I've read through several archived threads and decided that mounting an amp completely out of sight isn't really possible without building an enclsure so I just wanted to bounce some ideas off those who might have more experiance than I do before cutting holes, pulling wires and building an enclosure.

What you all might want to know:
A) '99 4 dr 2wd auto, split bench seat up front
B) Alpine CDA-9856 HU
C) Alpine MRV-F305 Amp (Thanks again Hillbillyinohio )
D) Infinity Reference 6012si speakers in the rear door panels, still undecided what component speakers to put up front.
E) I don't plan on ever installing a sub, this will be the only amp I'll ever mount and it will always be setup for 4 channel operation as long as I own the truck.

My preferred location would be right below the center of the dash on top of the transmission tunnel. The pros would be 1) short wiring runs, 2) doesn't take up precious cargo space, 3) easier to disguise an enclosure as a custom made center console. The cons that I've come up with so far are 1) Possibility of EMI interferance with the headunit, 2) the area under the dash is a little tight so it might not be as easy to measure and fit the enclosure as it would be in the cargo area, 3) I've never seen anybody mount an amp here so it might not work for some reason I haven't considered.

My second consideration is in the cargo area opposite the compartment where the jack is stored. I'd mount the amp just behind the fender well and then build an enclosure around it. Pros are 1) less chance of EMI interferance, 2) the center seat up front is free should I want/need to carry 6 passengers. The cons are 1) longer wiring runs, 2) takes up some cargo space, 3) it would be more obvious the enclosure was hidding something.

The biggest deal breaker would be EMI interferance. If it's absolutely not possible to mount the amp that close to the headunit then I won't but if there's even a remote possibility it might work then I'll give it a shot. Crutchfield's guides reccomend no less than 3 feet separation between the headunit and amp, Alpine reccomends no less than 10cm separation, I expect that more separation is necessary for larger amps but the amp I'm using is only 30X4 RMS so maybe it's acceptable to mount . Would it be possible to add steel or copper shielding inside the enclosure to suppress any noise emission? I'll be sure to add a fan or two to keep heat under control no matter what kind of enclosure I build.

 

edited

 

duh, helps if I read the post. anyway, just looked at an exact pic of a 99 4 door and I don't think that you will be able to fit an amp up in front. As the amp is about 10x11. I personally, would just mount it under one of the front seats, if you pull both seats out, you can easlily run the wires under the carpet, I mean, how often do you have a front seat all the way forward. I would mount it so the wiring is facing the front doors , not front to back, so if you have someone in the back seat, they wont be in danger of smashing one of the wires.

 

I'd do under the seat but I'm not sure there's enough vertical clearance under the seat to get an amp in there, the floor under the seat isn't flat either, there are all kinds of bumps to allow clearance for drivetrain components. Maybe I'll just have to hook everything up before cutting any wire or bolting anything down and see how things sound.

Thanks for all the tips, I might have to give you a holler when it comes time to wiring everything up, I've got a pretty good understanding of electricity and electronics but this will be my first system with an amplifier. I won't recieve my headunit until Monday and I'm helping a scout troop plan for a rock climbing activity on tuesday but if I can get in and out of work a little early next wednesday I should be able to get most of the grunt work done Wednesday afternoon. I'll be sure to take pictures of my progress.

 

with the 2 extra glove boxs in the back i plan on putting the smallest 4 channel i can find in one and a cap in the other, but im not to sure if the caps power wire should be that long. but its really a good spot if you can make it work.

 

Well I'm slowly making progress. So far I've got the amp wired up and the headunit and front component speakers installed. I left enough slack in the cables to move the amp around quite a bit and I can't tell that it's causing any ill effects on the head unit sitting on the floor right on top of the transmission tunnel just below the headunit. I was going to shoot for mounting the amp under one of the front seats but there just isn't enough vertical clearance. I think I'll get some adhesive backed velcro and keep it right where it's at.

The Boston Acoustics S60 speakers I decided on sound great, I ended up putting the component tweeters where the 4x6 speakers in the dash would have been. I found out that my blazer doesn't have the 6 speaker system with the 4x6's installed I always thought it had speakers in the dash, I even imagined that I could feel the sound waves coming from the speakers by putting my hand over them, oh well, it turned out for the best anyway. There was a convenient piece of material (I don't know what to call it, its some kind of heavy black paper) that was covering the holes where the speakers would have been with a little clip to hold the wiring harness. I was able to cut holes in the cardboard stuff and mount the tweeters below the factory grills in the dash. Hopefully I can get the rear speakers installed and wired up this weekend, I had no idea it would take so long to fish wire for everything, I've never had an amp in my car and I've always used factory wiring so this has been quite the adventure.

Next I want to figure out how I'm going to conceal the amp in an enclosure. I'm thinking next time I visit my dad I'll borrow his woodworking equipment to build a box that can fit over the amp. I want to make it look like it's something I added for convenience, the last thing I want is somebody breaking into my truck thinking I've got an expensive amp under the box, so I'll cut some cup holders or a depression with some dividers for holding a cell phone and a couple of CDs. Since I've got power wires already available I think I'll add a cigarette lighter socket or two for things like a cell phone charger or one of those portable DVD players. I figure I'll put in a relay to turn on a fan or two to give the amp plenty of cool air.

I'll try to get pictures tomorrow, I planned on taking pictures of everything as I was installing it but it took so long to pull wire for the amp I didn't really want to stop for pictures. If anybody wants to see where I mounted anything or how I routed wires let me know and I'll get some pictures. I'm getting pretty good at pulling the dash apart so one more time won't be that big an inconvenience.