DIY sub based on 17" cube and 15" driver?

[NoMSG]

As a compromise between getting a cheap-a$$ sub and the 12" Titanic kit that I can't afford, I'm considering builing my own sub. This will be used for HT, about 80 percent of the time.

I am not confident in my skills at creating an enclosure from whole cloth. I also want the sub to be of moderate size. At this point, my starting point will be the 2.0 cubit foot sealed box that's already fabricated, from partsexpress.com. This 17" cube is the biggest I can fit for my application.

I've also heard from kexodusc (thank you!) that the Dayton 15" Quatro mated with the 3.0 cubit foot enclosure would be even better than the Titanik 12" kit, but this would be too big. Also, when I looked at the specs for the 15" Quatro, partsexpress suggested a 2.0 cubic foot sealed box. Alternatively, the 12" Quatro looks like it'd need only 1.0 cubic foot enclosre for a sealed configuration.

So, here's my question: If I'm limited to the 2.0 box, should I mate it with the 15" Quatro or the 12" Quatro? The 15" looks like it'll go down to 20 Hz.

With respect to the plate amp, is there much of a benefit going from the Dayton 240 watt amp to the 300 watt BASH amp?

I realize these are probably very simple questions, but I've never built a speaker/sub before. Thanks for your patience.

[kexodusc]

So, here's my question: If I'm limited to the 2.0 box, should I mate it with the 15" Quatro or the 12" Quatro? The 15" looks like it'll go down to 20 Hz.

You can pull off the 15" Quatro in the 2.0 box. However, there is a trade-off though. I have little doubt the sound of this sub in such a small box will be tight and accurate, but your bass response will be considerably less deep. Quickly, I come up with an F3 of about 38 Hz, and bass extension down to about 26 Hz. This would be fine for music but for home theater you'd probably want more bass.

The difficulty here is your limitations in cabinet size. If you know what your goals for this sub are (music vs. home theater or both), it'd help narrow it down some. If you'll use it mostly for music and not for home theater, we can worry less about LFE extension to the low 20 Hz region, and stick with sealed cabinets.

I think for the 2.0 cubic ft box, I'd consider the 12" DVC ($110) in a ported cabinet. F3 of about 27 Hz, and in room bass response to 21 Hz. Pretty good sound quality as well.



With respect to the plate amp, is there much of a benefit going from the Dayton 240 watt amp to the 300 watt BASH amp?

Not really...the Bash amp is one of those funky newer style amps, Glass G or something probably. It'll deliver that little bit extra power, run cooler, and be a bit easier on your power bill. In terms of real performance, the 24 dB/octave filter on the 240 watt amp will make integration with your main speakers a bit easier. That 60 watts isn't going to matter to you, and your power bill might be a penny more. Maybe. Both are pretty good buys IMO.

If at all possible, it'd be great if you could find someone who could build a box for you to the size that best fits the woofer and your room. Not sure if there's any shops in your area, or if you know anyone who could. I'm sure you'd save a bit of money this way.

[NoMSG]

You can pull off the 15" Quatro in the 2.0 box. However, there is a trade-off though. I have little doubt the sound of this sub in such a small box will be tight and accurate, but your bass response will be considerably less deep. Quickly, I come up with an F3 of about 38 Hz, and bass extension down to about 26 Hz. This would be fine for music but for home theater you'd probably want more bass.

The difficulty here is your limitations in cabinet size. If you know what your goals for this sub are (music vs. home theater or both), it'd help narrow it down some. If you'll use it mostly for music and not for home theater, we can worry less about LFE extension to the low 20 Hz region, and stick with sealed cabinets.

I think for the 2.0 cubic ft box, I'd consider the 12" DVC ($110) in a ported cabinet. F3 of about 27 Hz, and in room bass response to 21 Hz. Pretty good sound quality as well.
...
If at all possible, it'd be great if you could find someone who could build a box for you to the size that best fits the woofer and your room. Not sure if there's any shops in your area, or if you know anyone who could. I'm sure you'd save a bit of money this way.

Thanks for the input, Kexodusc.

The sub will be for 80 percent HT at moderate (wife and kids) levels.

I'm taking your advice and now intend to build my own cabinet. This way I can get it to about a 3.0 to 3.5 cu ft. interior volume, while fitting it between the back wall and sofa. From a previous response of yours I understand that a 3.0 cu ft. sealed enclosure mated with the15" Quatro and 240 watt Dayton amp would go low and loud enough for HT. So, what kind of performance can I expect with a 3.5 cu ft. enclosure?

Per your previous advice, I'm also posting a similar thread (with substantially more detail) at the Parts Express forum.

Now I just have to get up to speed on the basics of cabinet making!

[kexodusc]

Making cabinets is easy enough...measure twice, cut once. Use .75 inch MDF, double the front baffle. The Quatro is a versatile woofer that will work awesome anywhere from 2.5-3.5 cubic feet. I choose 3.5, could easily have gotten buy with 2.7 or so.
If you want to save a bit of space compromise with a 3.0 cubic foot cabinet. Remember, that's internal volume...add the thickness of the walls for external, dimensions.

The Parts Express forum is a far, far better resource than I am. You won't be disappointed. Good luck.

