Topic: ORTF/DIN/etc. when close to a wall?

[BradM]

At one venue here in Ottawa (Babylon, for those who might know it), probably the best place (in terms of sound and convenience and not getting in peoples' way) to tape from is close to the right-side wall of the club, just beside the sound board. This puts me maybe 30' back from the stage, which is about 20' - 25' wide. My concern with using something like ORTF/DIN/XY is that it'll end up having the right channel mic aimed at the wall, about halfway back from the stage to where I'll be. I'm using matched Oktava MC-012s, with cardioid capsules (I also have the omni and hypercardioid caps).

What I'm thinking of trying is aiming the right channel mic at the right-side PA stack (or its left-side edge, i.e., the boundary between the PA stack and the edge of the stage), the left channel mic at the left-side PA stack (or its right edge), with a line drawn between the centres of the capsules parallel to the plane of the front of the stage. I'm not sure what angle this'll give between the mics, but it'll probably be less than 90 degrees. Is this approach crazy? In general, how do I (or even do I) adjust mic arrangement when I'm significantly off-centre?

Aloha,
Brad

[Javier Cinakowski]

If I am on the far right side lets say, I keep my mics @ 90-110 degrees and point them more to the left.  I am aiming at the center of the dance floor not the stage.  Whe you are not dead center I aim for the image, not the source.  I hope that makes sense.

[stigs]

couldnt this cause phasing issues

[Nick Graham]

Whe you are not dead center I aim for the image, not the source.  I hope that makes sense.

I would think it would work exactly the opposite, i.e. when not center it's better to just "aim for the stacks".

When DFC you can get into different streo configs, etc.

Am I wrong?

[Javier Cinakowski]

I am certainly no expert, but I think stereo mic configs are an art with some science to back it up. 

From what I understand you should keep a traditional stereo config no matter where you are in the venue in order to not have phasing problems.  The phasing problems are more from the way the mics are possistioned compaired to each other and not where the source audio is comming from.  Just point your stereo config at what you want to record.  If you do not want to record the sound comming of the wall, or point your mics at the wall then just turn the stand and both mics more toward the center of the room.  This is hard to describe without a drawing. 

[BradM]

Thanks, everybody. If I were to turn the ORTF setup so that it pointed at the centre of stage (from off of centre), wouldn't that put one mic closer to the stage than the other, making things imbalanced? Or should I pull one of them back (relative to the other) so that the plane of the front of the mics is parallel to the front of the stage?

Aloha,
Brad

[Javier Cinakowski]

oh, I dig what you are saying.  you are concerned about the time difference from one mic being closer.  I see.  Hmmm...  Interesting.  Pulling the closest mic back is a great thought.

[easy jim]

oh, I dig what you are saying.  you are concerned about the time difference from one mic being closer.  I see.  Hmmm...  Interesting.  Pulling the closest mic back is a great thought.

I often do something like that with a tighter angle of 70-80 deg. when I am off center, but still relatively close.  Off center and further away, or if the venue sounds calls for it, I switch to XY and tighten the image.

[rowjimmytour]

I am certainly no expert, but I think stereo mic configs are an art with some science to back it up. 

From what I understand you should keep a traditional stereo config no matter where you are in the venue in order to not have phasing problems.  The phasing problems are more from the way the mics are possistioned compaired to each other and not where the source audio is comming from.  Just point your stereo config at what you want to record.  If you do not want to record the sound comming of the wall, or point your mics at the wall then just turn the stand and both mics more toward the center of the room.  This is hard to describe without a drawing. 

I haven't been off center to many times but the few times I made up the difference w/ the amount of level I set Ie Left Right runnin' DIN. Not sure if this is what your all thinkin' but it seemed to work for me. Also I got my TL's for stuff like this so I could run Hypers when I tape at a place where the sound bounces off the walls.
Peace

[rowjimmy]

Thanks, everybody. If I were to turn the ORTF setup so that it pointed at the centre of stage (from off of centre), wouldn't that put one mic closer to the stage than the other, making things imbalanced? Or should I pull one of them back (relative to the other) so that the plane of the front of the mics is parallel to the front of the stage?

Aloha,
Brad

Having gone into a room planning to run ORTF only to get stuck too far back to run the config without wall reverb I'd say, abandon ORTF and go for something tailored to the sound in the spot you've got.

I'd think that aiming for the stacks from the right side would leave the left a lower than the right but you can try to compensate with a bump up on your pre, or some fiddling in post (if you're into that sort of thing  .)

As with all things, trial and error combined with knowledge and a little dumb luck will get  you there.

I'll be curious to hear how you decide to address it.

[morningdew]

I've taped in bar which is quite the challenge 3 times now.

The only way to get my mics up for these 3 bands was to have them off center.  Not a ton off center but definately off center.  The room is probably only 24' wide and I'm on a post which is about 6-8' off center to the left.  I'd say I'm 12-14' back of stage.  All three times I ran a strict DINa.  I adjusted my levels so the meters were bouncing in perfect unison when the whole band was playing in unison.  So obviously I had a bit more gain on the right channel.

The first recording came out great (as far as stereo imaging is concerned).  I can tell where each performer was and when the solos switch from guitar to keyboards I can hear the swtich from right to left on my playback.  My second recording didn't have as nice of a stereo image and was more centered.  The difference I noticed was that on my second recording the right mic ended up pointed at the right wall and the left mic was pointed directly at the main left speaker.  On my first recording (a different band) my mics basically ended up pointing at each main.  The left mic just being much closer in a straight line distance.

So, in my brief little test I think the most important thing for being off center would have been to keep it at 17cm in both cases but in the second case run a tighter angle (maybe 80 degrees) so the right mic was pointing more at the right main instead of the wall.

In summary, I'd run DINa if it's a narrow joint or DIN in wider room, put the mics at 90 degrees and see where they are aimed.  If both mics are shooting at the mains then I'd leave it and make my levels match while I was recording live.  If necessary I'd tighten my angle up a bit.  If the mics needed to be spread a bit I'd keep the 90 degrees and move to DIN (from DINa) before I opened the angle from 90 degrees.

I have no idea if this right but 3 shows so far and this theory is working but still needs a lot of testing.

[rowjimmytour]

In summary, I'd run DINa if it's a narrow joint or DIN in wider room, put the mics at 90 degrees and see where they are aimed.  If both mics are shooting at the mains then I'd leave it and make my levels match while I was recording live.  If necessary I'd tighten my angle up a bit.  If the mics needed to be spread a bit I'd keep the 90 degrees and move to DIN (from DINa) before I opened the angle from 90 degrees.

I have no idea if this right but 3 shows so far and this theory is working but still needs a lot of testing.

WQT
Peace

[Javier Cinakowski]

WQT?

World Queer Tapers Association?

[Jimna]

Ive found that when im close to a wall or the back of a venue(or a really bad room ) i generally get a heavy room reveberation(which always comes out as a midrange boomyness ), and that is almost always best delt with by XY set-up.  just aim them as you did at the stacks however the nessasary angle results, and maintain the XY axis.  this does wonders to clean up a bad room or a bad set-up spot.  it also helps any phasing problems and keeps a resemblence of stereo imaging.  this is the science that many stereo mic designers use in theory, atleast as far as i understand.......