Ideas for mounting two amps

I've almost got everything I need to put my stereo system together, so now I'm creating a plan for mounting the two amplifiers. I will create actual plans with AutoCAD when I have it figured out, but for now I'm using Sketchup for conceptual 3d modeling.

I haven't built a car audio system in about a decade, and back then I didn't care how the installation looked. I would mount the amp straight to the speaker box or it would just sit loose somewhere, on the floor or behind the back seat. This time around I'm going to do a better job, and I'd like some creative input from others.

I have two amps with approximate dimensions of:

1'-3 1/2" long by 9 1/2" wide by 2 1/2" tall (2-channel for subs)
1'-1 1/2" long by 9 1/2" wide by 2 1/2" tall (4-channel for components)

(Notice they're the same size, except one is 2" shorter than the other)

I have a pre-built speaker box (with 1.8 cubic foot volume of air per chamber and 40" transmission line ports) for dual 12" subs that looks similar to this:

http://www.drdesignz.com/Tahoe/SpeakerBox2.png

I modeled the exterior box dimensions exactly to scale. I found the subs in the Sketchup Warehouse, since I was too lazy to model those (the brand I'm using is different). The box dimensions are:

2'-8 3/4" wide by 1'-6" 3/4 deep by 1'-2" tall

The space in the back of the '99 2-door Tahoe is about 4-0" wide by 3'-0" deep. The add-on I'm building will match the width and height of the speaker box, so I have up to ~17" in depth to work with.

My idea is to build onto this box to mount the amps, component crossovers, and power distribution block. I have two 4' X 4' sheets of 5/8" thick MDF board and three 6'-0" long 3/4" by 1 1/2" (aka: 1x2) pieces of SYP wood (+ wood glue & misc. hardware). I intend to spray paint it flat black once it's built.

I had originally planned on mounting the two amps in a straight line, but after I modeled it I noticed they're too close to each other. I thought I'd try placing them at angles, like this:

http://www.drdesignz.com/Tahoe/SpeakerBox6.png

...but they're still way too close. I can easily reach the adjustment knobs on one amp, but not the other (unless it's mounted upside down, but I want access to both sides anyway).

With some revisions, the first design that works looks like this:

http://www.drdesignz.com/Tahoe/SpeakerBox3.png

I liked it at first, but then realized the lower amp is too enclosed and I am concerned about heat.

This is what I'm doing on the bottom, by the way, with the 1x2's:

http://www.drdesignz.com/Tahoe/SpeakerBox4.png

This will give me room to route and hide the wiring.

My latest design, and my current choice, is this:

http://www.drdesignz.com/Tahoe/SpeakerBox5.png

I think that's what I'll go with, unless a better idea comes my way. Any input is helpful and appreciated.

I agree, I think the current choice looks best..

http://www.drdesignz.com/Tahoe/SpeakerBox8.png

I realized I could do this too. I don't like the placement of the amps as much, but I like the idea of extending the MDF over the speaker enclosure. It'll be more structurally stable and look cleaner. Plus I added handles to make it a little easier to pick up (with a forklift).

If you are worried about room back there, I would mount them to the back seats. Place a piece of MDF inside the seat cover and screw the amps to it. It looks very clean when done correctly.



DRUNK POST FTW.

Transmission line boxes do not have volume, only a long "port". You have a crappy prefab with a long port. I would build a nice custom box that you will be much happier with, then you can design an amp rack into the box.

I don't know, it's not that crappy (as in, it's very well made, at least). This project is already becoming much bigger than I had intended, and really did not want to build a box.

It would have been helpful to me to meet pl4yboy about a week or two sooner than I did. I could've really used used the car audio consulting. My initial budget was $500, but soon increased to $1,000. I'm approaching $1,500 now, including all of the wiring and miscellaneous stuff, + a pile of stuff I'm not using. It's a little out of control.

Originally, I just wanted a head unit, with four speakers (original factory size), one budget amp, and a small pre-built custom-fit enclosure with one 10" or 12" sub, or two 10" subs. I soon found a custom built speaker box made of 5/8" MDF that fits under the rear seat and I had a choice between 10's or 12's, so I decided to step it up to dual 12" subs. I figured I'd mount the amp straight to the speaker box or to the back of the seat. I just wanted an easy setup that sounds decent (didn't want to spend a ton of time or money).

Well after I bought the enclosure I discovered it was built for a 4-door, not a 2-door like I have. I had to get a different box, so I also had to get different speakers. I wasn't exactly excited about shallow mount subs anyway. I did not have the time for extensive research, but I found a good deal on two 12" MB QUART subs with a recommended ported box volume of 1.75 cubic feet (per speaker). The above mentioned enclosure has a volume of 1.8 cubic feet, per chamber. I never had a ported box before, but figured I could always seal off the openings (the maximum recommended sealed box volume is 2.0 cubic feet).

I really liked the Kenwood Excelon KDC-X794 head unit, so I bought it. It's way more than anything I used to have, and half as much in cost as the latest-greatest Kenwood I paid for a decade ago. I removed the panels to figure out the stock speaker sizes and bought 6 1/2" components (Kenwood Excelon KFC-X1720P) and 4x10 two-way speakers (Kenwood KFC-415C 4x10).

I got the components and a few days later I looked closer at the box and noticed they run at 2 ohms. Oops! I did American Dream-thing to do and decided to buy an amp for it, instead of the more reasonable idea of selling. Well hell, the head unit has 6-channel preamp outputs, so why keep the junk 4x10's? I bought a four-channel amp (PPI S320.4) to match the sub amp (PPI S420.2). It looks like I have plenty of room to work with where the 4x0's are, so I bought Infinity Kappa 50.9cs 5 1/4" components to replace those.

Building this giant contraption for amps is certainly not what I had in mind at first, but they need somewhere to go. I think I'll play around with Sketchup for a while and look for another method.

It's funny. I intentionally did not join a car audio enthusiast forum because I do not need another hobby to consume my time (or money), but here I am using it up anyway.

I'm saying in general pre-fab boxes are junk. I use nothing less than 3/4 birch or MDF when building boxes. It seems you have a good handle on the equipment, but honestly a custom box would be your best bet. They are not very hard to build, some people just don't take the time to do things right and they end up with a crappy box. I'll design you a custom ported box that will fit snuggly in the back and still leave you some room for groceries.

I'm not very educated on the subject, but if you can convince me this design is flawed enough to warrant (yet another, 3rd) enclosure I will consider it. This one is built with 3/4" MDF, glued and screwed. The design looks like this:

http://www.drdesignz.com/Tahoe/SpeakerBox12.png

Even with a better design, I don't think I could do as good of a job building one. I like the idea of more space, but I could always temporarily remove the box if I need to, since I'm going with a different amp solution. I'm thinking something more like this:

http://www.drdesignz.com/Tahoe/SpeakerBox9.png

http://www.drdesignz.com/Tahoe/SpeakerBox10.png

It sits behind the rear seat, between the inner fenders, with the angled (amp) side towards the seat. This conceals the amps (which is good), but it could cause excessive heat, so I was thinking of adding fans. I have a few leftover 120mm fans laying around anyway, from computer builds.

I'm gonna guess and say there is not enough port area for the volume of the box, and that port looks like it would put the tuning of the box quite low.

Okay, I'll take your word for it, but I don't know what that means, so you'll have to to better than that to convince me :lol:

Quote:

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Originally Posted by amsterdamn

Okay, I'll take your word for it, but I don't know what that means, so you'll have to to better than that to convince me :lol:

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Should have 15-16" of port area per cubic foot of space (not including port volume)