Reverse Design of a sub

[APLJaK]

So I need a HT Subwoofer for my main viewing room (15' x 20' x 8') but it must disappear into the room in the form of a piece of matching furniture. This dictates that the box itself is approximately 79 litres before bracing - I estimate 75+ litres after bracing. In addition, I only have room for a single down firing driver and no tuning ports so it must be sealed.

Originally I had intended to use a 12" Rythmic servo system but before committing I would like to explore a few other options. Price and availability (Western Canada) will be considerations. As for performance I do not need to move the house, but I would like to add a bit of depth to the sound, especially movies that seem to fall flat with my current bass response. The Rythmic 12" fits the size requirements quite nicely, but runs $650+ after factoring in shipping. In addition, I have not seen too much discussion on their performance.

Being new to this, I have limited knowledge and would appreciate a push in the right direction. I have looked at the Trio12 with Bash500 (available from Creative Sound), but I think my enclosure is a bit small and I have no room for the passive radiators suggested. I have also looked at the Peerless XXLS 12" but I seem to be getting more confused instead of less. After the effort and cost, I would like to end up with a decent sub. Any suggestions on how to proceed?

[Cokewithlime]

Just as a FYI with the size of your room you would be better off with two subs instead of one. A sealed enclosure will give you a fairly tight bass response but will not go as low as a ported or PR enclosure.

A couple of questions:
- what is you overall budget ?
- is this just for HT or HT and music ?

[APLJaK]

Wife will not be happy with two cabinets in the room - 'nuff said. As with everything, I don't want to spend more than I have to. I am willing to spend the money for the Rythmic, but not too much more. The sub will be used primarily for HT however it will also be used for music. I am not as interested in getting extended bass response for music as much as I am for HT.

After this project is complete, I may find a bit more latitude with design, size, etc. for my next project (basement). I am willing to experiment more in the basement than I am in the room this current sub is destined for.

[Cokewithlime]

OK. here's is my suggestion

I would go with a single 15" driver - the Dayton RSS390HO-4 15" Reference HO Subwoofer 4 Ohm and either the Bash 300 or the Bash 500.

Best suggestion for mainly HT use
In a ported 75 l enclosure tuned to 24Hz with a 4" x 19" port this would get you (with the Bash 500) a 115db with a F3 of about 28Hz with a gentle slope down to a F10 of about 19Hz without boost. (the use of boost is NOT recommended with ported enclosures)

Compromise Suggestion for mixed music and some HT use
In a 75 l sealed enclosure this would get you (with the Bash 500) a 115db with a F3 of about 44Hz with a gentle slope down to a F10 of about 24Hz without boost - you could play with the Bash boost levels to fine tune this to your room

BTW - CSS can order you the Dayton driver and get it to you cheaper than you bringing it up from the USA yourself.

I can post or PM you with the WinISD sims if you want to have a look

Comments ???

[APLJaK]

Thanks for the quick response. I will think this through and let you know how I make out. I do not see the Dayton on the CSS website but will inquire about it.

[taloyd]

The Rythmik subwoofer is the best I've ever heard - I wouldn't worry about the performance.

I have the DS15 unit, though I'm sure the 12" is similar with a tiny bit less headroom.

cheers,
-Tal

[Cokewithlime]

Originally Posted by APLJaK

Thanks for the quick response. I will think this through and let you know how I make out. I do not see the Dayton on the CSS website but will inquire about it.

Rob(Bob)Reimer who owns CSS does not stock Dayton Drivers, but as I said, has an arrangement with PE to get the drivers into Canada far cheaper than you could yourself.