Amp Cooling fans

[racer808]

Cruising around yesterday I lost power to my tower for a few minutes. I am assuming it was a cooling issue, but it wasn't more than 70 degrees outside. Thought maybe a couple of fans should be added to the compartment. Where or what fan do I buy? Does a hole need to be cut to draw fresh air in or is just circulating the air enough?

[shawndoggy]

you shouldn't overheat at 70 degrees. What amp, wired to what? Did you feel the amp when it cut out? Did you burn your hand?

[racer808]

you shouldn't overheat at 70 degrees. What amp, wired to what? Did you feel the amp when it cut out? Did you burn your hand?

I did not, didn't even look. Just assumed that was the problem. Maybe I just made it clip turning it up too loud. I have a precision power p600.2 running a pair of MB8's & p900.4 briged running a pair of pro 80's. I have the gains maybe 3/4 up?

[shawndoggy]

3/4 sounds wrong. What procedure did you use to set the gains? Both amps cut out? How is the signal passed between them (are they daisy chained or is the RCA input for the tower run to a splitter and then run to the amps)?

Edited April 14, 2013 by shawndoggy

[Earmark Marine]

If two different amplifiers combine to drive two different pair of speakers at different loads, then both amplifiers certainly did not thermal at the exact same time.

Is it possible that the midbass set was off before the fullrange set?

I would suspect voltage before thermal, or even the audio signal, because it is common to both amplifiers.

A fan is a bandaid that can help on the extremes of July & August days. But if you thermal in April then you have an unresolved core issue that must be dealt with or you will eventually have product failures.

David

[nyryan2001]

You need to verify if they cut off due to overheat/thermal.

How do you have them wired to those 2 amps? Bridged or 2 channel stereo?

[racer808]

The 600.2 has feed thru RCA's so it is jumped from the out on that amp to the in on the 900.4. Both amps are fed directly from the batteries using correct gauge wire. The deck's max volume is 35. clipping happens at 31-32, which seems normal in a sense I guess? David, I am not sure exactly what you mean, if I follow did one amp clip before the other? I am not sure on that either. No issues if I don't go past 30 on the deck. Should I keep it there & just turn the gains on the amp a bit more?

[Earmark Marine]

The 600.2 has feed thru RCA's so it is jumped from the out on that amp to the in on the 900.4. Both amps are fed directly from the batteries using correct gauge wire. The deck's max volume is 35. clipping happens at 31-32, which seems normal in a sense I guess? David, I am not sure exactly what you mean, if I follow did one amp clip before the other? I am not sure on that either. No issues if I don't go past 30 on the deck. Should I keep it there & just turn the gains on the amp a bit more?

From the description in your original post it appeared that you lost power to the tower as a whole. Yet, you have different amplifiers driving the two different tower speakers with a very different impedance load since one is running stereo and the other is running bridged. That is why I question whether it was truly a simultaneous event.

Then comes the question of voltage. You should measure the voltage at the amplifier terminals with the amplifiers under load in the near time frame that they shut down.

Also, if the first amplifier has an active/buffered RCA output then the signal 'OUT' would be cut to the second amplifier if the first amplifier shut down for any reason. You can temporarily replace this configuration with 'Y' adapters to determine what is really going on.

If the remote turn-on or supply voltage drops it is possible for different amplifiers to have different thresholds and turn off selectively.

You could also be heating up the speaker voice coils to the point the amplifier is going into protection. 3/4 input gain seems high even when using a 4-ohm stereo load but particularly high on a 4-ohm bridged load (which is equal to a 2-ohm stereo load).

To stop the speculation and get this in concrete terms, you need a multimeter and a distortion detecting device whether by another ear or by an Oscope or by a dedicated distortion detection device such as a Steve Meade instrument. Tuning and crossover selection can be a factor also. I hope you are highpass on both tower products.

Btw, if you are using any type of EQ, tone or bass boost then the source unit setting as a percentage of full goes out the window. As EQ accentuation goes up at any frequency, even if the effect does not sound that significant, the overall gain or volume level must go down.

Make sure your heavy supply and ground connections are REALLY secure.

I suspect you have other underlining problems as a pure thermal issue in 70 degree conditions is very unusual.

David