[audioferret]

Pardon if I was unable to locate a thread answering my particular questions, but I am unable to locate the best answer.

I am looking at building a Rythmik Audio Servo Sub, a 12" sealed design that uses servo tech to achieve deep extension. I am also going to build a 5 channel setup of identical speakers to match. (Raw Acoustics HT2s - MTM using XBL motors and ribbon tweeter)

What speaker style (ported or sealed) will blend best with such a sub? My room is about 13' wide by 12' deep with 9' ceilings. It is in a finished basement and hs openings to the left and right rear corners.

I am leaning towards sealed and get the sub rolled off at 12dB slope. Thus, the speakers would have an acoustic roll-off of 12dB to blend in together.

BUT,

The 80hz crossover applied in my receiver's bass management will add to this, won't it? With sealed speakers, will this result in a 24dB slope or will it remain at 12dB?

Ideally, I think 12dB will be easiest to blend, but I am not sure.

Help?

[warnerwh]

A 24 lowpass to your sub is fine. My speakers use first order high pass networks but I am using a Behringer CX2310 crossover with 24db Linkwitz-Riley slopes. This blends perfectly. I am crossing at 60hz. In case you're not aware you should go here:   http://www.htguide.com/forum/index.php4?

to the Mission Possible forum. There's world class sub builders there who will help diyers. I just finished a sealed sub 2 days ago and it's the best low to 60hz I've heard anywhere. Didn't cost much either compared to buying a new sub. Brian's Rythmik subs I'm sure are good and I use one of his amps on my other sub but if I were you I'd ask those guys their opinions, some with decades of design experience for major companies.

In case you're curious about the sub I just finished I'd been advised in a few places to use the Dayton RS HiFi 15" driver. My only goal had been accuracy and speed. This driver is only 139 dollars right now with free shipping. I told them I'd been willing to spend at least double that on a driver and everybody said that was an excellent choice.  Peak output in my box is 107db at 30hz which is where my F3 is. I thought I may have to use my DEQ 2496 to get a Q of .5 or so but didn't.  In your room it should be plenty of output.

The box size of my sub is 36"h x 19"w x 28.25" d.  It ended up weighing 135 pounds before fiberglass and driver. A pain to get down the stairs by myself holding onto the hand truck with 1 hand and the stair rail with the other. Not easy for a guy who weighs 152lbs to do. If you use Baltic Birch ply you can use only one thickness due to it's extra strength and it's lighter. Plus when you're done you can just stain and varnish if you want. Now that I know this my next sub will be Baltic Birch instead of double thick mdf.

 Be sure to buy or make some bass traps, they're worth every penny. There are quality differences too, I'd go with Realtraps if I were to buy but being a diy type of person you can make some. In your small room with those dimensions you'll need them. Hope this helps