Car audio - what would cause an amp to cut out?

[jlee]

LOL, no. That was taken without any amp wiring connected. Blue is speaker wire. RCA's go through there too right now (no other convenient location).

 

[Howard]

Why is there speaker wire in the engine bay?

 

[jlee]

Why is there speaker wire in the engine bay?

There isn't.

Don't mind that ground loop isolator...it helped a little with the old audio setup (reduced the power steering whine), but I'm trying to do this one properly so as to not need it. 😛

 

[SuperSix]

Is it a 4ohm output amp hooked to an 8 ohm sub?

 

[Smoove910]

Is it a 4ohm output amp hooked to an 8 ohm sub?

That won't make a damn bit of difference. In fact, the amp would run cooler and easier since there would be less load...


To OP - You need to run the RCA's away from your power/ground. That's probably why you are getting engine noise... There should also be no reason for RCA's or speaker wire in your engine compartment. Did you happen to install car stereos for Best Buy at one time cause this is starting to look like the type of work they do. 😛

 

[jlee]

That won't make a damn bit of difference. In fact, the amp would run cooler and easier since there would be less load...


To OP - You need to run the RCA's away from your power/ground. That's probably why you are getting engine noise... There should also be no reason for RCA's or speaker wire in your engine compartment. Did you happen to install car stereos for Best Buy at one time cause this is starting to look like the type of work they do. 😛

This is not an engine:

This is an engine:

Did you happen to work for Jiffy Lube at one time? 😉

The only other place I could really put the amp is behind one of the seats. I'd rather not drill into my firewall to mount it, and I know for a fact that mounting it where I have it should work (it has been done).

I played with it this morning..if I unplug the speaker's RCAs and leave just the sub running, it's fine. With just the components running, it cuts out. If I run just the left or right channel, it cuts out. If I run everything but set the gain on the components to minimum, I can run the gain on the subwoofer at maximum and everything stays working. Battery voltage never dropped below 12v (lower than usual because the car is not running).

This is how it was wired:

Which matches this:

According to this:

When I initially unplugged one channel of the main RCA's, I still had sound from both speakers (wtf), so I switched the amp to 4 channel mode (instead of bridged):

Checked the crossover wiring:

It seemed to work slightly longer in 4 channel mode than in 2ch/bridged, but it still cut out after a short time (less than a minute).

I find it highly unlikely that there's a problem with my wiring for both speakers, and also unlikely that both speakers are defective. I will try running them off the rear channel in the amp, and if that doesn't work, I'll try the old 4x50w Rockford Fosgate amp I have kicking around and see if that works.

 

[sdifox]

Capacitor problems? What about the transformer in the amp? you are overloading when you should not be. The sub is fed from a different amp?

 

[jlee]

Capacitor problems? What about the transformer in the amp? you are overloading when you should not be. The sub is fed from a different amp?

It's one (5 channel) amp running everything.

 

[sdifox]

It's one (5 channel) amp running everything.

overloading... don't power the sub and see how it goes.

 

[jlee]

overloading... take out the sub and see how it goes.

It did the same thing with this...

I can run the current sub (Dayton RSS265HO-4) at max gain indefinitely. When I give the components anything, it conks out on me. I'll try unplugging the sub and cranking the components up, but I'd bet money that it will do the same thing.

 

[sdifox]

It did the same thing with this...

I can run the current sub (Dayton RSS265HO-4) at max gain indefinitely. When I give the components anything, it conks out on me. I'll try unplugging the sub and cranking the components up, but I'd bet money that it will do the same thing.

take a picture of the top control panel to show me the settings you got on there. This is bizarre.


may just be a defective amp

 

[jlee]

It works fine if the front gain is set at minimum, but if I increase it it'll quit after a few seconds. Gain in this photo is max, but everything else is the same:

 

[sdifox]

It works fine if the front gain is set at minimum, but if I increase it it'll quit after a few seconds. Gain in this photo is max, but everything else is the same:

So the speaker is dual coil, with the x-over set at 3500Hz. And you want the high pass at 80Hz right?
also, what about the manual page on input.

Leave the gains in the middle. Let's first figure out what is going on before you play with gains.

 

[jlee]

why do you need xover when the amp does it?

Sorry, by 'gain' I meant the 'level' indicators...old terminology, I guess?

http://manuals.harman.com/INF/CAR/Owner%27s Manual/KappaFive.print.friendly.pdf

Edit: Apparently their link is dead. I'll go get a photo.

 

[Howard]

why do you need xover when the amp does it?
also, what about the manual page on input.

Leave the gains in the middle. Let's first figure out what is going on before you play with gains.

I don't think it has xover capabilities, just simple low/high-pass filters. The other part of the signal doesn't seem to go anywhere.

