Cellphone interference in car speakers - Team-BHP

ozzyrules · 13th April 2008, 00:06

To the Gurus:
I got my ICE setup for my Swift diesel recently and discovered that there is a lot of cellphone interference through my speakers.
After trying(unsuccessfully I must add) to identify the cause, I took the car to my installer (Sound Factor) and surprise, surprise, there was no problem at all and everything seemed normal. I took couple of spins with the installer and after looking quite stupid, I dropped him back and made my way back home grumpily. And again, it happened...the irritating sound (like the one you get when your cellphone is close to your landline) was back. After spending more time trying to troubleshoot, here's what I've discovered:

the interference occurs in all source modes i.e tuner, USB, CD.
engine running or not does not have a bearing on the interference (happens in both states).
bluetooth on or off also does not affect the interference (happens in both modes).
I just now found out that the interference happens when the cellphone is close to the HU or placed on the front co-passenger seat. If I leave the cellphone in my pocket or near the driver side door, then there is no interference.

I've never had this problem before in my earlier cars or in other cars that I've travelled in. My ICE setup includes a Pio 5090 HU, JBL GTO 607c components, and JBL GTO 637 coaxials at the rear.
My cellphone is a Nokia 6151 and am on an Airtel connection.
Any inputs on solving this problem will be greatly appreciated!!

DerAlte · 13th April 2008, 12:25

This is likely to happen with any HU
* when a call is active
* when a call is being connected or disconnected
* if GPRS is on and there is data activity

Did you check by actually trying to make a call when you were testing?

Solution? The simplest is to keep the handset away from the HU. Also, check the grounding of the outer shell of the HU.

ozzyrules · 13th April 2008, 14:01

Thanks DerAlte
Yes, I did try making a call while I was testing.
The interference occurs when a call is about to come in or when a number is being dialled. After connectivity, the interference goes away.
The closer the handset is to the HU, the louder the interference.

Quote:

Originally Posted by DerAlte

Did you check by actually trying to make a call when you were testing?

Solution? The simplest is to keep the handset away from the HU. Also, check the grounding of the outer shell of the HU.

How do I check the grounding of the HU? Will the installer help me with this or will I need the help of an electrical guy?

shyamhegde · 14th April 2008, 16:43

Quote:

Originally Posted by DerAlte

This is likely to happen with any HU
* when a call is active
* when a call is being connected or disconnected
* if GPRS is on and there is data activity

Also when the phone changes/switches the cell tower.

ozzyrules · 14th April 2008, 22:54

Found quite an interesting article after some Googling:
macosxhints.com - How to prevent iPhone audio interference in speakers

The suggestion is to use some aluminium foil behind the cellphone to prevent the interference.
I tried that and voila, it worked!! Also, juggled with removing and replacing the aluminium foil. The interference was not audible as long as the aluminium foil was behind the handset, and came back as soon as I removed the foil.
The HU in my previous car was a Sony 5500 (I think...) and it had an aluminium trim around the border. Maybe that was what prevented the interference. My current HU is a Pio 5090 and has no aluminium trims.
It would be interesting to know from fellow T-BHPians their experience of HUs with/without aluminium trims with regards to cellphone interference.

mithun · 30th April 2008, 21:14

I never had any cellphone interference in my Pio 2950 when using any of the cellphones.

Did you try using any other cellphones other than Nokia 6151 ?

ozzyrules · 1st May 2008, 00:00

Quote:

Originally Posted by mithun

Did you try using any other cellphones other than Nokia 6151 ?

Yes, I've tried a MotoSlvr and couple of other cellphones. Same problem. Interestingly, a co-worker at office has the same HU in an Alto and faces the same interference problem. Quite weird

Will try visiting my installer over the weekend for any possible solution.

Jaggu · 1st May 2008, 00:29

If you have the habit of leaving the cell phone on the dash, under the HU (on the double DIN space) this will happen, look at the bright side, i use this to intimate myself, of incoming calls

13th April 2008, 00:06	#1 (permalink)
ozzyrules Newbie Join Date: Mar 2008 Location: Bangalore Posts: 8	Cellphone interference in car speakers To the Gurus: I got my ICE setup for my Swift diesel recently and discovered that there is a lot of cellphone interference through my speakers. After trying(unsuccessfully I must add) to identify the cause, I took the car to my installer (Sound Factor) and surprise, surprise, there was no problem at all and everything seemed normal. I took couple of spins with the installer and after looking quite stupid, I dropped him back and made my way back home grumpily. And again, it happened...the irritating sound (like the one you get when your cellphone is close to your landline) was back. After spending more time trying to troubleshoot, here's what I've discovered: the interference occurs in all source modes i.e tuner, USB, CD. engine running or not does not have a bearing on the interference (happens in both states). bluetooth on or off also does not affect the interference (happens in both modes). I just now found out that the interference happens when the cellphone is close to the HU or placed on the front co-passenger seat. If I leave the cellphone in my pocket or near the driver side door, then there is no interference. I've never had this problem before in my earlier cars or in other cars that I've travelled in. My ICE setup includes a Pio 5090 HU, JBL GTO 607c components, and JBL GTO 637 coaxials at the rear. My cellphone is a Nokia 6151 and am on an Airtel connection. Any inputs on solving this problem will be greatly appreciated!! __________________ *Honk only if u're horny*

13th April 2008, 12:25	#2 (permalink)
DerAlte Team-BHP Support Join Date: Mar 2007 Location: Bangalore Posts: 1,915	This is likely to happen with any HU * when a call is active * when a call is being connected or disconnected * if GPRS is on and there is data activity Did you check by actually trying to make a call when you were testing? Solution? The simplest is to keep the handset away from the HU. Also, check the grounding of the outer shell of the HU. __________________ Never believe it cannot be done - it's only that you haven't found out how!!!

14th April 2008, 22:54	#5 (permalink)
ozzyrules Newbie Join Date: Mar 2008 Location: Bangalore Posts: 8	Found quite an interesting article after some Googling: macosxhints.com - How to prevent iPhone audio interference in speakers The suggestion is to use some aluminium foil behind the cellphone to prevent the interference. I tried that and voila, it worked!! Also, juggled with removing and replacing the aluminium foil. The interference was not audible as long as the aluminium foil was behind the handset, and came back as soon as I removed the foil. The HU in my previous car was a Sony 5500 (I think...) and it had an aluminium trim around the border. Maybe that was what prevented the interference. My current HU is a Pio 5090 and has no aluminium trims. It would be interesting to know from fellow T-BHPians their experience of HUs with/without aluminium trims with regards to cellphone interference. __________________ *Honk only if u're horny*

30th April 2008, 21:14	#6 (permalink)
mithun Senior - BHPian Join Date: Jan 2006 Location: Cochin/Bangalore Posts: 1,130 View My Garage	I never had any cellphone interference in my Pio 2950 when using any of the cellphones. Did you try using any other cellphones other than Nokia 6151 ? __________________ Hold fast to dreams, for if dreams dry, life is a broken-winged bird that cannot fly.

1st May 2008, 00:29	#8 (permalink)
Jaggu Team-BHP Support Join Date: May 2004 Location: Bangalore Posts: 4,198	If you have the habit of leaving the cell phone on the dash, under the HU (on the double DIN space) this will happen, look at the bright side, i use this to intimate myself, of incoming calls __________________ The strength to change what I can, the inability to accept what I can't, and the incapacity to tell the difference. -Calvin

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