Acoustics in India - Part II

What are those that can make to be acoustics materials? Wood, metal plate, gypsum board, ply board, mineral wool, sponge, fabrics etc. If you go through any book you will find a long list of materials along with their values for NRC, NAC, and AHV. We once made a recording theatre in the ground floor of a place wherein on just the floor above there was a parlour of snow bowling with nine tracks. Prior to our treatment, there were no ways that was available to control the thundering noise of the balls rolling on tracks and the noise of the pins splashing. We made five layers of insulations out of which one with lead sheets and another one with 128kg/m3 weaved glass wool mattress, and ahoy every effort failed. I apologised to the chairman and requested him to give me some more time. Guess the fun that followed? I dismantled every thing and, pulled out all glass wools, gypsum boards, and lead sheets, and replaced it with some bags of pest treated river sand and patched it on ceiling by strong supports and over that I made a simple, regular treatment; the thundering noise had now totally stopped from entering into the studio. Until such time, no one had ever revealed that sand is one among the best acoustics materials, for insulation as well as absorption.


When we started the acoustics treatment, we decided to use the cheaply available materials. We found coconut fibre and treated it against pest and made it as our prime material and stuffed the same in jute bags. We painted these bags in ethnic colours and it became very rich in looks. Here and there we placed few reflectors with packing materials (pine wood) to make the room live and it became wonderful. We made a booth for percussion with terracotta tiles and it matched with the jute. This became our percussion room (for tabla, dolak, miruthangam).


Believe me; the percussionists enjoyed a lot playing inside that room. That was the time so many companies were making cost effective multi track recording machines in quarter inch magnetic tape format; we bought one machine along with a multi track mixer and an Eventide effect processor. Now the studio having been readied, competitive with professional studios of those days; we named it EMMA Communications. But our cinema musicians called it ‘Jute Studio’. Most of the leading musicians of Chennai cinema industry have played in that studio. I used to tell my friends that it is a concept; that’s all. After that we have tried with so many other types of materials for acoustics and succeeded. To name a few - book shelves, bed mattresses, cushions, eggs containers, used tyres for bass traps, slate stones, red stones, polished glass pieces, copper plates, carton boxes, iron pieces using nuts, bolts, bottle caps, horse shoes, tins made as a collage, bamboos, utensils, bricks without plastering over that, unbaked bricks made of clay mixed with straws to create pores; all these methods succeeded.


But you cannot create every studio like this; you need a conventional style or look in order to satisfy your client. The people visiting the studios are creative artists and professional performers. A studio owner and an acoustician have the responsibility in impressing these people with the aesthetic and pleasing interiors of the studio. These visiting artists and professionals can not be satisfied simply with book shelves as acoustics material; they might doubt on the sound produced from such a studio. One should understand a thing, that sound is heterogeneous. What you are listening to in a control room is not what others will listen to when the same is reproduced in their music system. My friend and my mentor Mr. Emmy used to mention that a sound engineer has to correlate the quality of work with the final results that is expected to be reproduced. I have witnessed his works, that most of his final mix of his fabulous works including super hit film songs as well as the famous music album “How To Name It” were mixed down in a cue speaker of Neve mixer - in those earlier days Prasad Studios of Chennai were using broadcast mixer for film recording. Normally, all broadcast mixers are provided with a 5 to 10 watt speaker of 3” size. He always mentions that any distortion free and non hi-fi speaker is acceptable to be used as a monitor. It is all simple. What an engineer needs, is to study the relationship between the monitor speaker and himself. For an example, my speaker reproduces very little amount of bass guitar sound, but I know it is the level for that particular speaker, and then keeping it in that level is correlation. Believing that, we bought two pairs of speakers one for the producer or the person who pays money and other pair for engineer’s mind set.