Constructive interference

[JonJT 10+ year member]

Two Situations

1. A second woofer is added to an enclosure for a total of 2 woofers. Alignment is optimized to perform with the second woofer

2. A second speaker is added to the listening environment playing the same information as the first

In both situations, by how much would the intensity of the sound waves increase?

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[thch 10+ year member]

same power?

in anycase the gains should be similar if the speakers are close to each other.

 

[LuNaTiC 10+ year member]

wtf

for 1 theres no way to tell but for 2 the intensity is doubled.

Terrible wording FTW...

EDIT: There isnt enuff info in either scenerio to tell the gain.

 

[JonJT 10+ year member]

Ok, there is a definite rule, I know because I've heard it before, but I just don't remember.

1. Adding a second woofer to a speaker. Like going from 1 sub in a box to 2 subs in a box. Without counting room interactions, there is a set increase in intensity for the same power input measure in dbs. I want to know what that is.

2. Throwing a second sub into a room that already has 1 sub. The total now becomes 2. Without factoring in room gain and other interactions, what is the increase in intensity for a given input of power to each sub. ex: (only one sub is present and recieves 400 watts, then the second sub is added and also gets 400 watts).

 

[JonJT 10+ year member]

Lunatic, for the first senario, you could use math to calculate it, WinISD and Bassbox do it with specific woofers.

 

[JonJT 10+ year member]

Just tested senario 1 with WinISD. Used an AV-15 in both sealed and vented alignments, first with 1 woofer, then with 2. Average increase was 6db, theroticaly. That's what was looking for, I just didn't bother to model it in WinISD.

 

[JonJT 10+ year member]

The second senario can be calculated by some excel spreadsheet that is on the net somewhere, but I don't have it.

 

[LuNaTiC 10+ year member]

Just tested senario 1 with WinISD. Used an AV-15 in both sealed and vented alignments, first with 1 woofer, then with 2. Average increase was 6db, theroticaly. That's what was looking for, I just didn't bother to model it in WinISD.

No.

 

[LuNaTiC 10+ year member]

1. A second woofer is added to an enclosure for a total of 2 woofers. Alignment is optimized to perform with the second woofer

It wouldn't be 6 db increase.. 1 sub is in a box, you add another sub in the same box. The box happens to be optimized to perform with the second sub. Assume the subs are exactly the same. The box is optimized for the second sub, therefore isnt optimized for both which can drastically decrease output compared to a box optimized for BOTH subs. See what im trying to say? its hard to explain.

2. A second speaker is added to the listening environment playing the same information as the first

this one seems like it would be acoustically doubled or 3db increase ASSUMING by information the sub is getting the same power also.

 

[JonJT 10+ year member]

1. A second woofer is added to an enclosure for a total of 2 woofers. Alignment is optimized to perform with the second woofer
It wouldn't be 6 db increase.. 1 sub is in a box, you add another sub in the same box. The box happens to be optimized to perform with the second sub. Assume the subs are exactly the same. The box is optimized for the second sub, therefore isnt optimized for both which can drastically decrease output compared to a box optimized for BOTH subs. See what im trying to say? its hard to explain.

2. A second speaker is added to the listening environment playing the same information as the first

this one seems like it would be acoustically doubled or 3db increase ASSUMING by information the sub is getting the same power also.

Your saying the same thing I'm saying and your not realizing it. Optimizing for the second sub means that you optimizing the box to work with both subs, You can't optmize a with 2 woofers in it for just one woofer.

And the average increase is 6db, I found and answer elsewhere, it's 6db. This is assuming the alignment has reach its mechanical or electrical limits, whichever comes first.

 

[LuNaTiC 10+ year member]

err, kk. As long as I'm almost right lol.

 

[squeak9798 5,000+ posts]

Double power to a single sub, or add a 2nd sub without increasing power = theoretical 3db gain.

Adding a 2nd sub and doubling power = 6db gain.

 

[LuNaTiC 10+ year member]

Double power to a single sub, or add a 2nd sub without increasing power = theoretical 3db gain.
Adding a 2nd sub and doubling power = 6db gain.

That is the most irrelevent thing I've ever heard. We already know that.

 

[bimma85 5,000+ posts]

That is the most irrelevent thing I've ever heard. We already know that.

3+3=8 //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

is that your mt in your avatar?

 

[squeak9798 5,000+ posts]

That is the most irrelevent thing I've ever heard. We already know that.

But both of you said it in rather unclear, horribly worded statements.

Mine was clear and concise //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif