Microphones Mic Placement

[Studio]

My school had a new theater built in 2003, it has been good but some things are a bit wierd (don't get me started on that) however the recording microphones have never been moved from their original position.

You can see 2 SM-81's hanging from the Catwalk in the house.
However many people have complained about the quality of the recordings. We have been recording to DV tape with our video system (don't get me started on that either) so I thought we could try recording the way the band and orchestra are recorded (digital recorder/done by someone outside school but with our mics) however when listening to their recordings they still don't sound the best.
Attached is a mp3 of the opening song of our recent pops concert http://dl.dropbox.com/u/268877/I%20Gotta%20Feeling.mp3, and I was wondering what I could do to make these recordings sound better (because we will be making CD's and DVD's next year (no more recording guy-to expensive $5 more for a Cd wasn't going well).

We can't have anything onstage (see photo 2)

with choirs extending off both sides of the apron.

We do have mic stands (up to 10 ft. boom and all - don't ask), and a boatload of choir mics, which we can't hang but could put along the stage if necessary.

And yes we can move the SM-81's

Any Ideas?

 

[MarcusL]

Is there any particular reason you are tied to using mics to record? Why not get a line out from your board?

Also, why is your orchestra shell not lined up properly? Does it not fit on the stage?

 

[Studio]

Is there any particular reason you are tied to using mics to record? Why not get a line out from your board?

Also, why is your orchestra shell not lined up properly? Does it not fit on the stage?

The board (Soundcraft Series TWO) has no mics connected to record from (during concerts) and we are recording from a line out in the first photo (musical) but for the choir concert the only mics on stage are the 4 handhelds.

 

[MarcusL]

Can you explain your set up a little more? How are the SM-81s being used to record? Are they run to a separate system?

Even if they are, all you need to record direct from the board is an open line out and any form of recording hardware, even the same thing you are using to record from the SM-81s, just disconnect them and switch to the line coming from the board.

 

[Studio]

Actually here's a better reason why we can't have mics on stage.

As you can see there is no room left!

 

[MarcusL]

I totally understand the lack of space (we just had a 120 person orchestra on our stage the other week. We lifted up the legs and had chairs in the wings and behind the cyc line), but what I'm saying is that you don't need a mic to record sound. You can use the mix from your board.

 

[Studio]

Can you explain your set up a little more? How are the SM-81s being used to record? Are they run to a separate system?

Even if they are, all you need to record direct from the board is an open line out and any form of recording hardware, even the same thing you are using to record from the SM-81s, just disconnect them and switch to the line coming from the board.

The SM-81's are patched into our board (Soundcraft Series TWO) and are sent as Group 1/2 to our recording mixer on our video table in the house, and then the 4 handhelds are sent as group 3/4. The problem is not connections, I know how to fix that, the problem is the sound of the recordings. I have met the person who designed the sound system, when he came in to record the band and he used his own microphones one time on a stand in the 6th row and "supposedly" it sounded better. So should I try this? Does anyone see something horribly wrong with where the mics are?

The sound shells fit when the risers are on stage and not separated like they are in the photo.

And we are recording line out from our board, the problem is there is nothing to record the choirs (musicals are just fine) I put the musical photo in so you could see where the mics were in the house.

 

[MarcusL]

I am still not sure why you are using the SM-81s...

You would get much cleaner sound if you don't introduce another mic (and subsequent gain level) that the sound has to pass through. You can bypass the SM-81s completely and just record your mix. This will prevent any feedback or extraneous sound from being recorded. You will get pure sound that sounds exactly the same as what you are sending to the house.

 

[MarshallPope]

You will get pure sound that sounds exactly the same as what you are sending to the house.

I think the problem with that is that you don't necessarily want to record what's going to the house. It seems as if his other mics are being used for solos, etc, which need to be pushed above the sound of the entire choir in the house mix. The house mix would not need to mic the choir as a whole, as it is likely loud enough without any reinforcement.

