Installing an amp without the bottom plate
 

I have 2 amps that have a cooling fan built into the center of the circuit board. I had the bottom plate off the amplifier while the amp was on and the fan was running. I placed the bottom plate on and began to screw it into place. As I placed the bottom plate on, I heard the fan slow down. I lifted the plate and the fan resumed full speed. I rested the plate on the bottom of the amp again and the fan slowed as all 4 sides of the plate made contact with the chassis.

I think the fan is slowing down because the air flow is getting restricted as I put the bottom plate on.

To that end, I was contemplating keeping the bottom plate off to allow maximum air-flow. What are your thoughts or concerns about this idea?

I am planning on mounting the amps underneath my driver's seat and passenger seat. Naturally I am concerned about moisture, so I plan on elevating the amp 1" from the floor boards with spacers so the amp itself should not be in danger of floor moisture.

Or, since this will be a mount just above the floor, should I keep the bottom plate on to protect the internals from corrosion?

Thanks,
Ryan

I don't know about removing that plate it doesn't sound like a good idea, like u said dust, moisture and who knows what else could get in there. If I were you I would drill a few small or large holes where the fan sits. There for allowing flow for the air. Like u said tho I would stull raise it off the floor about 2 cm min.

That's if u absolutly have to remove this "bottom plate" I personally. Would leave it as it was built.

I am going to assume the fan blows the air towards the bottom plate and that the bottom plate is solid. If this is the case, where does the air exit the amp? At the end plates? If so, that air comes down from the fan, is dispersed by the bottom plate, and travels along the lenth of the amp, picking up heat from the components on the way by. If you remove the bottom plate and the air can blow straight out, it may actually cause those components to run hotter - the opposite of your intent.

check it out.

^^^ That an interesting observation. I didn't even check to see which was it was moving the air. I (probably wrongly) assumed that the air was moving up and out and that it would cool the heat sink on the way out. Your observation is more logical - and yes, the air exits at the 2 ends of the amp where the connections are made.

I think I'll just leave the amps completely assembled and trust the design.

Thanks

It might be easy to flip the fans over and see if they still reduce speed. Obviously thats not what the manufacturer intended, but you could give it a try.

Checked it today, it draws air up and out . . .
Yet, I believe that Dukk's comment is still valid. Instead of blowing air past the components, it will be sucking in cool air which will need to move past the components before it goes up and out past the heat sink removing more heat.

What I might do, is drill a few extra holes in the bottom plate on the ends to maximize airflow in, while still having the air flow by the components before it goes up and out.

I tried a short cut to that idea and reversed polarity on the fan, but there is some type of protection circuit in the fan itself because it won't run at all with the +, - flipped. I turned it back to the way it was and it worked fine. :dunno:

the main thing i would be concerned about if i were you would be debris and such getting in the amp, but in terms of any problems the only one i see is overheating. i say this because i took the top covers off of my kenwood to try and help keep it cool so you can see the guts and stuff, and then i went as far as to put a computer fan on top blowing air into the amp, but thats only because there was no fan in the first place. to try and limit debris i then mounted the amp to the box so that the top of the amp becomes a "side" and the holes aren't affected as much by gravity bringing things into the amp. the position you mentioned kind of limits that, so i would say if possible try and find an opening on the top of the amp and get a small fan on the outside sending fresh air into the amp. my major problem was overheating but since i did this little mod i haven't had a problem.

in my eyes i see overheating as a problem because under the seat creates a cavity where heat will leave the amp and then maybe collect under the seat itself, making the air around the amp hot, so that fan thats already there might end up creating a flow of hot air which will heat everything up. i'm not a pro but that happened to me too because i used to keep the amp under the back seat, then pulled it out and had to deal with sunlight, but the way i have is optimal so if possible i would suggest something like that