My objective is to record small groups playing classical music. No voice-overs, no dialogue, just music.

The groups I will be recording will be brass ensembles (mostly brass quintet) as well as classical piano either solo or together with stringed or brass instruments( ie string quartet with piano) and occasionally woodwinds.

Most of what I've been reading up on about recording for DV seems to focus on dialogue rather than just music,so I'd appreciate some comments on the following

For the kinds of groups I've mentioned, what would be a good microphone recommendation? A couple of folks have mentioned Neumann 184 or KM 100 with the AK40 cartridge. Any comments, pro or con, would be appreciated

Also, for such small groups would X-Y or ORTF or M-S be preferred?

Output would be as audio/video on DVD, or web page, of performance excerpts, as well as stand alone audio CD of complete performances. I'm thinking of recording to an external recorder rather than to the camera.

Lots of questions! I'm quite new to all this, so any thoughts, comments, suggestions, etc would be highly appreciated.

I would fist make sure you also have a mixer setup and recode to both to the camera and a seperate external recorder. In this situation, the audio is too important. Get your self as many options as possible.

If I read your post correctly, you are recording them for a CD as well, so I would recommend thinking of it as an audio project first. Multiple Mics, one for each person, leveled for each person...

Then the camera would be setup the same way you would with any other project on top of what you did to get on the camera. Of course, syncing everything is key so either need some common time code or teh old tried and true slate with a clapper to sync by audio.
M

In my opinion, condenser mics are too harsh for brass and woodwinds. Consider ribbon mics, like Royer or Beyer. KM184 would be good for violin, but you won't like it with brass or flute. If your want to use condensers, use Schoeps. For a small ensemble ORTF gives a natural stereo image. Get a mixer/preamp with 70-80db of clean gain, and record to external unit and also feed to camera for scratch track.

If the intention is to record what the instruments really sound like, then whatever you do - do NOT multitrack, or multimic - you get a very sanitised performance. Classical music has it's own internal balance and close miking can destroy this - the mics are also damn ugly!

We do a fair bit of this kind of thing from the audio perspective, although rarely with video. My own preference is for a co-incident recording technique - spaced pairs tend to give a kind of hole in the middle effect. One thing you have to do is decide early on if you are going to aim for an audio recording, that has matching pictures or a video recording with matching audio. The BBC are pretty expert at this - We have frequent national broadcasts of classical music from the Royal Albert Hall. On radio, these are balanced for conventional stereo, while the audio for the television is slightly different - as the cameras 'pick' on individual or section specific lines, the level of these is sometimes brought up, above what it would be as just a part of an audio recording. So, if in bar 64, the Cor Anglais gets a lovely melody to play, the cameras will provide a close up, and a spot mic may well be blended in giving a closer perspective - on the audio only recording, this melody line may not be so prominent.

I'd suggest that unless you have the equipment and the people to do this properly, you concentrate on just getting images for the balanced audio track.

One trick is to try to avoid static camera shots. Slow and steady movement works really well - you can do lovely disolves and highlights if the background is dark - and brass instruments can gleam if you set up decent lighting. So a jib or two, or decent wheels on the camera support will all work rather well.

The art of stereo recording is quite a difficult one to master, despite the simplicity of the equipment. As has been said, Ribbons are lovely, but not so common, and I find that decent quality condensors work very well. Personally, I favour large diameter diaphragms (but that is because I simply don't have any quality ribbons). The new Chinese ones seem to be getting pretty good reviews - but need love and care to keep going.

"The art of stereo recording is quite a difficult one to master, despite the simplicity of the equipment."

Of course, music itself is sort of the same kind of animal. There are few things simpler than a tight string or a hollow tube, but mastery of the instrument is - difficult at best.

Thanks to everyone who has responded so far. Lots of food for thought. Please keep the comments coming!

I think I'm quite squarely in the camp of not mic-ing the individual instruments as, after all, what I'm aiming for is the sound of the ensemble itself.

The idea of a ribbon mic has quote a bit of appeal but I have absolutly zero experience with them and am not sure whether they'd be generally useful for other stuff as well or not, also I wonder about their robustness or other aspects of their care and handling. Comments and recommendations about specific microphones would be more than welcome.

I think (particularly considering the cost of mics and workload) that I would be better off thinking of this as an audio project with video accompaniment.

That's one reason I was thinking of video excerpts, as there isn't much of inherent visual interest in the rather static nature of these small groups, aside from individual expressions, so I agree completely with adding the visual element with camera moves and zooms as well as close up cuts to individuals during solos, etc. I think because of the small size of the groups it probably isn't as essential to mic from several different positions as it would be with the whole BBC. If you think I'm wrong on this point, please let me know!

I have thought of doing tight close ups during rehearsal to get material for the quick cuts, and then doing the slower and softer moves during the performance. Of course, I'd script the moves in advance to follow the score.

I'd appreciate any critique of the above as well as some recommendations for specific microphones that you think would work well, particularly for the brass, as well as some education on the pros and cons and ins and outs of ribbon mics.

I'd be buying new equipment for this. The budget I have in mind would be between roughly $1500 and $2500 for the mics - is this reasonable?

Thanks again!

If audio quality is the first concern consider using a matched pair of really high quality omnis (DPA or Schoeps, rent them) with a Jecklin disc (which you can make yourself for a few bucks). Good acoustics, fairly tight group, hang the mic assembly on wires about 7 feet in front and above the band (experiment). No mic showing in pictures, realistic stereo image.

Thanks much for the suggestion re Jecklin disks. Interesting idea!

My objective is to record small groups playing classical music. No voice-overs, no dialogue, just music.

The groups I will be recording will be brass ensembles (mostly brass quintet) as well as classical piano either solo or together with stringed or brass instruments( ie string quartet with piano) and occasionally woodwinds.

Most of what I've been reading up on about recording for DV seems to focus on dialogue rather than just music,so I'd appreciate some comments on the following

For the kinds of groups I've mentioned, what would be a good microphone recommendation? A couple of folks have mentioned Neumann 184 or KM 100 with the AK40 cartridge. Any comments, pro or con, would be appreciated

Also, for such small groups would X-Y or ORTF or M-S be preferred?

Output would be as audio/video on DVD, or web page, of performance excerpts, as well as stand alone audio CD of complete performances. I'm thinking of recording to an external recorder rather than to the camera.

Lots of questions! I'm quite new to all this, so any thoughts, comments, suggestions, etc would be highly appreciated.



A lot depends on the setup. Where the instruments are and the acoustic situation. The best mics in the world won't give you good results in a bad space, or if one person is PLAYING TOO LOUD. :)

Regards,

Ty Ford

Ah yes, sooner or later we all see the ugly face of reality!

Room acoustics in this case! I think outside of a studio or a well designed space we have to take our chances and deal with whatever hand reality deals us. And as you say, the best equipment in the world in and of itself won't make up for poor placement of mike and performers, crying kids in the 3rd row, air conditioners, fans, etc (particularly here in southern Arizona!) or fundamentally lousy acoustics.

On the other hand, great equipment (if one knows how to use it of course) can give us more options to make the best of the situation.

I have little experience with video, but have been a still photographer for a long long time, and I always sort of envied the guys with paints and canvas.

Much easier to just be able to put something else in place of the bear proof trash can chained to a tree in the middle of the scene, or the porta-potty, etc etc etc. Whereas we poor photographers had to somehow find a way to deal with it and still get the images we wanted.

Once I got my 5 X 7 Linhof, though, I suddenly found that I had a much better tool kit to use to fight back against reality. Mirror in the picture? Offset the camera and shift the front lens sideways until you can avoid the camera's reflection. Need extreme depth of field? Tilt the lens or camera back.

None of it was perfect, mind you, but it sure helped. And because the camera itself was certainly capable of capturing magnificent images, I could start elsewhere in tring to find out where I had messed up.

I think that's why I'm working so hard to get started on the right foot in this case. I'm certainly not under the illusion that great mics will make up for lack of skill or crappy room acoustics, but at least when trying to diagnose what went wrong I can start from a position of confidence that some shortcomig or excessive variability of the equipment itself isn't the most likely suspect and this should give me exponentially fewer suspects to rule out to tack down the culprit.

The problem with classical music (at least that's what my instructors told me) is that they're usually listened on million dollar hi fi systems. I'm exaggerating here but the audience know what they're listening to. Every squeak, unnatural colorization of the sound, they'll get it. Not counting a very wide dynamic range (ridin' faders.) Mics and crystal clear pres count for alot. But don't forget the acoustics. The room plays a very big part. Everybody else has covered the subject. Detail, detail. Pay attention. Use your ears, move the mic around the room with a very good pair of headphones. You might find that "sweet" spot.

Fortunately or unfortunately you're 150% right.