[mixadude]

Making cabinets is easy enough...measure twice, cut once. Use .75 inch MDF, double the front baffle. The Quatro is a versatile woofer that will work awesome anywhere from 2.5-3.5 cubic feet. I choose 3.5, could easily have gotten buy with 2.7 or so.
If you want to save a bit of space compromise with a 3.0 cubic foot cabinet. Remember, that's internal volume...add the thickness of the walls for external, dimensions.

The Parts Express forum is a far, far better resource than I am. You won't be disappointed. Good luck.You might want to look at this! (http://rythmikaudio.com/servo_product.htm) I built up a pair of these. Actually I had Brad at Woodstyle products build the 2.2 cu ft boxes out of 1" MDF. They sound great, actually respond quite nicely well below 16Hz. One of them should be adequate for normal listening levels; I'm an old deaf rocker and my system here in my little room far outperforms large rigs I've had on tour for Bonnie and Lobos in real venues :D

[NoMSG]

Making cabinets is easy enough...measure twice, cut once. Use .75 inch MDF, double the front baffle. The Quatro is a versatile woofer that will work awesome anywhere from 2.5-3.5 cubic feet. I choose 3.5, could easily have gotten buy with 2.7 or so.
If you want to save a bit of space compromise with a 3.0 cubic foot cabinet. Remember, that's internal volume...add the thickness of the walls for external, dimensions.

The Parts Express forum is a far, far better resource than I am. You won't be disappointed. Good luck.

I went with the Q15/240 watt plate amp combo.

After losing a bit of time, skin, and blood, I finished my sub. Because of weight, cosmetics, and toxic dust issues, I decided to go with 3/4 inch 13-ply birch. I doubled the front baffle and used two windowframe-shaped braces. Despite this, there is still some resonance if you rap on portions of the side or top. It's 3.3 cu ft nominal, or 3.0 cu ft net internal volume. I stuffed it with 20 oz. of polyfill.

I finished it three days ago and have just started testing it out on music and HT. I cross it over at 80 Hz with my Pioneer 1014's bass management system. This sub is almost transparent. You hear/feel it only when you're supposed to. When I played the Eagles "Hell Freezes Over" DTS concert DVD, my 8-year-old remarked, "it's like you're really there."

For music, it blends incredibly well with my Energy C2s. I can't tell when the Quatro actually kicks in. It fills out the male vocals too, which I didn't expect.

For HT, at movie theater levels, the sound is just perfect; the action-movie impacts are all there (LOTR, Return of the King was almost punishing). But at lower listening levels, it is much less noticeable and I feel the need to bump the sub level up. I think I just have to tweak it before I'm finally satisfied.

Anyway, I still have to sand, stain (dye?), and poly coat the beast, so it'll be out of commission for a while.

Thanks again, Kexodusc. I couldn't imagine getting a better sub for my $260.

[kexodusc]

I went with the Q15/240 watt plate amp combo.

After losing a bit of time, skin, and blood, I finished my sub. Because of weight, cosmetics, and toxic dust issues, I decided to go with 3/4 inch 13-ply birch. I doubled the front baffle and used two windowframe-shaped braces. Despite this, there is still some resonance if you rap on portions of the side or top. It's 3.3 cu ft nominal, or 3.0 cu ft net internal volume. I stuffed it with 20 oz. of polyfill.

I finished it three days ago and have just started testing it out on music and HT. I cross it over at 80 Hz with my Pioneer 1014's bass management system. This sub is almost transparent. You hear/feel it only when you're supposed to. When I played the Eagles "Hell Freezes Over" DTS concert DVD, my 8-year-old remarked, "it's like you're really there."

For music, it blends incredibly well with my Energy C2s. I can't tell when the Quatro actually kicks in. It fills out the male vocals too, which I didn't expect.

For HT, at movie theater levels, the sound is just perfect; the action-movie impacts are all there (LOTR, Return of the King was almost punishing). But at lower listening levels, it is much less noticeable and I feel the need to bump the sub level up. I think I just have to tweak it before I'm finally satisfied.

Anyway, I still have to sand, stain (dye?), and poly coat the beast, so it'll be out of commission for a while.

Thanks again, Kexodusc. I couldn't imagine getting a better sub for my $260.

Hi NoMSG...
Glad to hear you're satisfied. I love my sub. I did use MDF, but I was able to use dado (rabbet or mortis and tennon, can't remember) for all my MDF cuts...Dado blades are a terrific investment, rabbet joints offer almost double the surface area and 3 times the bonding strength of regular butt joints when building cabinets. I don't have any resonance problems, but the darn thing is super heavy.

The low volume output issues are probably setting related (possibly room related). Don't give up on those...your sub shoudl be fine at any levels...

By the way, you aren't the dude at the PE forum having the problems with the output on this combo, by chance? If so, have faith, I had a few minor issues too (ground loop, sub amp output),but they were sorted out in a few days, and I haven't looked back. I'm building another...

Enjoy!

[NoMSG]

Hi NoMSG...
The low volume output issues are probably setting related (possibly room related). Don't give up on those...your sub shoudl be fine at any levels...

By the way, you aren't the dude at the PE forum having the problems with the output on this combo, by chance? If so, have faith, I had a few minor issues too (ground loop, sub amp output),but they were sorted out in a few days, and I haven't looked back. I'm building another...

Enjoy!

Yeah, I just need to tweak it.

And no, I'm not the guy with the ground loop problems on the PE forum. Oddly enough, I also have the Pioneer 1014 receiver, so I'm trying to help that guy out. I think he's figured out most of this problems. I think the 1014 is a good value and a solid unit.