I have an SAX50.4 bridged to a dual 4ohm sub. Tuesday at the end of my 3 hour commute the amp shut off. I thought I fried the speaker but 10 min after the amp shut off, it worked again. I had already stopped when I turned the stereo on again and the amp was hot to the touch.

This is the same thing that happened with another small amp that I had but it was 2 channel bridged. Except it shut off after about 30-45 min.

I have an SAX125.2 running two 6x9s right next to the 50.4 and it hasnt ever shut off since Ive had it. Doesnt get hot either. They are both screwed to a seperate piece of 3/4 mdf behind the back seat agaisnt the side of the box.

Ive also had 2 other amps in the place of the 50.4 which never shut off either. They were both monoblocks over 1000rms.

Why do these multichannel amps get hot and shut off running the same sub but not the monoblocks?

My other thread is "amp cuts out".

How do you have that dual 4 ohm sub wired to the amp?

My thoughts are one of two- either you have the voice coils wired in parallel and bridged two channels of the amp to it, in which case you'd be running at 2 ohms bridged which is below rated impedance levels, or because the amp (and the other small amp) were not powerful enough for the sub you overdrive the crap out of them trying to make up the difference in output.

You may simply be pushing it too hard -- simple as that.

Most mono amps are Class-D and generate less heat as well.

I have it bridged to each vc seperately @ 4 ohm. I put my seat back up to have more room and shortened the amp board to fit it behind the seat. Would have to reconfigure setup again to use monoblock due to space restrictions. Would it be better to use the 1 channel to each vc from the 125.2 to the sub and bridge the 50.4 the 6x9s? Its not a permanent solution but temporary cause I need tunes for a 3 hour ride.

I also have had the 50.4 over heat on me a few times. Mine is bridged to 4 ohms pushing a set of components. I even have 2 computer fans pulling heat away from it.

Edited August 20, 200916 yr by Jacob86

I've seen the 125.2 combo with an icon or dcon on the ssa site so that's why I thought it might work.

Edited August 20, 200916 yr by bigrank916

So I switched the 50.4 and the 125.2 around today. The 50.4 sounds even better on my 6x9's. This is the best they have sounded so far switching through 4 amps. I cant imagine it will overheat anymore cause I also put my seat down again and the air will flow right over it. The sub doesnt sound as loud as it did before but it has less power now so go figure. Not worried about it though as my new Z15 will be coming soon to replace the polkmomos and I will go back to using a class d amp. Cant wait for that somma bitch to get here!

I also have had the 50.4 over heat on me a few times. Mine is bridged to 4 ohms pushing a set of components. I even have 2 computer fans pulling heat away from it.

I am waiting for a 50.4 to power my comp set. I hope I will not have those heating problems.

I also have had the 50.4 over heat on me a few times. Mine is bridged to 4 ohms pushing a set of components. I even have 2 computer fans pulling heat away from it.

I am waiting for a 50.4 to power my comp set. I hope I will not have those heating problems.

Hopefully not but I did have mine in a pretty tight ass spot. Im sure it just didnt have enough room to dissipate the heat well enough. I'll find out for sure on my commute back home on Friday.

I also have had the 50.4 over heat on me a few times. Mine is bridged to 4 ohms pushing a set of components. I even have 2 computer fans pulling heat away from it.

I am waiting for a 50.4 to power my comp set. I hope I will not have those heating problems.

Hopefully not but I did have mine in a pretty tight ass spot. Im sure it just didnt have enough room to dissipate the heat well enough. I'll find out for sure on my commute back home on Friday.

The amp still heated up on the way back but never shut off though. I have a 125.2 right next to it that felt fine. Try it on tweeters is my next step for it I guess.