chamber ensemble recording...spaced pairs?

[Erichx]

Hi, I've been doing some chamber ensemble recordings, mainly quartets/quintets, trios, etc., and usually strings. I've started experimenting with omni spaced pairs. Is that the right choice, given a good room? Of course, XY and ORTF are fool proof, but i like the extended and open low end.

some problems i've run into w/ wide AB (4-5ft) are:
-violin bounces around sometimes (usually fixed in post)
-center is weak

I love the sound of omni pairs. But can these problem be solved by using using a center mic, or puting an XY in the middle, sort of like a decca tree config?

here are some samples of the recordings: Portfolio
the clips are under teh "classical" column.

The first 2 clips are bass quintets, with neumann km100/30capsules spaced pair as main, and a 414 as a bass spot. schubert quintet also has a pair of 184's in xy on the piano.

the 2nd 2 clips are schoeps XY main mics, with a km184 on violin and pair of dpa 4011's on piano--no omni's in these recordings.

thanks in advance!
-Eric

[rumleymusic]

For AB spacing of small chamber groups, you should really be looking at 40-60cm between mics. 4-5 ft is wide even for orchestra. I usually max out at 3ft. The idea is to have good frequency separation without creating a hole in the middle. The 40-60cm number is kind of the magic distance that DPA suggests. If you insist on going wider, then you really should look into a center mic. Or if you need more obvious channel separation, go for a coincident pair or directional mics.

[boojum]

Williams in his Stereo Zoom papers specifies from 38 to 49cm, depending on recorded included angle/2. I usually run at ~40cm with good results. It seems counter-intuitive that this close spacing would work, but it does work just fine.

Cheers

[dtf]

If stereo imaging is the only thing you care about, go ahead and use smaller spacings. If you care about sound as well, you will find that using/adding wider pairs will help.

[rumleymusic]

If stereo imaging is the only thing you care about, go ahead and use smaller spacings. If you care about sound as well, you will find that using/adding wider pairs will help.

I don't know what that is supposed to mean, how is poor imaging an indicator of good sound? A "better" sound will not necessarily be achieved by wider spacing. That will only serve to distort the image if placed too close to an ensemble of this size. You can achieve a different sound by widening the spacing and using them further back as ambient mics, supporting that with individual spots, but the technique of spaced pairs has been set at this distance because it achieves optimal frequency separation and imaging, i.e. the best sound you can get with the two mics.

[Erichx]

Thanks for the replies, they're really helpful!

what do you guys think about a wider AB w/ say an XY in the center? I've heard that that gives you pretty accurate image while still maintaining omni characteristics. how would the XY be panned in post--hard left/right, or in between?


a thought on the 40-60cm...i've been looking for a stereo bar that does that, that happens to be cheaper than $600 like the dpa/schoeps ones. i'm thinking $100 or less? do they make them? All the one's i've seen are 30cm or so max.

[BrianHanke]

Originally Posted by Erichx

a thought on the 40-60cm...i've been looking for a stereo bar that does that, that happens to be cheaper than $600 like the dpa/schoeps ones. i'm thinking $100 or less? do they make them? All the one's i've seen are 30cm or so max.

Buy On-Stage Stands MY700 Mic Bar | Mic Clips & Clamps | Musician's Friend

[Erichx]

Originally Posted by BrianHanke

Buy On-Stage Stands MY700 Mic Bar | Mic Clips & Clamps | Musician's Friend

ah,
this isn't long enough. I'm looking for something that can go up to 2 feet/60cm.

it's also been my experience that On-Stage products kinda suck after a while....

[resound]

Buy a Sabra-Som bar and then just replace the hex rod with a longer one. That cost me about $4 and a trip to a local metal yard.

[rumleymusic]

a thought on the 40-60cm...i've been looking for a stereo bar that does that, that happens to be cheaper than $600 like the dpa/schoeps ones. i'm thinking $100 or less? do they make them? All the one's i've seen are 30cm or so max.

They all seem to be on the expensive side. I just made my own. Many people here did the same.

[Erichx]

thanks
i will probably go w/ resound and get sabra-som and replace the bar w/ a longer one.

any comments on the wider AB config w/ xy in the middle? or ORTF
I seem to like XY for chamber strings over ORTF though

[rumleymusic]

any comments on the wider AB config w/ xy in the middle?

There have always been versions of Decca trees with a Blumline stereo mic or a surround mic in the center rather than an omni. There shouldn't be a reason an XY or similar coincident pair in the middle of a widely spaced AB stereo pair would not work, even in a straight line array. You would just have to find a good way to mix the signals together since there is no dedicated center channel to fill the hole in the center of the AB, i.e. it is possible the sound would be unnaturally wide. That might mean the XY would be the prominent mics and the AB would be for extra space and color.