 

[MarcusL]

In that case, you would want to suspend a mic above the chorus itself, not in the house.

 

[pmolsonmus]

Please explain your set up completely.

Mics into> what kind of board?> what recording device?>what software or??

If it sounds good in the room and the room is fairly good, easiest set up would be a few omnis back several rows from the front of the stage elevated 15' or so.

More complex stereo set ups including XY/ Blumlein/ M/S would allow you a bit more flexibility but also require a bit more knowledge.

Best way to set up a mic for an acoustic set up is to put the recorder into mono and just one mic live - walk around the space listening w/ just one ear in headphones. Get the best sound - a few feet back/forth up/down will make a huge difference. Do the same w/ the other mic and make sure you don't create phase problems - (keep them both on the same plane- that's why I'm recommending omnis at first) Keep the recorder in mono and turn on both mics. If it sounds good in mono - pan to the sides to taste and you should be able to get a fairly accurate representation of the performance. If you then have to add a line from your mixer in for the solo mics - you can add effects and blend to taste as well.

For Omnis - I would look into SD condensors. If it were me on a budget for a high school, I'd buy a pair of RODE NT5's and then get the omni capsules for another 80 bucks each. If my budget allowed I'd set up a pair in XY in the middle and omni outriggers.

YMMV - the SM81 is a great mic, but the placement may be all wrong for what you're trying to do. If you can use them in the set up I describe, I'd put it them in XY with some omni outriggers.

Phil

 

[MarshallPope]

Just a quick tip - If you are stuck using those mics, fishing line is good for placement adjustments. I can't really tell how it is hung from the picture, but, if possible, you could play with raising it, lowering it, pulling it toward the stage, pulling it back.

 

[Studio]

Lets see here, I am trying to record a large choir or band (no mics to mix or record!!!)

SM-81 > Mackie 1604 (Recording Table) > Panasonic MX-50 > DV tape deck > MacBook with FCP

Sometimes the house board (Soundcraft Series TWO) will be in-between the mics and the mackie.

This will be simplified with a firewire mixer I have found in the tech closet next year SM-81 > Firewire Mixer > MacBook (Logic)

We might get some condensors but are on a tight budget and mics are not on the top of the list.

We cannot suspend mics above the choir (not wanted, no lift, no anchor points,...etc). We might be able to place choir mics on the edge of the apron but I don't want to do this.

The Sm-81's are not sent to any mix or monitor mix they are for recording only.

If I were to move the mics where should they be moved FOH, 3rd row, booth?? Thats my main question. We have the stands I just need ideas.

 

[FMEng]

The SM-81s are great microphones, but not what I would choose for a choir. They have ruler flat frequency response. The human voice is usually flattered by some presence rise above around 5 kHz. Use the 81s for micing instruments. The high placement is really the big problem.

I don't like spaced omnis because the placement of them is pretty touchy to get the proper direct/reflected balance, and a widely spaced pair of any type of mic will have mono compatibility issues. Phase incoherence can also make digital editing at zero crossings a nightmare.

My favorite stereo method is ORTF, which is a cardioid pair 17 cm (6.75") apart, and angled at 110 degrees to each other. It yields a nice stereo image, a bit broader than XY, which is fairly phase coherent. Placement of ORTF is fairly forgiving, too.
ORTF stereo technique - Wikipedia, the free encyclopedia

Small diaphragm, cardioid condensers are ideal. Choose a model with some presence boost and a pretty smooth low-end. I would place the ORTF pair a few rows back from the stage, with the height about even with the top of the heads of the singers in the back row.

Try the ORTF pair with a stand and a pair of mics you have on hand (maybe even the 81s with a light touch of 3 to 4 dB of high EQ). If it works well, they could be hung if you want a permanent setup.

 

[museav]

SM-81 > Mackie 1604 (Recording Table) > Panasonic MX-50 > DV tape deck > MacBook with FCP

Sometimes the house board (Soundcraft Series Two) will be in-between the mics and the mackie.

