Now, however much we would like to believe that every problem and its solution is black and white, life really doesn’t work that way. And when we are talking about something that is invisible in itself (I mean sound, in case you were wondering), the shade chart between black and white becomes even more diffused. When something is invisible, the confusion when referring to it becomes acute. You might be sitting in the front rows of the venue at a Zakir Hussain concert and feeling a little uncomfortable with the overall volume whenever Ustadji is smacking the skin of the tabla daya with his powerful strokes, but the person sitting right beside you might feel that the high intensity volume is exactly what makes the concert exciting. Or, you might be unfortunate to find yourself behind the last barricade at some concert, some 120 feet from the stage, and feeling you can’t hear the vocals clearly. But just beside you an elderly gentleman feels this is absolutely the perfect volume, very close to how he listens to his radio at home. Now consider a small venue, which has 500 audience. If you ask each of them about their preference of how it should sound, you will get data that will be pretty much useless in coming to a logical conclusion about how to run the audio of the show. So then, how do we deal with this conundrum? How do we come up with a stable solution when the problem itself is a moving target? If the audience were asked to come up with a solution amongst themselves before the show starts, I am sure it would be something akin to our honourable ministers trying to decide on a matter in the Parliament.
But that is exactly the responsibility the sound engineer (or whoever is handling the sound) has to take for a live performance — deciding on behalf of a room of 500 people or a field of 50,000 how it should sound so everyone who paid for the tickets goes home happy. Needless to say, more often than not, he is criticised by a certain percentage of the audience after every show because remember, there is no common target of how it should sound that the whole audience will agree on.
There are two facets to this problem. One is the overall volume — how loud or soft the whole performance is, the other is the tonal balance — how blunt or sharp the tabla sounds or how clearly you can hear the vocals, etc. The tonal balance is an even harder target since tonality is like colours and two people might not like the same shade of green even if they both like green. So what you feel is the right amount of treble in the tabla sound, might be too much for the person right next to you. It is, again, a subjective choice and there is no right or wrong about the colour you prefer. Someone in the audience will always be disappointed but hey, you live in a world where global inequality is very real so this concept should not be hard for you to grasp.
About the clarity of the vocal, or any other instrument for that matter, you could argue why the volume can’t be increased and made more audible like you do on your earphones. You are partly right, it is just a matter of pushing the fader (the volume control for the vocal or other instruments) and making it clearer/louder. But if it was that easy, don’t you think this problem wouldn’t be so common and the audio person in charge would have done it, instead of inviting displeased comments from the audience? How much volume you can push for the clarity of vocals (or any mic-ed instrument) depends on a lot of factors, like how adequate the sound system is for that venue, how they have been placed and angled with respect to the mic and how loud the voice itself is. Imagine running a 1 tonne AC on your residential meter. It is going to run fine even on the hottest of summers as long as the room is adequately sized. But if you try to cool a room double the size of what this 1 tonne can cover, it will struggle. Conversely, if you add another AC for the other room on top of this 1 tonne one, you run the risk of frying your electric supply. You need to pay for a meter of higher load capacity. But we wouldn’t go and blame the AC manufacturer or the person responsible for installing the AC in our home in this scenario. The AC here is analogical to the sound system, the electric supply is analogical to the strength of the voice being sung into the mic and the room size is analogical to the size of the venue.
Let’s talk about the other facet of the problem — the overall volume distribution. Things might get a bit technical here onwards, so it might be more applicable for people who are involved in the organising of events where sound reinforcement is necessary. The general rule of thumb when talking about volume distribution is to have a sound system that can produce a non-distorted and full-bandwidth level of 110db SPL with a variance of + or - 3db between the front row and the last row of audience. Read that a couple of times if needed, it could be a little difficult to grasp but I will try and simplify it. What this means is, if you are standing in the middle of a venue of 50 feet by 30 feet, and you play a song to check, the sound system should be able to play it fine at a volume of 110db SPL in the middle of the venue. If you move to the first row with the song volume unchanged, the volume from the speakers should not be louder than 113db and at the last row not less than 107db. You can then be pretty confident that during the performance, the audience at the front won’t be complaining it’s too loud and the ones at the back complaining it’s too soft while people in the middle cannot understand what the other 2/3rd are whining about. So it is a kind of minimising the huge difference between the shades of black and white. Equality is never possible in audio transmission, it is always about choosing the best compromise.
Also, I mentioned the terms non-distorted and full-bandwidth, which means we cannot use speakers that can attain the 110db number but cannot reproduce sound with those qualities. An example of such a speaker is the image below.