The fact that it's classical means that it's a classic, ie, people who are into classical music know what it should sound like because they've probably heard it played by real pros and listened to CD's made with million dollar equipment (and smart guys who know how to use it.)

They also know what French Horns and trombones sound like, and things like pianos and brass and woodwinds are notoriously hard to capture well.

My wife is a former concert pianist, and finding recordings that she'll tolerate is quite a chore. Interestingly enough, I've discovered that musicians are radically different than audiophiles. They can "hear through" the defects of speakers etc, and they all know that the sound of an instrument to a performer is largely transmitted to the performer through contact and so they know that what the audience hears and what the performer hears are different. I play brass myself, and I can hear/feel clearly that the sound comes from different parts of the instrument on different notes, for example.

But the balance and the overall sound and dynamics of the ensemble have to be right.

I think you've summed it up well. Good mics and crystal clear pre-amps are necessary but insufficient. Placement, acoustics, good ears and musical sense on the part of the recordist count for most of it.

But I think that the equipment has to be good enough to stay out of the way.

One additonal comment, your original post asked about the mic'ing arrangement. Since this project is destined for video you might want to consider M/S micing. I say that because it gives good results for stereo but when collapsed to mono avoids the phase problems that other mic techniqes can produce and it's a fact that a lot of stereo video gets collapsed to mono somewhere along the line for some of the audience.

Steve,

Thanks much for the comment. I had thought about M/S and interestingly enough the Schoeps web page seems to recommend ORTF for orchestras, but not so much for ensembles - they suggest M/S instead.

Probably because the small spread of the group wouldn't lend itself to a widely spread spatial context and ORTF might make it sound un-naturally wide - just my thought.

The point about mono on the web is a good one, and I suspect a CD from the M/S recording wouldn't sound so bad either, considering that the group is in pretty "tight formation", so what you're after is more of a sense of space and 3D ambience than a real sense of location of the different instruments.

Steve,

Thanks much for the comment. I had thought about M/S and interestingly enough the Schoeps web page seems to recommend ORTF for orchestras, but not so much for ensembles - they suggest M/S instead.

Probably because the small spread of the group wouldn't lend itself to a widely spread spatial context and ORTF might make it sound un-naturally wide - just my thought.

The point about mono on the web is a good one, and I suspect a CD from the M/S recording wouldn't sound so bad either, considering that the group is in pretty "tight formation", so what you're after is more of a sense of space and 3D ambience than a real sense of location of the different instruments.

For what it's worth, the most realistic stereo soundstage I've ever heard was an analog master tape of the NY Philharmonic and chorus recorded using a Blumlein array, a single point stereo mic arrangment very similar to M/S. The M/S arrangement is just as capable of a wide stereo stage as other coniscident or near coincident arrangements. Plus if you record each mic directly and do the matrixing to stereo in post you can get a tremendous amount of control over the exact rendering of the stereo image, especially with some of the plugins such as the several M/S tools from Waves, etc..

The problem porting music to video applies to almost all video, not just that destined for the web. If people are viewing on a conventional TV, they may only have a mono set. Or if it's broadcast or cablecast, it can get converted to mono at any number of different places in the chain. If they connect a DVD or VTR to their TV with an RF adapter feeding the antenna input rather than the Audio/Video connectors those will almost always collapse the stereo down to mono as part of the conversion to RF. Even if it makes it to the viewer with the stereo intact, their sets may just have a couple of dinky speakers on the cabinet mounted so close together that they may as well be mono and the comb filtering from phase cancellation issues in the signal occurs in the air between the TV and the viewer.

Well, I might be curmudgeonly, but maybe in the end a good mono recordiing using one really excellent ($$$$) mic might be better than a stereo recording using two not so great ($$ each) mics, although maybe not as good as a stereo recording made with two really excellent ($$$$ each) mics.

Hmm - forward to the past as opposed to back to the future?

Seriously though, I'm starting to lean more strongly toward the M/S idea.

Any thoughts about what might be a really good integrated M/S mic for the job? Or am I better off with two separate mics?

By the way, do you have a link to the M/S plugins?

One thought might be a pair of the modular systems with three cartridges - two cardiod and one figure 8. I think with this kit as a base one could handle just about anything that came along.

Jim, you have a basic choice in front of you:
2 condensor mics, which allow several stereo recording techniques.
1 M/S mic, which can do MS or also serve as a cardoid or hypercard (depending on the mid capsule, usually but not always cardoid).

I love ORTF, and use it as much as I can.
MS is one mic, and is great for run and gun stereo recording (yes, it exists!)

