Hi

Classical music has been recorded with a 2 (sometimes 3) mics for years, as almost all of the stereo miking techniques are derived from the experimentation and techniques developed by engineers working at Decca or Deutsche in the 50s 60s and 70s.

The aim of those techniques is to have the most true to life, natural and real representation of the orchestra as a whole in front of a listener, so often the approach used is to have the mics placed to mimic the position of the listener's ears (in 2 mics coincident or near coincident capsule techniques).

There are more involved and multimic techniques like Decca Tree, which is one of the most widely used, but a simple 2 cardioid mics in a ORTF configuration almost always works well (at least it did for my projects) provided that you have a good pair of mics, a good preamp and recording chain, and you spend the necessary amount of time placing and pointing the mics.
For details on such a technique (or others like XY or MS) do a search on this forum or on the web and you'll find the exact specs (like angles and distances of the mics).
I usually go for an ORTF main pair (in front of the ensemble or just behind the conductor, distances depending on the enseble's size)
and usually supplemet that main over head pair with spot mics placed on each (again depending on the size of the ensamble) section, going multichannel on HD recorder. Editing and mixing of the project is done afterwards in my studio.
With the two mics stereo technique you'll have to work (as a conductor) on the balancing of the various instruments and sections yourself, as that balance will be captured by the mics and the recorder and won't be adjustable in post.

A lot of the sound of the recording will be dictated by the sound of the room you'll be recording in, usually concert halls or theaters are the best, but I've recorded in places ranging from churches to lecture halls, and sometimes a bit of post production helps bring the sound of those spaces to the right shape.
You should be OK with the Rode NT 100 for this task, they wouldn't be my first choice, but their low self noise and bright response should be good for a stereo pair.
Also try to use a good pair of clean and uncolored preamps and keep the cable lenght as short as you can from mics to pre.

In the end this isn't a subject that can be exausted in three words, but I hope I gave you some usefull tips, experience and parctice are key factroes in this.

Good Luck

Hope this helps

L.G.

Lorenzo Gerace,

Very nice summary of classical recording.

We have been using the Decca Tree for the last 8 years,
see http://www.acmi.net.au/AIC/DECCA_TREE.html or http://www.nucleus.com/~lockwood/deccatre.html or http://mixonline.com/ar/audio_decca_tree/
for more information.

It works GREAT!

The biggest problem we face today is that most of the concerts we record are also video taped and the Decca Tree is a large stand that the video people do not like. They would rather see microphones flown (which we cannot do) or a single slender graceful microphone stand with a pair of small diaphragm condensers on it (what they would really like is no microphones visable but seeing as we are feeding them the audio while we record the concert this isn't possible). So in certain situations we use the ORTF (The French Radio Organization developed this technique. A high quality, matched pair of cardioids condenser microphones are placed 17 cm apart at an angle of 110 degrees)

Other techniques are the spaced OMNI and M-S single point microphone technique and more information on them can be found at Session 7 - The Mixes - Part 2

Try and use the best microphones you can not afford (possibly rent some better microphones) and use the best possible preamps and A to D converter. ( there is a location recording company near hear that does some school concert recordings and they advertises "high quality recordings" they are using a pair of Shure SM-57s, a Mackie board and a prosumer DAT machine and claim a frequency response of 20 to 20K and zero distortion I have heard their recordings and they suck! They spend a lot more money on their advertising than they do on their equipment)

The better the equipment and the better the hall and ensemble the better your recordings will sound. Try and get some idea of the sound of the ensemble BEFORE the concert hopefully at the rehearsal just before the concert. Remember that the hall will sound, in many cases, much deader when their is an audience present and the tonal balance of the hall may change as well.

Best of luck and don't be afraid to experiment with different types of microphones and setups till you find the one that works best for you and the hall.

Thank you for your help, I will try those mics thecnics you 2 told me, although is not my aim to record myself professionaly (because I know it is really difficult and expensive) I think that i can make a real good monitoring of what it sounds the orchestra that way. I have my little project studio with modest but good working gear and a little bit of acoustic knowlegde and I know it is really tricky to get a big sound of a simple instrument...

