New Problem: regarding sub amp, RF Prime 750

[PittViper 10+ year member]

Hi,

In brief, my system consists of the following:

HU: Pioneer 80prs

Main amp: RF Punch p400-4

Sub amp: RF Prime 750

Front Components: Polk db6501's

Sub: Alpine 12" type R wired at 2 ohms.

Plus, both power and grounds use distribution blocks. Chassis ground is good.

Signal wires: streetwires zn5

Speaker wire 16 gauge, not fancy

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Now the problem.

My sub amp, which has a bass remote connected to it, is, I believe, going on and off intermittently.

The system has worked flawlessly for quite a while, no this!

I noticed that when the sub quits, the blue led on the bass remote knob goes off. When the bass plays again, the blue led turns back on. I was just driving one day a few days ago and all of a sudden there was no bass. I pulled into a nearby parking lot to look things over, and then the bass started playing again. I have NOT disturbed the wiring to the electronics in this system at all

in quite a while.

I don't see what could be the problem or what might have changed. Surely, this is not a good sign.

So, I welcome all help to fix this problem from anybody who wishes to chime in.

What I have done so far: checked all connections on both amps. All are tight and secure.

When I turn the car on, usually, the blue light on the bass remote doesn't immediately come on like it used to as soon as the ignition key was turned. Leading me to believe that the amp is having problems with the turn on wire. But, the turn on wire is split into a Y, and feeds both amps. The main amp never cuts out.

Then, if I'm lucky, the remote knob light will illuminate, and I will have bass again. Also, the bass knob is only slightly being used, only turned max about 1/3 of the way, but usually not even that.

I don't know if there are any settings on the hu that I could have adjusted that would cause this behavior.

Can someone please let me know how to test the system with a dmm?

Thanks,

Jason

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[PittViper 10+ year member]

UPDATE

Noticed that even when the bass control knob light goes off, the amp still has power light on, just no output. At first I thought that it was the modular cord connected to the bass knob. So, I removed that from the circuit. Still same bass off, bass on problem.

Pulled hu, checked all wire connections, could not make it fail when it was working, nor make it work when it was not working. Seems completely random. This happens with the car on or off. (ignitioin on)

Replaced hu. Removed sub from box. Checked connections to speaker and to terminals; all good. Made sure speaker wires were solidly plugged in to terminals, that was ok.

So I want to know is, what does it mean when the bass knob light goes out and the amp blue light is on? The only time I have ever seen that bass knob light go off is when the car and ignition are off. Or the hu is off. Otherwise, as long as the hu is on, so is the light.

Since it works sometimes, and sometimes not, I am thinking that there is a problem with the amp itself, but how could I narrow this down to know for sure?

I need some troubleshooting tips!!

Ciao for now...

Jason

 

[PittViper 10+ year member]

I am sure it is the amp itself. There seems to be a problem in the output stage of this amp. It has power, ground is good, no shorted wires, sub tests out fine. But, the output of this amp is intermittent. I spent quite a while troubleshooting the problems. Pretty much checked every wire in the car, lol. But really, examined the entire signal path from hu to sub. The amp has to be the problem. What are your thoughts?????

 

[maylar 10+ year member]

My thoughts are that you're a good troubleshooter.

 

[Massive spl]

I am sure it is the amp itself. There seems to be a problem in the output stage of this amp. It has power, ground is good, no shorted wires, sub tests out fine. But, the output of this amp is intermittent. I spent quite a while troubleshooting the problems. Pretty much checked every wire in the car, lol. But really, examined the entire signal path from hu to sub. The amp has to be the problem. What are your thoughts?????

Put another amp in and see if another amp does the same thing.

 

[PittViper 10+ year member]

My thoughts are that you're a good troubleshooter.

Wow, hey, thanks very much. I used to work in the electronics field. I started out troubleshooting system boards, and repairing them, and then moved on to system test and troubleshooting. I really appreciate the complement!

 

[PittViper 10+ year member]

FINAL UPDATE!!

I just knew that the rf amp was bad, so I went out and bought an Alpine mvr-m500 mono amp.

Installed that, and wammo, no cutting out problems! But also, the bass is much stronger, louder and smoother than it ever was with the Rockford amp.

I have owned a total of 6 Rockford Fosgate amps since I started in car audio. None have ever given me a problem until this one. I am thinking about swapping out my Punch 400-4 for a 4 channel Alpine maybe next summer.

I'll keep you all posted.

Ciao,

Jason