Free Air Subs?

About 10 years ago I was into car audio, but I've kinda fallen out of touch with new trends and such. I was thinking about building a system for my 70 chevelle, and I was thinking of using a free air sub mounted in the rear deck between the 6x9's. I was looking arround on the net for free air subs and I couldn't find any.

I'm not looking for a booming bass that will crumble buildings and can be heard 10 miles away. I just want a well rounded sound. The other requierment that I have is that the system doesn't intrude too much on the interior space. Should I just forget about free air and do a 10 or 12" sealed box?

For anybody that doesn't know what a chevelle looks like, it's about the same size as a newer caprice or crown vic, like they use for taxi's and cop cars.

Thanks for any help,

David

Free-air is fine and there are a few drivers that can still handle it.  You will end up with a very low Q and somewhat boomy bass, but if that's OK there is no reason not to do it.

That being said, if you have your 6X9s operating free-air in your rear deck and you also put a sub there, all three drivers will actually be operating into the large air volume of your trunk.  This may or may not be a problem, but if you intend to push the sub with any significant power (say greater than 100 watts) I suggest you enclose the 6X9's so they are not affected by the much larger air volume that a sub can push around.

David,

A lot of the new subs require a lot smaller enclosure than years ago. I'm into the older Chevrolets and I did a buddies 70 Monte Carlo a few years back  and a 70 Malibu last year and and we just built a custom enclosures for the subs in both cars. There are a lot of ways to build one and not loose a bunch of trunk room you just have to get creative. Some of the 10" subs only require 3/4 cubic feet of airspace and 12" about 1 1/4 cubic feet. Also with an enclosure around the sub you have more protection around it to keep it from being damaged and allow it to operate and perform properly.

Jim/Saint Louis

If you free air a sub, you can't feed it to much power either, like 1/4 of the recommended power.

I have seen the Alpine type-s subs in free air applications, we fed 50 watts to each sub and they moved almost there full travel, still sounded good too.

Well, it's kinda carved up... http://68.60.252.120/Chevelle_qtr_1.jpg

It's getting two new quarter pannels, fenders, hood, misc. floor parts...

I'm most likely going to build a box (or buy one) as I don't want a real boommy sound.

Thanks for all the help

David

I'm doing the work myself with alot of help from my cousin. Right now it has a 307 in it, but someday I hope to have a big block 4spd combo in it.

As for the system, I'm just getting ideas now, but here's what I'm thinking right now.

6.5" in the doors or kick pannels with tweeters in the dash.

And depending on the head unit that I get, either 2 or 3 amps. About 50w rms to the front, 60-70 to the 6x9 and about 150 to the sub. If the head unit I get has three outputs I'll use three amps, If it only has two preamp outputs then I'll use a 2 channel in the front and 3 channel in the rear.

Do you think the power levels are good for a balanced system?