Everything recorded is edited with Final Cut Pro. Soon we will be doing multichannel recording with Logic with this MultiMix 8 FireWire because I found it in the tech storage room near our TV studio, and I'm tired of the sound op for recordings not turning down the handheld group when their too loud (i'm on stage for the choir performances), so I'll just edit later (and also get to learn how to use logic).
Microphones Mic Placement
- Thread starterStudio
- Start date
Everything recorded is edited with Final Cut Pro. Soon we will be doing multichannel recording with Logic with this MultiMix 8 FireWire because I found it in the tech storage room near our TV studio, and I'm tired of the sound op for recordings not turning down the handheld group when their too loud (i'm on stage for the choir performances), so I'll just edit later (and also get to learn how to use logic).
I'm looking at your pictures and seeing four or five solo mics plus the recording mics, that little Alesis mixer has four mic and two stereo line inputs. If you really want high quality recordings you probably want to be able to mix each mic and any backing tracks, etc. independently. Having the recording mix of all the four or so stage mics limited to a single stereo mix that is based on mixing for the house, which is what you are getting from the Group 1/2 output on the Soundcraft, may be part of the problem. If you can't bring every mic into the recording mix independently, then maybe try to at least use pre-fade, pre-eq aux sends rather than Group outputs, although that also means that mixing the recording send would require operating two consoles.
pmolsonmus
Active Member
The "plane" I'm referring to is geometric plane that the mics should be on to avoid the comb filtering that results from the same source hitting different mics at different times.
The EQ on the OP's board are analog and will likely cause significant problems to the eventual recording that cannot be anticipated without accurate monitoring. What may sound great will (in all likelihood) not translate onto multiple systems.
In my experience, again YMMV, it has been easier to avoid phase issues (comb filtering) using spaced omnis.
I don't think we disagree too much. Perhaps its just the medium of quick forum posts.
The EQ on the OP's board are analog and will likely cause significant problems to the eventual recording that cannot be anticipated without accurate monitoring. What may sound great will (in all likelihood) not translate onto multiple systems.
In my experience, again YMMV, it has been easier to avoid phase issues (comb filtering) using spaced omnis.
I don't think we disagree too much. Perhaps its just the medium of quick forum posts.
With a choir, especially a situation like that shown in the pictures, you have multiple sources separated in space in all three dimensions. As a result, there is no plane or even line upon which two receivers (mics) can lie and have the same phase relationship from all sources. About all you can do is either make the two mics so close that they start to resemble being at the same point such that any relative phase issues are pushed very high in frequency, as done for X-Y, Blumlein and M-S techniques which use the mic patterns to create the stereo separation, or you locate the mics far enough apart that they become randomly coherent at any frequency of interest, the A-B or spaced approach which uses differences in phase and amplitude to create stereo separation. The ORTF previously noted is sort of an intermediate approach between A-B and X-Y. A quick summary of these techniques can be found at Recording: Stereo Microphone Techniques - Pro Sound Web and http://www.shure.com/americas/how-to/stereo-miking-basics.
Maybe there is some confusion. I would suggest that you always monitor a recording, in fact while a simple recording does not require it, if you really want the best quality the recording should be a separate mix with a dedicated operator who only listens to what is being recorded, and I mean ideally what is actually recorded and not just what is going to the recorder. In fact one of my arguments against the current signal routing with the recording signals derived via the FOH mixer Groups is that any channel EQ applied or balance between channels applied for the house is also applied to the recording send.
By the way, one of the reasons I like to ask "why" questions here is so that through the responses others may gain an understanding of the underlying principles, which can then be more broadly applied, rather than just the answer for that situation. I believe that understanding why something works or not can be much more valuable than just knowing that it works or not.
You seem to be suggesting that spaced omnis don't have time differences. Of course, it is pretty simple physics that tells us that is completely wrong.
Any time there are two microphones, separated by some distance, and they are both picking up sound from one source, there will be phase errors due to the different path length to each microphone. If the output of the two mics never gets summed together, such as when each one feeds a separate stereo channel, and they never get mixed (summed) together, then no problem.
When they do get summed together, the phase error causes cancellations and comb filtering which alters the frequency response of the summed signal. This is why we need to employ the 3:1 rule when micing choirs, orchestras, etc. when multiple microphones are summed together. The 3:1 rule reduces the problem because any source picked up by multiple mics will be much stronger in one than the others. But, the 3:1 rule doesn't apply here because we cannot mic this big choir with just 2 mics if we follow it.
This is an important issue for TV and radio sound, because often times a show produced in stereo is heard in mono. In my work as a broadcast engineer, I always check stereo sources by monitoring in mono to listen for compatibility problems. You'd be surprised how often issues sneak up. Just a mis-wired XLR connector can cause a nasty problem.
