Audiocontrol ESP-2 Installation help [engine noise]

[_H4cK_]

I have setup my ESP-2 already, but for some reason am getting some annoying engine type noise coming from my speakers now. I have tried changing the audio jacks but nothing changes, the only think I could do was turn the gain down on the amp to an acceptable level to cut out the noise, but as a result it kills the total performance of the system. I also tried grounding the RCA's but that didn't help. Do you guys have any other suggestions as to what might be wrong?

The system works fine w/o the ESP-2 and I have tried another unit in the car and it does the same thing, so the problem is not the ESP-2. I was thinking maybe it was the amp, but I'm not sure, it works fine on it's own...

[nigel1977]

flip open the esp, and switch the ground jumper from iso to ground.

basically that jumper grounds the rcs's sheild to chassis ground.
if that doesnt help, there is something else wrong.

[trini_ravi]

^^^ yup that what i like about audiocontrol products...

[_H4cK_]

flip open the esp, and switch the ground jumper from iso to ground.

basically that jumper grounds the rcs's sheild to chassis ground.
if that doesnt help, there is something else wrong.

nope that didnt help....

[greenman]

i had that problem with a audiocontrol four.1... n to fix it, i changed the ground jumper inside the unit and i also changed the jumper from balanced to unbalanced input....... I also had my rca's grounded on the chasis.

[_H4cK_]

when you say change the ground jumper, you mean switch it over right? Done that.
I also tried grounding the rca's to the chassis...nada


I was told that the amp would be causing the problem, but I havent had the chance to change it

[nigel1977]

if grounding the rca's chassis doesnt help, its not a ground loop issue, nor its a damaged internal ground on the deck.

you mentioned you turn the gains down on the amp... where do you usually have them?

gains are designed for level matching. the esp usually goes before another processor.
depending on the output of that processor, you need to level match the amp. i suspect the gains may be a tad too high.

[_H4cK_]

well I would normally have the gains about 3/4 way (maybe a bit lower), but now I have had to put them down below half.

Here is how mine is setup:

Head Unit ---> Epicentre ---> ESP-2 ---> Amp

[nigel1977]

the epicenter has up to 10volts line drive. your amp gains therefore should at be either very low, or at zero.

[Lance]

whats the input sensitivity on your amp?

[_H4cK_]

the epicenter has up to 10volts line drive. your amp gains therefore should at be either very low, or at zero.

should I bring down the level of the line drive? I think its on 7.5 (its been years since I opened it, cant remember)

whats the input sensitivity on your amp?

What do you mean?

[Lance]

You positive its engine noise?, you getting only when the car is on?

Every amp has an input range which it will allow for the signal drive

for example your amplifer may have a range of 500 mV to 4 V input,
and the Signal drive coming out of your ESP could be maybe 7-8V.

[_H4cK_]

actually im getting the noise with engine off too...hmmm


I think the amp is a Kenwood 748 series, not sure of the input range..

[_H4cK_]

http://www.crutchfield.com/S-drp0S7K26Q ... =113KAC748

[nigel1977]

Definately sounds like too much gain.
If youre sure the epicenter's output is set to 7.5v, then you need to drop the amp gain to ZERO. According to the owners manual, the input range is 0.15 - 4.0v. youre already overdriving the amp, so drop the gains all the way down.

[_H4cK_]

well im not using this amp for bass, dunno if this makes a difference. But what I find is that if I put down the gain on the amp, and well I have to lower that on my monoblock too, I end up having to put the volume on the deck right up...I mean past 1/2 way for me to feel satisfied. I normally will never go past 25-26 on my deck, and this is the max, normally I will play it at about 15 ( no I dont like LOUD music, prefer clarity ) . BTW I use a Pioner DEHP-760MP

[Lance]

I must ask you something

can u ever pass 25-26 or your music starts to distort? if so then this is another indication that your gain is too high,

You should always use the deck's full bandwidth.


your gains are definately too high, lower them or else you will eventually have some damaged equipment.

[_H4cK_]

it will start to distort at about 35. So is it bad to have it setup so that I don't have to raise the volume on the deck too much or should I just "use the full bandwidth" of the deck because I can....?

[Lance]

you run the risk of damaging your equipment,

your gains will be too high as what is happening right now, the Amp will be overdriven, your amplifier will clip at around that 35 mark or even before, if you for some reason cross 35, massive clipping and distortion will occur and it will damage speakers/subwoofers.

from my limited experience, using the full bandwidth of the deck usually results in a much cleaner sound and greater control over your system.

Alot of people do what you are doing now, I think its a Ego thing, they rather have there volume max at 20 for the reason they can tell the padnas that it only on Vol 20. but whats the sense if its on 20 and you max at 22 and you clip at 23 and your equipment is destroyed at 24.

[_H4cK_]

makes sense...

I'm going to sit down today and play with all my gains etc see what I come up with. What about the voltage on the epicentre, should I leave it as is?

[nigel1977]

i would back it down to 5v.