voltage problem cause this???

[F150Matt]

Ok, heres the story...Yesterday I'm installing an amp in my friends truck. His battery terminals were rather corroded and his battery was leaking some acid. When I went to unbolt the wires from the pos. terminal to connect the power wire for the amp, the whole terminal popped out of the battery. The battery was junk. Instead of going to get a new battery from autozone, my friends dad goes back to his house to pick up a battery that has been sitting on his porch for about a year now. He throws it on the battery charger for about 10 mins and comes back over to my house. We put the battery in, it has enough voltage to crank the truck. I go ahead connect the power wires, make a good ground, run the RCA's put the speaker box in, connect the speaker wires. I turn it all on, amp powers up fine, speaker vibrates on bass notes, I begin adjusting the gains. As I turn the gains up the speaker doesn't really get any louder, the engine sounds like it is about to stop running the higher the gain goes up. The speaker vibrates to the music but the cone isn't moving in and out hardly at all. Is this a voltage problem and therefore the amp isn't making enough power to move the woofer? On a bass sweep from 100hz-20hz with the gain cranked about halfway and the volume on 35/50, I clearly hear the engine sound like it is cutting out and about to die. I believe this battery the guy used didn't have enough voltage to run everything(it was much smaller than the factory battery and probably not even charged up all the way). Is voltage/battery my problem or is there a problem elsewhere? It seems to me that voltage can be the only thing to make it do that but I wanted to check with you guys. The cone on the speaker in the center got really hot even though the speaker wasn't even doing much...I disconnected the amp, pulled the inline fuse and left it all disconnected. I plan to tell the guy he needs a new battery and when he gets that we'll try again. Let me know what you think. Thanks guys.

[jbl_marshall21]

new battery for sure. what kinda car?

[F150Matt]

Its a 2000 model Chevy truck.

[Savant]

He should have a new battery, but that's not your problem.. (or at least it doesn't seem that way to me).. While the truck is running the alternator powers everything, but if that battery is sooooo far down, it could be sucking up all the available power trying to re-charge.. A new battery or waiting until that one is properly charged is a must..

The speaker should NOT be getting hot if it's not making music.. Is the speaker new? if not, maybe it's blown? See if the cone actaully moves smoothly.. Did the amp get hot as well? Could be a wiring issue, but I'm not sure what would cause a hot speaker if it's not a dual voice coil.. and even then, you would have to have one wired out of phase and on a seperate channel to cause it to overheat at lower powers and not produce volume..

Anyone else have ideas about the hot woofer?

[CarAudioAddict]

Well, I know from experience that all subwoofers generate heat. The higher power subwoofers generate more heat - this applies to DVC and SVC subs.

Noticable heat levels in an SVC sub, after a short playing time, usually points to overpowering. It is natural for a sub to get hot after a long playing time - I've been burnt many times from hot subs.

As for the electrical problems - Get a fully charged batery with at least the same capacity as the OEM battery. Try it out, if the problem is still there it is an alternator problem, if the problem disappeared it was a low charge problem.

[Savant]

Originally posted by CarAudioAddict
Well, I know from experience that all subwoofers generate heat. The higher power subwoofers generate more heat - this applies to DVC and SVC subs.

Noticable heat levels in an SVC sub, after a short playing time, usually points to overpowering. It is natural for a sub to get hot after a long playing time - I've been burnt many times from hot subs.

As for the electrical problems - Get a fully charged batery with at least the same capacity as the OEM battery. Try it out, if the problem is still there it is an alternator problem, if the problem disappeared it was a low charge problem.

But, if you are powering the sub enough to heat up, it really should be moving.. I'm getting the impression that this thing is barely vibrating and getting 'very' hot.. Now, if the concern was just a hot woofer after playing a while, I'd agree with you completly.. but since there is almost no volume at 35/50, there is something wrong.. Or so it seems to me..

[F150Matt]

it is a DVC woofer but I wired it correctly, doublechecked that a couple times to make sure. The cone barely moves at all with music, it barely vibrates, we only played it for like 4 or 5 mins and the center piece where the dustcap looking thing is was hotter than it should be. The amp did not get hot at all. If its not a voltage problem then why does the engine almost completely cut out(off) when I crank the gains???

[Savant]

Originally posted by F150Matt
it is a DVC woofer but I wired it correctly, doublechecked that a couple times to make sure. The cone barely moves at all with music, it barely vibrates, we only played it for like 4 or 5 mins and the center piece where the dustcap looking thing is was hotter than it should be. The amp did not get hot at all. If its not a voltage problem then why does the engine almost completely cut out(off) when I crank the gains???

The 'heat' shouldn't be a voltage problem.. but with a mostly dead battery and trying to 'power up' the amps, that "can" cause the computer/engine to crap out..

Fix the battery problem, that is a must.. but, I don't think that will solve your sub not moving problem.. if it does, let me know.. I'll try to investigate that as it makes no sense to me..

EDIT: Oh, how many channels are you running to the sub? Just one? and have the coils wired that way, or do you have sepperate channels to each coil?

[F150Matt]

One channel to both coils, wired in parallel for 2 ohm load.

[Savant]

Originally posted by F150Matt
One channel to both coils, wired in parallel for 2 ohm load.

Hmm.. All I can think of at this point would be a bad sub

So, get the battery issue fixed and see what you get? *shrug*