Odd background noise on stream audio

[aliby19]

Hello,

On the audio stream that I provide there is a strange background noise which I can't seem to get rid of (it is quite noticeable when there is no audio coming from the scanner/the scanner is idle. When audio is coming from the scanner, it is somewhat noticeable).

The background noise is only on the audio of the actual transmitted stream. It is not on the scanner audio output (ie: if I use the scanner's internal speaker or connect an external one, it is not there).

I do have a ground loop isolator in line on my audio cable. Does anyone happen to have any idea what the cause of this sound might be?

My stream is available here: Monroe County Public Safety Live Scanner Audio

Thanks in advance for any help!

 

[aliby19]

Sorry to bump an old thread, but I'm still having the odd noise on my stream/feed.

Anyone care to take a listen and give me a hand in figuring out A) what it is and B) how to get rid of it?

The feed is here: Boone County Public Safety Live Scanner Audio Feed

Thanks!

 

[176002]

I would check and make sure that your audio level coming from your scanner is not past 1/4 to 1/2 volume and put your line in setting on your PC to about 30. Sounds like a volume on either the scanner or PC is set to high. Also make sure Audio boost is OFF.

 

[talkpair]

I'm assuming you're referring to the 60~ power hum on your feed.

I'm guessing you're also using the MIC-IN jack on your sound card.

First, rule out a defective sound card....Do this by just unplugging your radio from the sound card and see if the hum is still there......take into consideration the audio delay, and wait up to two minutes.

If the hum goes away, try using the sound card's LINE-IN jack.

Remember, the MIC jack amplifies audio coming into the jack.......
If you were to put your ear up to the radio's speaker at it's lowest audio level, you'd probably hear this hum, and any incoming radio traffic at a slightly higher level......This is what the MIC jack amplifies.

On the other hand, the LINE-IN jack needs amplified audio coming in, so your radio's volume control would need to be set at a higher level in order for the card to 'hear' it........This would be equivalent to listening to your radio across the room at full volume. In this scenario, you probably wouldn't hear the hum at all.....
Some radios cannot produce the necessary audio level to drive certain sound cards, so this may or may not be an option.

Use the NOAA weather channel, your soundcard's mixer program, and radio's volume control in setting your audio levels......Again, take into consideration the streaming delay.

Another thing you can try if you have a mobile radio, is to use a well filtered 12V DC power supply connected to the EXT DC connector, instead of the wall wart.

 

[aliby19]

Volume coming from the scanner is halfway between 1/4 and 1/2. I only have the Microphone input on my soundcard, which was initially set to 100%. I have dropped it to around 30-40%. Audio Boost or in my case Automatic Gain Control (AGC) has always been turned off.

Mind taking a listen now and seeing if that's any better?

(Note: I'm running this feed off of an old Regency MX3000 scanner, which could be the cause of all these issues. )

Thanks!

 

[176002]

Sounds much better also make sure you are using good shieled cables. I use mic in on mine set at 30% and scanner at 1/4 here is my feed
Franklin County Fire and EMS Dispatch Live Scanner Audio Feed

 

[aliby19]

176002 and talkpair, thank you very much for your assistance.

I have made the final modifications/adjustments per your suggestions and am now (hopefully) done with any further ones.

Mind taking a listen once more and letting me know your thoughts?

Thanks!

 

[176002]

Ok I am listening I would start your web player put it on wx and make sure audio on the player does not go past 3/4. I would maybe move your mic in up a little but would leave scanner at 1/4. you do not want to blow your soundcard.

 

[aliby19]

176002, just sent you a PM

 

[talkpair]

Sounds good now.......hum is gone.

You might want to post a follow up with 'action taken' to resolve the problem, so others can benefit.

Then call it a 'case closed'.

 

[aliby19]

Good suggestion, talkpair.

As for what I did -- it's all pretty much been documented in this thread already, but here's the final settings/results:

Scanner volume - between 1/4 and 1/2 (mine's in the 10 o'clock position)
Microphone volume (using Windows mixer) - Approximately 70%
Automatic Gain Control - OFF (not checked)

To figure out what worked best for my situation, I tuned my scanner to the local NOAA All Hazards Radio frequency and adjusted the scanner volume and mixer volume until the hum started to go away. It's still there, but barely audible.

My suggestions for others are -- Reduce your scanner volume (especially if using the microphone input instead of line-in). Use the Windows mixer to increase your microphone input volume (usually found under the "Recording" settings).

Thanks again to all for their help!

 

[176002]

No problem Sounds much much better. It is nice when everybody helps each other with their issues.