I gotta problem with my amp. It is a punch 500a2. It is running one 12" Infinity Kappa DVC. The amp is wired at 4 ohm bridged. it started cutting out some and I could turn the volume down and it would come back on. Well, one morning it just went out, nothin.

Well the other day it came back on, listened to it for all togther about 1 hour and it went back out again. Not been back on since.

A friend of mine said it could be the resistors going bad, I don't know that is why I'm asking y'all. The amp is probably 10-12 years old. I used for about a year with no problems at all.

thanks for the help

Tim

Well... Obviously you can test the 12 switched and constant line. Check continuity with a DMM for your ground.

If both of those are good, check the ohm load at the amp. If the sub is starting to go, I have seen resistance both drop low and raise up to several thousand ohm'*. Obviously dropping low may not work to well with the amp in question.

If that'* all good, then check your RCA'*. I keep a few spare sets in my toolbox. Just run them outside of the vehicle to the amp itself. No need to run the wires if it'* not going to make a difference.

Otherwise, it'* most likely the amp.

Thanks Chris. I'm figurin the amp is about to go. Sub is only a year old and I haven't ran it that hard.

Thanks for the info.

Tim

How long have you had the sub bridged on the amp ?

I know you said the sub is a year old, but have you always had it bridged or is this something that you just recently did ?

I guess you get were I'm going with this.......Are you sure that the amp is bridgeable ?
If not that would explain your problem.

Good Luck,
Dutch

Actually I dont't think it is the amp anymore. Yesterday after work I opened the trunk and tried something. With the system powered up and running I pushed in on the cone of the sub, and it started playing. I called Crutchfied last night and the tech dude said he thought it may be a short. I brought the sub in today and put the multimeter on it to see what I got. Can anyone give me some numbers that if the sub is still good I should get.

I tried to check the ohms and with the switch on the 8 ohm side I got 10.0. With the switch on the 2 ohm side I was gettin like 4.6. ( To clarify the Infinity sub I am using is the DVC model with impedence selection switch.) When I tried to check the voltage I can't get a stable reading. The numbers stay mostly in the negative though.

I need some help,

Thanks


Tim

Is the sub dual 4 ohm or dual 8 ohm? Just measure each coil independently. Because multimeters measure Ohm'* in DC, and your sub'* 4 ohm load is actually in AC, it should read right about 3.7 ohms per coil. If each coil is 8 ohm, should right 7 something. If each coil is 2 ohms, should read right about 1.8.

The sub is dual 4 ohm. It can be run in 2 ohm or 8 ohm.

Thanks for the help Chris


Tim

There is most likely your problem......
When you bridge an Amp it has to see 4 Ohms, not less like how you have your sub wired for 2 Ohms
The Amp is probably building up too much heat and going into protection, because your showing the amp a 2 Ohm load when its looking for a 4 Ohm load.

If your running just the 1 DVC with 4 Ohm coils, then you need to do one of the following;

Use only one channel of the Amp and run it at the 2 Ohms (how you have the Sub wired now)

or

You need to run each coil seperately, 1 to each channel.

The reason they make amps bridgeable is for when you have a SVC 4 Ohm sub, and are unable to drop the resistance down to 2 Ohms to get more power you can combine the channels of the amp, but the resistance has to be 4 Ohms, not less.

Here are some typical specs for a 2 channel amp.
These are from an amp similar to yours from Fosgates site the Punch 500-2.
Rated Power continuous power
125W x 2 @ 4-Ohms RMS
250W x 2 @ 2-Ohms RMS
500W x 1 @ 4-Ohms bridged RMS

Good Luck,
Dutch

I went to a local audio store yesterday and had the sub checked out. It checked out okay. I talked to the teck dude at the store and he said it sounded like a bad or loose ground at the amp.?? I am gonna check everything out and see what I find.
He also said the power supply could be going bad.

Thanks for all the help guys,

Tim