This will be simplified with a firewire mixer I have found in the tech closet next year SM-81 > Firewire Mixer > MacBook (Logic).

This is a live performance recording and not a studio, you want a sense of being there and being part of the audience, so you probably do not want to record only the stage mics and the ambient mics out in the house can become very important.

If you are looking for a simple archival recording then the mics out in the house might be fine by themselves and FMEng offered some good input on alternate micing, the only thing I would add is to consider how much the mics might be in the house speaker coverage. And some mics on stage might help, something like this Audix would be nice but you could probably work with your existing mics and booms. However, regardless of how you mic, for a higher quality recording you are probably going to want to mix the recording independent of the house mix. You would normally want as much flexibility and control as possible for both mixes while minimizing how what you do for one impacts the other. The fact that it looks like your house system is either LCR or mono while you are apparently doing a stereo recording also probably adds to the complexity and difficulty with any ties between the two mixes.

I do not understand your running through the house mixer and to a second mixer or your using the Group outputs for recording or your running through the DV recorder to the MacBook. I think that is all just making things more difficult. I also don't understand how the FireWire mixer will fit in, will it be replacing the Mackie 1604 or will that still be used for the video mix?

Anyways, what it sounds like you really want is three separate mixes; a house mix, a record mix and an audio-for-video mix. One option would be to just use one mixer for everything but to use pairs of aux sends for the recording mix and/or audio-for-video mixes. That way you could mix on the faders for the house and create a separate aux mix for the recording feeds.

However, since you have at least two mixers, it might make more sense to dedicate one console to the house mix and one (or two) to the recording and video mixes. The challenge there may be getting the mic signals that would be in both mixes to both consoles. Unfortunately, the Direct Outs on the Soundcraft Series 2 and Mackie 1604 are line level, post EQ and post fader, so you can't really use them as an effective splitter. If the consoles are in the same room and using the same power circuit, you could simply 'Y' the related stage mics to both the house and recording consoles, with the ambient mics also going to both consoles or to only the recording console(s). Even better would be to use mic splitters (Whirlwind, Pro Co, Radial Engineering, Jensen, etc.) that would provide the mic split and isolate the two mixers.

With this approach you could mix the house mix on the Soundcraft without worrying about how anything you do affects the recording mix. At the same time, you could create an independent recording mix.

 

[Studio]

Thank you all for the feedback and ideas. I will be trying to have separate mixes the reason why they were together was because the guy doing the CD had his own recorder and we needed the same mics but now that we are doing the CD and DVD I most likely will do the following:

Use a boom stand in the front-middle of the house with the SM-81's EQed, and run the recording mix through the firewire mixer.

Thanks I now have some ideas for next school year.

 

[noozer42]

Hello.

The first thing I would do is experiment with the positioning a little bit. All the equipment seems fine, so I'm not sure you could significantly improve the quality of the sound by re-patching things around. I would take the two SM-81's and hang them just behind or just in front of (preferably behind) and just below the proscenium curtain, maybe from the first electric or the first catwalk over the stage. The angle that they hang at, and the distance apart (i would suggest 1/3 of the way in on each side) can be crucial and you'll probably have to move them around some to find a good spot. Think of it like focusing a light, you want the two mics to pick up the whole front of the stage as evenly as possible, at the optimal distance.

I think part of your sound issue is that the mics are hanging in the house, and are therefore picking up a lot of room sound with the (more distant) source sound of the chorus. The closer you can get them to the source with a nice even pattern, the better.

This is more unlikely, but the holder that they are in may also be causing some of the problem. If they are set crooked, they may be interfering with each other's pickup patterns (causing weird drop-outs in the EQ). Adjusting them or maybe reversing the polarity on one might also improve the sound quality.

Hope that helps. Interesting topic. I'd like to know what you end up doing...

