Input on "big" obsidian setup?

[Kangaroux 47]

So I'm looking to go bigger (who isn't? ) and I was checking out obsidians. They look pretty nice, I'm pretty sure that the product is going to be great unlike some brands that are just starting out since obsidian was established by some reputable people. I've been wanting to do a big build for a while now and I've been hopping between brands, doing price checks and just seeing what I like most. I think I've decided that this build will work pretty well...though like I said it is a decent sized build so I was hoping that some of you could give me some tips on the best way to set it up. I know that's a really general statement, but hopefully you know what I mean.

Anyways, I was planning on doing 3 Obsidian 15's being pushed by a Soundstream Rubicon 2500d. Haven't decided on dual 4/2 coils yet. At 1.3 ohms I will be fine, but if I go with 0.67 ohms I think some of the box rise will take over and it won't hurt my electrical quite as bad...

Was fooling around in winisd and they really liked 3.5 cubes each @ 30. An hour or so later and I came up with this:

Final box is 11 cubes net @ 30hz. There is about 15 sq. inches of port area per cube so I think that should really help with some air movement. Port is braced, flush baffle, and there are 3x 1.25" dowels placed around the rear sub. I've never done a big setup like this, so I'm curious as to what you guys like to use for bracing, what works best, common problems, etc. If you have any experience with the Obsidian line then feel free to give me your opinion. Going for an ""SQL"" build that can drop low but still maintain well in the 25-40Hz range.

[Kangaroux 47]

Biggest reason I didn't do 2 18's was because I have a pathfinder, and unless I really squeeze them in there I just don't have the width for it. This is a pic of my current setup

As you can see the tire wells stick out quite a bit so I'm stuck with around 38" unless I did some modding. The rear hatch supports around 43" of total width

Edited July 30, 2011 by Kangaroux

[Electrodynamic 2]

It looks like a solid box volume and tuning frequency. 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. Simply stick with 12 in^2 to 18 in^2 per 12" driver and you will be fine. An adequate port for the Obsidian 15's is 30 in^2, or 90 in^3 for three 15's. The enclosure you have listed above is 165 in^2, or nearly double what you need. You can go with a huge port but your bandwidth/response will suffer as larger ports tend to peak higher than smaller/adequate, ports. Or if you had 9000+ watts and were interested in competing only, then the 165 in^2 has the possibility to put up a better score than a port that is 90 in^2.

For instance, with 1500 watts of clamped power using a single 6" aero port (28 in^2) I managed 144 dB in my CRX legal on the dash sealed up using a single 15" Obsidian. Switching to the 8" aero port (50 in^2) and raising my tuning closer to the peak of the vehicle (mine peaks at 56 Hz) I managed a 145 with the same power. However, increasing the power to 3000 watts saw a peak score of 148 dB with the 8" port. If I didn't have the large 3000 watts of power the huge port was not very beneficial.