I have a 96 maxima with an aftermarket system. Lately my sub and amp have been acting up. I have an old eclipse HU running into a MTX Xover then to an OLD auto tec400 amp and alumapro 12". The last few months the sub will not start making loud bass unless i put in a heavy bass cd and crank up the music for a few min, then it works fine. Any ideas what is amater with it? Maby wiring, HU, time to get a new amp etc? thanks

 

Did you try adjusting the gain on your amp?
Is your sub a DVC?

 

I messed with the gain on the xover and all it did was make it super loud when it eventually starts to work. I believe its a 4ohm single voice coil sub. The sub is older then the amp and was bouth 2nd hand. I dont have any other amps or subs to try and see if its the sub or the amp causing the problem.

 

Not sure how technically inclined you are but if you have a Digital Multi Meter (DMM) this may help. This will let you know if your amp is acting up.

1. For both scenario keep all setting the same, remember the volume settings for the readings you will be taking.
2. Set the DMM to measure AC Volts.
3. Put in a CD where the BASS note is considerably loud, a test CD is prefered, if you use a music CD make sure you remember the Playback time on the CD at which you started the BASS note and when it stopped.

Now you will need to take readings when your system is playing normal and when it looses the power.

4. Take the DMM and have the black on the (-) of the speaker out of the amp and red on the (+) of the speaker out of the amp.
5. With the bass note playing make note of the reading!

Assuming the last reading was taken with the system playing normal the next reading should be taken when the system looses the power it should have or vice verses.

6. Repeat steps 4 and 5.

If the readings when the system looses power is lower, this could be an indication your amp is on its death bed, however it could also be the pre-amp output of the HU acting up. If this is the case disconnect the RCA's coming into the amp for both scenario and check the voltage of the pre-amp outputs. The out part of the RCA is negative and the inside (male part) is the positive.

If you amp has the same reading on both scenario then it is possible your sub is going down hill.

 

i have a similar problem.. WHen the volume is low, the subs/amp don't play. I have to turn it up a little higher in order the the subs to work. I always thought it was the Pre-outs on my deck but never tried to figure it out.. btw i have a cheap Sony deck and a cheap amp. (might have something to do with it also)

 

Awsome info Dohcser! Ill dig the mutimeter out of the closet some time soon and check it out. I wouldnt be suprised at if one or more of the components was on its way to car audio junk heaven. The HU is now 6+ years old, has been installed in 3 cars, and has survived years of lowered suspention pounding and its share of car totaling accidents. Same goes for the sub and amp excpet they probably older because they were bought 2nd hand. If its the sub OR amp im probably just going to buy one of thoes package deals I always see in the bestbuy or CC flyers. Tnaks again a TON for the help.

 

Save your money and buy from a professional audio shop, atleast they will be able to give you expert advise.

Also if you think it is your HU, try to get a buddys car and get a long RCA connect it to his HU and attach it to your amp, this is a simple way to tell you if the HU is bad.