One very important thing to bear in mind for any stereo recording technique - there is really only one right spot for the mic(s). If on a mic stand, that spot is usually objectionable to a paying audience or to video cameras. Fly rigs can be very helpful, of course they take time.

As a starting point, the mic(s) might form the point of an equilateral triangle, with the ensemble being the base of the triangle. Then, adjust back and forth for a good ratio of room sound to direct sound - this is typically more important than adjusting for stereo spread. If in MS, of course, you can have a spread adjustment in post (I'd always decode in post, not at the point of recording).

MS has the obvious advantage of a very nice collapse to mono, I think we all have to make our own choices about how important this is. There are several older threads where this has been debated.

In your budget range two very fine cardoid mics are perhaps more available than one very fine MS mic. A pair of cards are, IMHO, more versatile as well.

Seth,

Thanks for the insightful comments.

I think what has me on the fence is exactly the fact that the two cardiods would probably, as you say, be the more versatile choice. That's what's leading me down the path of a modular system, as I'd be able to start with either two cardiods or one each cardiod and figure 8 and add the other mic capsule down the road. So it becomes a question of starting point.

What's your feeling about ORTF for a small ensemble as opposed to a large group? Do you think it exaggerates the sense of space?

I also appreciate the comments re placement - in the end that's probably more important than the hardware itself (assuming the hardware is of good quality) - as, of course, are room acoustics.

Oh, and by the way, the quality of the group might play a small(?) part in all this too!

M/S does not necessarily mean 1 physical mic (as some readers might have thought on reading Seth's post - I know he didn't mean to imply that) although that is frequently adopted by manufacturers for stereo mics iwth the decoding done in the mic. The classic M/S is a figure-8 and a cardiod mounted in a coincident arrangement with the cardiod facing front and the figure-8 pointed transversly. I think your idea of a set of 2 power units with a pair of cardioid capsules plus a figure-8 capsule is an excellent approach, giving you a very flexible kit to cover a variety of situations, the Schoeps collette series and AKG ULS or Blueline series comes to mind as candidates. What the heck, add a pair of omni capsules and a hyper capsules as well and cover all the bases.

The Waves plugin I was thinking of is the S1 Stereo Imager

http://waves.com/Content.aspx?id=275

Steve,

Thanks much for the link to the S1 plug in. I have to admit though that their web page gives very little info on the plugins.

For example - what packages do they plug into? Also they show a TDM and a Native version, but no explanation about what these choices mean. Any hints you could give?

I think right now I'm close to making a decision to go with the Schoeps Colettes, just still waffling back and forth about whether to start with a pair of cardioids or a cardioid and a figure 8. Or to go for all three right up front (Budget, budget, did someone say "budget"?)

A bit of a budget buster indeed, but do-able. I think mics of this quality will be a good investment and and actually cheaper than fooling around with lower end stuff, considering both my time and the fact that it's for classical music.

When I add in a couple of miscellaneous bits and pieces, the investment in sound gear will wind up beng about 2X the investment in camera gear, which is probably a reasonable ratio, considering the kind of stuff I'll be recording. After all the heading on this forum says that sound is 70% of what we see!

If I were still a "kid" I might be tempted to play around with a variety of lower cost stuff as a great learning experience, but with the big Seven Zero fast approaching, the time vs money equation gets evaluated differently than it used to!

Steve,

Thanks much for the link to the S1 plug in. I have to admit though that their web page gives very little info on the plugins.

For example - what packages do they plug into? Also they show a TDM and a Native version, but no explanation about what these choices mean. Any hints you could give?

...

If I were still a "kid" I might be tempted to play around with a variety of lower cost stuff as a great learning experience, but with the big Seven Zero fast approaching, the time vs money equation gets evaluated differently than it used to!

The TDM version is for ProTools while the native version is a plugin for all VST/Direct X compatible workstations like Vegas, Soundforge, Premiere, Nuendo, etc

Glad to see there's a fellow geezer taking their career in new directions like I am. Just coming up onto my 62 milemarker next week and in my case I've been working the last couple of years to update my skills and get my career back onto a track that it got diverted from about 20 years ago. I agree completely on your assesment of the time/money trade off. I've found that it's always more expensive overall to start low and upgrade to the stuff you really need later than it is to get the right stuff from the very start. I try to get the best tools one can afford.

Thanks much, fellow geezer! I'll be 67 in a couple of months and I'm still working a full time job as a business development consultant for a Japanese company in partnership with a US tape drive maker. I really enjoy it.

