Buzzing sound in my radio ? Need sound advise, Link added to a car audio DIY Education |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Buzzing sound in my radio ? Need sound advise, Link added to a car audio DIY Education |
TC 914-8 |
Jun 13 2011, 10:30 PM
Post
#1
|
Senior Member Group: Members Posts: 812 Joined: 23-May 08 From: Sequim, WA Member No.: 9,090 Region Association: Pacific Northwest |
I was triing to clean up my center console the other day and moved my booster from inside the console to the outside, passenger side. once I did that I have a very loud and obnoxious buss in my raido. If I plug in and play my I Pod directly into the booster, no noise (IMG:style_emoticons/default/confused24.gif) . I have grounded the raido, booster, even went as far as grounding the sheilds of the RCA cables (and tried different cables) into the booster. That seemed to quiet it up a slight bit but still buzzes when the FM, CD is on.
I then went to raido Shack and picked up a noise supressor (inline capacitor) Still didn't help. I am begining to think Ignition or Alternator? Every thing was fine till I moved the booster from inside to the outside. This happened once before but not as severe, I just moved a few wires around and it went away. Any ideas?? Here is the link I found good for the DIY guy who knows enough to be dangerous. http://www.bcae1.com/ |
Mike Bellis |
Jun 14 2011, 11:09 PM
Post
#2
|
Resident Electrician Group: Members Posts: 8,345 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
Usually grounding the RCA's does more harm than good. You should only ground the radio side. But that can cause a ground loop and induce noise too.
I'm thinking you should move your booster (amp?) around and see if the noise level changes. If you have an old walkman. You can remove the tape head and extend the wires. Press play, put the head phones on and wave the head around your equipment. the head will pick up the source of your noise. You will hear the engine/alternator noise when you get the head close to the source. once you pin it down, make minor adjustments to the mounting, grounding , wiring until you hear a difference. I have a walkman setup for this from when I managed a car audio shop years ago. |
windforfun |
Jun 15 2011, 05:25 PM
Post
#3
|
Senior Member Group: Members Posts: 1,822 Joined: 17-December 07 From: Blackhawk, CA Member No.: 8,476 Region Association: None |
Usually grounding the RCA's does more harm than good. You should only ground the radio side. But that can cause a ground loop and induce noise too. I'm thinking you should move your booster (amp?) around and see if the noise level changes. If you have an old walkman. You can remove the tape head and extend the wires. Press play, put the head phones on and wave the head around your equipment. the head will pick up the source of your noise. You will hear the engine/alternator noise when you get the head close to the source. once you pin it down, make minor adjustments to the mounting, grounding , wiring until you hear a difference. I have a walkman setup for this from when I managed a car audio shop years ago. Excellent suggestion. I need one of these. Don't you mean that ungrounding the RCA phono connectors (or going to a floating chassis) will eliminate ground loops. The shielding must have zero current flow. (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/confused24.gif) |
Mike Bellis |
Jun 15 2011, 06:39 PM
Post
#4
|
Resident Electrician Group: Members Posts: 8,345 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
Excellent suggestion. I need one of these. Don't you mean that ungrounding the RCA phono connectors (or going to a floating chassis) will eliminate ground loops. The shielding must have zero current flow. (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/confused24.gif) some drain wires are shunted to the shield. When this is the case, a ground loop can form on the signal ground. The cheap thin RS RCA cables have very little shielding. These do not protect from EMF noise. I should ask what brand and how old is the radio? if the radio amplifier circuit board looses its ground, noise can happen as it uses the RCA shield as a ground path to the booster (amp). The RCA ground loop isolator can eliminate the noise at the cost of fidelity. At this point I would first consider splitting up the amp and radio ground wires and screw them seporately. sand the paint down at the connection point and drive a new screw into the chassis. You may have too much ground potential going through your existing connection. |
windforfun |
Jun 15 2011, 08:08 PM
Post
#5
|
Senior Member Group: Members Posts: 1,822 Joined: 17-December 07 From: Blackhawk, CA Member No.: 8,476 Region Association: None |
Excellent suggestion. I need one of these. Don't you mean that ungrounding the RCA phono connectors (or going to a floating chassis) will eliminate ground loops. The shielding must have zero current flow. (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/confused24.gif) some drain wires are shunted to the shield. When this is the case, a ground loop can form on the signal ground. The cheap thin RS RCA cables have very little shielding. These do not protect from EMF noise. I should ask what brand and how old is the radio? if the radio amplifier circuit board looses its ground, noise can happen as it uses the RCA shield as a ground path to the booster (amp). The RCA ground loop isolator can eliminate the noise at the cost of fidelity. At this point I would first consider splitting up the amp and radio ground wires and screw them seporately. sand the paint down at the connection point and drive a new screw into the chassis. You may have too much ground potential going through your existing connection. So the ground is floating? It is a car after all. BTW, what's a drain wire? |
Lo-Fi Version | Time is now: 1st June 2024 - 03:11 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |