Carnatic Music - Additional Audio Pointers

BHADRAM KARNEBHIH SHRUNUYAAMA DEVAAH !

Oh Gods, May we hear only good thrings with our ears !

Here are some fine points to attend to that will bring you closer to being a real professional:

1. The audio person cannot set the audio once and walk away.  Our concerts are long, and musicians inevitably move or shift their positions.   You need to be watchful and compensate for that.   I am not even talking about major impairments such as the ones to follow.  Sometimes, the violinist turns around resulting in a big hum from his/her mic picking up the monitor speaker.  Someone needs to be there to take care of these exigencies instantly.  During solo, the volume has to be slightly increased for the involved channel; it is true that two musicians together sound twice louder (due to the way signals behave in an additive manner and vice versa.)  This is where people who know nothing about our music and cannot anticipate various distinct parts of the performance do terribly at the board. Be warned, however, that constant meddling with the system can also become disconcerting too, both to the musicians and to the audience.

2. No one appears to use the pan controls properly.  Used properly, in a vocal concert, we should be hearing the violin more from one side and the mrdangam from another.  Perfect stereo sound cannot be obtained in the auditorium as in a studio where musicians sit in separate booths and there is no leakage from one source to another's mic, but one can come close to it with a proper selection of microphones,  the use of pan control, and running the volume at a reasonable level.   Not setting the volume too high (especially on the monitors) is necessary to minimize leakage of sound from one end to the mic at the other end either as echo from the hall or from the monitors.  [Musicians from India especially are used to very high volumes and ask for it, often  affecting negatively the enjoyment of the audience.  My advice to them: if you are serious about your music and sound quality, please take a course on audio.]

3. Sruti: Some musicians keep the electronic sruti box so loud as to drown everything else.  This is very annoying and is something that all musicians should pay attention to when they are performing on stage.  It also makes it hard to discern problems and to make corrections.

4. Microphones:  (a) It is important to pick high quality microphones appropriate for vocal and/or for the specific instrument.  Shure 58 is the minimum, yes the minimum, quality to shoot for.  Try to pick mics in such a way that their response curves do not tail off in the frequency range of whatever frequency range you are trying to capture and remains pretty flat in that range with high fidelity; this is particularly important for violin and the left side of mrdangam.  (b) Be wary of powered microphones.  The slightest movement of the musician towards or away from the mic becomes highly noticeable, with the former making a vocalist look like he/she is shouting.  These may be great for studio recording in a controlled environment with one song at a time, but it is unrealistic to expect musicians to maintain a constant distance throughout a 2.5 to 3 hour concert.  Note also that the closer the vocalist gets to the mic, there will be increased bass in the voice.  With powered mics, if their lip touches the mic or if the violinist's bow touches the powered mic, God help you!  (c) I personally hate the cheap contact microphones that many Indian instrumentalists use; these days, some leading artists do use good mics, but the audio people have not learned to deal with them.  The cheap mics and/or poor audio settings distort sound, and I bet have very bad response curves.  Once the source is bad, there is little the person at the mixer board can do, especially if the channel gets overloaded and clipping occurs.  Musicians who insist on using contact mics should purchase one from a good store with the help of someone with a high level of expertise and after testing in the store with several of them.  (It is customary for professionals in most professions to invest in equipment for one's own trade!)

5. When you have a duet like of various famous sisters, please equalize so that they sound reasonably as one voice when they sing together.  Same for violin duets etc.

6. Speakers: The high frequency cone (which is the uppermost in the speaker) should be above the head of the audience close to the speaker.  Otherwise, they get a headache from the higher frequency sounds.  This is often forgotten by many who do audio.   When the hall is long and deep, it is often a bad idea to blast from just 2 speakers in the front.  Have 2 additional speakers somewhere half way, but run the volume low and just enough so that those farthest from one pair of speakers don't hear two distinct versions of the same music.  Turn the speakers so that they are centered towards the center of the half portion at the back of the hall (or the last row) you want to serve with them.

7. Recording: Remember that a lot of things can be fixed later but not the overload resulting in frequency clipping.  [When you exceed the maximum level, your system just sets things to the highest level and you lose information totally].  So make sure your gain and volume levels do not overload the channel.  When preparing a recording, please do not shut off the sruti between pieces and let it sound like a continuous concert, and also avoid abrupt starts (what technically is called 'attack') etc. and consider using fade in and fade out if necessary.  Set the recording level at about -6dB (and not at 0dB as most Indian technicians do) to avoid overload.
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The author Dr. V. Ramaswami is a former President and Secretary of CMANA (Carnatic Music Association of North America).  As a volunteer, he has managed the audio for CMANA and some other non-profits for many years.  As a researcher in the citadels of technology - Bell Labs, Bellcore, AT&T - he has also had the privilege of learning many technical aspects of audio and video from experts and sometimes the very inventors.  He himself holds several patents related to video distribution over the Internet and related communication technologies.