Video is something I've been interested in since the days when the term "portable camera" referred to something that was B&W and recorded on 1/4" tape and the 10 pound camera was attached by an umbiical to a luggable tape deck that hung from the shoulder. But I mainly worked with large format still cameras until recently.

I'm planning to buy the mics in the next couple of weeks, and I'll be sure to post on the experience as soon as I get some mileage on them.

And sincere thanks also to everyone who's helped educate me in this thread.

M/S with 2 ribbon mics. This one

http://www.beyerdynamic.com/cms/Studio_microphones.42.0.html?&L=1&tx_sbproductdatabase_pi1[showUid][showUID]=11&tx_sbproductdatabase_pi1[showUid][backPID]=42&cHash=5c79858b5c

And this one.

http://www.beyerdynamic.com/cms/Studio_microphones.42.0.html?&L=1&tx_sbproductdatabase_pi1[showUid][showUID]=10&tx_sbproductdatabase_pi1[showUid][backPID]=42&cHash=3a176923df

or:
http://www.musiciansfriend.com/product/Beyerdynamic-M-130-Dynamic-Double-Ribbon-Microphone-Figure-Eight-Pattern?sku=272027

http://www.musiciansfriend.com/product/Beyerdynamic-M-160-Dynamic-Double-Ribbon-Microphone-Hypercardioid-Pattern?sku=272028

$600 each. Total=$1200

HI - Jim, nice to see someone really going for good stuff.

Just a thought - is there someone with a pair of Schoeps you could borrow? I've used them for sound effects fieldwork when I was at the BBC, because of their neutral sound and incredibly low noise, which is vital for recording sometimes very quiet sound sources - way quieter than anything you'd encounter in music! We trialled some of the switchable-pattern ones, which physically changed things around in the capsules, but ended up using just the fixed capsules. Again from memory, they have a very "neutral" character, which you might / might not like when it comes to music recording. They're expensive mics so if you have the opportunity (a good store ought to let you do this, I would have thought) you might want to check them out first. I have to say I wouldn't choose them for music recording.

If you have the chance to experiment, perhaps the best thing of all is to use / borrow a multimic interface, record the mics individually into a computer and then you could really compare the sound and miking techniques. I don't think there's one single answer to the question of technique, and in any case it varies with instruments / rooms, as you and others have mentioned. And a good balance for TV will be very different from one for audio-only.

You might also enjoy this article my former colleague Hugh Robjohns has written, covering useful overviews of the different techniques here: http://www.soundonsound.com/sos/1997_articles/mar97/stereomictechs2.html

I think what has me on the fence is exactly the fact that the two cardiods would probably, as you say, be the more versatile choice. That's what's leading me down the path of a modular system, as I'd be able to start with either two cardiods or one each cardiod and figure 8 and add the other mic capsule down the road...
Well, this is a great approach! So few mic systems have a figure-8 capsule available... there is a Sennheiser, AKG, Schoeps has both a figure-8 and a multi-function capsule. I'm not aware of any others. It would be nice if there were some products from mid-range manufacturers such as Audio-Technica or Rode.

M/S does not necessarily mean 1 physical mic (as some readers might have thought on reading Seth's post - I know he didn't mean to imply that) although that is frequently adopted by manufacturers for stereo mics iwth the decoding done in the mic. The classic M/S is a figure-8 and a cardiod mounted in a coincident arrangement with the cardiod facing front and the figure-8 pointed transversly...
Um, well, glad Steve caught me on that. It is true, I've become somewhat focused on single-body M/S mics. It all started on a shoot a couple years ago in which a buddy brought out his $5,000 US Beyerdynamic M/S mic. Wow, what a versatile and outstanding mic on a video shoot with acoustic music groups. The sound was indeed incredible.

Unfortunately, I can't afford such a mic, and have been more focused on mics like the AT 835ST (soon to be replaced by something much more expensive), the Shure VP-88, Studio Projects LSD2, etc. But I've not had a project to justify purchase - still using my Oktava MK-012 in ORTF for music and loving the sound.

What's your feeling about ORTF for a small ensemble as opposed to a large group? Do you think it exaggerates the sense of space?
Most of what I've done with ORTF has been small group, with good results. Typical would be a small Turkish ensemble - a reed flute or two, a few strings, a hand-drum, sometimes vocals. Around 3-6 pieces. I've never heard an objectionable exaggeration of space... but, I've been very careful in mic placement, and, I'm not afraid to pan each channel a little to center in post if needed. Never mind that the math of phase cancellation tells you not to do it, if it sounds good (on decent reference monitors), it is good.

