Car Amplifier acting funny

[TechBoyJK]

Hi,

I have a 97 Civic Ex. It has an Alpine head unit, boston components up front, infinity kappa 6x9's in back, and 2 10" Boston Pro subs.

The amp is some 380watt (rms)2 channel Pioneer amp. Not my first choice but on a limited budget, it does the job well. Each sub is 2 ohm's. I run each sub to each channel respectively. This puts each channel at 2 ohms, which the amp can handle and has been handling without a problem.

Anyways, I was doing a bass test, and the bass was so intense that it vibrated on of the speaker terminals loose in the speaker box. I immediately knew that one of the speakers cut out. So I unscrewed the speaker, fixed the loose connection, and done. The problem is, ever since this happened, the power coming out of the amp is almost none. The subs play, but very softly. If I turn the balance to the left, the sub on the left gets a lot louder. If I turn the balance to the right, the sub on the right gets a lot louder. Think of it this way, with the balance centered, it is like the sub volume is all the way down. When I move the balance to the left or to the right, its as if I am turning up the volume on the sub. The subs hit hard when I adjust the balance to the left or right, but when its centered, i cant here them at all. What could be causing this?

I have heard that if you have a two channel amp, running only one channel(left or right) without having the other channel hooked up to something (regardless of balance settings) can damage the amp. I am wondering if the brief moment that the one sub was not hooked up, it caused damage to the amp. The problem is, the amp still hits hard for both subs, except not when i have them both set to play together. I would think that if the amp was damaged, it wouldn't play at all. I am also wondering if for some reason the amp can't handle the load of both subs together.

Another thing could be the RCA plugs. I'm not sure, but it looks like I need to spend this weekend with the multimeter. Any advice is appreciated.

 

[TheCorm]

You have 1 AMP powering 2 subs....hmmm....I have a 400W Amp powering 1x 10" sub and I think it could be louder, how have you got that wired?....you must have them connected as if they are speakers?....never heard of this before.

Normally you wired them up in a bridged connection and set the amp to this so that it uses it's low pass filter and acts like a Sub amp.

I did a Bass test on mine and it blew the fuse on the Amp itself, went int the boot and it felt like it was working but very softly but turned out to be vibrations/noise coming from the 6x9's...longshot but it could be that.

I presume there is the standard fuse on the amp and an inline fuse going to the battery? Both of these OK and the right Ampage?

Jamie

 

[TechBoyJK]

Two Channel Amp. Two Subs. One sub goes to left channel, the other goes to right. This isn't abnormal. BTW, im not going for loudness, but sound quality, which is why i bought the boston subs. At 180Watts (rms) to each sub, they are loud enough and sound great. the amp only has gain control and low pass filter on/off switch. This is a temp amp.

My real question is, what could be wrong with an amp if it will play both channels fine individually, but not simultaneously? I turn the balance to the left and the left sub plays fine, and I turn the balance to the right and the right sub plays fine, leave the balance in the center and nothing. I know that if you only hook a speaker up to one of two channels, it will fry the amp. But then it won't play at all. I am wondering if for the 30-40 seconds that my amp was playing with only one sub hooked up to one channel if it could have damaged the amp? Why could it play one channel or the other but not both at same time?

 

[TechBoyJK]

bumpity bump bump bump

 

[ThisIsMatt]

Originally posted by: TechBoyJK
I am wondering if for the 30-40 seconds that my amp was playing with only one sub hooked up to one channel if it could have damaged the amp? Why could it play one channel or the other but not both at same time?

I've always been told that yes, this can damage an amp, although I don't know why...

 

[speed01]

It sounds like you have crossed leads.....recheck your connections to the subs.

 

[Pepsi90919]

it sounds like you have a wire crossed, like the mono sounds are canceling each other out because you have the speakers connected to both positive terminals.

 

[TechBoyJK]

thanks for the help. In my experience, if my amp was damaged, it wouldn't still be able to deliver normal power to each sub. I had an amp fry from only using one channel, and it just wouldnt work afterwords. This amp still turns on and kicks hard as long as i adjust the balance to the left or right.

 

[ThisIsMatt]

What happens if you run the amp bridged and the subs in series for a 4 ohm load?

 

[Pepsi90919]

Originally posted by: TechBoyJK
thanks for the help. In my experience, if my amp was damaged, it wouldn't still be able to deliver normal power to each sub. I had an amp fry from only using one channel, and it just wouldnt work afterwords. This amp still turns on and kicks hard as long as i adjust the balance to the left or right.

right, because a signal that's unique to the left or right won't get canceled out in your little wire-crossing fiasco you have set up.

 

[TechBoyJK]

could this wire crossing involve the RCA cables? Before the speaker wire became disconnected, the subs worked fine, left, right, and center. I simply reconnected the one disconnected wire and this started happening.

When I run the wires in series, nothing happens. When I run it in stereo, aka normal hookup, it worked fine before the one speaker became disconnected. The channel that became disconnected still works fine if the balance is turned only to that channel.

 

[Drakkon]

I say its time to get a new amp....this one sounds pretty well fuxored and it probobly was blown during the bass test.
If you have a digital multimeter you can always disconnect all speakers and check what sort of outputs your getting (once again from the bass test)...if you havent heard of this pm me cause i cant find the link right now you might of accidently hit the gain turning it down just enough to underpower both subs while just enough to power one (why it gets louder once you do the balancing) More likley than not you've blown something inisde of there causing the system to underpower just enough that its not going to power 2 subs fully, but just one enough. Don't run em for too long on the low setting...you might be underpowering them which is a no no

 

[Ladies Man]

First off....

Check all fuses..... You can have a blown fuse and the amp will still kinda play... electricity can jump over the broken gap
Check all wires..... It's quite easy to wire speakers incorrectly. I doubt it's your RCA wires. Just make sure they are plugged in all the way.

After you do all that come back to us.

 

[TechBoyJK]

what could i have blown to allow the amp to only play one channel at a time? I would think anything powerrelated would have shut that amp down completely.

I've got a multimeter. What should I start checking and what settings should I be looking for?

 

[TechBoyJK]

just out of curiosity, what causes an amp to fry if you only hook up one channel? My first amp went down hard when I did this, it smoked and everything. Since I had this experience, i turned my car off asap when I realized the speaker terminal came undone.

 

[TechBoyJK]

Knowing that I checked all of my wires many times, I am a little spooked to find that one of my speaker wires was indeed crossed. Pos was in negative and vice versa. Problem solved. amp still works. bumpin good. Thanks for the help guys!

 

[speed01]

Glad you got it fixed, good call Pepsi90919...

Speed