The Ultimate shootout begins ...  

Craig,

Did you post your shoot out comparisons on the DD18 and Maestro?

Regards,
Will

I think the tuning should be lower then 18hz. I don't think a oversized dual 15" 8.5cu ft sub is worth the trouble without some real extension. I really think it should be tune to 15-14hz. That way, in room you should be flat to 10-12hz.

Craig,

I don't know if it would be practical for this shootout, but I know you are not exactly practical anyways :D, but do you think it would be possible to try different types of amps with the sub?

I am currently using an ICEpower based amp to run my mains, and I know the ACI Maestro is now using an ICEpower based amp as well. So selfishly, I was wondering for subs, if amps of different technologies but same power output make any measureable or audible differences.

Craig,

Thanks. I look forward to the comparisons and write up.

Regards,
Will

Sounds like fun craig, I'm going to keep an eye on this.

So we can keep things crystal clear with this custom subwoofer of yours, will you be revealing the specs of the final design (including the amplifier) and taking pictures of the enclosure before it is closed off? Also, did you order the D2 or D4 version of the RLp15s?

Great!

Yes...I'll take the sub when you are done with it. :)

Hey, I'm closer to Erie than you, Curtis. I'll act as customs for you and "inspect" the sub before it ships to Cali!!

and likewise....it'll never make it out of customs!

Curtis.....there's always a way To Insure Proper Service! ;)

Some people get all the fun! :p

on a serious note craig, I'm wondering why such a high tuning point for the SS driver? Unless the parameters are just completely different than the current batch drivers (for example, the RP-L drivers), with 8.5 net cu volume (on say, a 15" or even 18" driver) you could easily tune it to 15hz flat! Using the RP-L15 on winISD yields an impressively flat FR at 15hz Fs, with an 8.5volume.

I'm curious on the details on these "new" drivers, as perhaps the coils, motor, etc, could be different thus causing the T/L params to be such as to require a higher Tuning point given the rather large Volume.

cool stuff nonetheless

The drivers aren't different, he's just being suggested a traditional ported design.

The dual Rl-P 15(d2 i assume) setup will obviously kick butt, but I decided to run it through unibox to see what kind of output to expect. I assumed 800watts/driver, rounded off the volume to 250 liters as it was close enough...
Tuned to 15hz
http://i9.photobucket.com/albums/a79...rRL-P15800.gif
Tuned to 17hz
http://i9.photobucket.com/albums/a79...erRL-P1517.gif
I assumed Le to be around 4.0, seeing as LS was 5.2 for the d2.

that's insane....

:eek:

Ian

DIY for the win. :p

Yeah fellas, imagine what could be done with a good design ;)

The 2nd graph down is @ 17hz tuning, the first is @ 15hz tuning. Both with Mike's maximum suggested enclosure volume of around 8.5ft^3.

Craig,
What are the objectives of this shoot out? Are you going to compare a DIY sub to a commercial product in a $4$ comp? Are you going to compare a DIY ported to just ported subs or will you comp it to sealed subs as well?

What commercial products are you going to compare to?

With the DIY sub, is this going to be a Frankenstein design with all the AVS mad scientists contributing to it? Are you trying to make a DIY that would make a practical commercial offering (size, weight, cost)?

For us interested by-standers, will someone do the specs/results to common English translations?

ahh! well in that case.... :D

swing for the fences my brotha....swing for the fences, and join teh dark side (vented sonotubes and boxes, a la Stevecallas and Sherv designs)... dual RP-L15 D2's in an 8.5cu volume enclosure, with a nice 10" pipe or dual 6" pipes, slap a Fs=15hz, and you will have something to cheer about that will make any Ultra/2 dual EP600s dual HO turbos (pick your poison, etc) look like child's play.

For a dual sub, the box enclosure will surely be easier to make than the sono, but again, let others chime in their 0.02 ;)

Exocer - What size port are you using in your sims? Just wandering.

craigsub - That box size only seems big enough for a single driver. In 15hz tuning it only seems to gain you about 6db at 15hz over a sealed box at 250l, or 6db at 17hz in 17hz trim. An 8" port will have to be over 44" in a box that small to get the port speed down, but then you end up with a resonance at 141hz. A highpass will also be a must, not an option with this design. Maybe your boys in the factory can whip up two test boxes? :D

I'm sure we could get up some sort of MDF reimbursement fund going. I can pay-pal $10-20. ;)

I found that funny :D :D :D it's all in the delivery :D

There is more of a difference as the Vb increases.