Amp on the back of a box is bad?

[bumpinthanite 10+ year member]

I've heard mixed opinions on this....is it bad or fairly harmless to have your amp mounted on the back of your box? I'm just kinda curious on what u guys have to say (u people seem to be knowledgeable and have helped me out before) since i have heard many different views on this. Mainly, i've heard that the vibration doesn't compliment the amp too well..lol......so, any input? thanx

Click to read more...

 

[infamous49ers 10+ year member]

I prefer to not have it on the box b/c if you happen to get jacked i'am not saying you are but it happens they wont get all your shi** at one time. but thats just my opinion.

 

[icedbimmer 10+ year member]

Don't mount an amp to a box. The vibrations can damage the amplifier.

 

[bumpinthanite 10+ year member]

just curious, but what damage can be done to the amp?

 

[icedbimmer 10+ year member]

The internal parts of the amplifier can come loose or break off.

 

[more_spl 10+ year member]

i was juist reading more of the eatel site and copied this. READ ALL WHOEVER POSTED IF YOU WANNA KNOW WHY.

Amplifier mounting:

DO NOT mount an amplifier on your subwoofer box. I know that there has been a great deal of discussion over mounting an amplifier to an enclosure and many people do it all of the time with no problems but those people probably build good enclosures from 3/4" (or thicker) MDF with extensive bracing. Most people (especially young impatient people) are too lazy to do that and build unbraced enclosures from 5/8 MDF. These enclosures will flex considerably more than a proper enclosure and will likely cause amplifier failure if the amp is mounted to the enclosure.

REASON:

When the woofer(s) moves in or out, the box flexes and therefore causes the sides of the box to vibrate. This vibration is transferred to the amplifier mounted to the box. All of the electrical components in the amplifier have mass. Inertia (an object in motion tends to stay in motion, an object at rest tends to stay at rest) tells them to stay at rest, the box vibration is trying to make them move. The energy from the box's vibration is transferred to the components through the electrical leads which are soldered into the circuit board. All of this will cause the components to break loose and therefore cause the amplifier to fail prematurely. Basically, the amplifier will commit suicide! I'm not telling you this because someone told me it was bad. I've been repairing amplifiers since ~1985. Virtually every amplifier that's come into my shop with parts rattling around inside them have been mounted on the speaker box. It causes the legs of the semiconductors to break (which causes amplifier failure). It causes the capacitors to break off of the board (which can cause catastrophic amplifier failure). It causes solder joints to break on the semiconductors mounted to the heat sink. It causes transformer windings to grind into one another (which causes lots of smoke to pour out of your amplifier). People who repeatedly tell others to mount their amps on the speaker box because they've never had a problem remind me of people who drink and drive and say there's nothing wrong with it because they've never crashed their vehicle. Eventually, in both cases, problems will arise.

NOTE:

Mounting the amplifier on the enclosure also allows someone to steal BOTH your amps and speakers at the same time with no extra effort. It's bad enough to have one or the other stolen but losing amps and speakers (and anything else mounted to your speaker box) is really gonna ****.

 

[Sting_MK1]

personally, i have my calibra amp to my box of my kenwood 12" subwoofer, and no problem thus far... my friend also have his to his box for longer than me, and no problems. i placed rubber pacers between the box and amp. just remember to keep a distance from what the amp is 'facing'... be sure to have as much possible air flow to the amp's heat fins ... i think that limiting the air flow will damage your amp more than the vibrations ... that's my 2c worth of info //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[chris229 10+ year member]

unless you been on the moon you know that subs cause the whole car to vibrate. Plus driving the car causes vibration. UNLESS the amp is going in your house it cann't escape vibration. True vibrations aren't good for any circuit board BUT there is nothing you can do about it . Placing it anywhere in your car will cause it to vibrate for the bass and car it self.

 

[ss3079 5,000+ posts]

Originally posted by Sting_MK1 personally, i have my calibra amp to my box of my kenwood 12" subwoofer, and no problem thus far...

Put a good sub in there and that amp will bite the dust.

 

[maylar 10+ year member]

I was a Test Engineer at an aerospace electronics company for 17 years. Part of my job was to do vibration testing on electronics systems we sold to the government. I can tell you first hand that even low levels of vibration over sustained periods will shorten the life of components, and ultimately cause fractures and failure of wire leads, solder joints, etc.

The frequences we used were all in the audio range.