Audio Leveling

ddoppke

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After monitoring for a number of years I've noticed that the AGC in the scanners is not that great. Has anyone found a decent leveling device to keep the audio coming through at a fairly equal level? At times I find myself turning up the volume only to turn it down on the next transmission. - Thanks
 

AB5ID

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There are ways to achieve this using dedicated hardware such as a compressor limiter or through a computer. Personally, I use VST plugins on my computer, paired with a program called VST Host.
 

a417

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After monitoring for a number of years I've noticed that the AGC in the scanners is not that great. Has anyone found a decent leveling device to keep the audio coming through at a fairly equal level? At times I find myself turning up the volume only to turn it down on the next transmission. - Thanks
No, onboard AGC is not that great.

I find that feeding flat audio into a computer and then allowing a purpose built(written) software suite to manage audio levels to be far superior. Hardware solutions such as a compressor/limiter are available if you are Daddy Warbucks or such. YMMV.

Are you listening via headphones, local onboard speaker or via computer feed?
 

serial14

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I use an external audio compressor/limiter for this purpose. Its worked really well at making levels consistent and limit loud noises that may come through randomly. I can really tell the difference in listening fatigue between my home setup( with the compressor ) and my travel setup that uses a scanner only.

In the pro audio world, you can certainly spend $$$ on compressors. However, I just use a Behringer MDX4600 which is not very expensive new and also readily available on the used market for better prices. IMHO for the quality of audio coming out of a scanner, a Behringer compressor is just fine.
 

Omega-TI

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Something that should be included in the programming for the SDS100 in my opinion.

The SDS100 has a way to increase or decrease the volume on specific programmed frequencies. I've used it on a couple of frequencies that had lower audio to boost it. I believe it's listed in the manual as "Individual Channel Volume Offset". Check it out, it may help.
 

a417

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The SDS100 has a way to increase or decrease the volume on specific programmed frequencies. I've used it on a couple of frequencies that had lower audio to boost it. I believe it's listed in the manual as "Individual Channel Volume Offset". Check it out, it may help.
OP didn't specify if this was a channel specific issue, but referenced "transmission" which could indicate a quiter than average user on a busy channel or a particularly loud, overdriven dispatcher mic. Every system has users that deepthroat the mics, or ones who key it from 4 feet away.

The OP (@ddoppke) also didn't specify that this was specific to a SDS100/200. That was the 3rd commenter in this thread, who is @Thomaspj2 .
 

bob550

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Every system has users that deepthroat the mics, or ones who key it from 4 feet away.
I monitor using SDRTrunk coupled with Trunking Recorder through my SDRPlay RSP1. Audio is processed using basic Dell software. I have found considerable variability in the intelligibility of transmissions, even from the same agency. In some cases, I've had to replay the transmission several times and still couldn't understand it. As far as volume levels is concerned, maybe it's just my local systems, but I've not found any great variability in audio levels using either my computer and SDR, or with my Uniden 536. Once I've selected a comfortable volume, it tends to stay there.
 

ratboy

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Other than being quite deaf, it's my main complaint about my 2 SDS200's. Listening to it as I type this morning, it's the usual blasting loud units and others so low they can't be understood. I might have to try a Behringer MDX4600 and see what happens. I sure wish it was smaller though, like the size of a pack of cigarettes.
 

serial14

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Other than being quite deaf, it's my main complaint about my 2 SDS200's. Listening to it as I type this morning, it's the usual blasting loud units and others so low they can't be understood. I might have to try a Behringer MDX4600 and see what happens. I sure wish it was smaller though, like the size of a pack of cigarettes.
Well if anybody knows of a physically small 1 channel compressor/limiter type device, I'd sure like to hear about it.

The MDX4600 is great for a rack mounted situation where you have space and lots of scanners/sources/devices feeding into it. But for a one off, or a portable type situation, yeah its big.
 

Thomaspj2

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OP didn't specify if this was a channel specific issue, but referenced "transmission" which could indicate a quiter than average user on a busy channel or a particularly loud, overdriven dispatcher mic. Every system has users that deepthroat the mics, or ones who key it from 4 feet away.

The OP (@ddoppke) also didn't specify that this was specific to a SDS100/200. That was the 3rd commenter in this thread, who is @Thomaspj2 .
You clarified my exact meaning. Occasionally an individual user will blow your ears out. I would like to see an addition to "volume offset"
 

a417

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You clarified my exact meaning. Occasionally an individual user will blow your ears out. I would like to see an addition to "volume offset"
Totally understand, and I figured that's where you were going with that. Too bad that's per-user issue, and more aptly handled by training than hardware. Worked with people who retired after 25 yrs and shouted the last 22 that I knew them, because their first 3 years they keyed the mic from the holder and that practice became permanent, and new management decided to try to break them of the habit...over 2 decades.

A pipedream feature-set could be a per RID audio offset in a software suite, but that's likely more trouble than it's worth. I could script something up for a system that I have that records everything to mp3 easily, but realtime would take integration into the decoding software.
 
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ratboy

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I still haven't found anything small enough to use mobile or at work for this issue, at least pre built. Yesterday, I was listening to the morning traffic as usual and the SDS200 sat there, apparently silent, then I heard a slight mumbling. I fired up my Pro 106, got it on the same freq, and there was a woman paramedic talking about a patient just pulled from a wrecked car. To even understand her on the SDS200, I had to go to "12" on the volume, and when the hospital replied, it was at blast level. Normally at work, I run the volume at 8 to avoid one of the engineers, who has hearing aids, complaining about the "scanner noises". He has great difficulty understanding anything on a scanner or HF radio. The above traffic was plain old analog. Digital does the same thing. It really annoys me. IF I could find a small automatic level controller, even if I needed to run an external amp/speaker, I would be fine with it. I just guess I need to find something and build it and try it out. Of all the radios I have that can receive the "problem" channels, the SDS200 is hands down the worst, worse than little "junk" radios that cost like $30-50 brand new. Most of them have little problem with it, the level is close enough that I can still make out what they are saying without riding the volume pot like I have to do on the SDS200.
 

n8zcc

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I hear the same with our P25 system, one transmission is very low and the next one blows your hat off. I also experience the same issues with Yaesu's Fusion system (ham radio), with the addition of "popping". I lack the skills to develop a circuit that could help with this but I keep looking. Seems the need is there.
 

dispatchgeek

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I run some audio tools on my private scanner feeds. There's a few options here:
A Fix For Widely Varying Police Scanner Audio Levels Using a Free Windows Program (Also Linux and macOS)
(Thanks to @wtburton !)

But I have recently followed a different methodology and had great results:
Bote Man's Scanner Feed Audio Tips and more info at Bote's Streaming Audio
(Thanks to @Bote !)

Portable? No. It makes base scanning a heck of a lot more enjoyable though. My local audio level problem here is a dispatch center that overdrives the paging tones and then the dispatcher is much quieter. Both of these solutions have made listening/streaming much more enjoyable. I run a private proscan stream in the car instead of my SDS with these audio fixes applied.
 
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ratboy

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I'm going to try Dispatchgeek's free Windows program. If it works on this machine, great, if this PC has too little horsepower, I guess my old laptop that I hardly use anymore can do it.
 

prcguy

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This little guy looks interesting, wish I had some spare pocket change to try it ou

I have a few compressors and this one is exceptionally good and can be very transparent. The inputs and outputs are unbalanced, which is unusual for a compressor but that might make an easier interface for scanners. Since all compressors will work at line level you would need to greatly attenuate speaker audio to feed one then make up with an audio amp. If your scanners have a line level record out that would be perfect for feeding a compressor.

 
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