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mic-channel

Posted: 03 Nov 2012 13:19
by Adger
Sometimes PFOA is starting up with all channels unmuted, volume maxed, while blocking all interaction because of hell knows why for several long seconds. This just lead to a catastrophic feedback loop which killed one of our speaker pairs (or the Amp, or both). Thank you.

Re: mic-channel

Posted: 03 Nov 2012 17:02
by Adger
PFOA was closed regularly with line MIC1 and OUT muted - as it shoud be and always is. When starting the splashscreen appeared, and while the UI was built, the mixer was created unmuted, hence the feedback / loopback. Muting was initiated once the UI was fully "there". At this point it was "too late". What did the User do wrong? At what point should the user do something different? The only option that she had was "start the software first, wait five minutes till everything might be settled, then start the hardware". But this lifesaving advise is not in the manuals. We learned it the expensive way today and we really love to learn this way. This should be in the manuals. On Page One. In Red.

Re: mic-channel

Posted: 03 Nov 2012 20:45
by radio42
ProppFrexx starts with the same settings as it was closed and doesn't change any volume settings.
If you create a feedback loop with the mixer channels, I am affraid there is not much proppFrexx can do about it?!

Re: mic-channel

Posted: 04 Nov 2012 02:56
by JonyKanal80
Confirm... me too having the same radom issue

Re: mic-channel

Posted: 04 Nov 2012 19:08
by radio42
In the new v3.0.11.14 any mixer-input channel is now initially muted.
However, once your mixer settings are restored a given feedback loop might still be present.
So I really suggest not to define such mixer setup!

Re: mic-channel

Posted: 04 Nov 2012 22:55
by Adger
How can a Mixer-Setup prevent a "Rückkopplung" (aka feedback)?

Re: mic-channel

Posted: 05 Nov 2012 00:06
by radio42
A mixer-setup can not prevent it, as it is unknown to the software, if a certain output is connected to headphones, speakers or to any other external device.

Re: mic-channel

Posted: 05 Nov 2012 20:53
by Adger
However, once your mixer settings are restored a given feedback loop might still be present. So I really suggest not to define such mixer setup!
A mixer-setup can not prevent it, as it is unknown to the software, if a certain output is connected to headphones, speakers or to any other external device.
Oo :?: Was denn nu?

Re: mic-channel

Posted: 05 Nov 2012 21:40
by radio42
Pretty simple:
You can theoretically define a feedback loop with your mixer-setup, e.g. you route/copy-to (or SND2) your mixer-input-channel (i.e. a MIC) to a mixer-output-channel, which directly plays over connected loudspeakers.
If those loundspeakers are close to your MIC a feedback loop might be the result!
As long as the MIC mixer-input-channel is MUTED all would be okay. But as soon as you unmute that MIC channel....boom!

When ProppFrexx is started it now starts any mixer-input-channel muted by default.
Finally however, your last mixer settings are restored - as such the last mute/unmute state is restored.
If this last mixer settings was now an unmute state...the feedback might happen again!

The same would happen, if a user manually unmutes such mixer channel.
That's why I said: try to avoid defining such possible feedback loop.
And that's why I said: ProppFrexx doesn't know what is connected to your mixer-output-channels...is it a headphone, is it speakers, are those speakers close to the MIC...??
It is unfortunately only you who knows this...