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Discussion Starter #1

I've spent too much time here, and have gotten to the "A little knowledge is a dangerous thing" level.

In the mail, as we speak, are an iNuke 3000DSP, two leftover 15" MFW's from Erich, and two 15" subwoofer boxes from PE:

http://www.parts-express.com/dayton-audio-swc15-15-subwoofer-cabinet--302-830

My original plan was to create a thread entitled "The 'I hate DIY' build," but then I started with WinISD (about which I know nothing), and came up with this for one driver in one 2.5 cf box:

 



 

 

The thought I had was that (please don't laugh) if I take the two boxes and glue them together, amp cutout to amp cutout, that would give me a 5 cf dual-opposed setup that models like this:

 



 

Is this totally off the wall?

Michael
 

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The second design is isobaric which gives you the output of one driver, whilst using two, but in a smaller enclosure. Waste of time.
 

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Discussion Starter #3

Obviously I was going for dual-opposed, so the drivers would be facing AWAY from each other, which I don't see as an option anywhere.

But two separate small enclosures would be better anyway?
 

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Quote:
Originally Posted by LastButNotLeast  /t/1524972/is-this-a-crazy-idea/0_50#post_24549986


Obviously I was going for dual-opposed, so the drivers would be facing AWAY from each other, which I don't see as an option anywhere.
It won't model correctly if you use isobaric. Just model it as one enclosure with 2 drivers. There is nothing special about dual opposed.
Quote:
Originally Posted by LastButNotLeast  /t/1524972/is-this-a-crazy-idea/0_50#post_24549986


But two separate small enclosures would be better anyway?
2 enclosures of X litres or one enclosure of 2X litres won't make any difference.
 

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Discussion Starter #5

I've gotten the impression that dual-opposed is "better." More trouble than it's worth (in this case, anyway)?

Thanks for the input, BTW. I appreciate the help.

Michael
 

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Quote:
Originally Posted by LastButNotLeast  /t/1524972/is-this-a-crazy-idea#post_24550691


I've gotten the impression that dual-opposed is "better." More trouble than it's worth (in this case, anyway)?

Thanks for the input, BTW. I appreciate the help.

Michael
What's good about dual-opposed is that the cabinet won't move as much, assuming it is well built.
 

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Discussion Starter #7

Fine. Two little boxes it is.

Thanks for the input, folks.

Michael
 

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I think the overall point is that dual opposed is a good idea, but your modeling of it was wrong. Winisd does not have the ability to model multiple subwoofers unless you combine them in one box. Isobarik is not the right way to do it. For two subs, just double the drivers and double the box size, but leave the type as "normal." Dual opposed will not change the modeling.
 

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Discussion Starter #9

Then back to my original question (I was afraid that would happen):

Is dual-opposed - the way I'm thinking of doing it - still a good idea?
 

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If these will be your only subwoofers, then you would most likely benefit by putting them in different places in the room for more consistent response in different listening positions. The benefits of dual opposed are a reduction in vibration and resonances that may not be audible.
 

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Discussion Starter #11

It/they will replace a Klipsch RW12d that I'm selling and will team up with an SVS PB-1000 that I got recently. With two smaller cubes, I'm thinking I'll have them in a corner, facing two different directions.

I would have been interested in dual if it would give me, for example, more extension, otherwise I'll keep it simple.
 

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Facing them in different directions will make no difference. As long as you don't have them facing directly into the wall or something like that, the direction will have zero impact. Sub frequencies are omni directional. Up, down, forward, left, or right, will all sound the same. Down-firing requires adequate clearance of several inches.
 

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Quote:
Originally Posted by LastButNotLeast  /t/1524972/is-this-a-crazy-idea/0_50#post_24551415


I would have been interested in dual if it would give me, for example, more extension, otherwise I'll keep it simple.
It won't give more extension.
 

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Discussion Starter #14

Fair enough. Two "little" boxes.

Thanks for all your help.

Now I get to work!

Michael
 
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