Hello,
I've read recommendations that one should not rotate the microphone sensitivity wheel over 3 o' clock because doing so introduces high noise levels from the microphone.
However, looking inside the manual of my mixer-amplifier (TOA A1706) the sensitivity wheel is just a potentiometer after an amplifier and the main volume wheel the same. This means that it should make no difference whether I set the sensitivity high or the volume high, from the point of view of noise levels (more even, it should be better to have the main volume as low as possible, because it lets more of the sum pass, so it raises all the microphones). We should have no clip problems even at max sensitivity because the microphones are omni-directional ambient microphones, far away from the speakers.
Is it however possible for the electronic diagram in the manual to be just a simplification, and actually the sensitivity wheel modifies the signal from the microphones somehow and introduces noise? The microphones are condenser microphones.
I've read recommendations that one should not rotate the microphone sensitivity wheel over 3 o' clock because doing so introduces high noise levels from the microphone.
However, looking inside the manual of my mixer-amplifier (TOA A1706) the sensitivity wheel is just a potentiometer after an amplifier and the main volume wheel the same. This means that it should make no difference whether I set the sensitivity high or the volume high, from the point of view of noise levels (more even, it should be better to have the main volume as low as possible, because it lets more of the sum pass, so it raises all the microphones). We should have no clip problems even at max sensitivity because the microphones are omni-directional ambient microphones, far away from the speakers.
Is it however possible for the electronic diagram in the manual to be just a simplification, and actually the sensitivity wheel modifies the signal from the microphones somehow and introduces noise? The microphones are condenser microphones.
Last edited:
Both is possible. The "schematic" in your manual is indeed a simplification and you cannot be sure whether the headamp gain is adjustable and a master control follows afterwards or if there is a fixed-headamp followed by an attenuator plus a volume control. In this case the attenuator mainly is for setting the working position of the vol pot to a sensible point.
Hello,
I did a quick test and for one microphone it doesn't make much difference if it is at max gain or if the main volume is at max (the final sound level was limited by feedback).
But for more microphones it makes much difference. I saw that it is better to set the microphone gains at their max needed for each application, and use the main volume wheel to just lower the level as required by the application.
I did a quick test and for one microphone it doesn't make much difference if it is at max gain or if the main volume is at max (the final sound level was limited by feedback).
But for more microphones it makes much difference. I saw that it is better to set the microphone gains at their max needed for each application, and use the main volume wheel to just lower the level as required by the application.
It seams I was wrong. I set the microphones at the highest possible level, in order not to get feedback, and the noise levels were very high. Because the microphones clipped at loud sounds I decided to lower their levels a bit and also the main volume and raise the gain from the processors. The noise levels are waaaaaaay lower.
So, what I understood from this experiment is that microphones should not have to high gain (I stopped at 2 o clock), the main volume should not have to high gain (2:30) and the processors should not have high gain (3). For my setup, as long as I don't overdo the gain in any of the devices the noise levels drop. If only one device has high gain, noise levels increase, especially the first devices (microphones gain, preamp).
So it seams that gain staging is not as intuitive as I thought (I thought that microphones gave the most noise, so I set them at maximum gain and lowered the volume in the following stages, but this didn't work for me).
[edit] I have rotary controls, for a scale from 1 to 10: 1 is 7 o clock and 10 is 5 o clock. 12 o clock is 5.
So, what I understood from this experiment is that microphones should not have to high gain (I stopped at 2 o clock), the main volume should not have to high gain (2:30) and the processors should not have high gain (3). For my setup, as long as I don't overdo the gain in any of the devices the noise levels drop. If only one device has high gain, noise levels increase, especially the first devices (microphones gain, preamp).
So it seams that gain staging is not as intuitive as I thought (I thought that microphones gave the most noise, so I set them at maximum gain and lowered the volume in the following stages, but this didn't work for me).
[edit] I have rotary controls, for a scale from 1 to 10: 1 is 7 o clock and 10 is 5 o clock. 12 o clock is 5.
Last edited:
Correct gain staging is always a balance between getting enough gain, minimizing the noise floor, avoiding clipping at any preamp stage and of course preventing feedback.
In practical applications that often means that gain controls will produce best results when at the median position(5-6 on a scale of 1-10) give or take.
In practical applications that often means that gain controls will produce best results when at the median position(5-6 on a scale of 1-10) give or take.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.