It is always fun to speculate and experiment.

[Shureman]

Originally Posted by Erichx

Hi, I've been doing some chamber ensemble recordings, mainly quartets/quintets, trios, etc., and usually strings. I've started experimenting with omni spaced pairs. Is that the right choice, given a good room? Of course, XY and ORTF are fool proof, but i like the extended and open low end.

some problems i've run into w/ wide AB (4-5ft) are:
-violin bounces around sometimes (usually fixed in post)
-center is weak

I love the sound of omni pairs. But can these problem be solved by using using a center mic, or puting an XY in the middle, sort of like a decca tree config?

here are some samples of the recordings: Portfolio
the clips are under teh "classical" column.

The first 2 clips are bass quintets, with neumann km100/30capsules spaced pair as main, and a 414 as a bass spot. schubert quintet also has a pair of 184's in xy on the piano.

the 2nd 2 clips are schoeps XY main mics, with a km184 on violin and pair of dpa 4011's on piano--no omni's in these recordings.

thanks in advance!
-Eric

At the risk of sparking disdain, I'm submitting two samples of "chamber music", both of which I feel capture the desired qualities you speak of.
The center is strong, the field is rock solid, the sound is round.
They were both recorded with the same midside mic (Shure VP88), a mic which loves tight set-ups. You might consider giving one a chance. The time saved measuring mic configurations can be spent instead on finding that perfect sweet spot.

Siciliano from Sonata No_ 4 BWV 1017 - Ba.mp3 - DivShare (for peer review and analysis only)
Violin/Harpsichord recorded live in a large chapel in the French Quarter

Gene_ Gene_ the Dancin_ Machine.mp3 - DivShare (for peer review and analysis only)
Swing jazz combo (about 10 pieces) recorded outdoors at an evening barbeque in New Orleans)

Hope you enjoy, and GO SAINTS!

[Matti]

Both have balance problems as a recording but as document serve abouts well

Matti

[Petrus]

Start simple with narrower spacing in 35-50 cm range. Only after that start fooling around with center mics (which normally are not needed for small groups). Too easy to get overexited with all that gear and all different possibilities to "improve" (?) on the basic AB sound.

The only place where I have actually found an ORTF center pair to improve a widesh AB was with organ, where mics are quite far and wide to catch space and cardioids mixed in at about 1:2 ratio tighten up the image slightly.

I have made AB bars from carbon fiber tubes and cheap aluminum U-profiles from hardware stores. Just cut them to whatever lenght, file corners smooth, drill holes in them in desired places and attach mics with normal 3/8" screws and nuts, buy extra nuts as backstops. If you want to get fancy spray paint them matte black. Total cost for a 90 cm bar maybe $10 + a can of paint.

Another DIY project is a Jecklin disk, which works extremely well with chamber sized groups and smaller. I have 30 and 35 cm sizes meant to be used with 17-20 cm and 35 cm mic spacing. I have found that the smaller works better and the bigger one starts to emphasis bass (which of course could be used for an advantage also). They give more precise spatial placement with all the advantages of omnis.

[DCtoDaylight]

Originally Posted by Shureman

At the risk of sparking disdain, I'm submitting two samples of "chamber music", both of which I feel capture the desired qualities you speak of.
The center is strong, the field is rock solid, the sound is round.
They were both recorded with the same midside mic (Shure VP88), a mic which loves tight set-ups.

The stereo image in both is great, and there's really nice presence and warmth in the jazz band recording.

How far back from the musicians were you on these? I'm thinking of trying an M-S setup for the first time next week at a chamber concert; I know a spot in the hall that's back a bit but works very well with an NOS pair and was wondering if that would be a good place to start with the M-S.

[Shureman]

[QUOTE=DCtoDaylight;5071721]
How far back from the musicians were you on these? QUOTE]

Both were done at close range.

The Bach was recorded with violin standing at the end of the keyboard, harpsichord at full stick. The mic was about 7' high and about 7' away from the violinist, and roughly 1/2 of the way down the body of the harpsichord. The mic head was flush to the violinist, thus the violin is centered, the harpsichord is a bit to the right. I always use the mic's built in matrix, set to maximum spread.

The jazz combo piece was done on the back porch of a community center. The porch was covered, but only about 8' deep, so the band could only have two rows of musicians. Consequently, they were very spread out (piano to the far left with the drummer, trumpets in the back row, trombone front left, saxes front right). It was done about three years ago, so I'm not real clear on the particulars. If I can find a photo, I attach it. Anyway, the mic was centered, only about 5' from the front row, and about 7' high. This mic really shines in tight spaces.

