losing bass

[chris661]

Wait, the voltage on the amp drops to 12v when the bass goes.

That must mean something to someone. (I mean, I'm thinking internal resistances of batteries and potential dividers, but that'd indicate huge currents...)

 

[Perry Babin]

Does the dome light in the vehicle dim when the voltage drops to 12v?

Drops from what voltage to 12v?

Did you have the meter's probes directly on the amplifier's B+ and ground terminals?

 

[fridgidy]

The bass is normal when I first put the car on and if I put it around 1/2 volume the bass starts going a little less and more over and over it pretty much does it all the time now. When it works it seems to be around 14.25v or so and then it went around 11.9v when it would be messing up. I had the positive probe directly on the b+ and I was grounding the negative to the car.

 

[Perry Babin]

Does the dome light in the vehicle dim when the voltage drops to 12v?

 

[jacampb2]

I say check your ground, not just a quick visual inspection like you have done, remove the ground terminal from the chassis where ever it is bolted down, and look at the underside to see if there is evidence of arcing, pitting, and over heating. If it is okay, and actually, even if it isn't, what size power and ground wire are you using?

Later,
Jason

 

[fridgidy]

I don't know for sure if the dome light was dimming cause its always during the day that im working on it but I haven't noticed. I will check out the ground thoroughly and see if anything is out of ordinary. I'm using 1 gauge power and ground wire.

 

[Perry Babin]

It's important to know whether the amp is drawing excessive current (causing the voltage drop) or if there is a bad connection causing the voltage to drop. If the dome light dims when the bass drops, the amp is likely drawing excessive current. If it doesn't, it's likely that a bad connection is causing the voltage to drop.

 

[fridgidy]

ah ok I will play it for a bit maybe at night and see if it dims.

 

[luka]

don't need night to see, when you get 2v drop, light dimmes a lot!

 

[fridgidy]

Ok my voltage was at 11.88v on my meter and the dome light wasnt dim at all. I also checked my ground wire and evrything seems normal no signs that anything was a problem ever with the connection.

 

[fridgidy]

I'm thinking more and more its something wrong with my power wire since the voltage going to the amp drops all the time. See if there are any breaks or maybe just replace it and see. Sound like a good idea?

 

[Perry Babin]

With a meter, you should be able to find the problem. Start by comparing the voltage measured DIRECTLY across the battery terminals when the bass is high and low. Do the same DIRECTLY across the B+ and ground terminals of the amp. If the voltage is significantly different between the battery voltage and the amp voltage, you may have a problem.

As a side note, I don't think that Rockford amps lose bass when the voltage drops unless it goes low enough for the amp to shut down.

 

[Arty]

question, when you go over a bump and bass is lost, could you stop with your car, switch OFF the music, and mesure the B+ voltage?

supposedly if the voltage does indeed stay dropt, then its not a aproblem related to the amp it self.

 

[fridgidy]

The voltage drops all the time I don't have to be driving but I can try this anyways and see if it stays low.

 

[fridgidy]

Today I mesured the voltage at the battery connection and at the amp connection of the power wire and the voltage stays pretty much the same is about 12.05 at battery and 11.9 at amp. Maybe I was mesuring it wrong awhile ago when I had got 14 and touched the nods or something. I could here the bass coming on and off while I was doing the mesuring and the voltage stayed the same. I don't know what it could be next.

 

[Perry Babin]

If you were to play a constant test tone, would it do it often enough to be able to measure the AC voltage across the speaker terminals when the bass is normal and when it's reduced?

Does the bass drop even when played at moderate or low levels?

 

[fridgidy]

it does it all the time low and moderate volume also. I'm sure I could mesure it.

 

[Perry Babin]

Do you have a disc (or other source) with test tones?

 

[fridgidy]

Well I have my ipod connected to my head unit so I can pout some on there I usually get them on realm of excursion website

 

[fridgidy]

you mean at the connection of my sub speaker wires to my amp right?