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.

Built this box for demo purposes, not for the meter. Three 12" D2's wired with everything in parallel on the OA-3 prototype with no issues at all so far. Below will be a quick video showing excursion. We did put it on the meter though and it did a 140 at 26 Hz and in the 148's from 32 to 41 Hz. It's way too loud for my tastes but it is really cool to mess around with music on. Here is the box being put together. It's 6 ft^3 ported to 30 Hz via one 8" aero port. And here it is installed in the CRX for the first time. Last but not least a quick video showing the throw. I forgot to hold the camera sideways so it shot the video narrow. Oops!

Nice rounded port edges. I think the larger box will work out well for ya.

As STEvil pointed out, high roll surrounds can offer a smidge more surface area than a conventional surround if the total width of the surround is smaller than that of the surround it is being compared to. As far as a high roll surround effecting the sound; all surrounds impact the way the driver sounds. Narrow surrounds do shape the Cms curve differently than a perfect half roll surround. Most surrounds, however, are not a perfect half circle as they are renditions of a semi-circle usually found with some straightened edges towards either the basket landing or cone landing. Getting back to tall roll surrounds now; Yes they will have an impact on the sound of the driver. You must look at the material the surround is and how thick it is to get a rough notion of how it will impact the sonic performance of the driver. For instance, the old TC Sounds tall rubber surround is VERY thick and made from a pretty low compliance rubber compound. Because of the latter the surround acts as a lot of the mechanical restoring force of the driver. I think they may have changed their toolings or compounds for their current drivers, but the old surrounds used on the TC Sounds OEM drivers were so stiff that soft spiders were used to reach the target Cms (and in turn, Vas). The shape of the surround and spider together are what ultimately shape the compliance curve. The surround used on our Obsidian drivers is very tall on the 15" (and will be the same on the 18" version), made out of an adequately compliant rubber that's not too stiff or too soft, and together with the Nomex spiders shapes the Cms curve appropriately for the end user by aiding the spiders' mechanical "brake" towards the end of usable excursion. PS: I just noticed that I don't have good angled pictures of the drivers on Obsidian's web page so here is a good video that shows the surround on our 15":

With 600 watts per driver you won't be under powering them. They'll last forever with rated power and multiple woofers always looks better. However, if you are going to be on the small side for enclosure volume with four drivers compared to having plenty of room for two drivers I suggest going with two drivers. That way you can tune low, have plenty of room for your port(s), etc. I put in a temporary setup last night using two Obsidian 15's in a box that is 2 ft^3 per driver ported and I can't wait to yank it out. It's not enough volume for the driver (which I knew), so the low end suffers a good bit. Now in their proper enclosure size, like what was in my car before, of 3.5 ft^3 ported the 15's throw down! In the end I'm going to build another box and use three 12's instead of four 12's because I'll have the extra enclosure room to tune low and plenty of room for the ports.

The Obsidian Audio 15's are in stock ready to ship. If you send me an email ([email protected]) I can help you enclosure size and tuning with what you have to work with.

If you're eluding to a certain product or company and have concrete evidence to support your jab you should come out and name the company(s) instead of beating around the bush.

Not necessarily. That stronger motor could be pushing a heavier cone, or it could (and probably does) have a stiffer suspension (spider(s)). Probably shouldn't need to worry about it too much imo. If you want to try something new get the obsidians and give us a review, or get a stand by like some lvl 3's, or sa. You can't really go wrong with any of them. This. AT the same time however, that heavier magnet may not even be as strong as a lighter one. Two things come to mind. Supercharged motors (I know DD has them I think DC does as well) and Neodymium magnets. And if a motor can be "supercharged" then I also would think one can be "undercharged". And pound for pound, generally speaking, neodymium magnets will be stronger than ferrite. Judging a subwoofer's motor strength on the size or height of the motor is like judging a car's horse power by how it looks. There are too many factors; gap width and height, voice coil windings (material and shape), magnet grade, magnet ID and OD, etc.

Obsidian's 600 watt rated 18" driver isn't out yet so you can rule that out for now.

We put Sundown Audio's FedEx rep inside the truck for a demo / hair trick without the loading wall being installed yet:

We took out the loading wall / port and got it prepped for fiberglass mat and resin today. We wrapped the bolts with latex so the resin would not get inside the "tubes" and make it hard to get the bolts back in: Then we laid down fiberglass mat and resin on the back side of the port wall to seal it up completely: Right now we are waiting on it to dry. Tomorrow we will sand down the high spots on the back of the port face where the glass and resin is and re-install it along with using expanding foam to seal up any gaps.