Electrodynamic

Much better. I would put the port off to one side and not in the middle of the box. That way the port isn't obstructed by anything like a big motor.

A single 6" will do very well. That's what I used in my daily setup with a single Obsidian 15" in 3.5 ft^3.

I don't know where the idea of X in^2 per ft^3 started but it is not a very good ideology to follow. If that were the case a single port for a single 12" driver in 3 ft^3 would be 36 in^2 for 12 in^2 per 1 ft^3 which is a 3x12" port...and good luck fitting it inside the enclosure due to the port length required. That's a huge port for a single 12"! Most drivers out there can't excite that huge port area, so that huge port is wasted for the most part. As I mentioned in my last post I would ditch the third port because you don't need it / will never be able to utilize that much port area with the power you are using. In my testing with a single OA 15" I saw an increase of 1.2 dB going from a single 6" aero port to a single 8" aero port...but only while using a clamped 2700 watts. With 1500 watts there was almost zero gain (IIRC it was 0.2 dB).

It looks good besides the port area. You don't need that much port area for a single 600 watt 15". You could drop one port to end up with two 4" ports and shrink your enclosure down a bit to keep the same ft^3 and tuning. It would save you some trunk/cargo room.

^ You are correct on all counts. The SA is the loudest out of the three mentioned in this thread (about 1.6 dB louder than an Obsidian and a tad more than that louder than a Skar) and it ought to be seeing as it is the most expensive at $195. Next in line is the Skar $179 and the most affordable is the Obsidian at $138 in a 12" size. I'm bias so I believe that the Obsidian is a superb contender in all enclosure formats in SQ and SPL. But if I was competing or I was going to throw 2000+ watts at a driver rated for 600 watts all day long I would go with the Sundown SA woofer as it has the most advanced VC cooling of any driver using a smaller coil than a 3". If I had between 600 and 1000 watts to throw at a single driver and wanted to compete here and there I would go with the Obsidian.

Also the Obsidian subwoofers have a more powerful motor with a BL^2/Re of 100 compared the P3's BL^2/Re of 71, have lower moving mass, have a lower compliance suspension that allows them to be both ported or sealed, handle more power, etc.

There. 'fixed now.

well i have a poweracoustik 5500, and it does 1700 at 4ohm, and i've been running my kicker CVR 15"s on it. there aboiut the same RMS rating as the obsidian. i just didnt know if they could take the 600 RMS rating they have on the site. or possibly take more than the 600. i'm kinda new to this stuff so i dont know a whole lot The Obsidian subwoofers can take every ounce of the 600 watts they are rated for.

New video taken today:

*added 08/29/2011* In addition to the above items, the raffle now additionally contains a Sundown Audio 125.2 and two Sundown Audio neo pro 8" woofers. That's right, the entire lot now contains the following: 1) Obsidian Audio 15" D2 subwoofer 1) Sundown Audio 1200D amplifier 1) Sundown Audio 125.2 amplifier 2) Sundown Audio 8" Neo Pro woofers

The ideal alignment per 12" woofer is 1.75 ft^3 tuned to 32 Hz. I've got my three 12's in 2 ft^3 each tuned to 30 Hz and the low end is a bit on the retardedly loud side. They are literally tearing my CRX apart bit by bit. I'm having to rip everything out and bolt down the enclosure because it jumps too much if I play screwed music. I enjoy how they sound but the extra 0.25 ft^3 per driver is not necessary in order to get them to play loud or low.

Here's a couple of pics showing what is being raffled off:

please read the rules...... And it also looks like your advertising in your SIG, so i'll edit that as well....

Answer is in the second paragraph of my initial post.

We tested the OA-3 doing 3250 watts at 11.5 volts.