Rear Deck Speaker Box

[mr_naler]

I am currently looking into upgrading most of the components to the audio system in my newly purchased 86 325e. I have decided on an Orion XTR 10" sub, Cobalt 500.1 and the XTR 5.25 components for the front. The problem lies in the rear deck. I don't want to mount my rear deck speakers (likely XTR 6.5 components) to cardboard. So I was talking to a guy at a local audio shop and he suggested building a box to replace that whole back panel with wood. I looked at it today and it seems to me if I simply cut out the middle recessed area, and replaced just that, it would be easier and more practical. I know many people are opposed to rear deck speakers all together or at least prefer mid-bass, mid-range speakers, but I often have people ride in the back. I have searched to no avail for anyone else who has attempted this. I wanted to know if anyone has done this or has any information that would be helpful.

Thanks

[Jean]

http://www.e30tech.com/forum/showthread.php?p=1007881

[IRON-E]

http://www.e30tech.com/forum/showthread.php?p=1007881

^^^ thats a pretty sick set up, mine is a little more subtle, see if you like it?

[mr_naler]

Thanks guys, I want something more like the first one, except more simple and actually separate the speaker box from the rest of the rear deck, and make it easy to take out.

[Gooch]

Here's how I did mine:

http://www.r3vlimited.com/board/showthread.php?t=116616

[mr_naler]

I like what you did there, more like what I'm thinking. I'll have to figure out how best to position the tweeters, so they don't overpower the front. After removing the rear deck speakers this morning it does sound much better.

[StereoInstaller1]

Are you talking about a subwoofer box for the 10 firing up through the rear deck, or just different housings for the 6.5's?

If you are talking about a sub box, keep in mind there are torsion bars running actrsoss the underside of the rear deck, they are the trunk springs.

Luke

[mr_naler]

Oh no, I just want something for the 6.5s, eventually I want to run an amp to them and something more solid to mount them to. I will be making a box for the sub to go in the trunk. Thanks for the info though.

[StereoInstaller1]

I see.

My general rule of thumb on powering the rear speakers is 1/3rd however much power you have on the fronts, assuming stock locations.

So, like most decks make about 12 Watts of actual RMS power per channel, you should have about 35 watts per channel of (again) actual RMS power up front, all other things being equal.

Personally, my car has no rear speakers at all, but I don't use stock locations. This summer I am building an entirely new dash, but this is not the place to discuss that...

If I can help on the sub design, let me know. I have built quite a few, and that woofer works amazingly well in the boxes I make.

GL!
Luke

[NC325iC]

jean that is beautiful.

I have some 6x8s that i am using in my rear deck and i need to build an adapter to fit them to the rear deck, and some kind of cover for them cause they didnt come with any. (theyre left over from my brothers old mustang) I have been trying to think of a decent way of doing it.

[StereoInstaller1]

jean that is beautiful.

I wanted to mention that, too.

Is that your car, Jean?

[Jean]

It's not my car, I want to do something like that eventually with two 8s :)

[mr_naler]

I have a JVC Arsenal HU, it says it puts out 20w RMS, but I was planning on running 60w to all four from an amp and adjusting the gain settings. I had also planned on running 6.5s in the front doors as well. Any advice on where to mount the tweeters in the rear?

As far as the box goes I was just going to build a box exactly to the specs of that specific woofer. Mostly I just enjoy building them. I have looked at yours though, and I will seriously be considering one of them.

I should probably look up more specs on your boxes and the XTR sub to get a better idea on what I really need.

As I was looking at more info on the sub and amp that I had originally decided on I noticed the Cobalt 500.1 did not come with a subsonic filter. So now I must decide if I want to double that price for the XTR 500.1 or not. Probably will though.

I also found the recommended specs for an enclosure. 1 cubic foot and a port 2.659" x 2.659" with a length of 9.88" and a port tuning frequency of 40hz. I know little to nothing about what the port tuning frequency means or how to apply it to building the box.

Seems simple enough though, minus the port tuning frequency, since it's such a small volume required.