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Discussion Starter · #1 ·
I bought a a/v component switch for my pc cause i actually have two pc's and a xbox 360 and ps3 and only one set of speakers for all those. I figure i would just use a a/v switch to swap between them for the audio. Ps3 and 360 connect to computers monitor through hdmi switch and i have the audio going out through rca cables to the av switch. The monitor doesn't have audio out btw. Well I figured this would solve everything but what i noticed is i was getting a feedback noise when i got either pc selected. It's very annoying, it doesn't happen if I have have one pc connected to the switch and the line out to the speakers. If i connect any other device to the switch i get the sound. It happens with either pc connected to it. I bought a new switch thinking it was a bad a/v switch yet the problem is still there. I figured a/v switches would cut off other devices when they aren't selected so im not sure where this feedback is coming from. It also happens if i switch out the speakers for headphones. Ive tried connecting and unconnecting devices to the switch multiple times, different combinations but it's always there. This is very disappointing, any ideas what's causing this?
 

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Quote:
Originally Posted by morpheus305  /t/1470006/hum-from-a-v-component-switch#post_23246806


I bought a a/v component switch for my pc cause i actually have two pc's and a xbox 360 and ps3 and only one set of speakers for all those. I figure i would just use a a/v switch to swap between them for the audio. Ps3 and 360 connect to computers monitor through hdmi switch and i have the audio going out through rca cables to the av switch. The monitor doesn't have audio out btw. Well I figured this would solve everything but what i noticed is i was getting a feedback noise when i got either pc selected. It's very annoying, it doesn't happen if I have have one pc connected to the switch and the line out to the speakers. If i connect any other device to the switch i get the sound. It happens with either pc connected to it. I bought a new switch thinking it was a bad a/v switch yet the problem is still there. I figured a/v switches would cut off other devices when they aren't selected so im not sure where this feedback is coming from. It also happens if i switch out the speakers for headphones. Ive tried connecting and unconnecting devices to the switch multiple times, different combinations but it's always there. This is very disappointing, any ideas what's causing this?

Is the noise you are getting like a loud low hum?
 

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Quote:
Originally Posted by morpheus305  /t/1470006/hum-from-a-v-component-switch#post_23251087


I wouldn't call it low as in bassy but a hum is about right. It sounds like some feedback of some sort. Im surprised by it tbh and really want to get rid of it.

Hum is usually caused by grounding problems. It is probably not feedback, because feedback usually shrieks.


Placing one of these in the audio signal path from one or both of the PC's should help:

http://www.radioshack.com/product/index.jsp?productId=2062214

 

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Discussion Starter · #5 ·
Well i bought 2 of these http://www.monoprice.com/products/product.asp?c_id=108&cp_id=10844&cs_id=1084402&p_id=6909&seq=1&format=2 and received them today. Hooked them up anddddddd the noise is still there
For all those wondering what the sound sounds like. It's basically the same sound you hear when you turn speakers up loudly with nothing playing but for some reason with a/v switches every time i hook up a device to it gets louder and louder so it becomes noticeable even at regular listening levels. I have to a/v switches and it does it on both. Any help would be appreciated.
 

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Quote:
Originally Posted by morpheus305  /t/1470006/hum-from-a-v-component-switch#post_23272252


Well i bought 2 of these http://www.monoprice.com/products/product.asp?c_id=108&cp_id=10844&cs_id=1084402&p_id=6909&seq=1&format=2 and received them today. Hooked them up anddddddd the noise is still there
For all those wondering what the sound sounds like. It's basically the same sound you hear when you turn speakers up loudly with nothing playing but for some reason with a/v switches every time i hook up a device to it gets louder and louder so it becomes noticeable even at regular listening levels. I have to a/v switches and it does it on both. Any help would be appreciated.

At this point, you need to document your entire system to us with lists of all relevant components and a wiring diagram.
 

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Quote:
Originally Posted by morpheus305  /t/1470006/hum-from-a-v-component-switch#post_23277325


I have this switch Sima switch with two 3.5mm female to rca male adapters for both pc's. I bought two of these 4 Channel Ground Loop Isolator but they didn't help out at all. Here's a rough diagram of my setup.

