I.C.E. Advice

[Bludger]

Following on from an earlier thread 22131, I have now wired up my Amp and Sub, but the sound is less than impressive.

When I have it wired as in the picture below, I seem to pick up a lot of background noise through the sub. When I put my foot down, the sub picks up the noise of the Turbo and Engine.

The sub is constantly pumping away like a heart beat (probably my own!) which shouldn't be happening, and the sound through the speaker is very low.

I have a few theories that I would appreciate anyone with Amp and speaker knowledge to tear to shreds and call me stupid (form an orderly queue please)

1. I have a bluetooth car phone kit which is wired to the stereo. Could the Amp be picking up interference from this?

2. The Earth wire isn't fitted properly?

3. The wiring is incorrect?

4. All 4 channels have to be wired up and operating?

5. The R Gain & F Gain are set too high

6. The Amp is $$$$!?

Any advice and suggestions will be greatfully received.

Thanks Peeps.

[mooter]

hmmm... for a start you're wiring the sub to the Rear Right channel only? I would probably bridge it across both rear channels - one on positive and one on negative. this should give you an overall sound, instead of just the right channel.

as for the sound interference it probably isn't grounded properly. check this handy pdf for some hints on solving the issue - http://www.installdr.com/TechDocs/999502.pdf

[Bludger]

hmmm... for a start you're wiring the sub to the Rear Right channel only? I would probably bridge it across both rear channels - one on positive and one on negative. this should give you an overall sound, instead of just the right channel.

as for the sound interference it probably isn't grounded properly. check this handy pdf for some hints on solving the issue - http://www.installdr.com/TechDocs/999502.pdf

Cheers for all that info. I'll give it a try at lunch.

Now, call me stupid, but are you saying I can simply wire the Sub in the following way

+ lead to Right Rear +, &
- lead to Left Rear - ?

I don't need to connect the RR- or LR+?

Does anyone know of a good place to ground the Amp? Don't want to drill the boot floor and have Diesel start flowing out!

Dave

[Bludger]

Just been out and checked all the wiring, done a few tests, and the result is that It's definitely the Ground lead not being connected well enough.

Which brings me to my next and final question.

"Where is a good grounding point in the boot?"

Thanks for all your help mooter.

Dave

[mooter]

can't help with a good grounding point but make sure you take your time and do as thorough job as possible - it makes all the difference later on. Perhaps you could use one of the bolt points that holds the chassis down? you know, one of the 6 bolts that has to be undone for a body-lift

and yeah, you're right on the sub and no, you're not stupid just connect one to right rear plus and the other to left rear negative. i think. it's been a couple of years since I wired a sub up!

[AndyLala]

Okey dokey...

Is it a $$$$ amp? Depends who you ask. It is more about the install than the quality of the products.

First thing to investigate... http://www.davidnavone.com/MutingPlug/Muting2.wmv

Build yourself a couple of these... to ascertain if the noise is in fact coming from the earth on the amp... the interconnects, or in fact the head unit (source).

Turn the amps on with these plugs inserted directly into the amps. Turn the gains up, rev the engine, turn on/off the lights, electrical accessories, etc. to see if the amp picks up any noise.

Plug your interconnects in, put these plugs in the other end of the interconencts, run through the same tests. Any difference, have the interconnects picked up any noise?

Plug the head unit into the interconnects, check again... (could be the earth on the head unit)...

You are now going to be working with 12v car batteries, make sure you are comforatble with this, because if you mess up, you could fry a component (head unit, amp, speakers, etc...)

Next is to measure the impedance between the head unit earth and the battery earth (what loss there is on the metal of the body between those two items). (NOTE: with both ends of the power cable and earth cable disconnected!) Measure the impedance between the amp earth and the battery earth. Compare this to the impedance of the amp power cable.

If required move the earth point until this measurement becomes as close as you can to identical.

Sometimes, we have earthed all the components (head unit, processor, amp) to the same point in the vehicle.

