Hi all, im from Brazil...
a long time ago , i was looking for a audio phase inverter, and today i find this cirucit (showing in this topic).
i have a question :
This circuit can be used to avoid feedbacks?
im musician in my church, and there all we have trobles with high sound lvls, and feedbacks, if this circuit can be used to cancel that feedbacks, maybe our problems can be solved....
tnx for any hlp, and tnx for your time...
[]'s from Brazil
Manassés
This circuit won't avoid feedback. It looks like an active phase inverter module either found in
an audio desk or as a box much like a di box.
Your first step to solving the problem is to reduce the levels at the mixing desk, this may mean the musicians turning down slightly so that microphones can still be heard.
Check that the gain on each microphone channel is at the minimum it needs to be, to be heard, rather than all the way over to compensate for loud musicians. When doing this, the channel slider should be at the 0 mark as should the master slider and any group buss sliders.
Only the sound engineer and one person walking from microphone to microphone singing or speaking at the levels normally experienced at that microphone should be involved/in the room at this point..
A side point here is that if the singers are expecting the pa system to do the work for them, i.e. amplifying the sound, then the system is being used poorly. It is better to have them sing full volume (projecting their voice) and amplify that rather than try to boost a (relatively) quiet performance.
Once the microphones are set up on the desk, bring in the band/musicians and singers. Have them play a loud song. At this point it is the bands responsibility to match their volumes to the singers, not the other way around. Now have them play a quiet song.
By properly setting up the gain structure on the pa system and getting the band to play within that gain structure, your feedback problems should disappear. Avoid the temptation to turn the desk up to compensate for musicians who do not cooperate. If you have problems, remind them that they are their to assist in the praise not to be praised.
If the above is not possible or does not work because of other factors, then you need to invest in something like the Behringer or Alto range of equalisers with feedback squelch circuits