I've got an Audiobahn A4004T 4 channel amp in my car right now. Channels 1 and 2 are bridged to power a 10" Alpine Type E sub and channels 3 and 4 run the front speakers. Recently, I've noticed a lot of distortion in my sub, although I haven't changed the gain, bass boost, crossover, or the settings on my CD player as well. The bass is also a lot quieter than it was before. Before it sounded amazing...now it sounds weak! It sounds like it's only getting about half the power it did before, if that. However, the front speakers still sound the same as before. I did notice a fair amount of condensation on the amp, wondering if there might be some internal condensation causing this, a bad ground, or maybe a blown channel? I don't know much about the internal workings of an amp, so any help would be appreciated. Thanks!
Replies (10)
swez on 01/17/2007 17:32:42
Try pulling the amp and bring it indoors for a day or so to dry out. (Remove the battery fuse first)
Just put in in a warm, dry place and maybe a fan on it. It may help to pull the top cover off it too as this will speed up the drying process. After a night of drying out, reinstall and see what ya get. With luck, the system will be back to normal.
FYI: On cold nights, consider covering the amp with a towel or blankie. This will wick up moisture and condensates.
Swez
brettlar85 on 01/17/2007 19:13:06
Thanks a lot.... I'll have to give that I try! I'll let you know if that doesn't fix it.
ttocs on 01/17/2007 21:33:23
try switching the outputs and see what you have. Also switch the inputs(switch rca's) and see if anything changes.
brettlar85 on 01/18/2007 13:26:56
OK, so I dried out the amp really well last night and re-installed it in my car today, and it still sounds the same. I went through and checked my connection at the battery, the ground, and my connections on the amp. Also, I switched the inputs (put channel 3 and 4, which run the front speakers) and put those into channels 1 and 2...still sounded the same. I then hooked the sub just up to channel one and channel one worked. Hooked it up to channel two, that worked as well. Bridged both channels again...still sounded the same. Honestly, it didn't sound much different running it off of a single channel (50 watts RMS) as it did off of both channels bridged (200 watts RMS). I then took the sub out and checked all of the connections there, put it back, and again, it still sounded the same.
Could the problem be with my sub? I'm off at college right now, but I've got a spare Type E at home that I could try to see if that's the case. Or could the problem be with the amp? If that's the case, the warranty is still in effect with it, so I'll probably just send it in.
swez on 01/18/2007 13:57:27
It's hard to say what you have going on here bud. That SWE 10" sub is 4 ohms and rated for 250 watts RMS. This amp can deliver 200 RMS @ 4 ohms. (Good match here)
Can you try adjusting the rear channel gain control a tad and see if this brings things back to snuff? Having an AC voltmeter handy would sure help too. With a 4 ohm speaker, should get about 28 volts at full power on a 50 Hz test tone.
Swez
brettlar85 on 01/18/2007 14:25:35
I adjusted the gain as well...sorry, I forgot to mention that earlier. It sounds distorted to me at any gain setting. Unfortunately, I don't have access to a AC voltmeter here...at home I could get one, but I won't be home for another month and a half or so. I'll try hooking my other sub up to it when I get a chance to (hopefully by Sunday).
swez on 01/18/2007 15:51:41
That almost sounds like a few bad amp channels here.
Can you test your sub on a buddies amp and determine if the sub sounds OK off another rig? If the sub sounds good, your amp probably needs service. If the sub sounds bad here, your amp is probably OK but sub is failing.
Did you try channels 3 & 4 on your mids/high? (stereo, not bridged?) If they sound good, the sub is probably dying.
Swez
brettlar85 on 01/18/2007 16:44:50
No, actually I haven't tried that yet...I'll see if that works.
brettlar85 on 01/18/2007 17:51:52
So I hooked my two front speakers up to the channels the sub was originally on. Channel one works, but is pretty distorted, and channel two is dead...just what I was afraid of . Looks like I'll be sending her in for repairs...good thing it's still got a warranty. Thanks a lot for your help guys, I appreciate it.
ttocs on 01/18/2007 18:14:25
ohh better hurry, rumor is that bahn is folding soon.......
Replies (10)
swez on 01/17/2007 17:32:42
Try pulling the amp and bring it indoors for a day or so to dry out. (Remove the battery fuse first)
Just put in in a warm, dry place and maybe a fan on it. It may help to pull the top cover off it too as this will speed up the drying process. After a night of drying out, reinstall and see what ya get. With luck, the system will be back to normal.
FYI: On cold nights, consider covering the amp with a towel or blankie. This will wick up moisture and condensates.
Swez
brettlar85 on 01/17/2007 19:13:06
Thanks a lot.... I'll have to give that I try! I'll let you know if that doesn't fix it.
ttocs on 01/17/2007 21:33:23
try switching the outputs and see what you have. Also switch the inputs(switch rca's) and see if anything changes.
brettlar85 on 01/18/2007 13:26:56
OK, so I dried out the amp really well last night and re-installed it in my car today, and it still sounds the same. I went through and checked my connection at the battery, the ground, and my connections on the amp. Also, I switched the inputs (put channel 3 and 4, which run the front speakers) and put those into channels 1 and 2...still sounded the same. I then hooked the sub just up to channel one and channel one worked. Hooked it up to channel two, that worked as well. Bridged both channels again...still sounded the same. Honestly, it didn't sound much different running it off of a single channel (50 watts RMS) as it did off of both channels bridged (200 watts RMS). I then took the sub out and checked all of the connections there, put it back, and again, it still sounded the same.
Could the problem be with my sub? I'm off at college right now, but I've got a spare Type E at home that I could try to see if that's the case. Or could the problem be with the amp? If that's the case, the warranty is still in effect with it, so I'll probably just send it in.
swez on 01/18/2007 13:57:27
It's hard to say what you have going on here bud. That SWE 10" sub is 4 ohms and rated for 250 watts RMS. This amp can deliver 200 RMS @ 4 ohms. (Good match here)
Can you try adjusting the rear channel gain control a tad and see if this brings things back to snuff? Having an AC voltmeter handy would sure help too. With a 4 ohm speaker, should get about 28 volts at full power on a 50 Hz test tone.
Swez
brettlar85 on 01/18/2007 14:25:35
I adjusted the gain as well...sorry, I forgot to mention that earlier. It sounds distorted to me at any gain setting. Unfortunately, I don't have access to a AC voltmeter here...at home I could get one, but I won't be home for another month and a half or so. I'll try hooking my other sub up to it when I get a chance to (hopefully by Sunday).
swez on 01/18/2007 15:51:41
That almost sounds like a few bad amp channels here.
Can you test your sub on a buddies amp and determine if the sub sounds OK off another rig? If the sub sounds good, your amp probably needs service. If the sub sounds bad here, your amp is probably OK but sub is failing.
Did you try channels 3 & 4 on your mids/high? (stereo, not bridged?) If they sound good, the sub is probably dying.
Swez
brettlar85 on 01/18/2007 16:44:50
No, actually I haven't tried that yet...I'll see if that works.
brettlar85 on 01/18/2007 17:51:52
So I hooked my two front speakers up to the channels the sub was originally on. Channel one works, but is pretty distorted, and channel two is dead...just what I was afraid of . Looks like I'll be sending her in for repairs...good thing it's still got a warranty. Thanks a lot for your help guys, I appreciate it.
ttocs on 01/18/2007 18:14:25
ohh better hurry, rumor is that bahn is folding soon.......
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