It does okay at a distance, but it is a bit noisey. I recorded the organ at St. Louis Cathedral last night at the full length of the church (organ in the loft, mic near the altar - about 125'), and was surprised at how well it came out, but I had AC and a standing room crowd to cover the mic noise. I'll add a clip of that to this post tomorrow when I get a minute. Not my best work, but it might be helpful for you to hear it.

I'll admit, my love for an all in one midside is I put a huge premium on their convenience and reliability. Luckily, I like the way they sound too.

Freddie Freloader.mp3 - DivShare

This was recorded live with three midsides to a portable multitrack. Even with three mics (6 channels), noise accumulation is minimal, the fields are steady, and the sound - unenhanced except for a slight bump in the bass - is good. Best part - the set-up took 15 minutes, and there was no need for a sound check because I could count on what the mics would do. Mixing was equally easy, with no phasing cancellations - it almost mixed itself. Three identical mics seems to help.

Hope this is useful info.

Shureman

[meltemi]

Originally Posted by Erichx

some problems i've run into w/ wide AB (4-5ft) are:
-violin bounces around sometimes (usually fixed in post)
-center is weak

Spacing of omnis in an A-B setup is dependent on the distance of the mics to the performers and on the recording angle (angle from the mic setup to the outer edges of the performing group).
The following brochure from DPA will give you all the details: DPA Microphones :: Stereo Recording
Correct spacing will avoid the weak center.

If the mics are placed outside the reverberation radius (50% direct sound and 50% diffuse sound) you should use diffuse field mics in order to compensate for the high frequency loss.

A bouncing violin may indicate some phase problems between the mics (differing off axis responses). To avoid this, only use a factory matched pair.

[Plush]

When experimenting with mic technique, keep to changing only one thing at a time.
So firstly, take the recommendations of the group here and place your omni mics closer together on a bar. See how you like it and see how it changes the image you get.

YOu have already told us that you are in a good room. Are you really in a good room?
If so, keep using your omni mics.

With string quartet it is desirable to mic the cello and bring it out since cello sitting on RT and behind the viola tends to offer a buried sound. This highlight on cello is called for whether or not you use omni or cardioid mics.

Your original spacing with omni mics is incorrect for string quartet. One give away that this is not correct is that it presents the group as sounding much wider than it actually is. Another problem is hole in the middle.

Using cardioid mics in an XY or ORTF array is fine. Move back from where you have your omni mics since the cardioids must be 1.4 times the distance to the group to imitate your desired omni sound.

Spaciousness can be added with omnis but then again you are back to presenting a very wide string quartet sound. It may not be desirable.

[Erichx]

thanks for all the advice!
i'm currently in florence italy recording a series of chamber performances and rehearsals. The rehearsals would be a great time to experiment.

given that it's florence, most of the performance spaces will sound great...i'll certainly be using mostly omni's neumann km183 or km130, and CAD e70's are the only ones i have access to here. I'm curious to see how the cad's sound, especially through some 3124's.

thanks again!
most helpful.

[meltemi]

Originally Posted by Erichx

i'll certainly be using mostly omni's neumann km183 or km130

Neumann KM130 / KM 183 are both diffuse field equalized and will therefore give a high frequency boost on axis .

If the sound becomes too bright, try to angle them between the instruments or
choose a larger distance to the performers and adequately adjust the spacing.

Luckily there will be rehearsals, so you will have the opportunity to find out what mic placement 's sound will suit you best. Good luck.

[sonare]

Every year I record a festival with a series of chamber concerts from 2 Vlns to Pno quintet to a Strauss 12-pc work. I was frustrated for years trying to make omnis work with enough presence but not too much spread.

And then I tried the Jecklin Disc (by M-B) and all the problems went away. Yes, piano and vc spots are still needed but the basic sound is finally coherent and not TOO stereo.

Simon Eadon used a Jecklin on the fabulous Takacs Beethoven that won a Grammy. Of course a great quartet, great hall and great music don't hurt either!

Rich

[Shureman]

A bit off topic, but sounds like this group might have some good leads...
I do almost all live recordings in rather formal settings, where looks count.
Any suggestions where I can get attractive, graceful mic stands (custom made if necessary), which will enhance and not detract from the setting?

[roonsbane]

Keep it closer to 1 meter. You will not get a hole in the middle and you will avoid the buildup in the low mids. The "Schlock" as I like to call it. It will not sound as open with omni's around 40 cm than it will at about a meter. Time and time again I have tested many omni's, identical sets at 1 meter and closer and every time I hear it in the closer configuration. It is slight but it's there. Yuck!
Cameron

[Ozpeter]

The practical advantage of over-wide placement of omni mics for chamber music is that the mic stands then tend to flank the musicians rather than standing between the musicians and the audience (assuming we're talking about live recitals).