About the clarity of the vocal, or any other instrument for that matter, you could argue why the volume can’t be increased and made more audible like you do on your earphones. You are partly right, it is just a matter of pushing the fader (the volume control for the vocal or other instruments) and making it clearer/louder. But if it was that easy, don’t you think this problem wouldn’t be so common and the audio person in charge would have done it, instead of inviting displeased comments from the audience? How much volume you can push for the clarity of vocals (or any mic-ed instrument) depends on a lot of factors, like how adequate the sound system is for that venue, how they have been placed and angled with respect to the mic and how loud the voice itself is. Imagine running a 1 tonne AC on your residential meter. It is going to run fine even on the hottest of summers as long as the room is adequately sized. But if you try to cool a room double the size of what this 1 tonne can cover, it will struggle. Conversely, if you add another AC for the other room on top of this 1 tonne one, you run the risk of frying your electric supply. You need to pay for a meter of higher load capacity. But we wouldn’t go and blame the AC manufacturer or the person responsible for installing the AC in our home in this scenario. The AC here is analogical to the sound system, the electric supply is analogical to the strength of the voice being sung into the mic and the room size is analogical to the size of the venue.
Let’s talk about the other facet of the problem — the overall volume distribution. Things might get a bit technical here onwards, so it might be more applicable for people who are involved in the organising of events where sound reinforcement is necessary. The general rule of thumb when talking about volume distribution is to have a sound system that can produce a non-distorted and full-bandwidth level of 110db SPL with a variance of + or - 3db between the front row and the last row of audience. Read that a couple of times if needed, it could be a little difficult to grasp but I will try and simplify it. What this means is, if you are standing in the middle of a venue of 50 feet by 30 feet, and you play a song to check, the sound system should be able to play it fine at a volume of 110db SPL in the middle of the venue. If you move to the first row with the song volume unchanged, the volume from the speakers should not be louder than 113db and at the last row not less than 107db. You can then be pretty confident that during the performance, the audience at the front won’t be complaining it’s too loud and the ones at the back complaining it’s too soft while people in the middle cannot understand what the other 2/3rd are whining about. So it is a kind of minimising the huge difference between the shades of black and white. Equality is never possible in audio transmission, it is always about choosing the best compromise.
Also, I mentioned the terms non-distorted and full-bandwidth, which means we cannot use speakers that can attain the 110db number but cannot reproduce sound with those qualities. An example of such a speaker is the image below.
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| A typical horn-only speaker that can easily reach high levels of SPL but severely lack in low distortion and full bandwidth though it's good enough just for transmission of speech |
There are already solutions researched and developed by reputable audio speaker manufacturers like JBL, RCF, D&B, L-Acoustics, etc. who have all gone to the extent of designing simulation software that give you the exact number of speakers you need and where to place them to get that kind of volume or more, if required, with those qualities. So, there needs to be no guesswork involved. Once you plot the venue on the simulation software, it shows you exactly what volume every audience in the venue is receiving. If you want more, or less, it’s just a matter of changing a few parameters inside the software and checking the angles, positions and numbers of speakers to reach your desired output. Tweak till you are happy and no need to spend hours at the venue itself trying to figure all this out. These software also predict the tonality of the speakers in use (minus the acoustics of the venue) but getting a consistent tonality across every seat in the venue is a huge subject on its own, commonly known as sound system design and engineering, which takes years to learn and master. We will not be getting into that chapter here.
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| A line array speaker system by JBL. Notice the 8 identical speaker boxes that make up the array. Pic credit: desch-audio.de |
But as with everything else, this kind of convenience also comes for an added cost. The speakers in use (above) are purpose designed for more even distribution and are called line array systems. They are required to be flown from a hangar of some kind (also an added cost) and not put on top of tables like traditional speakers, which are called point source speakers (mostly). Not to mention, after doing all the simulation in the software you figure out your client (or you yourself) do not have the budget or the number of speakers that the software is asking you to use for that application. So, even though the solution to this problem exists on paper, in practicality, more often than not, it does not. Mostly due to budget constraints, unless you are organising a Coldplay or A.R. Rahman concert or something of that scale.
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| More common speaker that you see around known as Point Source Speaker |
With that constraint in mind, I would like to recommend solutions that are easier to implement if there is no budget for line arrays, or even the adequate number of boxes needed in the line array. In no way is it a replacement for a proper line array system, designed accurately as per the simulation software for that particular venue, by an experienced system engineer. Nevertheless, the show must go on, line array or not. So, instead of complaining about what we cannot do without it, let’s figure out how we can utilise the boxes at hand. We will look into a few things we can try and follow, and things we should avoid, in the second part of this article, which will be up soon.
Very detailed and smart
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