Where else could the noise be coming from:
http://www.termpro.com/articles/noise.html

Is your electrical system up to the demand...
http://www.termpro.com/articles/electsys.html

[dirtydog]

peel up the boot carpet im sure there is somewhere to ground too.. one of the tie down rings for example?
best to run power/RCA's down different sides of the car to try and help interference.

[da SLUG man]

1. why you bought a 4ch amp for 1 sub?
2. it doesn't have a low pass filter?
3. is it bridgeable anyway?


what power is it?... only a 10a fuse in it?

is it a cheap ported sub box off the market?. try covering the hole.

[AndyLala]

didn't see that...

10amps at 12v is no more than 120watts...

10amps at 13.8v is no more than 138watts...

Lets hope its a rather efficient sub...

[da SLUG man]

didn't see that...

10amps at 12v is no more than 120watts...

10amps at 13.8v is no more than 138watts...

Lets hope its a rather efficient sub...

that's the maximum power drain from the battery, not the power output.

most of it will be converted into useful heat , buzzing and a touch of electrickery!

[Bludger]

1. why you bought a 4ch amp for 1 sub?
2. it doesn't have a low pass filter?
3. is it bridgeable anyway?


what power is it?... only a 10a fuse in it?

is it a cheap ported sub box off the market?. try covering the hole.

Got a 4 channel Amp because I'll be adding a pair of 6x9's once the box is built (photos will follow)

It does have a Low Pass Filter - will this reduce any engine noise? It's picking up a good sound now that I've grounded the Amp to one of the tie down clips, but there is still some engine noise.

The instructions say it is bridgeable, but I'm something of a novice when it comes to ICE, so I'm still working out all the techno jargon.

It is just a 10 Amp fuse - could I put in a higher one?

I'm going to re-run the power and output leads to opposite sides of the car this weekend to see if it has any effect.

The Amp was just a cheap one from Germany off Fleabay, so I wouldn't expect concert hall sounds, and a bit of engine noise doesn't really bother me, because Pearl Jam usually drowns out all other sounds!!

Thanks for all your help. Will keep you all busy with more questions soon!

[dirtydog]

Cheers for all that info. I'll give it a try at lunch.

Now, call me stupid, but are you saying I can simply wire the Sub in the following way

+ lead to Right Rear +, &
- lead to Left Rear - ?

if its bridgeable as you say then yes do that you will get twice as much power going to the sub.

[Bludger]

if its bridgeable as you say then yes do that you will get twice as much power going to the sub.

Ok here's an odd question.

I've got some LED's lying about which I thought I could connect to the power supply so they come on when the Amp is on. Sounds very 'boy racer' doesn't it. I probably wouldn't leave them on, just thinking about the theory part at the moment.

Could I connect the LED's to the + terminal and GND terminal? Would the amp pick up 'noise' as a result?

Should I quit while I'm ahead?

[da SLUG man]

Got a 4 channel Amp because I'll be adding a pair of 6x9's once the box is built (photos will follow)
ok... thought about some components... no need for extra bass of 6x9s with a sub

It does have a Low Pass Filter - will this reduce any engine noise? It's picking up a good sound now that I've grounded the Amp to one of the tie down clips, but there is still some engine noise.

no, it means that only low frequency sounds will go to the speaker.


The instructions say it is bridgeable, but I'm something of a novice when it comes to ICE, so I'm still working out all the techno jargon.

It is just a 10 Amp fuse - could I put in a higher one?

NO!!

I'm going to re-run the power and output leads to opposite sides of the car this weekend to see if it has any effect.

The Amp was just a cheap one from Germany off Fleabay, so I wouldn't expect concert hall sounds, and a bit of engine noise doesn't really bother me, because Pearl Jam usually drowns out all other sounds!!

Thanks for all your help. Will keep you all busy with more questions soon!

and the LED thing... they'll come on all the time if you connect them to the +ve and GND

you need to connect them to the Amp Rem wirefrom head unit and the GND, perhaps use a relay as i'm not sure of the current on the amp rem wire.