I've replaced all four speakers in my Lightning with aftermarket speakers.

I have two output converters, one for front channel, one for rear channel.

The front channel I've got run to a cheap Radio Shack amp and I have the four speakers hooked up to it.

The rear channel is running to an MTX 4250D which powers my loaded Thunderform. I have the EBC **** hooked into it.

When I have the bass pumped up and turn the volume up real high while playing a CD it does fine for a few seconds and then silence..........no sound from anywhere. The counter on the HU will stop where it is until I turn the volume back down a little or lower the bass freq.

I have tried lowering and raising the outputs from the converters, adjusting the gains.....it still shuts down. I've got 6ga wire run to the 4250d, 10ga to the Radio Shack.

I can't figure it out....any suggestions?

Thanks,

JohnRude

 

Where are you getting the juice to run your amps? Depending on this maybe your HU is competing for power with your amps. If the juice comes straight from the battery maybe you need a capacitor for your sub.

Have you checked the polarity on your output converters? How about the polarity to your speakers and sub? Just other things I would check.

Good luck.

Alf

 

Hi Alf,

Sorry for not getting back sooner...been too busy.

I'm getting the power for the amps straight from the battery. If the sub amp was pulling enough juice to need a cap wouldn't I notice some headlight dimming, etc?

I haven't checked the polarity on the converters or the subs/speakers. If they were reverse could that cause the problem?

One thing I've been meaning to do is check the amps when this happens to see if they are shutting off. All I do when it goes silent is turn the volume down a little and everything goes back to normal.

I'm getting worried.....'fraid I'm gonna have to take it to a professional shop and let them sort it out. Not that I mind them doing it.....I just hate giving up on a challenge.

JR

 

Hey, I like challenges too, especially with electronics.

Well, you're getting the power straight from the battery. That rules out that problem. Have you tried one amp at the time. If the problem disappears when you disconnect any one of your amps then you know the amp that you disconnected is the one causing the mess.

You say you got four speakers and one Radio Shack amp. Have you checked the load your amp can take? Did you hook all four speakers to this amp?

Having the polarity of your speakers reversed will overload your amp.

I don't know what else to tell you without being there. If you can't make the problem go away then my best advise, as you said, would be taking it to the pros (not Best Buy or Circuit City please) and let them figure it out.

Once again, good luck.

Alf

 

By the way, where is Hampton? I live in Montgomery, AL (for now) and Georgia is only about 1.5 hrs.

 

Hi Alf,

Hampton is where the Atlanta Motor Speedway is located...about 25m due south of Atlanta. It takes me about 1.5hrs to get to the Bama state line on I-85.

I cranked it up this afternoon and watched my amps. When the sound stopped the amps were still on according to the lights. If I don't touch the volume **** the sound starts back up for a second, then cuts back off. If I back he volume **** down or lower the crossover freq on the bass amp the sound starts back up.

The Radio Shack amp is capable of 2ohms according to them. I may try unhooking speakers one at a time to try and localize it. I'm pretty sure that if I unplugged the sub amp the problem would go away though. The higher I turn the crossover freq, the quicker everything shuts down.

I ain't giving up yet. I've been busy with another project here lately, when I can give this one my full attention I'm sure I can localize it......I hope...

JR

 

Having the polarity reversed on your speakers will have no effect on your amps. Sounds like the problem is related to your LOCs. If your amps have speaker level inputs try using those for a test. Check the wiring of the LOCs. They may be pulling down the output of the HU amp.

 

Hi Norm,

What you say makes sense about the polarity not affecting the amps.

I never thought of the LOC wiring because it is so simple. However, now that you mention it I'll have to dig up the instructions that came with them. I think the brand name is Tsunami(sp). There is a brown wire that comes out of each one that I don't have hooked to anything. Seems like I remember the instructions saying to ground the brown wire if no sound is present.

I'll have to re-read the instructions to verify the above, but that is what my problem is all about......no sound....at high volume levels.

If that doesn't fix the problem I'm gonna by-pass the 12v turn on wire from the wiring harness and go straight to the battery for the amp juice. If that don't get it either then I'll try the speaker level inputs.

Thanks for the input,

JR