DIY Sonosub: $300 goal realistic?

[Josh Wilken]

For the past year I've been building my home theater piece by piece. I'm now at a relatively complete stage - the only remaining piece is to put a real sub in place.

Currently I'm using a Logitech 560 sub. I know, I know. :roll: I originally installed it just to get a sub in the room, but its actually pretty impressive considering it was intended for computer use - it reaches down to 30Hz without effort in my room.

I've been looking very hard at SVS... I'm interested in the PB10-ISD, and at $450 it seems to be a steal... but then I stumbled on a number of users that have "Sonosub" in their equipment list. I did a little searching, and bam, what a tremendous amount of information there is out there... a little too much!

So I am here at the feet of the masters of DIY for a little guidance. ;x(

The basic facts:

1) My room is roughly 1700 cuft
2) With my current setup I do most listening at the -25 to -15 level on my Yamaha RX-V2500.
3) I really want to hit 18-20 Hz with authority and impact, lower = better, but not required.
4) Usage is 80% HT, 20% audio
5) Amp should be included in costing, but does not have to be attached to the sub.
6) I'm handy with tools and have what I need to do the project.
7) Nothing too monstrous. Ideally less that 4ft tall or 20" diameter, but those are just guidelines, not hard stops.

Ideally if there is something someone has done already, I'd take a materials list and dimensions of the key components!

For those interested, here is a link to a thread where I have been documenting my progress:

Josh's Home Theater Thread

Thanks to all for your help!

~Josh

[SteveCallas]

I don't think you'll be able to get it done for $300. The cheapest decent driver you can get that is suitable for downfiring is the Dayton DVC 15" for ~$130. The 240 or 250 watt plate amps will cost you another $130. Figure $20 for shipping. Depending on if a concrete place let's you only buy a 4' section of tube or makes you buy all 12', you could be looking anywhere from $30-$70. Port material is probably another $10. A sheet of MDF is going to be ~$20. Then factor in the odds and ends - wood glue, wire, binding posts, stuffing, legs, etc., probably another $25. Finally, spray paint and a fabric sock to finish it will be ~$10.

So ~$400 is more reasonable for a decent sonosub. Rather than rush into it and make something subpar (no pun intended), I'd save up for a few more months so you can at least get to the performance level of a Dayton DVC 15".

Sorry, that's probably not what you wanted to hear.

[Josh Wilken]

SteveCallas,

That's exactly what I wanted to hear. $400 doesn't scare me, but its does put me close to the $450 for a SVS PB10, which makes me question the validity of the DIY approach.

In general, should I expect more out of the $400 Sonosub than the $450 PB10? And if so, what aspects?

I've read a lot about the Shiva 12" driver - any reason why that would not be an acceptable (less expensive) substitute for the Dayton DVC 15"?

Thanks again,

~Josh

[Brian Walter]

I suspect you would be happy with a Dayton Quatro 15 and their 240/250 watt plate amp. For HT, it is generally recommended to use a 6.5 cf ported box, tuned to about 20 hz. It won't give you quite as much total spl as some of the larger xmax drivers, but you probably won't find a better bang for the buck out there. I don't think there have been many people that weren't happy with that combination, at least not for HT use.

Brian Walter

[SteveCallas]

$400 doesn't scare me, but its does put me close to the $450 for a SVS PB10, which makes me question the validity of the DIY approach

:B For the money, it's probably one of the best commercial subs you can get, and if you want to play it safe, I'd say get it, but a 10" driver with a 3" port can only do so much, and that's not a knock. The sonosub would give you a 15" driver with an 8" port. You can chose to have the same extension as the PB10 with more max output, or the same max output with more extension. A lower tune and the much larger port should also give you a noticable sound quality improvement.

[Scott Simonian]

Dude... wtf, Steve!

The Dayton DVC will waste the PB10!

[Josh Wilken]

:B For the money, it's probably one of the best commercial subs you can get, and if you want to play it safe, I'd say get it, but a 10" driver with a 3" port can only do so much, and that's not a knock. The sonosub would give you a 15" driver with an 8" port. You can chose to have the same extension as the PB10 with more max output, or the same max output with more extension. A lower tune and the much larger port should also give you a noticable sound quality improvement.

Again, exactly what I was looking for. And by the way, I just checked out your link and YOU are the guy with the enormous escape-capsule of a sub that got me started on this! I am honored! ;x(

So where should I look to spec in the dimensions of the enclosure / port pieces... or is there anything proven that someone has done previously that would get the job done?

~Josh

[Josh Wilken]

Another thought:

If I were to pick up an amp off Ebay, pawn shop, etc - would I be able to use it - what would the key parameters I'd be looking for?

Thanks again,

~Josh

[SteveCallas]

The Dayton DVC will waste the PB10!

Yes, the DVC sonosub should be better in just about every way, I was trying to be polite :W

So where should I look to spec in the dimensions of the enclosure / port pieces... or is there anything proven that someone has done previously that would get the job done?

Lol, it likes a big enclosure :B . ~350 liters with an 8" diameter port that is ~30" long (~17.5hz tuning) with the 240-250 watts. If you can get a pro amp for cheap, that would be better, and the enclosure size and tuning would change a little bit, but most pro amps typically won't have a rumble filter built in, and this driver won't be able to "run free" without one. The older Crown XLS amps had a selectable 15hz filter if I'm not mistaken.

[Josh Wilken]

Lol, it likes a big enclosure :B . ~350 liters with an 8" diameter port that is ~30" long (~17.5hz tuning) with the 240-250 watts. If you can get a pro amp for cheap, that would be better, and the enclosure size and tuning would change a little bit, but most pro amps typically won't have a rumble filter built in, and this driver won't be able to "run free" without one. The older Crown XLS amps had a selectable 15hz filter if I'm not mistaken.

8" port - should I do two 4" PVC ports here? Or where can I get an 8" cylinder?

Help me understand the rumble filter thing - is it HP or LP? What does it do?

If I'm feeding it from a sub-out that is crossed over at 80Hz, does it matter?

Thanks again for all the very helpful responses.

~Josh

[SteveCallas]

8" port - should I do two 4" PVC ports here? Or where can I get an 8" cylinder?

No, two 4" ports doesn't come close to the port area of a single 8". Just as you can get 24" sonotube, you can get 8" sonotube.

Help me understand the rumble filter thing - is it HP or LP? What does it do?

Highpass - it filters out the extremely low frequencies from being fed to your sub. If you were to go with a beefier driver and a lower tune, you wouldn't have to worry about one, but the DVC will need it, as they can cause the driver to damage itself trying to reproduce them.

If I'm feeding it from a sub-out that is crossed over at 80Hz, does it matter?

That's what you should be doing, and it doesn't affect the need for a rumble filter.

[Josh Wilken]

[QUOTE=SteveCallas]No, two 4" ports doesn't come close to the port area of a single 8". Just as you can get 24" sonotube, you can get 8" sonotube.

Duh, its the whole squared thing- I should have been able to answer that!- It would take 4x 4" ports to do what an 8" does.

How can a newb to the sonotube like myself come up with a good design? Is there a program or something that I can model this with?

~Josh

[SteveCallas]

WinISD Pro, Unibox, Bassbox

[nick77]

http://www.quux.net/roo/diy/sonosub/sonocalc.html

Sonotube calculator, figure your 300 or so liters and it gives you correct size tube.

[Josh Wilken]

Awesome, thanks. I'll try these out.

~Josh

[jdybnis]

Quik Tube building forms are good for 6"-12" diameter. Cheap too (<$10).