Amp Rack On Top of Subwoofer Box

I'm hoping this subject is in the right area. I had an epiphany at work today...

I'm building an amp rack ontop of my subwoofer box. Yes, I'am aware of the risk of the damage that can be done by this. I'm not too worried, since I have a solution, but 'am thinking there may be more solutions, that can also be better.

The main problem to building an amp rack right on the box is the amount of vibration caused by the subs. Doing so is going to eventually damage your amp because of the intense vibration of the internal parts.

Therefore, my mind has been racing for better solutions. I can come up with many different variations of the same idea, but it is for testing that which will really prove these really work.

I would rather make pictures instead for all you to see, but I also think it should be sufficient enough to type this all out to you. Since I'm not the best at making pictures in mspaint. Haha!

I believe it is a crucial thing to follow the experts of car audio. I AM NOT one these people. It is merely an elaborate and sophisticated idea from an audio enthusiast junkie.

One of the best places of information regarding car aduio is:  http://www.bcae1.com/

If you see here, he shows us a lesson of amp rack building. And the factor you must put in with construction. Here, he shows you the best places to put an amp for least vibration.

It is however plausible that there may be better ways to reduce the vibration. The informer on this site is not technically dealing with the structure of the box. But rather the most ideal spot to mount your amp.

Instead of amp placement, deal with the structural design of the box to lessen the vibration.

My ideas(maybe a combination of all?):

1. Instead of mounting the amp right to the top of the box, put four blocks ontop of the wood and secure them down. However best you feel. (Me personally, I would use some gorilla glue and nail it in.) I would say then cover the top of these blocked piece with something like dyamat or some sort of rubber material so it will dampen vibration. I would also think that even an inch of foam pad would probably ideally work well too.

Why I feel this will work. In this situation I apply the rule of surface area. I think that by reducing the surface area of the amp contact to the box, will in turn reduce the vibration of the amp. This in combination with say a strategic placement of the amp (if you have the ability) would in my mind, work quit well.

2. This idea has many different variations. Almost infinite possibilities.

2.1. Make a dead space between the amp rack and sub box. I would think that since the rack is not in direct contact with the surface of the box enclosure, there would be minimal vibration.

2.2 Same as 2.1. but instead of leaving it a dead space, fill it with some sort of deadening material.

2.3. Instead of leaving a dead space, make a cross hatch or a honeycomb style structure to put in between. Or many bracing boards... By doing this, you have less surface contact but also makes the box much more stable. (Then fill it with a material.)

These merely are only curious ideas. I do plan on making some sort of solution for my own. I dunno which would be better out of these. I just need some sort of feedback from you all...

I for one can say, that maybe this idea is not workable. Maybe it will cost too much money or time...

Raising the amp directly off of the sub box also allows for running cable underneath if you are limited on space, or want to hide the wires in some way. That is what I did on my box, and it worked spectacularly.

The other thing that I did, and was required, actually, since I was using a triple-sub configuration, I had to make 3 seperate chambers, one for each sub. The two internal pieces served as extra bracing for the box, as well as being the dividers for each chamber. No other bracing was needed, and I think it is rather stout and won't flex (more due to the shape of the box itself than to the extra bracing, but both work to my advantage).

It is obvious that I also 'am trying to obtain cosmetic and security features also... The wires are going to have to come out of that box sometime...

My box is double chambered. One brace is in the middle. Although, now that I thought of it, I may just put another in to seperate the subs and leave a slot. Maybe put in an LED light strip? This can also work to my advantage because I made the box a little bigger than specified.

I don't really buy into his theory. Fact is I have had subs destroy 4 Xtant amplifiers last year and the amps were not mounted to the box. The box was made so as not to flex as well so I could have mounted the amps to it. So what killed the amps? The acoustic shockwave of the sub rattled the caps right off of the circuit boards.

If one can expect a sub to flex a box so much that it is going to warp a heatsink of an amp that a circuit board is attached to, well let's say that I have yet to see such a creation. If the box is flexing so much as to cause sucha vibration to occur, obviousely one would be losing drastic amounts of energy being lost to such vibrations and would brace the box to keep it from happening. If that much abss energy is coming out of the sub in the form of sound, then the energy would still cause a board to flex or other damage to occur even if the amp is in the vicinity of the sub system. Think about it for a minute, if you can feel the bass in your car and watch the mirros shake, it doesn't really matter where your amp is either. End result, I don't buy that theory.

Poorly designed equipment, eh?

Ahhh a very striking comment, forbidden.

The same guy from Car toys told me the same thing. He said he feels it wont matter where the amp is really because no matter where its at, its going to have bass traveling through it. I agree with this, to an extent.

The thing is, I feel that there is a distinct line in this. I feel that when you mount something to the box, it is going to feel "amplified" bass. Because it is not transfering through the air and the vehicle. It is transfered to the amp through the wood.

This is why I feel that if there is a way to build some sort of structure that would dampen the vibration, you could use the top of the box as an amp rack also.

On Friday, I will post up a pic of my sub box that is being made for an amp rack addition...

There are ways to isolate an amp, to a degree when it's mounted in a sub area, whether it's on the box or off.  It's true that an amplifier will take some jolts when it's attached directly to either the enclosure or the chassis of the car.  When I installed an amp rack in my car, I used wire shelving as an isolator.  The plastic-coated wire is attached to a rack which is bolted to the chassis.  The amps are attached to the wire shelf.  The wire acts as a damper of vibrations and makes a huge difference in the amount of energy that I can feel when touching the amps.

I also noticed a big difference when I separated the shelves from the enclosure, which is where they were mounted at the start.  But then, this isn't a three or four sub system either.

Interesting...

That sparks me another idea. Bolt the amplifier to the box, but make it a floater. Get extra nuts and tighten it below the amp so only the bolts are touching the box... I would think that the vibration be greatly reduced since its only the bolts that touch the amp... Whattya think?

There is still transfer of energy, only it will be through the bolts instead of over the entire body.  You would have to determine if there is a noticeable difference by doing and testing, I suspect.  But it's a worthy idea for the little effort that would be involved.  For one thing, if the bolts are at the corners of the enclosure (its most rigid areas), there would be less energy than at the center of the surface.  Another factor is that the bolts themselves can act somewhat as damping devices through their lengths. 

Something I thought of:  use the four bolts at the corners to a plywood platform.  The platform is only the size of the footprint of the amp, but it is extended to the four box corners by appendages of the same material.  Clever cutting out of one solid piece of wood will keep the platform and "legs" all on one plane.  The plywood legs will act as shock absorbers but still be strong enough to support the amp; and plywood is a better choice than MDF for something like this because of its elasticity.  Carpet it for a nice look that matches the box.  The amp is just bolted through the platform and sits snug against it.

Other ideas found if you do some research into isolating techniques used in building home theaters.