 

[sdifox]

I don't think it has xover capabilities, just simple low/high-pass filters. The other part of the signal doesn't seem to go anywhere.

yeap, looked closer and it's just high/low pass filter. Read up a bit more about the speaker + x-over combo.

 

[jlee]

Volume on the head unit goes to 62. With volume somewhere in the 50's, it cuts out (pretty decent volume, but with gain in the middle and each speaker only getting 50w RMS, it's not really loud - they are rated for twice that). Doesn't matter if the sub is connected or not, as long as the regular speakers are connected, it will cut out.

I may run through the "proper" gain set process just for kicks but every speaker I'm running can take much more than the amp is capable of dishing out. I think if anything, the amp would be clipping before the speakers had too much?

Unfortunately, I need to sleep...I'll check back this afternoon!

 

[sdifox]

Volume on the head unit goes to 62. With volume somewhere in the 50's, it cuts out (pretty decent volume, but with gain in the middle and each speaker only getting 50w RMS, it's not really loud - they are rated for twice that). Doesn't matter if the sub is connected or not, as long as the regular speakers are connected, it will cut out.

I may run through the "proper" gain set process just for kicks but every speaker I'm running can take much more than the amp is capable of dishing out. I think if anything, the amp would be clipping before the speakers had too much?

Unfortunately, I need to sleep...I'll check back this afternoon!

Sounds like there is something going on with that amp. I understand you checked your cable work and no intermittent short has been found. Time to check one channel at a time 😛

 

[DominionSeraph]

I played with it this morning..if I unplug the speaker's RCAs and leave just the sub running, it's fine. With just the components running, it cuts out. If I run just the left or right channel, it cuts out. If I run everything but set the gain on the components to minimum, I can run the gain on the subwoofer at maximum and everything stays working. Battery voltage never dropped below 12v (lower than usual because the car is not running).


When I initially unplugged one channel of the main RCA's, I still had sound from both speakers (wtf), so I switched the amp to 4 channel mode (instead of bridged):

It seemed to work slightly longer in 4 channel mode than in 2ch/bridged, but it still cut out after a short time (less than a minute).

I find it highly unlikely that there's a problem with my wiring for both speakers, and also unlikely that both speakers are defective. I will try running them off the rear channel in the amp, and if that doesn't work, I'll try the old 4x50w Rockford Fosgate amp I have kicking around and see if that works.

Sound coming out of both sets of speakers with a single input is normal when it's bridged. You're bridging across the left and right channels, so the output is the SUM of L+R. (Which is why I wouldn't recommend bridging. It turns the stereo effect into a half-volume effect.)

Now, if what you've said is the totality of what you've tested, you haven't yet tested your L+R components separately. (You've tested them together in bridged with a mono input, and together in Front with a stereo input.)
For testing them individually, remove the speaker leads, not the input RCA. This is necessary because Left and Right aren't electrically isolated in the amp. (L- is actually the same as R+.) So if you have a path to ground in one side you'll pull the other side down as well.

 

[jlee]

Ah, ok. All I did was pull one input RCA with the amp in 4ch mode (so I got sound from one side). I'll pull the speaker wires and try again later.

 

[EightySix Four]

Unplug your front right component and leave the left one in. Don't run it bridged, try it in each of the amps four channels and see if it cuts out. If it never does, try the same thing with the right component and the left unplugged. If it doesn't cut out, try the two unbridged on the front and then again on the rear and see if it cuts out together.

overloading... don't power the sub and see how it goes.

That amp has no problem with that setup. My friend's truck is running 2 sets of the Kappa Perfect 6.1's (same as JLee's, except 4 total) and a JL 10w3.

 

[sdifox]

Unplug your front right component and leave the left one in. Don't run it bridged, try it in each of the amps four channels and see if it cuts out. If it never does, try the same thing with the right component and the left unplugged. If it doesn't cut out, try the two unbridged on the front and then again on the rear and see if it cuts out together.



That amp has no problem with that setup. My friend's truck is running 2 sets of the Kappa Perfect 6.1's (same as JLee's, except 4 total) and a JL 10w3.

I know that amp is not supposed to have issues, but the symptoms point to overloading.

 

[EightySix Four]

I know that amp is not supposed to have issues, but the symptoms point to overloading.

They point to a lack of power, whether that is from the amp overloading or not getting enough power we do not know.

JLee, when the amp "turns off" do any of the diagnostic lights come on?

 

[JulesMaximus]

Crank the volume
Ears are bleedin'
I still don't know
What I'm singin'

 

[jlee]

They point to a lack of power, whether that is from the amp overloading or not getting enough power we do not know.

JLee, when the amp "turns off" do any of the diagnostic lights come on?

If you call the lights 1 2 3, 1 and 3 are blue when it's working. When it quits, 2 comes on red.