BIG PROBLEM with my system! SO weird. Please help!

[Hifonics]

So I was driving along last week and all of a sudden the bass seemed lower... Then all of a sudden it got loud (normal) again. A few days later it happened more and more frequently. Now it's just playing at the low volume setting and doesn't flicker back to being loud at all.

List of components:

-Crescendo BC3500 (power and ground coming from the 2nd battery)

-2nd battery in the back (hooked in parallel to the front battery and grounded to the chasis).

-Pioneer AVH-P3300BT radio with 3 pre-outs @ 4v

-Older 18" AA mayhem

I started my troubleshooting by checking voltage to my 2nd battery, which was resting fine at 13.0v with the car off and 14.5v with the car on. Then checked the grounds... seem fine. Checked to see if I had any protection lights on the amp, none were one, only the power light. Tried disconnecting my bass knob, no change.

Checked Radio settings, which were the same as before... unchanged.

So then I thought maybe my RCAs are pinched... so I replaced those today with brand new ones. No change.

I checked the Ohm load on the amp from the sub and it was reading 1Ohm with the amp off. When I turn on the amp at 0/40 (muted) volume, I get an Ohm load of 25Ohms... is that normal?

I'm out of ideas here. I don't know if it's my amp. sub, or radio that's going. My amp is just past the warranty period and I'm really hoping it's not dead since it was quite expensive. I can still get the amp to play really loud on DECAF, but I just have to crank the bass knob all the way, whereas before I was just turning it half way to get the same results.

Any ideas guys?

[bman8891]

I had that problem with an saz 3500d. Mine was the rca jacks on the amp. Wiggle them and then they would work.

[ShadeTreeMechanic]

That happened to me one time when one of my 15s got stuck. I "unstuck" it but it would not play unless cranked up. LOL! Is your sub DVC? Maybe a bad coil? Do not check resistance with power applied. It will kill your meter. Disconnect the speaker wires and check the speaker.

[3vil]

And when you're testing each voice coil, don't just out the meter on it and call it good. Gently push and pull the cone in and out and see if the resistance changes. I once had a mostly broken tinsel lead, coil would read 2Ω and would increase as you pressed in, but if you pressed the cone it would hit break the tinsel connection and read 0.

[Hifonics]

Sorry I missed your previous post so I had to edit this. I will check the resistance with your advice.

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My woofer is DVC dual 2ohm, coming out to a 1ohm load right on the dot as per my DMM.

I also replaced my RCAs and made sure that they were properly installed. I wiggled them on both ends as well (at radio and at amp).

I'm starting to think the radio is failing to send a full signal to the amp via its subwoofer RCA jacks... has anyone seen this happen before? It's definitely not the amp because I can get it to play loud if I turn the gain up more.

[Hifonics]

UPDATE:

I was working on troubleshooting this issue and I decided to mess with the gain on my amp... With the system off, I moved the gain to the max position, then min position, then back to where it was and now the issue is gone. That's messed up right there. I have never seen this before.... anyone have any ideas?

I also noticed that one of my RCA terminals on my amp is loose. I don't think it's causing the issue because I was wiggling it while playing music and there was no noticeable change from volume output.

[3vil]

It's possible that the potentiometer for the gain control is fucked up.

[x infektid x]

try a professional type of cleaning spray like deoxit and see what ya get.it works very well for me on all my dj stuff like knobs, sliders and what ever . http://store.caig.com/

[Hifonics]

I'm pretty sure my amp is out of warranty so I'll just wait to see if the issue comes back... if it does I'll send it in for repairs.

I'll try that cleaning spray. Thanks x infektid x.

Thanks to everyone who helped as well.