That was what I was thinking. I usually don't run the bass more than two notches above center on my HK head unit (with low level outputs added by Iron Cross Audio). I did testing at near max volume without distortion separately on the front then the rear so hopefully I don't have the gains set too high. I'd rather lose a little volume than risk blowing speakers. Those Motos up front put out more sound than I can stand. I don't feel the need to push them.

The only other thing that concerns me is the pop when the amp turns on or off when you turn the radio on or off. If I just leave the radio on all the time it isn't an issue.

Iron Cross said this is normal with some amps when you have the 12v turn on lead hot all the time. That being said I still would like to try to eliminate it somehow. They recommended a turn on delay which I have heard some folks using but if the turn on voltage doesn't come from the head unit I don't see how this would help the situation if the radio is turned off and back on again to set the clock.

I have read somewhere that pin 12 on one of the plugs of the HK head unit goes to 12v when you turn it on but I have heard others say that it doesn't work. Maybe if that wire was connected to a PAC TR-4 remote trigger that would work? Anyone tinkered with that on the HK units before?

 

Pin 12 is a 12v switched input. The head unit does not have a 12v output. Stock amps are turned on by the CAN BUS circuit, eliminating the need for a 12v out.

 

Thanks for the clarification. I had to do some Googling to find out what a CAN BUS circuit was. My initial experience in mobile audio was wiring up a Weltron 8 track deck in my 1970 Ford in high school, so a lot of this stuff is new to me.

I wonder if a lot of folks just deal with the turn on/off pop or if some folks have found work arounds. I guess only folks with stock head units have to deal with it though. I imagine the aftermarket units have proper remote turn on circuits.