I can tell you from both theory and experience that any spaced, stereo pair of mics will sound a bit funky in mono. It doesn't matter if the spaced microphones are omnis, cardioids, or figure-8. This is why ORTF, XY, mid-side, and other stereo techniques were developed and remain widely used. Spaced microphones are useful and can sound great under the right circumstances, but not as a lone stereo pair for video or radio.
Last edited by a moderator:
Would using the direct out's of the Soundcraft Series TWO allow me to do this?
And to answer the mic phase questions, these mics are set up in the same arrangement of many mics which is Coincident-Pair Shure Notes Issue #25 - Stereo Miking Techniques I am going to continue to have the mics in this placement because I know what happens when two mics are on opposite sides of the room someone speaks.
Well, that answers the question I had as to whether it was a Series 2 or a Series TWO, which are actually two different Soundcraft models.
On some consoles the channel Direct Outs can serve as a splitter. On the Series TWO the Direct Outs can be selected as pre or post fader via the "DIR PRE" button, however they apparently are always post the channel polarity, trim, high pass filter and EQ controls. There is a pre/post EQ switch for each channel but I do not think there is a way to make the Direct Outs pre-EQ without also making all the aux and main buses pre-EQ, essentially the EQ affects everything or nothing. So using the Direct Outs set for pre fader would be better for recording then getting the signal post fader but would still have the high pass filter and any EQ applied for the house mix.
Well, that answers the question I had as to whether it was a Series 2 or a Series TWO, which are actually two different Soundcraft models.
On some consoles the channel Direct Outs can serve as a splitter. On the Series TWO the Direct Outs can be selected as pre or post fader via the "DIR PRE" button, however they apparently are always post the channel polarity, trim, high pass filter and EQ controls. There is a pre/post EQ switch for each channel but I do not think there is a way to make the Direct Outs pre-EQ without also making all the aux and main buses pre-EQ, essentially the EQ affects everything or nothing. So using the Direct Outs set for pre fader would be better for recording then getting the signal post fader but would still have the high pass filter and any EQ applied for the house mix.
Luckily we almost never EQ mics for the majority of concerts (I know it's a work in progress) and that should work fine...now to find some short 1/4" cables (we seem to stop at 20' feet at my school) and install some drivers on a macbook and I'm good to go.
Thank you guys so much!
pmolsonmus
Active Member
To make it clear FMEng and Museav are correct re: phase issues and summing to mono.
I didn't mean to imply that spaced omnis don't have phase issues - merely (and this is the point I was trying to make as a result of recording choirs in similar settings for the past 20 yrs- while also conducting and playing piano and doing everything else a choral director does before a concert) that in my experience in a typical auditorium and a large choral ensemble - I can get 2 omni mics set up in a matter of minutes (which is usually all the time I have on concert day) that USUALLY gives me a fairly good, down and dirty stereo mix even if summed mono - which is why I suggested it as a starting point only for the OP. All other stereo options mentioned: XY, Blumlein, ORTF, M/S are preferred over A/B anything when summing to mono but require more finesse (and time) with mic placement or the net result is "funkier" when summed in mono.
I didn't mean to imply that spaced omnis don't have phase issues - merely (and this is the point I was trying to make as a result of recording choirs in similar settings for the past 20 yrs- while also conducting and playing piano and doing everything else a choral director does before a concert) that in my experience in a typical auditorium and a large choral ensemble - I can get 2 omni mics set up in a matter of minutes (which is usually all the time I have on concert day) that USUALLY gives me a fairly good, down and dirty stereo mix even if summed mono - which is why I suggested it as a starting point only for the OP. All other stereo options mentioned: XY, Blumlein, ORTF, M/S are preferred over A/B anything when summing to mono but require more finesse (and time) with mic placement or the net result is "funkier" when summed in mono.
WooferHound
Well-Known Member
I can't see your recording mics in any of the pictures.
My sound system is a rental system and it gets set up in all kinds of rooms. I have always gotten a really decent recording by mounting a stereo pair of mics on a single Boom Stand at the Mix Position. The mics should be at 90 degree angles facing the stage and the Mic/Boom stand should be fully extended.
The sound has always sounded just like it did when I mixed it because they the mics were there with me at the mix position.
My sound system is a rental system and it gets set up in all kinds of rooms. I have always gotten a really decent recording by mounting a stereo pair of mics on a single Boom Stand at the Mix Position. The mics should be at 90 degree angles facing the stage and the Mic/Boom stand should be fully extended.
The sound has always sounded just like it did when I mixed it because they the mics were there with me at the mix position.
MisterTim
Active Member
This depends on your situation. In ORTF they should be at 110 degrees; in XY they can be anywhere from 90 to 130 degrees.
Why? Why wouldn't you put the mics at the height you want them? You do not necessarily want them as high as they can go.
WooferHound
Well-Known Member
The same probably applies to the patrons in the audience, if individuals talking is a distraction then you probably want to address that anyways.
I believe that it really comes down to what you are trying to do. If you are trying to create the impression of being alone in a studio or an empty room you may approach some things differently than if you are trying to create the impression of being part of the audience for a performance.
