[Rochford77]

Ok i have a 15" kicker L7, and a 1500W Digital Audio amp. the amp is a class d mono amp. ok well about 2 weeks ago i was driving through campus and my sub made a noise which i can only explain as a "sub fart" lol. so i looked back and the volt meter on my amp displayed "Er.r" (instead of a voltage) and the protect light came on. the amp rebooted and was fine. well for about a week when ever i would turn the music up the bass would cut out and the amp goes into protect. so i thought maybe i had a short, so i looked at all wires, even the ones on the back of the sub (its a DVC) and i didnt have one, i also checked the ground and it is fine, and all connections at the sub are fine. i inspected the sub and it is not blown and the voice coil is fine. my inline fuse is a 100A and its not blown, and i have 3 40A fuses in the amp and they are fine as well. at first i only had a problem when the music was loud, but now it cuts in and out all the time, and 2 days ago i didnt even have music on (tho the amp was on) and i got a huge burst of feedback and the sub hit real hard...totally randomly with no music even on....any one have any ideas...im out :-(

[Nick07]

I was gonna say short cuz that's what it sounds like. If your 100% sure NONE of the wires are shorting out ANYWHERE and your positive the sub is fine, then my next step would be to check the components on the inside of the amp, it could be as simple as a cracked solder joint on a tiny little transformer or resistor. Your gonna need a magnifying glass or an eye loupe for this. Do you play the tunes even somewhat loud when it's cold out? Also do you turn the music way way down or to 0 when you shut your car off?

Edit- what did you all mess with when you were tryin to fix your other power issue you just had problems with? Check the terminal on that fuse box again, your battery, and any other electrical terminals for corrosion. Give them a quck scrub with a wire brush to be sure and make sure they're all tight. Especially the positive battery terminal, I'm hoping that's where you have the amp power wire hooked up to

This post has been edited by Nick07: 10 February 2010 - 12:37 PM

[Dbl_D718]

It's pretty unlikely that this is an issue with any of the main power wire terminals or fuses. I'd say either you blew either the sub or the amp. If the sub is blown, it could very well be that the amp is going into protect because the sub's impedance is now too low. But since you say you're pretty confident that the sub is ok as is the wiring, I'd suspect the amp has reached the end of it's life. For whatever reason, be it a power surge or condensation, overheating, whatever. Try hooking up a different amp and see if the problem persists.

[talonted1990]

I would say check the sub again. It seems like it is ok down low but it may have a bad spot on one of the voice coils. I had a sub do that and it would only mess up at higher levels when the voice coils really move. It would short out then make the amp go into protection when turned up but work fine at lower levels.

[Devin]

check your speaker wires from the amp to the sub

[Rochford77]

Nick07, on 10 February 2010 - 12:30 PM, said:

I was gonna say short cuz that's what it sounds like. If your 100% sure NONE of the wires are shorting out ANYWHERE and your positive the sub is fine, then my next step would be to check the components on the inside of the amp, it could be as simple as a cracked solder joint on a tiny little transformer or resistor. Your gonna need a magnifying glass or an eye loupe for this. Do you play the tunes even somewhat loud when it's cold out? Also do you turn the music way way down or to 0 when you shut your car off?

Edit- what did you all mess with when you were tryin to fix your other power issue you just had problems with? Check the terminal on that fuse box again, your battery, and any other electrical terminals for corrosion. Give them a quck scrub with a wire brush to be sure and make sure they're all tight. Especially the positive battery terminal, I'm hoping that's where you have the amp power wire hooked up to

i thought it might be a broken solder that would have been my next step because yes, i live in michigan and im always bumpin hard. the amp is fan cooled and has a heat-sink and does not get that hot to the touch even in the summer, and its a $600 amp so i think the solders should be pretty good (though you would think they would be good in your $300 xbox 360 but we all know how that turned out *cough cough RRoD*) lol. and yeah the sub is fine, i checked it out.

DBL: thanks for the input, uve been helpful with system issues in the past, but you were actually dead wrong this time. It was the connection to my fuse holder from the battery. on the battery side of the fuse there were a few stray wires that were barely touching the brass connector and causing mini power surges, but because my fuse is so large (100A) it wasent blowing the fuse, but the unstable power supply was causing the amp to go into protect. so yes it was an issue with one of the main wires... I think i need a new fuse holder mine is trash its some crappy schoche brand from meijer or something like that and the brass clamps on it are all warped out, but i got it working for now so...

[Dbl_D718]

Interesting. A few stray strands making intermittent contact shouldn't cause any problems really assuming the vast majority of the wire was connected securely.

[RedZMonte]

Dbl_D718, on 18 February 2010 - 07:15 AM, said:

Interesting. A few stray strands making intermittent contact shouldn't cause any problems really assuming the vast majority of the wire was connected securely.

Ive only gone into "protection" mode when im running the amp hard with to low of a OHM load... use a meter and see what the ohms on the sub is... if the Voice coil is bad could cause to low of resitance tripping the amp to protect mode... I had a MTX100D amp go bad.. sent it to MTX and had it referbished, it was CHEAP and has bascly all new guts and works like a charm... Im sure JL would be able to do the same thing... I want to say it was like $75 inc. shipping when MTX referbed my amp... (new power supply and circut board in my old case... so yeah its basicly brand new).

S

[Jared]

Rochford77, on 10 February 2010 - 12:36 PM, said:

Ok i have a 15" kicker L7, and a 1500W Digital Audio amp. the amp is a class d mono amp. ok well about 2 weeks ago i was driving through campus and my sub made a noise which i can only explain as a "sub fart" lol. so i looked back and the volt meter on my amp displayed "Er.r" (instead of a voltage) and the protect light came on. the amp rebooted and was fine. well for about a week when ever i would turn the music up the bass would cut out and the amp goes into protect. so i thought maybe i had a short, so i looked at all wires, even the ones on the back of the sub (its a DVC) and i didnt have one, i also checked the ground and it is fine, and all connections at the sub are fine. i inspected the sub and it is not blown and the voice coil is fine. my inline fuse is a 100A and its not blown, and i have 3 40A fuses in the amp and they are fine as well. at first i only had a problem when the music was loud, but now it cuts in and out all the time, and 2 days ago i didnt even have music on (tho the amp was on) and i got a huge burst of feedback and the sub hit real hard...totally randomly with no music even on....any one have any ideas...im out :-(

It's one of two things a blown sub (which can be tested with volt/ohm meter) or your amp could have gone bad most likely you have a blown sub since that's what protect mode if for. It helps the amp by turning off so the excess power that's coming back from the blown speaker doesn't "fry" the amp in layman's terms.

This post has been edited by Jared: 28 May 2010 - 10:55 PM