Sub design/selection advice needed

[GranteedEV]

For reference, here is an attractive, inert, NON downfiring endtable build using the Trio 12 + 2PR:

I don't think downfiring has any real advantages, besides being "invisible".

 

[generalkorrd]

If you can figure out a way to side mount, then your driver possibilities open way up, to pretty much any driver that you desire. Otherwise, you may be replacing drivers far more often than is necessary.

 

[generalkorrd]

For reference, here is an attractive, inert, NON downfiring endtable build using the Trio 12 + 2PR:

I don't think downfiring has any real advantages, besides being "invisible".

THAT'S a gorgeous sub! How did you deaden the walls? The only sonic advantage I can think of to downfiring is that the floor will be a loading wall, which increases the sensitivity a bit. Other than that, nothing.

 

[GranteedEV]

THAT'S a gorgeous sub! How did you deaden the walls? The only sonic advantage I can think of to downfiring is that the floor will be a loading wall, which increases the sensitivity a bit. Other than that, nothing.

It is not my build, mind you:

http://www.hometheatershack.com/forums/creative-sound-solutions/23297-trio-12-end-table-build-2.html

However two things need to be pointed out.

1) We don't really need to use constrain layer damping at subwoofer frequencies in our subs. Bracing every 8 inches, and using 1" walls is adequate, because actual panel resonances are too high in frequency to be excited. Baffles should be 1.5" or 2". You also might want to place latex or high resilience foam underneath and "above" your sub in order to decouple it from the floor. If you do want to reduce internal energy further, you really need to be looking at thick - IE 8" stacks of rigid fibreglass to line the internal walls. If it's a really high output stroker, then 2" thick walls and a 3" baffle, are maybe not a bad idea. But my Mal-X box only uses around 3/4" to 1" material all around and 1.5" baffle, and despite being an 18 i really haven't heard any muddying of the sound or resonance. I think the issue is not really one, at subwoofer frequencies compared to upper bass, lower midrange.

2) Because dual passive radiators are used for the helmholtz resonance, much of the box is very inert by nature. Much internal pressure is evenly released through the passive radiators, in equal and opposite directions.

Another very naturally inert design, is the dual opposed sealed design, although it won't have bottom octave efficiency of a PR setup.

 

[generalkorrd]

I can see how the config is a naturally inert one. OP however wants sealed or ported and I know that sealed especially is fairly violent with walls unless you take precautions. Especially if he goes with a kilowatt or more to a high xmax 15 lol

 

[GranteedEV]

There is a ~9 cu ft stuffed tapered transmission line for the W15GTI, that I'm aware of. Transmission lines have the advantage of evenly guiding pressure towards the terminus rather than randomly in all directions with a very clean impulse response. It has an anechoic F3 at 20hz (which might be a bit low and require EQing down after room gain.).

The somewhat slim internal dimensions, however, probably won't really lend well to an end table. 18"W x 22"H x 40"D.

Maybe TLSGuy could fold a Trio12 tapered-TL that has acceptable dimensions?

 

[generalkorrd]

There is a stuffed tapered transmission line for the W15GTI, that I'm aware of. Transmission lines have the advantage of evenly guiding pressure towards the terminus rather than randomly in all directions with a very clean impulse response. It has an anechoic F3 at 20hz (which might be a bit low and require EQing down after room gain.).

Isn't a TL especially long though? would something like that fit in an endtable box?

 

[GranteedEV]

Isn't a TL especially long though? would something like that fit in an endtable box?

A TL for a 15" driver, will likely be large. A 12 could be more managable. To give it a more cubic endtable appearance, one could add external drawers.

 

[Java Doc]

Boy, so many options. Not really sure where to go at this point. The whole point of the downfiring was to keep it hidden (per wife's preference naturally). I've looked into TL boxes in the past, and even 12" ones seem to be rather large for my purposes. The CSS is nice since the box required is only 20x20x20". Ideally, something I can fit into a 3-4 ft^3 gross box is ideal.

I would like to go ported if possible, but I'm not sure how many options fit in this size box. The PR is a good option, but it's not nearly stealth enough. I'll have to talk to the wife about that one. How much luck have people had with the Rythmik's? They only recommend a 3 ft^3 net box.

If worse came to worse, which would I have better luck with, a sealed 15" or a ported 12". Keep in mind, there will be 2 of these, and the main use will be home theatre.

 

[generalkorrd]

Correctly ported 12 will give more output, and should dig a little deeper. If you MUST downfire, you could go with a multiple 8 build, say 3 or 4 drivers per box. There are alot of 8's that take .5cuft or less net ported. Then you also don't have many issuees with sag either. I would think that could keep up with a ported 12.

 

[annunaki]

What about front firing with your grille as a pseudo door on the front of the end table?

You could make it look like a nice door with back grille cloth for panels. You would never see the woofer that way and people would not know the difference without a close inspection.

Boy, so many options. Not really sure where to go at this point. The whole point of the downfiring was to keep it hidden (per wife's preference naturally). I've looked into TL boxes in the past, and even 12" ones seem to be rather large for my purposes. The CSS is nice since the box required is only 20x20x20". Ideally, something I can fit into a 3-4 ft^3 gross box is ideal.

I would like to go ported if possible, but I'm not sure how many options fit in this size box. The PR is a good option, but it's not nearly stealth enough. I'll have to talk to the wife about that one. How much luck have people had with the Rythmik's? They only recommend a 3 ft^3 net box.

If worse came to worse, which would I have better luck with, a sealed 15" or a ported 12". Keep in mind, there will be 2 of these, and the main use will be home theatre.

 

[Java Doc]

Indeed, that is a very tempting idea as well.