To diagnose your problem, test in a logical way.


Remove the input cable from the speaker. Power it up. Does it hum?


Remove all cables from the switch.


Plug it into the speaker. Does it hum?


Add one component at a time until the hum starts.
 

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Discussion Starter · #9 ·

Quote:
Originally Posted by arnyk  /t/1470006/hum-from-a-v-component-switch#post_23277435


To diagnose your problem, test in a logical way.


Remove the input cable from the speaker. Power it up. Does it hum?


Remove all cables from the switch.


Plug it into the speaker. Does it hum?


Add one component at a time until the hum starts.

The hum doesn't get bad until you add a 2nd input device to the switch. Doesn't matter what it is or which input it is. Any of the 4 devices will do it if even one of the other devices are hooked up to switch. Now if it's just the speakers and say one device with nothing else hooked to the switch then it's fine.


"Remove the input cable from the speaker. Power it up. Does it hum?" no


Remove all cables from the switch.


Plug it into the speaker. Does it hum? no
 

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Quote:
Originally Posted by morpheus305  /t/1470006/hum-from-a-v-component-switch#post_23277509

Quote:
Originally Posted by arnyk  /t/1470006/hum-from-a-v-component-switch#post_23277435


To diagnose your problem, test in a logical way.


Remove the input cable from the speaker. Power it up. Does it hum?


Remove all cables from the switch.


Plug it into the speaker. Does it hum?


Add one component at a time until the hum starts.

The hum doesn't get bad until you add a 2nd input device to the switch. Doesn't matter what it is or which input it is. Any of the 4 devices will do it if even one of the other devices are hooked up to switch. Now if it's just the speakers and say one device with nothing else hooked to the switch then it's fine.


"Remove the input cable from the speaker. Power it up. Does it hum?" no


Remove all cables from the switch.


Plug it into the speaker. Does it hum? no

Try putting one of your ground isolators in line with the second component that you add. Does it still hum?
 

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Discussion Starter · #11 ·

Quote:
Originally Posted by arnyk  /t/1470006/hum-from-a-v-component-switch#post_23277753


Try putting one of your ground isolators in line with the second component that you add. Does it still hum?

Just tested and yes the hum is still there. I have also hooked up the isolator to the speakers and 3 other inputs at the same time after receiving them in the mail but still got hum.
 

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Quote:
Originally Posted by morpheus305  /t/1470006/hum-from-a-v-component-switch#post_23279084

Quote:
Originally Posted by arnyk  /t/1470006/hum-from-a-v-component-switch#post_23277753


Try putting one of your ground isolators in line with the second component that you add. Does it still hum?

Just tested and yes the hum is still there. I have also hooked up the isolator to the speakers and 3 other inputs at the same time after receiving them in the mail but still got hum.

Is it possible that that second component itself is humming?
 

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Discussion Starter · #13 ·

Quote:
Originally Posted by arnyk  /t/1470006/hum-from-a-v-component-switch#post_23280376


Is it possible that that second component itself is humming?

Well yes, it doesn't matter what the second component is though. Im guessing it's something with the ground or something.
 

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Quote:
Originally Posted by morpheus305  /t/1470006/hum-from-a-v-component-switch#post_23282297

Quote:
Originally Posted by arnyk  /t/1470006/hum-from-a-v-component-switch#post_23280376


Is it possible that that second component itself is humming?

Well yes, it doesn't matter what the second component is though. Im guessing it's something with the ground or something.

Or, one or more of the cables could be broken - say an open connection on the ground side.
 

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Discussion Starter · #15 ·

Quote:
Originally Posted by arnyk  /t/1470006/hum-from-a-v-component-switch#post_23283382


Or, one or more of the cables could be broken - say an open connection on the ground side.

idk, i have literally tried all different kinds of combinations of hooking things up just cause i thought the same thing. I guess if most of my devices had broken cables then yeah it's possible.
 
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