feedbacks..... help

[bolshoi]

good day po.

we normally sing inside an enclosed room.
but problem is the feedback.

meron bang electronic parts or gadget
na pwedeng ikabit yung mic bago sa amp
to lessen the feedbacks?

thank you

[mikep]

You need a room EQ, at least 1/3 octave. But then you also need a spectrum analyzer to know what frequencies are resonating in the room.  Or hulaan na lang.  You can tame the feedback by doing that.  A room EQ is better than an automatic feedback eliminator.  More often than not, these automatic feedback elim devices really make your room monitors' sound bad because they eliminate any frequency they sense that seems to give some feedback problems in th room.  Before you know it, your entire freq spectrum is eliminated.  1/3 octave EQ is your best bet.

BTW, the acoustics of the room also contributes to the problem.  Better to damp the room with curtains, etc.

FWIW

[bolshoi]

thanks sir mike.
not familiar with those stuffs.
where can i check those stuffs sir?

regards

[KitC]

A 1/3 octave EQ is simply a 31-band EQ, preferable per channel. Any brand will do.

[Tarkuz Toccata]

we normally sing inside an enclosed room.
but problem is the feedback.

how many mics open?
how many loudspeakers and stage monitors?
how are all the speakers and mics positioned?

meron bang electronic parts or gadget
na pwedeng ikabit yung mic bago sa amp
to lessen the feedbacks?

meron. parametric eq, 1/3-octave graphic eq, and feedback exterminator.

Sabine SM-610 FBX Solo - only P9,240
at Audiophile Paco tel. 588-0917, 588-0921

[Tarkuz Toccata]

You need a room EQ, at least 1/3 octave. But then you also need a spectrum analyzer to know what frequencies are resonating in the room.  Or hulaan na lang.  You can tame the feedback by doing that.  A room EQ is better than an automatic feedback eliminator.  More often than not, these automatic feedback elim devices really make your room monitors' sound bad because they eliminate any frequency they sense that seems to give some feedback problems in th room.  Before you know it, your entire freq spectrum is eliminated.  1/3 octave EQ is your best bet.

BTW, the acoustics of the room also contributes to the problem.  Better to damp the room with curtains, etc.

mikep,

I suggest we do a PAG & NAG Analysis also. Maybe the problem is with the design of the system.

[mikep]

Yes, that can be done.  I guess Bolshoi has to answer you questions on how many mics open, speakers, etc.

Regards

[bolshoi]

*1 - 2 mics
*a pair of mid-high speakers mounted on the wall i think 6ft from the   ground and a pair of woofers on the floor.
*the speakers are facing us.

indoor speakers only just for recreation.

thanks

we normally sing inside an enclosed room.
but problem is the feedback.

how many mics open?
how many loudspeakers and stage monitors?
how are all the speakers and mics positioned?

meron bang electronic parts or gadget
na pwedeng ikabit yung mic bago sa amp
to lessen the feedbacks?

meron. parametric eq, 1/3-octave graphic eq, and feedback exterminator.

Sabine SM-610 FBX Solo - only P9,240
at Audiophile Paco tel. 588-0917, 588-0921

[Tarkuz Toccata]

Yes, that can be done.  I guess Bolshoi has to answer you questions on how many mics open, speakers, etc.

More questions for PAG & NAG Analysis...

Distance (Ds) between the singer and the mic?
Distance (D1) between the loudspeaker and the mic?
Distance (D2) between the loudspeaker and the farthest listener?
Number of Open Mics (NOM) = 1 to 2
Ambient noise SPL?
Volume of the room (length x width x height)?
Reverberation time (T)?
Directivity factor (Q) of the loudspeaker?
If Q is not indicated, horizontal & vertical dispersion angles of the loudspeaker?
Singer SPL at distance Ds?

[Direk]

we normally sing inside an enclosed room.
but problem is the feedback.

meron bang electronic parts or gadget
na pwedeng ikabit yung mic bago sa amp
to lessen the feedbacks?

thank you

   This one might help you-  Avoiding Feedback

    * Turn down or mute any mics not in use. This reduces the risk of feedback and avoids the back line being picked up.
    * If feedback is a real problem, consider moving the main PA speakers away from the mics a little. Also check the back of the stage, because if the wall is acoustically reflective, some sound from the room will be reflected back into the mics increasing the risk of feedback.
    * Avoid excessive use of boosted EQ as this can encourage feedback and may also spoil the basic character of the sound. Consider it an aid to fine tuning rather than as a means of making radical changes.
    * The use of stage monitors will also worsen the feedback situation so run these at the lowest volume that the performers can comfortably work with. Position the cabinets so as to allow as little direct sound as possible to enter the vocal microphones. If possible, use a graphic EQ on each monitor.

Note: Remember, people soak up sound! The perfect mix achieved in an empty venue will have to be tweaked when the crowds arrive. Sound waves are also affected by heat and humidity.


 Here's another-  Ringing Out: Nulling Room Acoustics

Caution: Ringing out can cause howl around which can damage speakers, so use care when adjusting levels.

As experienced engineers will tell you, there’s no such thing as a perfect venue. To help tailor the sound to the room acoustics, insert a Graphic Equalizer into the console’s mix insert jacks which are effectively between the mixer and the power amp.

‘Ringing Out’ the system prior to the sound check will help reduce troublesome feedback. To Ring Out, follow this procedure:

   1. Set all graphic EQ controls to centre (0).
   2. Turn up amp volume until feedback is just beginning to ‘ring’.
   3. Turn back the amp volume slightly to prevent accidental feedback.
   4. Starting from the left, adjust the first graphic EQ frequency gain control to ‘max’: if the system doesn’t feedback, then this is not a problem frequency. Return this gain control to centre position. If the system feeds back, reduce the EQ gain by the same amount you boosted to get feedback.
   5. Repeat this procedure for all graphic EQ frequencies. Caution: Ringing out can cause howl around which can damage speakers, so use care when adjusting levels.
       


Direk