I have some more question for you...

It´s possible to achieve a good recording in a good frecuencies responding but dead sounding studio (I mean in all frecuencies and not only in highs like ones with acoustic foam), and then add some ambience later??? I heard recording of washington Symphony orchestra recorded that way and I did´nt like it at all..., i prefer much more the recordings of Deustche or Decca, which i think are made on the theaters.
Another: Which recording media do you prefer for classical recording???, i would imagine digital, because of low noise and before anything no kind of compression in ff.

Thank you.
Gustavo.

BydLo wrote: Thank you for your help, I will try those mics thecnics you 2 told me, although is not my aim to record myself professionaly (because I know it is really difficult and expensive) I think that i can make a real good monitoring of what it sounds the orchestra that way. I have my little project studio with modest but good working gear and a little bit of acoustic knowlegde and I know it is really tricky to get a big sound of a simple instrument...

I have some more question for you...

It´s possible to achieve a good recording in a good frecuencies responding but dead sounding studio (I mean in all frecuencies and not only in highs like ones with acoustic foam), and then add some ambience later??? I heard recording of washington Symphony orchestra recorded that way and I did´nt like it at all..., i prefer much more the recordings of Deustche or Decca, which i think are made on the theaters.
Another: Which recording media do you prefer for classical recording???, i would imagine digital, because of low noise and before anything no kind of compression in ff.

Thank you.
Gustavo.

We have usually used DAT in the past but are looking into direct to computer recordings.

I personally do not like recordings of symphonies made in dead room with artificial reverb added later. It just does not sound good to my ears. But sometimes it is the only way since the recording of orchestras is sooooooo expensive that they do multitrack recordings in a dead room and mix it all down later and add reverb. The Cleveland Orchestra records in the Masonic Temple or in Severence Hall both in the city of Cleveland Ohio both of which have GREAT acoustics and very nice sounding hall ambience which sounds real and not added.

Hope this helps.

Hi

Sorry for being late but I've been out all the week to record several concerts and festivals outside town.

Well, as far as sound is concerned I seriously doubt that recording in a dead space and adding ambience later (no matter how good the reverb can be) will equal the results of a well recorded ensemble in a pleasant sounding acoustic space; there's too many things that contribute to the realness of such recordings, like the sense of "air" and space you have coming from the room, plus, you'll be stuck with the predelay of the "dead" room. I'm not saying it's not going to work or sound good, but you'll have to work harder on it to make it sounding natural, and IMO this approach can work for smaller ensambles like duos, trios or quartets, I'm a bit skeptical about a bigger ensamble, let alone a full orchestra, which is an "instrument" that depends a lot on the room it's played in; also it depends on the style of music recorded: classical, baroque and the likes need a healty amount of ambience due to the nature of the rooms they were composed and played in back in their origin; contemporary or more modern music may get away with a dryer sound, and maybe that would benefit from a bit of reverb added in post. I sometimes do it when I'm not satisfied with the sound of the room I recorded in (it happens quite often...), so I only add a bit of reverb on the main pair I used (not on the spot mics) and work on it to make it blend in the most natural way I can.

As for the recording medium, I almost always record using a double method: I have a mobile rig with my mic pres, a rackmount mixer and a Mackie SDR hard disk recorder where I go multitrack @24/44.1 or 24/88.2 depending on the final destination of the project, plus I always send a rough mix of the recorded multitrack to a Sony DAT, to be used as a backup and to hand the musicians, conductor or producer (or whoever will be making editing decisions) a basic 2 track mix to select the material to be used. I think that due to the cost of tapes, the fact that it's a soon-to-be-obsolete format and the fact that's only 16/48 I'll soon replace the DAT with a CDRW that will allow me to have the 2 track mix on a instantly ready format and maybe have it on non standard red-book formats for different use (I think the Alesis Materlink does it).
Back when HD recorders weren't available it was a DA78, more than one when I needed to record 16 or 24 tracks, I'm glad that with a HD recorder I can fit 24 tracks in a 3U rackspace.

Hope this helps

L. G.