[afsar]

If you want to have shielded rca hu to amp cable for your wiring to mitigate any noise then where do you guys connect shield to? Ground at both the ends? or leave it disconnected?

[alexwhittemore]

Originally Posted by afsar

If you want to have shielded rca hu to amp cable for your wiring to mitigate any noise then where do you guys connect shield to? Ground at both the ends? or leave it disconnected?

Chassis ground, and connect only at one end (probably the originating end is best).

That said, it's probably pretty pointless with fully differential twisted pairs, as in the OEM wiring. The only noise I've ever heard is some engine squeal, and that's only at super high volume (listening to quiet talk radio from the iPhone) and it wouldn't be helped by shielding.

And that's with an iPhone running LTE full blast, sometimes many at various locations in the car (passengers). If anything were going to cause noise that could be mitigated by shielding, it'd be cell phones.

[ctuna]

There is no problem with the twisted pair setup.
Its designed to suppress noise .
If you have an amp or processor that accepts the signal you shouldn't
have a problem .
The problems I have seen on noise here generally are a bad grounds, bad head unit ,or
non compatible amp and gains set wrong.
If you have and RCA connected to a radio output the shield
is a live signal.
The Jl audio amps auto detect this and use the signal accordingly.

[afsar]

In my case output is BMW CIC in hifi coding, I am in process of tidying up the wiring a bit so got rid of old transparent ones (it was different requirement then) and laying new wires, now since they are brand new wiring I thought I would go for shielded ones, also the signal is low level so doesn't need thick gauge wiring.

Normally for shields cic gives dedicated pins (like for all fbas signal) so was wondering where can I connect newly laid cable's shield. Thanks for the answer guys, I would club them all up and connect to the cic chassis, better then leaving then dangling.

[makkan00]

Originally Posted by ctuna

There is no problem with the twisted pair setup.
Its designed to suppress noise .
If you have an amp or processor that accepts the signal you shouldn't
have a problem .
The problems I have seen on noise here generally are a bad grounds, bad head unit ,or
non compatible amp and gains set wrong.If you have and RCA connected to a radio output the shield
is a live signal.
The Jl audio amps auto detect this and use the signal accordingly.

What he said

[makkan00]

Originally Posted by afsar

In my case output is BMW CIC in hifi coding, I am in process of tidying up the wiring a bit so got rid of old transparent ones (it was different requirement then) and laying new wires, now since they are brand new wiring I thought I would go for shielded ones, also the signal is low level so doesn't need thick gauge wiring.

Normally for shields cic gives dedicated pins (like for all fbas signal) so was wondering where can I connect newly laid cable's shield. Thanks for the answer guys, I would club them all up and connect to the cic chassis, better then leaving then dangling.

If
- your amp accepts differential balanced input
- you are using shielded twisted pairs
- coded to hi-fi
- not using LOC
- Proper earth

then you should not have any noise.

You do not need to earth anything. Cure the things only, if you have problems.

[ctuna]

If you extend the RCA cable with balanced signals
do not allow the shields to touch each other as they are live seperate signals.
It would be a good to insulate them with some tape .
Some RCA extension cables have insulated shields some don't.

[taibanl]

Originally Posted by afsar

In my case output is BMW CIC in hifi coding, I am in process of tidying up the wiring a bit so got rid of old transparent ones (it was different requirement then) and laying new wires, now since they are brand new wiring I thought I would go for shielded ones, also the signal is low level so doesn't need thick gauge wiring.

Normally for shields cic gives dedicated pins (like for all fbas signal) so was wondering where can I connect newly laid cable's shield. Thanks for the answer guys, I would club them all up and connect to the cic chassis, better then leaving then dangling.

Are u wiring from front or only from amp area

[afsar]

Originally Posted by taibanl

Are u wiring from front or only from amp area

All the way from CIC to the boot mounted MS-8.

[Technic]

Originally Posted by afsar

If you want to have shielded rca hu to amp cable for your wiring to mitigate any noise then where do you guys connect shield to? Ground at both the ends? or leave it disconnected?

No need for any shielding with HiFi:

[taibanl]

Originally Posted by afsar

All the way from CIC to the boot mounted MS-8.

Originally Posted by Technic

No need for any shielding with HiFi:

For what its worth. I have been working on my noise issue with VP-Electricity and we suspect I am picking up noise along the harness run due to lack of twisted pair in the technic harness.

If you run twisted pair RCA you should be ok.

[makkan00]

What he said.
I ran normal wires in my first upgrade with hi-fi coded hu and picked up noise.
So I ran shielded + twisted pair of rca in 2nd upgrade and never had any issues since then.

[afsar]

Originally Posted by makkan00

What he said.
I ran normal wires in my first upgrade with hi-fi coded hu and picked up noise.
So I ran shielded + twisted pair of rca in 2nd upgrade and never had any issues since then.

Exactly, previously I had "stereo" coded going directly into amp thru loc and massive irritating alternate whine was the result. Ground was all good as far as I could see. Now I want to avoid that situation again.

Btw. does all shielded wire come as twisted pair inside, what sort of guage wires do you guys go for and with what kind of sheild (braided metal or foil)

[makkan00]

Afsar
Not all of them are twisted pairs and shielded.
I have used different brands on my car and I prefer;
1- Audison twisted / shielded (£25)
2- Knukonceptz twisted / shielded (£20 delivere)

Actually few days ago I sold 4 channel Knukonceptz at a bargain price. I guess you hardly visit UK classified.

There are cheaper stuff out there but would not go for them.

[taibanl]

Originally Posted by makkan00

Afsar
Not all of them are twisted pairs and shielded.
I have used different brands on my car and I prefer;
1- Audison twisted / shielded (£25)
2- Knukonceptz twisted / shielded (£20 delivere)

Actually few days ago I sold 4 channel Knukonceptz at a bargain price. I guess you hardly visit UK classified.

There are cheaper stuff out there but would not go for them.

Isn't ordinary non-shielded twisted pair sufficient?

[makkan00]

Not sure about your side of the continent but here in Uk, there is not a lot of difference in the price of both, so opted for shielded.
Shielded gives it another level of protection from any interference.

From different experiments, I have noticed that sub frequencies are least likely to pick any noise.
Since I am running 4 way active system, therefore I selected 4 different pairs of rcas.
One is Audison, two different types of knoukonceptz, and ordinary untwisted pair.
Last is used for sub frequencies.
All the installation which I do, I run a track of black noise to make sure there is 0% noise in the sound system.
So far it has worked 100%.