stereo system -- '91 GM

[monterey1962]

I'm starting to toss ideas in my head for a new stereo system in my mom's '91 GM. Plan so far:

1. Pioneer deck.
2. Pioneer 6.5" doors.
3. Pioneer 6"x9" rear.
4. 2 - 10" subwoofers.
5. Amp.
6. Custom built sub boxes.

Deck, speakers, subwoofers, and amp are no issue. Wal-mart specials. Sub boxes are what I plan to build. Plan is for 12" to 14" face and backing and about 6" to 8" deep. I want to set them up so they mount on the side ledges of the trunk and face inward. Amp will be mounted up beside the spare tire.

Building the boxes is where I need info.
1. I figure 2 sheets of 4' x 8' of plywood should do the trick (I can always use extra material for other projects). **Note: If it works out well for the '91, I will be building similar boxes for my cars. Not sure what thickness to get the plywood in. I'm thinking around 3/4".

2. Where can a guy get that gray covering for the sub boxes? Gotta have 'em look good, you know.

3. How can the boxes be mounted to the car? I don't want to go punching holes if I don't have to, but I also want the boxes to be secure.

[87mefull]

That's about the same setup I have, pioneer all around except for the subs and amp. Look for one with the IPOD port for the IPOD interface, its one of the features of the pioneer deck I have now. Some people might be against IPODs, but a pioneer player with some type of MP3 player interface is the best buy.

The IPOD interface is sold seperately but worth it, don't buy FM transmitters. I no longer have CD's in my car, I have a few playlists and I'm set for hours in the car. The sound quality is amazing, much better than a standard CD. Plus, I like it because I just plug in my IPOD and control it through the cd deck easily. Its a great setup if your on the road alot like I am and listen to alot of music.

Ported sub boxes are the best for sound quality, bass, and clarity. Look around ebay for some good deals on sub boxes, I see alot of people selling custom, parts, and used boxes for pretty cheap. Your can build a nice sub box with ebay parts, my friend did for the 15 in his car and its sounds great. You should install an external sub volume control, I bought mine off of ebay. The subs can be overwhelming with some songs, I have to adjust the volume on my setup alot.

Also, I would recommend pulling up the trunk carpet and seal the trunk (don't really have to do the lid with 10's but probably would help) with the knock-off dynomat from Home-depot. Its about $16 a roll and its some no-name duct insulation. Might need to do the gas door also, my subs were powerfull enough to rattle the gas door visably at low volumes. The bass from the subs will be strong and clear, plus you won't have a million rattles.

You should insulate the doors also around the 6.5 inch speakers, they can rattle even if they are mounted properly. Walmart sell knock-off dynomat for $7 for a size big enough to cover around both front door speakers.

[jasonh]

Have you ever used fiberglass before? You'd be much better off doing something like this
http://i83.photobucket.com/albums/j316/jasondh/Misc/2040800_67_full.jpg

Your gonna have to screw them down somewhere or you could use something like sprayfoam to stick them down but they will be very hard to remove with that stuff. You can buy the carpet at fabric stores or online at www.partsexpress.com

[monterey1962]

The more I've been thinking about this, especially with the cost and effort, the more I'm leaning towards just doing the same setup as my cars. Pre-formed box from Wal-mart. Only thing I'd do different than mine is set the wires up in the trunk with quick connectors for quick removal, when necessary.

[85crownHPP]

Sub boxes are what I plan to build. I want to set them up so they mount on the side ledges of the trunk and face inward. .

thats not going to work as well acousticly unless you plan to ride in the trunk right between them lol.
All the bass vibes are going to bounce back and forth between each sub and not as much is going to reach you inside. Gotta rememeber that the bass travels in waves and they may even cancel each other out.

[monterey1962]

thats not going to work as well acousticly unless you plan to ride in the trunk right between them lol.
All the bass vibes are going to bounce back and forth between each sub and not as much is going to reach you inside. Gotta rememeber that the bass travels in waves and they may even cancel each other out.

Just one more reason why I'll just buy a box. I didn't know that facing them towards each other had such an effect.

[85crownHPP]

at least I think thats how it works. you just have to figure the trunk itself as a sound chamber. Who knows maybe its the other way around, thats the way subs are oriented in some bandbass boxes, it could turn your trunk into a big speakerbox.

[88crwnvc]

bandpass boxes are both ported and enclosed, the subs ARE meant to face each other but the design of the box allows the ports to compliment the sound of the tight enclosed base. this is the reason bandpass boxes sound the best, perhaps not the loudest. if you do face the subs towards each other it will not sound good, however, i reccommend setting them facing directly towards the back. the bass waves will bounce off the rear and will be forced over the box into your back seat/firewall.

as far as securing the box, not a great idea. however, i've heard that insurance companies will insure boxes containing subs or amps that have been installed directly and are considered "part" of your car. it may be necessary to secure a cheaper box, but my custom box was heavy and there is no way it's going to move.

also, for the carpet you're wanting to cover your box, is just automotive replacement carpet that i used to carpet my box. like $8 for a 4'x6' roll. works/looks great.

[JumboFriendly]

I see you've already come to this conclusion, but unless you're either doing some crazy audio installation or just love designing speaker boxes, you're probably better off with a premade box.

A sealed box will provide the best sound quality, and the smallest size. Ported boxes are bigger, and sound quality can suffer if the box isn't tuned right. They will also make the limitations in your subs more apparent. They are much harder to build yourself. Sealed boxes aren't hard to build.

If you do decide to build you own box, I would reccomend using MDF instead of plywood.

[monterey1962]

I'll probably just go with a premade box. Seems to be the best route.

[boXman]

I need to get good box for my 15's. They rattle that pos like crazy.