I also appreciate the comments re placement - in the end that's probably more important than the hardware itself (assuming the hardware is of good quality) - as, of course, are room acoustics.
I can't believe we've gotten this far in the discussion without discussing room acoustics. The room is *everything* in stereo recording techniques. Most rooms designed for music are fine. I've done many recordings in churches, with their long decay time they can be problematic, usually the mic(s) will need to be closer to the performers. If I were doing a serious recording for release I'd want to bring my reference monitors and listen in a different room from the performance to determine mic placement... especially in a church.

Smaller rooms with their immediate slap tend not to be so good for stereo recording techniques.

...Just a thought - is there someone with a pair of Schoeps you could borrow? I've used them for sound effects fieldwork when I was at the BBC...

...You might also enjoy this article my former colleague Hugh Robjohns has written, covering useful overviews of the different techniques here: http://www.soundonsound.com/sos/1997_articles/mar97/stereomictechs2.html...

Excellent article! As good an overview of stereo recording techniques as I've seen. Do also look at part 1 of the article: http://www.soundonsound.com/sos/1997_articles/feb97/stereomiking.html

My understanding is that much of the resurgence of interest in M/S recording can be traced to a BBC requirement that ambient SFX be collected in M/S. Even here in the states, if you want to string on a BBC shoot you'll need an M/S mic.

Mark, can you confirm this?

Mark, Nice to hear from you again!

I think what you're saying is that the Schoeps are very neutral and perhaps a bit "clinical". I certainly understand the concern.

As I recall, you said you used Neumann modular mics on the recording of the pipes. I'd be most inerested in your feelings about the differences between the Neumanns and the Schoeps for music.

Also, thanks much for the link to the Sound on Sound article - just one question on terminology. He mentions a "Brixton briefcase" and I'm wondering if that's equivalent to what we in the US sometimes call a "ghetto blaster".

Oh, and by the way, they're forecasting temperatures in the mild 110 to 112 range the next few days here in sunny southern Arizona. Sure you don't want to pop over for a visit?

As part of my ongoing attempt to better understand the "mechanics" of microphone configuration, I've actually e-mailed a couple of mic makers with some hopefully not too dumb questions.

The folks at Schoeps were kind enough to send me the following link which helps visualize the stereo imaging of various configurations.

http://www.hauptmikrofon.de/ima2-folder/ImageAssistant2.html

I have little knowledge of the ins and outs of this black art, so can't comment too much on how good this tool is, but just thought I would pass the link along for what it's worth.

FWIW, the specific question I had asked was how suitable other microphone types (eg wide cardioid) would be for ORTF. In this specific case, they commented that a wide cardioid at 28 cm spacing and 90 degree included angle would probably be successful and, according to the tool they referenced, might image rather similarly to a standard cardioid at 17 cm and 110 degrees

Hopefully I'm not making too much of a hash of all this. Comments/criticisms/corrections welcome

Hi Jim,

Did you ever get to record those brass quintets?

Lots of good advice here. If you'd like to read a tutorial on stereo miking techniques, here is one:
https://pantherfile.uwm.edu/type/www/420_Field_Audio/StereoMicingTheory_Readings.pdf

If no mic stands must be visible in the shot, and hanging mics is not an option, you might consider using boundary mics on the stage floor to capture a small ensemble. They have the advantage of preventing comb filtering due to phase interference from floor sound reflections. If they don't pick up enough room acoustics, you could mix in another stereo pair back in the room, or add high-quality convolution reverb in post.

At the bottom of the page below is an audio sample of boundary mics picking up some small musical ensembles and singers:

Bartlett Boundary Recording Mic - Bartlett Audio (http://www.bartlettaudio.com/collections/boundary-recording-mic/products/boundary-recording-mic)

Hope this helps,
Bruce Bartlett
Bartlett Audio

Tori Amos did an album not long ago called Night of Hunters that consisted of vocal, piano and small classical ensembles. They close mic'd each instrument in a dry studio (no room ambiance) and the effect is as if you were sitting in the middle of the ensemble clearing listening to each instrument. It's absolutely brilliant and much more engaging than traditional recordings that use stereo mics and room ambiance. It gives you the perspective of being in the orchestra and not the audience. You can download hi rez 24 bit tracks of the album on HD tracks if you want to hear an example.