Protect mode on amp

[ShagggDiesel 25]

I have a friend running a 300w PowerBass amp to a 10" powerbass sub in his single cab Ford Ranger. He called me the other day and said he was driving around town "bumping" and his sub randomly quit working. This kid knows little to nothing about car audio, so he calls me with his problems. I went and looked at his amp and sub too see if I could figure anything out. The sub felt warm, and the amp was REALLY hot. When I played music through the system, at a very low volume, (vol 1-3), sound came out fine.. but when it got above that, the protect light came on on the amp, and would burp random thumps (not from the music) about every 3-5 seconds. With the key turned to "On", but with the engine off, I could get the volume to a higher level before it went into protect mode, but it still did. I told him to let the amp cool off for a little while and see if it started working again, for I figured that it just had overheated and needed to cool. He texted me this morning and said it's still doing the same thing. I'm guessing there's a capcitor in the amp thats fried or something.. anyone have any suggestions on what this could be, and what could be done?

I know a good bit about car audio, but I'm not the best electrician. So any help would be greatly appreciated.

-Shag

[ABXX49 20]

Sounds like there is something wrong with the amp. Where is his amp grounded to? I know that I had a problem kinda like that and it turned out to be a bad ground.

[Kanaworm$ 292]

Start to trouble shoot the wiring at the amp and work your way forward to the connection at the battery. Make sure nothing is shorted along the way.

Make sure the wiring to the subwoofer is not touching metal or shorting across the + to -

[ShagggDiesel 25]

I've checked all connections and it has a proper ground. I'm almost positive there's a problem with the amp

[KU40 173]

Sounds like an amp problem. But take a DMM to the coils of the sub as well to measure their resistance.

[ShagggDiesel 25]

Found the problem. The local car audio shop that installed his system had the sub bridged on the amp. I wired the sub to one channel and now it works fine..

[KU40 173]

I take it it's a 4 ohm DVC sub but 2 channel amp? If so, you'd be a bit better off wiring the coils in series then bridging the amp.

[ShagggDiesel 25]

I take it it's a 4 ohm DVC sub but 2 channel amp? If so, you'd be a bit better off wiring the coils in series then bridging the amp.

Well I'm pretty sure that it's a 4 ohm single coil sub.. I havn't taken the sub out of the box to look though. I think the dual 4 ohm version of this sub has a higher mounting depth that wouldn't fit in the enclosure he has it in.. but then again I could be wrong. I'll take a look at it today and see what it is, and if it's a dual 4 ohm then I'll take your advice and wire it in series, and bridge it on the amp.

[jcarter1885 995]

I take it it's a 4 ohm DVC sub but 2 channel amp? If so, you'd be a bit better off wiring the coils in series then bridging the amp.

Well I'm pretty sure that it's a 4 ohm single coil sub.. I havn't taken the sub out of the box to look though. I think the dual 4 ohm version of this sub has a higher mounting depth that wouldn't fit in the enclosure he has it in.. but then again I could be wrong. I'll take a look at it today and see what it is, and if it's a dual 4 ohm then I'll take your advice and wire it in series, and bridge it on the amp.

I never heard of that before, when did similar subs voice coil configuration change the mounting depth.

[ShagggDiesel 25]

They are similar, but not the same. It's like a 1/2 inch difference if that..

But I found the problem anyway. One of the 2 coils was blown, so he was running off one coil, which when bridged and it still being wired in series, doesn't seem to work so well.

He wanted me to "make it work", so I wired it to one channel, with the sub still wired in series. This of course over the course of a day, blew the other coil. Thus resulting in a dead sub. He sent it off to be repaired like an idiot. He wanted something to replace it til it gets back. So he went to wal-mart and bought a 10" Sony Xplod. I installed it while shaking my head and laughing. To my surprise, the Xplod sounds twice as good as the PB did. :|