Does box size make a big difference?

[Demi 10+ year member]

Invert mounting the sub would gain a bit too.

Why?

 

[Pickler 10+ year member]

Why?

My guess is because there will be more room inside the box.

 

[Demi 10+ year member]

My guess is because there will be more room inside the box.

Hmm, maybe. Everything ive read says that it makes no diffrence. Dunno though never tried it myself. I know that if you running two one firing in (wire in reverse of norm) and one firing out cancels some distortion. Called a push pull setup i belive. I wanna give that a go. Might add another type-x one of these days and find out.

 

[audioholic 5,000+ posts]

Hmm, maybe. Everything ive read says that it makes no diffrence. Dunno though never tried it myself. I know that if you running two one firing in (wire in reverse of norm) and one firing out cancels some distortion. Called a push pull setup i belive. I wanna give that a go. Might add another type-x one of these days and find out.

Actually, what you've read is that it makes almost no difference in audible terms. You have not read it makes no difference in enclosure volume specs, because it does. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif Clealry, when you take your sub out and mount it inverted, you are removing it from the enclosure volume, hence gaining some interior volume. There is simply no disputing this. Now, is it enough to be audible? Most likely not. But, add that to the space gained by removing the ports (and mounting them outside) and you are starting to talk about a decent amount of volume being added to the enclosure. Will those two factors combine to make an audible difference. IMO, yes, if he listens for it. Thos two things will probably yield not a heck of alot less gain in enclosure space than the .5 cubes he was wanting to rebuild for at the beginning of this thread.

The push-pull configuration you are referring to is called isobarik. If you want to try it, be my guest, but you wont like the results. Twice the speakers, twice the money, for the same output as only one of the speakers.... for what's usually an inaudible improvement in distortion output. Yaay? Not. And to correctly isobarik mount two subs, there is more to it than simply having one push in on one side of the box while the other pulls outward from the other side. The further the gap between the two subs, the less efficient the isobarik phenomenon would be. Ive done it, Ive know people who have also... has always turned out to be more money, work and hassle than its worth.

 

[hofffam]

Push pull configuration per se does not define isobaric configurations. You can have push pull without isobaric.

A system is isobaric ONLY if the two woofers are coupled together with a sealed chamber, then the assembly is mounted in a normal cabinet. The box can be vented, sealed, or even compound.

I agree isobaric probably doesn't produce the benefits people expect.

Look at the picture below:

 

[audioholic 5,000+ posts]

A system is isobaric ONLY if the two woofers are coupled together with a sealed chamber, then the assembly is mounted in a normal cabinet.

Exactly.

Oh, and the speakers must be wired out of phase with each other of course to be isobaric. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Demi 10+ year member]

Right i didnt mean isobarik. Just regular slot port with one firing in wire in opposite polarity. I hear what your saying on the space inside the box though, makes sense.

 

[audioholic 5,000+ posts]

Why?

Because if you mount the sub inverted, its frame and motor are no longer inside the enclosure, taking up space.

Right i didnt mean isobarik. Just regular slot port with one firing in wire in opposite polarity. I hear what your saying on the space inside the box though, makes sense.

There is virtually no advantage to the setup you are/seem to be describing. One sub mounted inverted, the other not, wired out of phase and without an isobaric loading chamber.... that would perform exactly the same as two normally mounted subs in the same box, wired in phase of course. Basically your example is just switching one sub around so you can see its ***, doesn't change performance of the system.

 

[helotaxi 5,000+ posts]

Oh, and the speakers must be wired out of phase with each other of course to be isobaric. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Only if they are mounted face-to-face. They neither have to be mounted face-to-face, nor wired out of phase for it to be an isobaric setup.

 

[audioholic 5,000+ posts]

Only if they are mounted face-to-face. They neither have to be mounted face-to-face, nor wired out of phase for it to be an isobaric setup.

Yeah, you're right. I was thinking of the traditional isobaric setup (TWF). //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif But sure, they could be mounted facing the same direction, running in phase with each other. Just so long as the motion of the two cones couple together, that is the key issue.

Good catch.

 

[sku 10+ year member]

Hmm..1 spec I can think of that may help might be Xmax.

Go with me for a second here...

Xmax is where the BL drops by 30% and that would be around 10% distortion.

BL distortion is usually the greatest contributor to overall subwoofer distortion (but there are others suspension comes to mind)....

Now having said that -- high Xmax doesn't tell you the SQ of the sub. What it tells you is that the sub will sound mostly the same at either 1mm of exursion or near Xmax excursion.

 

[audioholic 5,000+ posts]

Hmm..1 spec I can think of that may help might be Xmax.
Go with me for a second here...

Xmax is where the BL drops by 30% and that would be around 10% distortion.

BL distortion is usually the greatest contributor to overall subwoofer distortion (but there are others suspension comes to mind)....

Now having said that -- high Xmax doesn't tell you the SQ of the sub. What it tells you is that the sub will sound mostly the same at either 1mm of exursion or near Xmax excursion.

If you are concerned about a flat BL response, a better way to determine this than looking at xmax figures would be to purchase a BL optimized motor topology such as xbl^2, dual gap tech or the W7 series.

 

[MitchJ08 10+ year member]

box size makes a lot of difference..no matter how much u spend on tha subs and amps...if tha box isnt rite..its all a waste

 

[helotaxi 5,000+ posts]

box size makes a lot of difference..no matter how much u spend on tha subs and amps...if tha box isnt rite..its all a waste

Someone only read the title of the thread...

The change he's talking about is pretty negligible.

 

[MitchJ08 10+ year member]

lol my bad