I bought a Crunch P1400.4 a few days ago, and yesterday I found time to install it.
I got it all hooked up and tested it with my car off and it sounded great for how much I paid for it. It pushes my speakers harder than my 52x4 head unit, and there is very minimal white noise with the volume turned to 0.
BUT. Once I turned on my car, there was a high pitched whining sound that changes with engine RPM, and I have to turn the volume above 30 before it even masks the sound.
The speaker wires are ran down the left of my car, and the RCA/remote wire is ran down the right. To ensure that the RCA/speaker/power wires crossing was not my issue, I unplugged my 2 RCA cables that are ran down the side of the car and used a spare RCA cable I had lying around to run directly from the headunit to the amp right down the center of my car so there was nothing around it, and the noise still persisted.
SO.. right now I'm sort of stuck and I'm not sure whats causing this noise.
Its very annoying.
Any ideas?

 

It's the large toroidal transformers on the main board that make the noise, When they are cool or cold they vibrate/occsilate, But in most case when they warm up the vibration/noise dissappears It's not a fault or a problems.


Otherwise the ground wire seems to be the problem thats my problem right now

 

......ummmm....lets see could be power to close to the rcas....power wires should be 18inchs away from the rcas, could also be crappy rcas (try dual twist ones, will kinda look like thick shoe laces), also ground has some play in road noise and engine whine. You could try some ground loop isolators, or run a return ground.

 

my friends car has this prob also.

 

battery is in the trunk so its not power wires....

and I dobut its ground since it goes up and down with the engine rpms...

 

i know the battery is in the trunk, what i meant is that even the power wire running from the HOOD (jumper position) to the trunk area or even just thin electrical wires can cause engine noise on SHITTY rcas. Also could just be a bad amp!

 

I'm pretty certain that it is not my RCA's because I went out and spent nearly $70 on two 20' Monster cable RCA's.
Also, as I said before.. the problem persists even when a 5' cable is ran directly from the head unit to the amp through the middle of the vehicle.

But, as I said before, the amp sounds GREAT when my car is turned off so that leads me to believe that it is not a wiring problem or a problem with the amp (however it could still be a problem where one of the RCA cables is too close to a fuel pump or something else that can cause interference). As soon as I turn it on, however, the annoying whining sound begins and I can still hear it for about a second after I turn my car off.

SO.. after all that.. I have been lead to believe that my alternator is feeding some sort of noise in through the power lead thats causing the problem. Is this possible and if so, is there any way to get rid of it?

Finally.. I would just like to say that I tried grounding the system directly to the battery and on multiple different spots on the chassis and there was absolutely no change in the whining.

 

have you tried a different amp....hate to say it , but would rull out one thing!

 

damn all this arguing. well lets get it out of the way crunch makes shitty ass amps. now lets try and fix the issue. listen to CTC check ur amp ground, if possible ground straight to the battery. sounds like the rcas are fine assuming they are ran on the passenger side as u stated... so don't worry about them

lastly what kind of deck do you have? it wouldn't happen to be pioneer would it?

 

I did check the ground, and I did try grounding straight to the battery.

And yes, my head unit is a Pioneer which I was told is notorious for making background noise.

After doing a little research, I found out that:
1) Since my headunit is a Pioneer, grounding my RCA's/RCA shielding should resolve some of my issues
2) A ground loop is probably my biggest issue, because it is creating a potential difference between the headunit/amp which is allowing the alternator to introduce sound into the system. I have to ground my head unit to the same point as the amp.

I'm going to try doing these two things here soon and see if it clears up the sound issue.

 

thats what i said to do....a return ground!

 

do you have the amp sodered? dose your ground have a good connection with a connector? its probly your ground honestly

 

After like 3 hours of messing with this stupid thing today, I finally got it fixed.
I ran the return ground, grounded the RCA cables shielding, and wrapped wires around the RCA outputs which were then grounded to the body of the head unit. The return ground helped a little, but not much, and grounding the RCA outputs completely fixed the problem.
There is still a VERY slight whine which is masked by the music when the music volume is around 7 or 8, but it is much better than it was before!
Thanks for the help!

 

is it just me... or do the "crunch" amps kinda sorta look like, and have model numbers similar to RF's "punch" amps.

 

yup its all pico fuse. grounding the rcas isnt a real solution but it works for the most part. if u want to pull the unit apart to replace said fuse go for it but otherwise u should be good to go




how do u figure they look alike? model numbers ya looks no

07-09 RF punch

06 RF punch

04-05 RF punch

02-03 RF punch

01 RF punch

96-00 RF punch

 

Oh you missed the best ones




And to be honest they look more like these:


But thats about all they have in common

 

sorry spun the DSMs were like 91-95 or something... i wasn't sure how far back i needed to go. i figured 96-09 (13yrs) was enough examples. honestly if u looked hard enough u could find plenty of amps that look similar. same thing i did with cars to some dumb **** talking **** about gm's "looks" a while back

plus theres alot of rip offs. example the new power acoustick bamf is a rip off the the 07-09 rf power amps, and the kole kx series is a rip off of the 04-08 power elite amps

 

try turning gains down....if this was said sorry way to lazy to read it all

 

i was thinking of a different looking amp than the crunch you showed. i could be mistaken, but the ones i was thinking of, looked a lot like the old chrome style ones.

 

could you maybe post some pics of how you grounded those RCA outputs? I have this EXACT problem with the whining that goes up and down with the engine noise. I use an Infinity a475 i think it is, and all 4 Infinity speakers plus another amp and subs. (didn't have the issue before the Infinity amp) But I've been back and forth to the BB that installed the sucker, and he keeps telling me different things. First it was the power and RCA wires too close together, which was his first choice, so he ripped it all out and re-ran it but it did not stop the whine. So he told me that it's probably the harness still being factory, so I needed to get a new head-unit. that's on the to-do list, but if what you've done makes it a lot quieter, than I'm all for that. Any help would be GREATLY appreciated, the stupid noise is freakin annoying.

 

grounding the rca only works with aftermarket pioneer units

 

aww boo :'( I want this damn noise to STOP!! Emp do you think the harness could be the problem, me and the BB guy, who I respect since he fixed the first 3 screw-ups from the first BB guy, can't think of anything else it could be.

 

what harness? why would you have a harness?

 

this is just what he told me. He told me that because my HU is stock, the factory harness is still there, and that's the only thing he can think of that's causing the whine. I know I don't have a clue, but I do know that I can't have the gains up as high as they should be cause the stupid whine gets worse when you do that.

 

ok the stock HU and stock harness don't help but not inehrantly an issue

have you tried swapping out the LOC? possibly getting one with a ground and grounding to the same point as the amps. Where is the power and ground wire going to in the car? any pics of the install?