AGC versus Noise Suppression

[tmargetta]

I am looking for opinions or experience in XTS5000 program settings for Automatic Gain Control choices (Radio Wide, Tx Audio Control Per Mode). It appears as though there are settings for the Internal and External Mic with Analog, Digital, and Securenet choices, plus an overall AGC, a Digital/Analog Balance and then Noise Suppression with Standard and Advanced options.

Recent recommendation from the manufacturer is to enable AGC on Analog, Digital, and Securenet choices, with the values set at the "0" default because the system has Digitac and/or AstroTac Comparators already built in.

I understand that AGC is a volume issue, and Noise Suppression is a clarity issue: two distinct items.

Fire users following analog versus digital tests conducted in Orlando to compare audio quality of voice transmissions from an active fireground are inquiring about Noise Suppression. The internal CPS Help file indicates that Noise Suppression works best when the AGC fields are disabled, and when disabled, the Digital/Analog Balance field be enabled to reduce acoustical feedback.

The Standard Attenuation Level provides a "moderate amount of noise reduction to transmitted audio," and "should be used in areas where there is a reasonable level of background noise." The Advanced level provides a higher level of noise reduction, and be used in areas of high level of background noise. There is also an important note warning that this setting may also cause some degradation of audio when no background noise exists.

Seems to me like there are a lot of competing features here, all trying to do the similar things, but fighting each other in the process. I can't program some radios as "fireground radios" and "moderate noise radios" and "good condition only" radios unless I can ensure they are only used in those environments which is unlikely.

Does anyone have a "happy medium" setting recommendation, or opinion as to which is more important, AGC or Noise Suppression if I have to choose between the two, along with any data to support or justify that choice?

Thank you for any assistance you can offer.

[Will]

We do NOT use AGC on our radios out here.

[Jim202]

AGC is not a very good selection to use if there is any chance of high background noise. The use
of the AGC by itself will bring up the background noise when your not talking. If it was to be used
in a quiet room, then it might work for dispatching. Other than that, you probably going to make
matters worse by using the AGC selection.

Jim

[Max-trac]

The AGC in some JEDI series radios make the audio painful to listen to!
All fluffy and bloomy like HearClear or MotoTurbo, yuck!
It might work differently on your radio, try programming channels with and without and compare.

[Pj]

There was a field bulletin that came out around the time DSP8 was released for the orginal ASTRO series. This seemed to help with all sorts of noise enviroments.

I am sure some things changed when the ASTRO25 line came out, and may not be needed. I still use the recommended AGC of 0/0/0 total 6, and at least on simplex with other users, seems to be just fine.

Is there a situation that your running into or...?

If you do a search, a few posts concering (along with the text of the FSB) was posted a couple of years ago.

[MRFLASHPORT]

tmargetta,

The best setting's to use for your XTS500/2500 is

No AGC

Fixed Gain level of 3 for Analog, Digital, and Secure. For both Radio and Mic.

Enable the Digital Analog Balance. Radio will sound perfect.

[RKG]

We have found (more or less by trial and error) that AGC should be disabled in the Fire service. If the user is close to a running diesel or other high noise source, AGC makes communications difficult to impossible; but there is no apparent degradation in "normal" background noise situations.

[tmargetta]

Is there a situation that your running into or...?

I am building the templates/codeplugs from "the ground up" to standardize system/personality/talkgroup/feature layouts. The original suggestion I received in "field testing" the radios as part of the Rebanding process was just a PTT test, which I rejected. My belief is that a simple PTT test will verify IF a radio works, but will not conclusively test whether it is working OPTIMALLY. These radios, and the feature sets they contain, are too important to not do this right the first time.

[nmfire10]

In my limited experience around here, AGC works fine on astro for the police. For fire on Analog, it is more headache than its worth. I have the gains turns up to 3 or 6 on everyone but the AGC off on analog.