An electronic technique to simulate a closer spacing from such a recording would be handy but I suspect impossible.

[pkautzsch]

Originally Posted by Shureman

A bit off topic, but sounds like this group might have some good leads...
I do almost all live recordings in rather formal settings, where looks count.
Any suggestions where I can get attractive, graceful mic stands (custom made if necessary), which will enhance and not detract from the setting?

If you use Schoeps, their RC extensions are the de facto standard in unobtrusive miking. Seen (or not seen...) in most classical music on TV.
I think there's a similar thing for the Sennheiser MKH 80xx series, and DPA's "Flamingo" stands.
Not sure how high all these will go. Better way might be to fly.

Originally Posted by roonsbane

Keep it closer to 1 meter. You will not get a hole in the middle and you will avoid the buildup in the low mids. The "Schlock" as I like to call it. It will not sound as open with omni's around 40 cm than it will at about a meter. Time and time again I have tested many omni's, identical sets at 1 meter and closer and every time I hear it in the closer configuration. It is slight but it's there. Yuck!
Cameron

What would be the reason for low-mid buildup depending on mic spacing in a typical spaced pair panned hard L/R? You're not summing them.
A wider spacing will spread the group quite a bit. I'm not sure if I want to hear a string quartet spread out fully between my speakers like a symphony orchestra would be. Not a hole, technically, but still not what I expect from a string quartet recording. This is purely about aesthetics and conventions, though.

Originally Posted by Ozpeter

The practical advantage of over-wide placement of omni mics for chamber music is that the mic stands then tend to flank the musicians rather than standing between the musicians and the audience (assuming we're talking about live recitals).
An electronic technique to simulate a closer spacing from such a recording would be handy but I suspect impossible.

It wouldn't work for direct sound coming from different directions. If you delayed, say, the R mic by, say, 1 ms, you'd just virtually change the orientation of the system, but you'd not decrease the spacing by 1 ft. (well - you actually would do that for one single source, but not for an ensemble)

[rumleymusic]

Move back from where you have your omni mics since the cardioids must be 1.4 times the distance to the group to imitate your desired omni sound.

It is 1.7 I believe, just to be nit-picky.

[roonsbane]

pkautzsch said:

What would be the reason for low-mid buildup depending on mic spacing in a typical spaced pair panned hard L/R? You're not summing them.
A wider spacing will spread the group quite a bit. I'm not sure if I want to hear a string quartet spread out fully between my speakers like a symphony orchestra would be. Not a hole, technically, but still not what I expect from a string quartet recording. This is purely about aesthetics and conventions, though.

I am not going to try and explain why it's happening. It's there. Try sticking 4 of the same high quality omni's on a bar; One pair 1 meter apart and another pair at 40 cm and I am positive you will hear it. I can hear it the moment I walk into a room where the pair is too close.

I worked as the staff engineer in one of the very best chamber music halls in the country for 8 years (Jordan Hall, which was designed by the way by the same architect as Boston Symphony Hall at about the same time). This hall attracts many of the very biggest engineers in the business recording chamber music for either release or broadcast. I don't believe that I ever witnessed one single person use anything but a spaced pair of omni's at within 3" of the 1 meter spacing whether with or without additional highlights. Never were they close in like the DPA would recommend and no one used Cardioids and no one use ribbons for that matter in the main array. About the craziest people got were Brad Michaels and occasionally others used Schoeps tubes with the distortion control dialed all the way down. Others tried M50's (Mark Donahue) or M150's, but most of the time you saw Shoeps/DPA's/ Neumann/ or Sennheisers spaced at approximately 1 meter. That goes for Orchestral recording as well. Once you hear a direct comparison, there is a very good reason for this. I always thought there must be something to the DPA recomendations (after all it is DPA) so I have tried it along side the 1 meter setup. Everytime I hear that same buidup with the closer distance.

Cameron

[roonsbane]

By the way, solo piano recording spacing was always very different for almost everyone and usually at a greater distance and often with highlights. Oh crap, all these folks now know I was watching listening and taking notes.
Cameron

[rumleymusic]

I am not going to try and explain why it's happening. It's there.

There is probably a buildup in the low frequencies because they are in a sense mono in closer setups. There is no frequency separation between the two channels. This is a more natural way to hear the sound, but some people prefer more L/R distinction. Moving the AB pair further apart is frequently done, but there is a trade off involved with poor imaging. This can be disguised with the use of spots on the performers, but by itself, I personally don't think it is very effective