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[Samuel Rees]

I think we are talking about the same concept.

Using your example, the 25db gain on the Beta (established from the trim) would be the "starting point" (not the 40db - hopefully no one would start it that hot) with the slider or aux-send turned all the way down... with the channel PFL showing (i.e) +3db with a vocal input.  Then more db is added to the signal as it's passed through the aux-send or fader.  Maybe another way of saying it, the 25db level at the input is (do I dare say) less sensitive than 40db. 

It just sounds like the OP may have an input level too hot for the offending freq. if they are unable to notch it out.  At lease rule out a "hot" input.

If the preamp is actually clipping, sure it could make feedback happen more easily, but assuming there is no clipping, it doesn't matter if you run the preamp a little hotter and the fader a little lower or fader a little higher and the preamp a little lower. Sorry if I'm beating a dead horse but you keep saying that we're on the same page, then saying something which makes it seem like we're not

Channel gain  = preamp gain +\- fader level. So 20 db of preamp gain and fader at zero/unity is 20 db of channel gain. 25 db of preamp gain and fader at -5 is the same thing. 10 db of preamp gain and fader at +10 is also the same thing. 3 different preamp gains - no change in 'sensitivity' to feedback or output level of any kind. Seems to me that you are suggesting that the 25/-5 combo is most susceptible to feedback than the other two because of a "hotter" trim, but this is not true.

[Robert Weston]

If the preamp is actually clipping, sure it could make feedback happen more easily, but assuming there is no clipping, it doesn't matter if you run the preamp a little hotter and the fader a little lower or fader a little higher and the preamp a little lower. Sorry if I'm beating a dead horse but you keep saying that we're on the same page, then saying something which makes it seem like we're not

Channel gain  = preamp gain +\- fader level. So 20 db of preamp gain and fader at zero/unity is 20 db of channel gain. 25 db of preamp gain and fader at -5 is the same thing. 10 db of preamp gain and fader at +10 is also the same thing. 3 different preamp gains - no change in 'sensitivity' to feedback or output level of any kind. Seems to me that you are suggesting that the 25/-5 combo is most susceptible to feedback than the other two because of a "hotter" trim, but this is not true.

No, I was not suggesting the 25/-5 would introduce the most feedback (sorry if it came across that way); I was using it as an example.  What I was saying (referencing some bands), was not to use the preamps as a fader for their inputs, as many sometimes do; but, to keep the preamps down to a manageable level and use the sliders for +/- gain.

[Samuel Rees]

Haha ok, glad we're on the same page. Sorry to bog down the thread. Carry on.

[Tim McCulloch]

No, I was not suggesting the 25/-5 would introduce the most feedback (sorry if it came across that way); I was using it as an example.  What I was saying (referencing some bands), was not to use the preamps as a fader for their inputs, as many sometimes do; but, to keep the preamps down to a manageable level and use the sliders for +/- gain.

Hi Robert-

Another way of describing this phenomena is "top knob mixing."

[Greg Bartusch]

What do you mean by all the frequencies are pulled out? As in all the faders on the graphic are turned down? Because all that does is turn the whole level down and completely mess with the phase of the signal and give you way more problems.

Yes. All the frequencies are pulled down to the bottom of the EQ's

[Steve Garris]

Yes. All the frequencies are pulled down to the bottom of the EQ's

When you do this it completely destroys the sound of that speaker. You need to start by setting all of the sliders at the indent, in the middle, and then carefully ring the system out by finding the offending frequencies, and cutting those frequencies only. Too much cutting of too many frequencies will not work, and the EQ is not designed to be used like that.

Better quality equipment (EQ's, Speakers) will give you less trouble. In some situations, you may never get the speaker to be loud enough without feedback. Sometimes the solution is mic placement and speaker placement. Get yourself a nice DBX 31 band graphic EQ - I'm sure you'll notice a difference.

[Ivan Beaver]

Yes. All the frequencies are pulled down to the bottom of the EQ's

Well that's one way to destroy a system.  And a good indication of "not a clue".

Not only is the eq dropping the level in the system, it is also adding a lot of ripples in the response-where the filters overlap.

In this case the system would be MUCH MUCH  better WITHOUT the EQ!!!!!!!!!!!!!!

[Jay Barracato]

Well that's one way to destroy a system.  And a good indication of "not a clue".

Not only is the eq dropping the level in the system, it is also adding a lot of ripples in the response-where the filters overlap.

In this case the system would be MUCH MUCH  better WITHOUT the EQ!!!!!!!!!!!!!!

I walked into a venue down near Atlanta and found the eq's on the mains set like that, the eq's on each channel set like that, AND a 15 band eq inserted on each channel set like that.

And found we had the third string house guy as a system engineer who was afraid to touch any of the boss's settings.

[Patrick Tracy]

I walked into a venue down near Atlanta and found the eq's on the mains set like that, the eq's on each channel set like that, AND a 15 band eq inserted on each channel set like that.

And found we had the third string house guy as a system engineer who was afraid to touch any of the boss's settings.

I've been in this situation. The bypass button is usually my solution. Leave the stupid setting while getting better sound with no graphic eq at all.

[AllenDeneau]

Explain how lowering the level at one end of the equation and raising it an equal amount at the other end results in a lower level.

Only on a system with a non centered fulcrum = see-saw with a much longer end on one side than the other

I too was going to suggest a parametric eq BUT as was stated maybe running without an eq and limiting the input channels and mixes would be a better exercise for the op first?

IMO if he's not sure how to effectively work a graphic eq, won't a parametric just make things more difficult for him? I believe so.

[ProSoundWeb Community]