Passive Radiator design, looking for opinions

[russforrest]

I would really like a 10" Subwoofer design with 2 passive radiators in an extremely small box (kind of like a Sunfire light). I was looking at the drivers at the following links:

Active Driver - http://www.parts-express.com/pe/show...number=295-134

Passive Radiators - http://www.parts-express.com/pe/show...number=295-138

I was hoping this would fit in a box around a 13.5 inch cube, or close to it. Does this seem doable? What size would you use? The 12" drivers of the same class would also be options but I am trying to fit this in a very small box. The link to the amp from Elemental Designs I am looking at follows:

Amp - http://www.edesignaudio.com/product_...roducts_id=819

Thoughts?

[neuro]

There don't tend to be a lot of pure subwoofer threads here. You might get more replies at avsforum.
That said, I like the PR design if you are going to keep the amplification relatively modest, you should still get pleasant response.
If you can fit a standard subwoofer like the Dayton RSS265, you should get more bang for your buck. I like the efficiency of the shallow mount woofer, 93 dB 2.83V/1m, but the standard sub has over 50% higher xmax, which is what will limit output at low frequency.
What size room are you going to use this sub in? How low do you want the frequency response to extend? Have you modeled your proposed design to make sure that those particular PRs will support the weight necessary to provide the tune you want?

[kmibb]

The HiVi SP10 is the exact driver used in the 10" Sunfire.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=297-460&FTR=

Hooked up to the Dayton 500W or 1000W plate amps, which have built in EQ, you could get very similar results to the Sunfire.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-807

However, the actual Sunfire uses a very beefy PR and an amp that delivers 2300W because of all of the EQ that is going on. And the 2300W claim has been tested and is legitimate. You can usually find the amps on eBay for relatively cheap.

[brent_s]

Triska. I've built almost identical using a traditional 3" port instead of the PRs for my parents. Quite impressive for the money spent.

Russ, your usable cabinet size seems to have shrunk quite a bit! A 13.5" external cube is only 1 ft^3 gross internal. Time to start thinking sealed, I think. What are your goals for extension and output? Remember the law...low, loud, small; pick 2. Is there a budget?

If you can go a little larger, a 315HO-4 in 2 ft^3 with one of AESpeakers PR15-1050 PRs with the typical rumble filter of fc=18Hz/Q=1 will get you an f3=35/f6=19Hz. Should work really well with room gain. 500 watts yields 108dB or more from 20Hz up, ground plane. 300 watts will only give up 2.5dB or so across the board. John at AE has been having problems delivering his AV15 drivers due to supply problems for surrounds, but I don't know if that effects his 15" PRs. If not, Creative and DIYCable have suitable PRs as well.

When you start thinking PR, the PRs need to have at least 2x the displacement of the active driver. So, a 10" driver needs two 10" PRs with each having the same Xmax as the driver. A lot of times you'll see the driver paired with the next size up passive...say 12/15.

-Brent