-B

 

[museav]

I think part of your sound issue is that the mics are hanging in the house, and are therefore picking up a lot of room sound with the (more distant) source sound of the chorus. The closer you can get them to the source with a nice even pattern, the better.

Picking up the room sound is precisely the idea with ambient mics, for live recordings you typically want some of the 'being there' effect of the room, audience, etc. If you only close mic then you won't be getting what anyone in the audience hears. The goal is apparently purely recording the choir, not reinforcing it in the room and while perhaps a topic for a more general discussion, many of the things that apply to sound reinforcement differ for sound recording and vice versa, including how you might mic different situations. One major difference is that recording does not have to worry about acoustical feedback since the recording signals are not introduced back into the house system.

All the equipment seems fine, so I'm not sure you could significantly improve the quality of the sound by re-patching things around.

The way the system is apparently currently configured, running the ambient mics into the FOH console and using Group 1/2 out for recording those and Groups 3/4 out for recording other mics, would rarely make sense. A simple example is that any mics for solos, etc. would be mixed for the house and the recording feed is then stuck with the related trim, EQ, fader setting, etc. of that mix. If you have to EQ a mic running to the house system in order to avoid feedback, that EQ then affects the recording even though it may not be necessary or desirable for the recording. Since they apparently have multiple mixers, it seems to make more sense to have independent mixes.

I would take the two SM-81's and hang them just behind or just in front of (preferably behind) and just below the proscenium curtain, maybe from the first electric or the first catwalk over the stage.

Perhaps you missed the comments "...which we can't hang but could put along the stage if necessary" and "We cannot suspend mics above the choir (not wanted, no lift, no anchor points,...etc). We might be able to place choir mics on the edge of the apron but I don't want to do this." It sounds like hanging anything over the stage is not feasible.

 

[pmolsonmus]

I like ORTF as well but stand by the ease of set up for omnis. For my money, it may not be the best way to capture a realistic stereo image, but it is the easiest to accomplish without phase problems. If they're on the same plane and not rejecting any direction, you're golden. YMMV

However, I would disagree completely w/ EQing the 81s on the way into any recording device. EQ is created through phase manipulation and the EQs on all but the best of boards create far more problems than they help.

Without an accurate monitoring system to judge the effect of that EQ, you should save the EQ for mixdown later and keep all of them at neutral! A general rule in recording that stands the test of time is that it is almost always better to cut than to add.

FOH is a different beast and often requires changes throughout a performance.

 

[museav]

I like ORTF as well but stand by the ease of set up for omnis. For my money, it may not be the best way to capture a realistic stereo image, but it is the easiest to accomplish without phase problems. If they're on the same plane and not rejecting any direction, you're golden.

What phase problems are you referencing? What plane(s) and why is their being coplanar important? Why is the mics being omnidirectional important?

EQ is created through phase manipulation and the EQs on all but the best of boards create far more problems than they help.

Analog and IIR filters have associated changes in phase, changes that may vary with frequency, as a byproduct of the filters and differential phase between signals can cause frequency anomalies in a resulting summed signal, however equalization itself is manipulating amplitude. As an example of this you can EQ using digital FIR filters that are linear phase.

Without an accurate monitoring system to judge the effect of that EQ, you should save the EQ for mixdown later and keep all of them at neutral! A general rule in recording that stands the test of time is that it is almost always better to cut than to add.

If there is a later mixdown, in this case it sounds like they are not doing a multi-channel recording for later production but rather a live mix to a two channel recording, so if you wanted to adjust or process individual sources and not an entire channel it would apparently have to be done live. But this is a good point relative to the recording quality, it is generally unreasonable to expect a live two channel recording to equal the quality of a post-produced, multi channel recording, so think about what your expectation are for the results.

FOH is a different beast and often requires changes throughout a performance.

Agreed, and changes for different reasons than recordings such as gain before feedback, acoustical environment, etc.