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.

Acoustics in India - Part I

Acoustics in India

At last we decided to make a recording theatre ourselves for us with the little money and the little ideas that we had in our minds. It happened in 1982, when I was working with a social service institution, whose mission was to produce study materials for non formal education. The compulsion to make a studio was necessarily demanded as every ones’ prevailing reasons - more rentals, non cooperation of sound recordists, unsatisfactory result, non availability of call sheets, etc. But making a recording theatre was not an ordinary challenge, the reasons were two; one is procuring the equipments and another is treating with acoustics.

Today you don’t find much difficulty in sourcing the equipments, because they are easily available in the market. Internet search engines help you to find the right person who can genuinely supply these equipments and support you as well. But acoustics confuses every human being a lot: it is expensive; you need a consultant; whom you doubt in so many ways - right from his ability on job to looting commission from the suppliers of materials; without him sourcing the right type of material for insulation and acoustics is a taunting pain; you may know glass wool, but you may not know the density of that, and how many layers you may have to use. Acoustics involves a lot of labours, sincere labours; because once the insulation work is completed you can not check it up weather the materials (as they cause tremendous itching on the skin) are properly kept inside. And you need different types of skilled workers, mason, carpenters, air conditioning consultant - ducting persons, upholstery workers, metal fabricator, electrician, electronics engineer, and computer hardware/software experts in Audio Visual field. To integrate all these workforce is further a very tough job.

When any of these consultant or worker does not keep up to time schedule the entire project repels and collapses the total programme.

A good studio needs to look good also, that can create pleasing environment to the artists or at least that does not disturb mood of an artist. Simultaneously, the interior should not interfere the acoustics treatment. Many interior designers and architects have been enemy to the acoustician.

Understanding all these facts we decided to make our studio by our selves with the little knowledge we had and the forgotten theories what we studied about acoustics. First, we decided to buy some books about studio acoustics to recall the knowledge about insulation and acoustics treatment; and they came. But they all were written by outsiders. I still remember that I bought a costly book about hundred recipes of salad making, but nothing I was able to make because of the non availability of the particular vegetables and fruits of those kind referred to in our country. The same thing happened to me with the books I bought. The materials mentioned in those books were either expensive or not available locally. Even today the problem being the same, acoustics tiles, acoustics spray, corner traps, and any imported material, is enormously priced. Because it is imported, of course the reasons are there - transportation, customs duty, and being rarely selling products. Recently we approached a company that is trading acoustics spray on walls; guess the rate they demanded! Rs. 18,000/sqmt (in Chennai, the cost of the contractors’ building of per sqmt is Rs. 10,000 and in the outskirts of Chennai, one can buy beautiful apartment for Rs. 18000/sqmt. Not only the price, their conditions were also scary, since their marketing is monotonous and aristocrat (they normally do not reply you properly) their behaviour is also abnormal. The same situation prevailed in those days also where the glass wool was imported and the price was exuberant; any acoustics tiles you had to import, probably sonotex was the most popular but the transportation and customs duty and the importing process were very tedious and time consuming. Few companies that were making fibre wood boards demanded a lot of money, as they were rare (very recently lot of manufacturers of fibre wood boards have become competitive with the pioneers in quality and price).

Considering all these facts we decided to take a different route to make the studio; that is to make with inexpensive materials; it is nothing but not pre fabricated materials.