Feedback quandary

[WK154]

DpDan : Let me say that it's always good to know your talent and their idiosyncrasies but its not always possible. I agree with you on never grouping compression and its best not to even try to get coloration or other effects by using a compressor. In my opinion its a waste of time.  In Mary's case use it as a safety net (limiter) and tell her not to quit her day job. Four part harmony needs balance and no FOH engineer I know of could be fast enough to deal with that. That's were mic technique and there own sense of balance separates the men from the boys. I know having dealt with that for too long. It's a pleasure to actually mix for a group that has that under control like the Alley Cats or the Dukes of DooWop to name a few. I'm still chewing on the rest of the tricks you mentioned.

[RoadRanger]

^ Yup

[Greg C.]

DpDan : Let me say that it's always good to know your talent and their idiosyncrasies but its not always possible. I agree with you on never grouping compression and its best not to even try to get coloration or other effects by using a compressor. In my opinion its a waste of time

In theory it may seem like using group compression for vocals may cause a situation where one vocal "pushes down" the rest. But in practice this doesn't appear to be the case. I leaned the method of compression on vocal channels and groups from someone considered to be one of the best FOH engineers out there and I haven't heard a bad mix at one of his shows yet. There are also cool tricks you can do using VCAs when using bus compression, but that's another discussion.

It's a pleasure to actually mix for a group that has that under control like the Alley Cats or the Dukes of DooWop to name a few. I'm still chewing on the rest of the tricks you mentioned.

Agreed that mixing a band that's truly pro and has good control of their own dynamics is a pleasure. I knew another group called the Alley Cats, but they weren't doowoop. They were punk rock

[WK154]

OK RR one more time sloooowly: Lets take the whole post.

Basically anytime there is gain reduction you need more gain to get it as loud as it was without the gain reduction.
That's cool and pretty obvious and you have meters in the DL compressor for that labeled IN and OUT and the GR in between is just another Mackie way to let you know that compression is happening (Gain Reduction GR clever!). That's a good thing and gain hasn't changed going thru the compressor (IN and OUT are equal). The assumption of course is that your gain structure is correctly set and your away from the feedback limit by at least 3 dB FS preferably 6 dB. Also that your setup gets no feedback without the compressor engaged under normal levels or at least up to the compressors set threshold limit. Here's the problem statement:
That's fine until the gain reduction goes away when the signal is reduced or stops, then it's feedback city .
When the GR indicator goes away you should be at or below the threshold limit and unless your gain structure is incorrectly set there should be no feedback. I hope this clarifies things.

[WK154]

GregC; " There are also cool tricks you can do using VCAs when using bus compression, but that's another discussion." That's the CATEGORY I'm trying to convince RR to open up for just such reasons. Real experience and NO Monday morning quarterbacking. Contribute or be gone.

[Greg C.]

Real experience and NO Monday morning quarterbacking. Contribute or be gone.

Me? I've been doing it real world for years.

[WK154]

DpDan more observations: The open mic problem with pickup of drums can be addressed with the gate, of course mute on the channel will do the job. Done successfully with automatic mixers all the time and referred to as NOM (number of open mics). This when properly set should eliminate the drum pickup problem and also reduce potential feedback. It can also in Mary's case be a problem since she's all over the place with loudness cutting her in and out when too soft (below the set threshold). Voice lessons from an opera trained instructor and mic technique training would do wonders. A headset mic may help as well. I get the impression reading thru your explanations that the compressor lowers the sound level when activated but it really doesn't it only reduces the increasing level by the ratio set. When you drop below the threshold the compressor is out of the way. Even when nearing the threshold compressor effect is hardly noticeable. A 3 dB difference is considered noticeable by the ear. It also does not provide any kind of delay other than a few hundred usec for processing and certainly not noticeable by the ear. Again 3000 usec + before good hearing can pick up any difference. Hope this clarifies some of the explanations.

[lightguy48]

I think the problem people run into is running the compressor on the microphone where it's in a constant state of gain reduction.  Then as stated by other posters the operator starts raising the channel output to get the vocals back in front of the mix or raising the make up gain on the compressor.  This can be made even worse if the threshold is set so low that the on stage volume is coupled into the vocal mic contributing to some of the compression.  When the band stops and the threshold is no longer reached in effect the gain of the mic has been raised by so many db.  It's not a problem with the compressor, it's a problem with the usage.

I typically run my mic compressors where they're kicking about 25-50% of the time, basically on peaks.  I don't like the 'squashed' lack of dynamics sound

[dpdan]

wk,
you're preaching to the choir

[WK154]

Depends on the choir.

[Greg C.]

The open mic problem with pickup of drums can be addressed with the gate, of course mute on the channel will do the job. Done successfully with automatic mixers all the time and referred to as NOM (number of open mics). This when properly set should eliminate the drum pickup problem and also reduce potential feedback.

I've found gating of vocal mics to keep out other instruments & stage wash to be pretty ineffective, especially stages with loud drummers. The snare will always trip the gate if it's the loudest thing on stage. Also, even if you can get the gate to behave well enough to only open when the vocalist is on the mic, I find it disconcerting when the gate does open because it also causes a jump in the level of stage wash which then pops off when the gate closes again even if the gate is set for a relatively low level of attenuation. IMHO, it's better to use mics with high off-axis rejection like Audiix OM6s and 7s. If you have vocalists with poor mic technique on a loud stage where they can't use such a mic and have to go with a more forgiving SM58, no amount of processing is going to fix it anyway. It is what it is.

[WK154]

Agreed I don't use gates except in very uniform background situations and then rarely. I certainly agree with finding the right mic for the job and stopping the problem at the source instead of band aids down the road. In the above  case mute is the most effective.