Dynamic compression of voices
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Dynamic compression of voices
Do any of the MGL radios offer dynamic compression of voices? I'm fiddling way too much with my Becker AR4201's volume knob-- close-by is too loud and far-away is too quiet--, and would love a solution.
Re: Dynamic compression of voices
No we do not do that.
However what you are describing is an effect of AGC or automatic gain control. Normal radios have a variable gain amplifier that is controlled by the strength of the incoming signal. AGC has a control slope to prevent it from oscillating so the weaker the signal the softer the audio volume gets. Just by how much depends on the design of the radios receiver.
The V16 does not have any AGC circuit in the traditional sense so there is no variable gain amplifier. The V16 moves the radio signal into the digital domain at an early stage and from there everything becomes maths. This means we still need to amplify a weak signal (it would now be a multiplication) but we know what the input signal strength looks like so we know what the multiplication should be to get a defined output. This means we can have an output signal that is completely invariant of the strength of the input signal - there is no control slope at all.
I did experiment with amplification/attenuation of the actual audio voice as well as this is fairly easily done - not to cater for signal strength but rather the modulation of the transmitter on the other side - radios tend to vary greatly in how much they modulate the carrier and, as you know sometimes you get a nice carrier but with a very soft voice. In the end I decided to leave this out as there are circumstances where this does not work too well.
The only other processing that is done on the signal is the detection of sharp pulses such as you get from engine ignition systems. These can in most cases be removed from the audio signal to a large extent. In fact some old radios had an elaborate circuitry included to do just that (Some of the older Icom radios come to mind). The V16 does something similar just using digital techniques.
However what you are describing is an effect of AGC or automatic gain control. Normal radios have a variable gain amplifier that is controlled by the strength of the incoming signal. AGC has a control slope to prevent it from oscillating so the weaker the signal the softer the audio volume gets. Just by how much depends on the design of the radios receiver.
The V16 does not have any AGC circuit in the traditional sense so there is no variable gain amplifier. The V16 moves the radio signal into the digital domain at an early stage and from there everything becomes maths. This means we still need to amplify a weak signal (it would now be a multiplication) but we know what the input signal strength looks like so we know what the multiplication should be to get a defined output. This means we can have an output signal that is completely invariant of the strength of the input signal - there is no control slope at all.
I did experiment with amplification/attenuation of the actual audio voice as well as this is fairly easily done - not to cater for signal strength but rather the modulation of the transmitter on the other side - radios tend to vary greatly in how much they modulate the carrier and, as you know sometimes you get a nice carrier but with a very soft voice. In the end I decided to leave this out as there are circumstances where this does not work too well.
The only other processing that is done on the signal is the detection of sharp pulses such as you get from engine ignition systems. These can in most cases be removed from the audio signal to a large extent. In fact some old radios had an elaborate circuitry included to do just that (Some of the older Icom radios come to mind). The V16 does something similar just using digital techniques.
Re: Dynamic compression of voices
Interesting! And, yes, AGC was exactly the term I was looking for. I feel a bit sheepish for having forgotten it. 
One thing I'm still a little confused by is what the V16 does. You are very clear that it does not do AGC, but then you mention amplifying weak signals. Would that have a similar effect to AGC, in that there will be less of a speaker volume difference between weaker and stronger transmissions?
One thing I'm still a little confused by is what the V16 does. You are very clear that it does not do AGC, but then you mention amplifying weak signals. Would that have a similar effect to AGC, in that there will be less of a speaker volume difference between weaker and stronger transmissions?
Re: Dynamic compression of voices
There is no AGC and no control slope. There is no difference in audio amplitude between a strong and a weak signal assuming in either case the transmitter is modulated the same. The difference you do hear is an increase in the background noise level - this tends to be louder in the V16 compared to an analog radio (as we effectively have more gain - it's unlimited). But with the louder background noise also comes a louder voice (audio) signal.kubark42 wrote: ↑Mon Jun 05, 2023 6:44 pm Interesting! And, yes, AGC was exactly the term I was looking for. I feel a bit sheepish for having forgotten it.
One thing I'm still a little confused by is what the V16 does. You are very clear that it does not do AGC, but then you mention amplifying weak signals. Would that have a similar effect to AGC, in that there will be less of a speaker volume difference between weaker and stronger transmissions?
Well, the V16 DOES wind down the gain once the signal gets very weak - or else the level of noise will blast your eardrums. But the point where this happens is with really weak signals where there is no longer a benefit as the noise is very close to the level of the signal. The V16 also, be the way it works effectively has two parallel receivers, both providing a signal (with noise) - mixing the noise which is random reduces it while the actual signal we are interested in is not random and effectively adds.
The result of all of this is that the V16 has a very sensitive receiver by modern standards - modern radios sadly have reduced sensitivity to older radios - this is a result of newer ICAO regulations which are very tough on intermodulation rejection requirements. The V16 gets around this problem by avoiding the physics causing the problem in a manner of speaking...