enclosure volume, THEY EACH WANT 1 cu ft OF THEIR OWN. They don't want 2cubes to share between them. Then they are each gettin 2 cubes.

heck, with your logic, why even use baffles?!!! the sub will "know" how much of the infinite air space to use, right?

i got nothing against you mandos, but you're never able to admit you're wrong. i admitted i rushed and screwd up my calculation. And you're sitting here saying i think a box has 3 sides. real mature.

i think you just can't handle anyone saying you are wrong.

fyi, i don't claim to be an audio expert. But i KNOW that subwoofers are not intelligent enough to know how many of them are mounted in a box and the air volume of the box, so that they can Split (different from share) the air.

They do Share the 3 cubes. Just like sharing a taxi. each person doesn't get half the taxi, they all get the whole thing. thats just common sense. you don't need to be an "audio expert" at a company i've never even heard of before SL to know that.

mandos

Dude, what you're saying makes no sense.

They aren't sharing air. 2 subs = double vas = acts as one when modeled. And yes, only when wired in the same circuit as eachother, but again, wiring subs in stereo = totally pointless.

And 3 people in a taxi only use the space they're sitting in.

Your example is like this:

If we share a pie, we both at a whole pie.

No, we didn't we ate 1/2 of the pie each.

Basically, what you're saying, is that by putting 32 speakers in a common chamber they all have no power handling, since they all "see" 32x their required airspace and they can't play the same as they normally do?

What exactly do you need? Me to get out our termlab and show you 2 graphs, one with one sub, one with two in a common chamber to show you that they really do just get louder, and don't sacrifice power handling?

I will gladly do that tomorrow night in my spare time after work if that's what will make you understand.

I am happy to admit when I'm wrong...but only when I am. Your argument, as noted above by my pie exampe, makes no sense at all.

sddykstr

Dude Mandos, you are an audio god. Maybe you could respond to my question...

Neothin

mandos is done for the night, i kept him from teh girlfriend long enough so i let him go home

trialsindude

I cant even find what I am looking for right now well anyways.

Ok go with this a sub in a sealed box recommended volume is 1cuft, why is that when you use 2 subs you have to double the volume. Thats because each of those subs are using only 1cuft of space. And like Mandos say its now double the VAS.

I'm done people will believe what they want to believe, next thing you know he will say using a cap will stop your dimming forever.

Burb1996

Perfect example. I know its not audio but work with me here ti illustates Mandos' point exactly.

Go to your sink and fill it halfway full of water. The water is now your interior volume of your box. Drop something round in the water. What happens?

The water is displaced in waves that disperse from the point of impact. Think of this as if these were sound waves. The point of origin is the round object a.k.a. the sub. They leave the sub and travel until they hit the outside of the box.

Now drop two round things in at the same time (really works better if theyre the same size). What happens? The waves hit each other in the middle do they not? Two points of equal pressure in a finite space can not occupy the same region. Now put a plate in the middle and do it again. The SAME thing happens.

Not to be all "Bill Nye the Science guy" on here but its physics my friend.


Just try it. Oranges work best.




Plus you can eat your props after its all said and done.


Edit: For spelling...crappy laptop

SCI_TC_GUY

damn.... I leave work and "get PwNEd".....

mandos

27 10" chunks of a 2x4

Or expanding foam...sorry...that one was probably lost between the novels I was posting.

Neothin and I were talking about this last night. We could "share" $100 bills. By the logic in this thread, we wouldn't have $50 each, we'd each have $100...we could then share the $200 total, and end up w/ $400...we'd be RICH!!!!

sddykstr

Nice