Contour Enthusiasts Group Archives Forums Modifications Audio Dual Rear Deck Subs

So, I finally got around to installing twin 8" subs in the rear deck (free-air). I used a couple of Audiobahn 8s, and the installation took the better part of a day. I had two appropriately sized holes in the rear deck cut at the body shop (next to each other on the passenger side of the car). I made a baffle out of 3/4" MDF and bottom-mounted the subs to it. I used lots and lots and lots of sound deadening material including poly-backed roofing material and carpet padding.

Overall, I'm pleased with the performance. The bass extension is surprisingly deep for 8s. The sound bumps a bit more than rear fill now (like the previous single 8 in the rear deck) and it's pretty tight. I'd equate overall performance to an average 10 mounted in a sealed box in the trunk. But, I lose no trunk space and have very little trunk rattle.

Curiously, the bass seems a bit like a bandpass enclosure. You can tell when the sub is playing in its sweet spot. I was expecting a flatter response, but I like the little extra bump.

I'll post some pics of the install from start to finish for anyone interested when I get back home from Detroit tomorrow.

Edit:

Here's a link to the pics - Dual Rear Deck Sub Pics

Why didn't you me you were in the Detroit area?

btw, congrats on the free air experiment success.

Sure! Post some pics. I am always interested to find out if I wasted my time with my shelf box.

I'm interested in pics! Been thinking of putting a single enclosed 8 up there, but hey, if open air is good enough, that's all the better!

Oh, btw, what's the model of the Audiobahns you used? Thanks!

EDIT: Also, how much power do you have to the subs?

EDIT: I wonder how many times I can edit this post. Anyway, Colin, I did some searching and found a post by you, in which you said:

Sooo....do you think that I would be better off using that Kicker free-air instead of the Audiobahns? Two subs are out of the question, because I don't want to buy another amp.

Sorry for all the questions, but you seem to have the most experience with this.

It was a last minute trip (rush) to get some audit stuff done for a union, so it was work work work sleep work work work. Then, the partner decided to hitch a ride with me back to Chicago, so I couldn't bum around for a while (he had to be back ASAP).

I might be out sometime in the next month or two to possibly finish up some work for my Detroit clients. I'll be sure to let all of you Michigan guys, so you can check out my constant WIP.

Anyways, I had a friggin' wheel bearing start making noise on my way out to Detroit. Looks like some repair work this weekend (and a wash/wax/detail for my poor car).

The Audiobahn 8s were model AW831X. They're 4ohm DVC subs wired in in a 4ohm mono load to my amp. They're each receiving 120w.

I liked the Kicker sub in my original free-air setup better than the Bahn. But, the single Kicker also cost more than both Bahns together, and that particular model isn't made anymore. I got the pair of Bahn 8s for $75, while the Kicker cost me $85/each back in the day. I finally retired the Kicker and gave it to my BIL to play with. It was getting old and the surround is beginning to deteriorate.

Meanwhile, the Bahns in my new free-air setup sound much better than the single Kicker in my old setup. I used much more sound deadening. The baffle reinforces the deck much more. And, I made everything sonically transpearant as possible by including enlarging the OEM hole to match the sub and lots of scraping of the backing off the rear deck cover.

Here's the link to a whole buncha pics:

Dual Rear Deck Sub Pics

BTW, while checking some things, I have found that the MTX 4000 series is almost ideal for free air applications. High Q, medium vas subs make them good.