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View Full Version : fosgate amps overheating



doogie
03-26-2004, 08:17 PM
I have two fosgate amps. 1 is 1051s and the other is 750x. i have an over heating problem with the 1051. the 1051 is connected to 4 kicker 12". The system sounds great but it over heats (1051) ; does anyone have the same problem out in havasu? I have 1 fan blowing but it does help.

ROZ
03-26-2004, 09:07 PM
The first thing I will say is that RF amps usually run a little warmer than most amps... Atleast from my own experience...
So your 4 kicker subs are driven by a fosgate 1051s ?
It's a 2 channel class a/b amp designed to run bridged into 1 channel at 4ohms. If the load is less than that it will run HOT.. The lifespan of the amp will also be decreased. As HH says, it's like burning the candle at both ends...
What model and ohm ratings are your subs?
How long have you run the amp and is it running hot now, or has it always run hot? Does it go into thermal shutdown?
If it is shutting down and didn't last year, have you made sure your batteries are at full charge? It may be shutting down due to low volage...
ALL amps that are in boats NEED fan(s) and proper ventilation. Especially in the desert...

Havasu Hangin'
03-27-2004, 10:00 AM
Originally posted by doogie
I have two fosgate amps. 1 is 1051s and the other is 750x. i have an over heating problem with the 1051. the 1051 is connected to 4 kicker 12". The system sounds great but it over heats (1051) ; does anyone have the same problem out in havasu? I have 1 fan blowing but it does help.
Like Roz said, if the subs are wired into a 2 ohm mono load...you'll be in trouble. 2 ohm stereo and 4 ohm mono will be OK, but the amp will still run hot. My buddy's RF stuff runs VERY hot...and it's wired in specs.
I know I sound like a broken record (or CD)...but I'd ditch that class ab for the subs. A "class D" amp will be able to handle a lower ohm load...and still run cooler than that hotplate...er...Fosgate.
I run my class d at 1 ohm mono, and it never gets past lukewarm.
Like Roz said...the candle that burns twice as bright lasts half as long.

welk2party
03-27-2004, 03:39 PM
A old friend of mine had RF's and those things were always getting hot and shutting off.

Mr. Naudio
03-28-2004, 08:41 AM
Agreed that the fosgates will most likely increase the ice usage.

Tom Brown
03-28-2004, 01:06 PM
Doogie this information may be of use to you:
I've tried a lot of fans and the quietest fans I've ever found are Panaflo (Panasonic) FBA08A12L. They are extremely quiet at 12v and silent at 6v. You can wire two in series and you'll have to put your ear right next to tell if they are running or not.
Two FBA08A12L fans will put out about 30 CFM when run in series (6volt each). They put out 24 CFM each at 12v. The hydro-wave bearings last a long time, much longer than a normal sleeve bearing but not quite as long as a ball bearing. You should have no trouble finding them for 8 bucks a piece on the web.
The Panaflos create an air cone. I don't know of any other fan which does this. They focus the air so you can point them at a device and cool a hot spot quite effectively.
If you need more cooling than a couple of 80mm Panaflos can provide, you might want to try building a 3 sided tunnel around your amps and run a couple of 120mm Panaflo FBK-12G12LH fans. All 120mm fans are loud but the 12LH Panaflos are about the most quiet. You probably won't hear them if they're behind an interior panel and a pair of them run in series (6v each) will flow about 100 CFM. They flow 69 CFM each at 12v.
Let me know if you want some FBK-12G12LH fans. I've never seen them retail. They are an OEM part and far, far quieter than the FBA12G12L retail part.
-- Tom

Tom Brown
03-28-2004, 01:31 PM
Originally posted by Havasu Hangin'
I know I sound like a broken record (or CD)...but I'd ditch that class ab for the subs. A "class D" amp will be able to handle a lower ohm load...
I couldn't agree more but I'd like to add that when I last tested some amps, I found a class D amp that wasn't as efficient as it ought to have been. It's not that hard to create a standard test signal using a waveform generator and a ScopeMeter to measure the output level. The input current draw can be measured effectively with a Hall effect current sensor, as long as the output isn't varying too much.
For sub amps, it's all about the most efficient power conversion possible to keep the heat down and the supply current draw as low as possible. The guys who do it all the time will know which models deliver as promised. That wouldn't be me as I've been out of the business for several years and haven't worked with many current models.
-- Tom

doogie
03-28-2004, 02:05 PM
Thanks for your input. I am going to try adding some fans for now and see what happens. I was out in havasu last weekend and the amps didn't shut off and that was in 90 degree weather.

rivercrazy
03-28-2004, 09:56 PM
I also had a buddy running RF Power series gear. All wired at 4 ohms to components. Those amps would get hot enough to fry on egg on. I actually got a blister from touching them.
I helped him install a different brand of amps and the heat problem went away with the same wiring