sub cutting out

[assoutE12]

I have been having some wierd problems with my stereo lately. my sub will randomly cut out sporadially, but always work again when I resart my head unit (take the face plate off then replace it) what gives?

my first thought was it might be a bad conection, but that doesn't explain why it will work if I resart the head unit.
what is the most likely culprit? the head unit or the amp?

oh yea, I have an alpine head unit, alpine 400w 2 channel amp for the front speakers and a JL 250w amp for the 10in sub if that helps any.

[StereoInstaller1]

OK, here are my suggestions.

1. Provide EXACT model numbers of each piece of equipment.
2.provide pictures of the power and ground wires...not at the amp, but at the connection to the car.

If you are running a DVC 4 ohm per coil sub wired in paralell on a 2 channel amp, bridged, it would simply be a compatibility issue. Simple fix would be to change either woofer or amp to achieve compatibility, or re-wire sub to drop to 8 ohm impedance.

Full info and pics will give info as to what the exact issue is.

Let us know.

Luke

[BMW03]

Lukes got it, picks would help, I would definatly check the ground on the deck, and check you remote wires, those are the first 2 that I would look into.

[assoutE12]

model numbers
head unit------------- Alpine CDA-9855
front stage amp------ Alpine MRT-420 (2 channel)
sub amp--------------- JL e1200 (mono)

I don't have any pics right now, so I will need to take those. plus the dsl is down at my house so uploading them might be a bit of a challenge.

thanks for the help, the main thing I am trying to figure out is if the problem is in my head unit because if it is I can take it back and get a new one.

[92 mtechnic cabrio]

my sub amp cuts off when I turn it up to 30 out of 33 on the volume (with gains on the amps set so the head unit can go the full range, almost)

Is the sub amp just cutting off because of the fail safe? The bass is clean up to when it cuts off. I guess that's a result of underpowering a sub?

[StereoInstaller1]

model numbers
head unit------------- Alpine CDA-9855
front stage amp------ Alpine MRT-420 (2 channel)
sub amp--------------- JL e1200 (mono)

I don't have any pics right now, so I will need to take those. plus the dsl is down at my house so uploading them might be a bit of a challenge.

thanks for the help, the main thing I am trying to figure out is if the problem is in my head unit because if it is I can take it back and get a new one.

Any chance that your sub is dual 2 ohm? If so, that may be part of your issue. Unlikely though. JL doesn't sell too many dual 2 ohm subs.

Here are my recommendations:
Use a DVM to meter your voltage at the amplifier inputs. Rev your car to like 2000 RPM, and watch the voltage. Then, let the car idle and do the same.

You should never see above 16 volts, or below 11. I suspect your car is having voltage fluctuations beyond what your amp is happy with.

The chance of your head unit being the issue is slim, but it could happen.

Who did your install? You might want to take it back to the shop that did the original work. If your power or ground cable is not up to snuff, that would cause the same problem. You have decent gear...you should be able to make all the boom you want without anything shutting off.

Luke

[golde30]

my sub amp cuts off when I turn it up to 30 out of 33 on the volume (with gains on the amps set so the head unit can go the full range, almost)

Is the sub amp just cutting off because of the fail safe? The bass is clean up to when it cuts off. I guess that's a result of underpowering a sub?

i have this problem also, but it cuts off at like 25/40, and will come back on if i turn the headunit off/on again.

[warez1]

it could be a dead sub, you might have one dead coil

[assoutE12]

Any chance that your sub is dual 2 ohm? If so, that may be part of your issue. Unlikely though. JL doesn't sell too many dual 2 ohm subs.

Here are my recommendations:
Use a DVM to meter your voltage at the amplifier inputs. Rev your car to like 2000 RPM, and watch the voltage. Then, let the car idle and do the same.

You should never see above 16 volts, or below 11. I suspect your car is having voltage fluctuations beyond what your amp is happy with.

The chance of your head unit being the issue is slim, but it could happen.

Who did your install? You might want to take it back to the shop that did the original work. If your power or ground cable is not up to snuff, that would cause the same problem. You have decent gear...you should be able to make all the boom you want without anything shutting off.

Luke

I bought the head unit, a set of boston pros, and amp for those speakers from Kiefs, a local shop.
I bought the box with speaker (JL 10w3) from jordan.
I got the amp from my brother.
If I had bought it all from them I would just take it back and have them figure it out, but since I didn't I would rather figure it out and fix it myself. I'll hook up the volt meter next time I get a chance and try to get some pics. thanks for the help

[StereoInstaller1]

Cool, man. you do know I built your box, right? Jordo bought that sub from me, and I built that box after MUCH discussion. Great guy, but kind of a PITA to deal with...picky picky!

Luke

[assoutE12]

cool, I didn't know that. It's a damn fine box if I do say so myself, I still need to cut a whole in my parcel shelf for the port though.
it still sounds 50x better than the 12 I had had before.