And We're Back

[billroper]

Home again after the short drive from Windycon. I had a wonderful time, but boy am I tired.

I hope to say more about the con later, but given my recent track record, I may fail at that. So let me just say that all of our guests were an absolute delight to work with, especially the ones that I worked closest with, the members of Tricky Pixie.

And since this came up in conversation with s00j, our feedback problems weren't in any way due to her lovely Neumann microphone. :) It was a different problem altogether which won't be repeated once we go over it with everyone involved. The magic letters in this case were "PFL"...

Comments

[dave-ifversen.livejournal.com]

The AUX1 and AUX2 busses (monitor feeds for Alex and Betsy) were set to PFL (where they should be for stage monitors), but s00j was using AUX3 - which is hardwired AFL on the Mackie board. I see the problem now.

I rummaged around and found the schematic for my Mackie board, and I am going to modify AUX3 and AUX4 (and, by default AUX5 and AUX6) to be hardwired PFL - should solve that problem nicely. (AUX1 and AUX2 will still be selectable PFL/AFL, in case I use them for effects.) The only question remaining is, should I modify all the AUX busses to be post EQ (rather than pre EQ, like they are now)?

[billroper]

Actually, you might or might not want to make that mod. (Your board, so it's up to you, but...)

The reason we got the godawful ringing feedback was because Betsy's mic was moved back next to the wall. I'd pulled it down with the fader. I'd muted it. None of that affected the AUX settings with the PFL switch thrown. Oops. I finally grabbed the AUX1 and AUX2 knobs and twisted them down to make the feedback go away.

See, once the mic was next to the hardwall, it got all of the sound from the monitors bouncing back off the wall, and that's pretty much the recipe for feedback. (Well, you could just point it at the monitors, which would be slightly more effective in producing feedback. :) )

This causes me to wonder if it would be better to run the monitors in AFL mode. That way, what you're hearing in the monitors will mirror what I'm doing with the faders so that -- for example -- when I ride Betsy up or down because she's picking or bowing the cello, she will get more or less cello in the monitor as I move the fader, with the result that the monitor volume is actually pretty much constant for both modes of playing.

That's what I'm thinking anyway. I may be thinking incorrectly...

[dave-ifversen.livejournal.com]

AFL was really designed with effects in mind (reverb comes to mind right away), where you want the AUX send (with the 'wet' signal) to follow the house fader (with the 'dry' signal) without having to remember to adjust a separate knob.

The only real problem I see with using AFL for the monitor mix is the need to constantly ride herd on the monitors as the house mix gets changed. (e.g., if the monitors are in AFL mode and we bring up Gundo's screaming guitar solo in the house mix, everyone on stage gets blasted as well.) When using the FoH board to run monitors, the poor engineer would end up crazy-busy adjusting the house mix then re-compensating for the monitors.

When I was doing this for Sound and Lighting Services at Tech (mumble) years ago, I found that most performers wanted their monitors set and then not messed with much. (Of course, back then we used to split the signal at the stage end of the snake and run a separate board just for the stage monitors - sometimes we'd even put the monitor board and operator right up on the stage with the performers so it was easier to keep an eye (ear?) on the monitor mix, and the performers could more easily request adjustments.)

I didn't even think about the fact that Betsy's mic got moved back like it did, close to the back wall - no wonder we got feedback like that.

The big thing to remember when using PFL for the monitors is that the monitor mix is totally separate from the house mix, giving the poor board operator that many more knobs to remember to deal with when chasing feedback gremlins.

[billroper]

Well, the fact that the PFL was pre-mute was what gave me the conniption. I'd turned the fool mic off -- or so I thought! :)

I did a little web browsing and was amused to see that rock bands tend to prefer PFL monitors, while choral groups tend to prefer AFL monitors. So that would account for Gundo's screaming guitar solo...

I think ultimately it depends on how you've put the monitor mixes together overall and that's going to vary from group to group. If the volume variations in the house mix aren't too large, then a PFL monitor mix will probably work. And I'll guess that Gundo's solo (to continue to pick on it) was probably mixed lower in the other monitors to start with, so the fact we pulled it up some is frequently going to be ok.

Of course, I don't actually perform with monitors frequently, so my mileage is certain to vary. :)

[dave-ifversen.livejournal.com]

Well, the fact that the PFL was pre-mute was what gave me the conniption. I'd turned the fool mic off -- or so I thought! :)

I wish the board had 2 mute functions - one to mute the *entire* channel, and one that would only mute the house feed (for those times you don't want to mute the monitors) - that would make squelching feedback a tad easier. I suppose you could get that functionality if the mute button did the entire channel, and then if you wanted to just mute the house output you could always de-select the outputs (L/R, 1/2, 3/4) - you would just have to remember to re-select that channel's output appropriately when it was needed again.


I did a little web browsing and was amused to see that rock bands tend to prefer PFL monitors, while choral groups tend to prefer AFL monitors.

I can see this - I imagine that most rock musicians are more interested in hearing their fellow performers in the monitors in order to keep together, and trust the engineer to get the house mix right. Rock is loud enough that the performer on stage right probably can't hear the performer on stage left if it weren't for the monitors.

Choral groups would probably be much more interested in what was going out to the house so that they can adjust their singing as needed - especially if each performer doesn't have his or her own mic.


Of course, I don't actually perform with monitors frequently, so my mileage is certain to vary. :)

While I used monitors all the time at school, it wasn't until I bought the SMac system from you that I was even able to offer monitors for performers at the cons, and I'm still getting used to using them again. Throw condenser mics into the mix, and things get interesting (remember - it wasn't until just recently that I even had condensers to use (unless I borrowed them from you :-) - and my dynamic mics are less sensitive enough that it never really became an issue before now).