Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

PA Systems A forum for discussion of all parts of a sound reinforcement or DJ system: loudspeakers, mixers (desks) etc.

High microphone sensitivity vs high main volume
High microphone sensitivity vs high main volume
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 21st December 2017, 08:00 AM   #1
Zaharescu Mihai is offline Zaharescu Mihai  Romania
diyAudio Member
 
Join Date: Dec 2017
Location: Bucharest
Default High microphone sensitivity vs high main volume

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.

Last edited by Zaharescu Mihai; 21st December 2017 at 08:06 AM.
  Reply With Quote
Old 21st December 2017, 09:46 AM   #2
GeorgK is offline GeorgK  Austria
diyAudio Member
 
Join Date: Jan 2005
Location: Vienna
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.
  Reply With Quote
Old 21st December 2017, 09:52 AM   #3
Zaharescu Mihai is offline Zaharescu Mihai  Romania
diyAudio Member
 
Join Date: Dec 2017
Location: Bucharest
Thank you, I will do a test in the following days/weeks (because of holidays) and post the results, maybe they are useful for someone.
  Reply With Quote
Old 23rd December 2017, 07:15 PM   #4
Zaharescu Mihai is offline Zaharescu Mihai  Romania
diyAudio Member
 
Join Date: Dec 2017
Location: Bucharest
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.
  Reply With Quote
Old 26th December 2017, 07:45 PM   #5
Zaharescu Mihai is offline Zaharescu Mihai  Romania
diyAudio Member
 
Join Date: Dec 2017
Location: Bucharest
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.

Last edited by Zaharescu Mihai; 26th December 2017 at 08:13 PM.
  Reply With Quote
Old 26th December 2017, 08:02 PM   #6
conanski is offline conanski  Canada
diyAudio Member
 
Join Date: Mar 2013
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.
  Reply With Quote

Reply


High microphone sensitivity vs high main volumeHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
AC main power to high. Guarnera Power Supplies 4 1st June 2016 09:01 PM
high sensitivity Subwoofer william444555 Subwoofers 2 3rd February 2016 04:56 AM
Need Help: High Q, High Sensitivity Sub? ad70 Subwoofers 13 17th July 2013 05:15 AM
High sensitivity Loudspeaker Lutz_RE Multi-Way 4 6th March 2008 06:52 PM
high sensitivity 2way rebojorge Multi-Way 15 22nd April 2004 06:08 PM


New To Site? Need Help?

All times are GMT. The time now is 05:56 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki