A4 (B5 Platform) Discussion Discussion forum for the B5 Audi A4 produced from 1995-2001 B5 FAQ

I hate to do this, but...

Thread Tools
 
Search this Thread
 
Old 04-26-1999, 06:35 PM
  #1  
TGB
Guest
 
Posts: n/a
Default I hate to do this, but...

Sorry everyone, yet another stereo upgrade question. I have searched the archives.<p>I was feeling pretty good tonight. I have decided the setup I will use to replace my sub-standard Concert stereo.<p>I am going to keep the head unit, replace all four existing speakers, add a subwoofer, and power it all with one Rockford Fosgate 5 channel amplifier.<p>I decided to download the amplifier owner's manual off the RF website in anticipation of my purchase tomorrow when I noticed the following passage...<p>"Mounting the amplifier upsidedown to the rear deck of the trunk will not provide proper cooling and will severely affect the performance of the amplifier and is STRONGLY not recommended."<p>I seem to recall a number of individuals on this site talking about mounting amplifiers upsidedown on the rear deck. Has anyone done this with an RF amplifier? Is it really a big concern? I really don't want to mount the amplifier anywhere else.<p>An installer I spoke to years ago told me an amplifier would basically have to be set on fire before it would overheat...<p>Thank you for the input.<p>TGB 1.8T qMS
Old 04-26-1999, 06:48 PM
  #2  
The A4 Kid
Guest
 
Posts: n/a
Default Re: I hate to do this, but...

I can't (yet) vouch for any problems w/mounting an amp to the rear deck, but I can say that take what your installer said about not overheating with a grain of salt. Up until recently I had a Soundstream Reference 604 mounted in a well ventilated area in the back of my Tahoe. However, due to the semi-high load I was running it at (1 ohm) the amp became very hot (unbeknownst to me) and melted a key piece of sodder. Did the amp register a fault and "overheat"? No. Instead it sent a whopping 23 volts (46X what a speaker would normally see) to all of my speakers and fried, literally, 10 Boston Acoustics speakers in my car. I mean fried. The smoke started pouring out of every crevice in the car, and I had to pull over immeditately (In Seattle traffic no less!) I too was told that an amp "would not overheat." The moral of the story? The amp may not fault and shut off or even burn out, but beware of internals being subjected to heat they aren't prepared for. Damage to the amp is not your only concern. As far as problems w/ mounting to rear deck, I would like to know other opinions as well, as I have a pair of PPI amps that are already paid for and earmarked for my new A4 when in finally gets here. (Crossing my fingers that there isn't a problem w/ amp mounting.) Keep us informed on what you find. Thanks.<p>Bryan<br>1.8tQM<br>on order since 1/19
Old 04-26-1999, 07:00 PM
  #3  
markbradford
Guest
 
Posts: n/a
Default Hot air rises; heat sink upside down = useless!!!!

x
Old 04-26-1999, 07:12 PM
  #4  
The A4 Kid
Guest
 
Posts: n/a
Default Re: Hot air rises; heat sink upside down = useless!!!!

It seems as if this whole issue is moot then for fan cooled amps. (Like PPI) If this is so, then maybe TGB should consider a) a fan or b)an amp w/ a built in fan. Does this sound right to you, Mark?<p>Bryan<br>1.8tQM<br>on order since 1/19
Old 04-26-1999, 07:24 PM
  #5  
markbradford
Guest
 
Posts: n/a
Default good point (more)

Yeah, an internal fan cooled amp would help, but an external amp would produce minimal cooling gains bcause the heat would not be transmitted outside the casing where the fan would dissipate it. <br>Another option would be building a small shelf for the amp to sit horizontally about two or three inches below the rear deck - adding a fan would help then, because the heat sink would function properly; OR, if using a sub box, just mount it on top of the box. <br>The best options (for cooling AND minimal space consumption) are internal fans or just mounting your amp on the side wall of the trunk <br>Good Luck,<br>Mark
Old 04-26-1999, 07:33 PM
  #6  
Gordon Martin
Guest
 
Posts: n/a
Default You can do some amazing things with those miniature PC CPU fans - and they're cheap too!

(nt)
Old 04-26-1999, 07:46 PM
  #7  
Nim
Guest
 
Posts: n/a
Default Really depends on the Amp and the load the amp sees..... (more)

I mounted 2 PPI PC450s upside down to my rear deck about 2 weeks ago and don't have any problems. I knew pretty well in advance that I wouldn't because I had 1 of them mounted horizontally in my last car in possibly the worst ventilated area I could possibly find (i.e. I hid it really, really well after having 2 previous amps stolen). However the reason I feel comfortable having these mounted upside down is that at the rated loads (i.e 2-4ohms stereo, and 4 ohms bridged) they simply don't generate much heat. On another note the 2 previous PPIs I had, a A200 and A100 got extremely hot and would actually shutdown occasionally on hot days. I had one of these at an extremely low load also though. These were mouted right side up, but in a poorly ventilated area. So basically it really depends on the amp and the load you're planning on running it with. Ask around and see if anyone has the amp you're looking at, and see if they can tell you how hot it runs at a given load.<p>And as someone mentioned, you can always add fans
Old 04-26-1999, 08:00 PM
  #8  
JS
Guest
 
Posts: n/a
Default I've asked the same question at the car audio forum..

<br>below is the link to the discussion. Hope this helps.<br>
Old 04-26-1999, 08:11 PM
  #9  
JS
Guest
 
Posts: n/a
Default Second attempt (address inside)

<br>http://www.caraudioforum.com/Forum1/HTML/003466.html<ul><li><a href="http://www.caraudioforum.com/Forum1/HTML/003466.html">http://www.caraudioforum.com/Forum1/HTML/003466.html</a></li></ul>
Old 04-26-1999, 08:36 PM
  #10  
The A4 Kid
Guest
 
Posts: n/a
Default Re: Really depends on the Amp and the load the amp sees..... (more)

Did you mount your amps running front to back or side to side? My local installer and I have debated about this for the past few weeks, and my inclination is to go front to back. Until the installer can see the trunk, however, we won't know. Do you know offhand what the dimensions of the PC450 are? I am going to be stuffing a PC650 and a PC2150 in there, so I hope they fit. <p>Thanks for the info.<p>Bryan<br>1.8tQM<br>on order since 1/19


Quick Reply: I hate to do this, but...



All times are GMT -8. The time now is 04:54 AM.