Noise cancellation effects

[Bonehelm]

Whether you have 16-14-12-10-8 (total 60) or 18-16-14-12-10 (total 70) doesn't make any noticeable difference in sound pressure level and it doesn't really make a difference in texture either (provided the musicians always play well together which is obviously the case if they are the same). Maybe Messiaen called explicitly for these numbers (were there sections in which the strings were divided into many smaller sections, by stands).

I heard if a small group of players all play in tune, the volume can be much higher than a large group of players who don't play in tune, because of the sound waves produced by each player aren't going against other's in the former case.

[M forever]

Very true, out of tune playing causes cancellation effects. Another factor is the actual sound color. A richer overtone spectrum equals more acoustical energy and rich and well blended spectra add up to much more than narrow spectra, no matter how "loud" these may be perceived as.

[Renfield]

Very true, out of tune playing causes cancellation effects. Another factor is the actual sound color. A richer overtone spectrum equals more acoustical energy and rich and well blended spectra add up to much more than narrow spectra, no matter how "loud" these may be perceived as.

Fascinating; not unexpected, but fascinating.

[scarpia]

Very true, out of tune playing causes cancellation effects...

The explanation given here violates the laws of physics.  You can think of each violin as a sound source like a loudspeaker that produces a certain acoustical energy.  If violin A produces 1 watt of acoustical energy and violin B produces 1 watt of acoustical energy, then there are 2 watts of energy going into the room.  It doesn't matter if they are playing at exactly the same frequency or not.  If the frequencies are different then the two acoustical waves will not stay in phase, there will be a "beat" or variation in volume for a given listener as the two waves shift in and out of phase, but the average energy is the same 2 watts.  If there are N violins, then all of the beats will average out and you will hear the effect of N watts, regardless of the tuning. 

If the two violins are at exactly the same frequency, it is theoretically possible for them to be exactly in phase, in which case the waves would add coherently, causing them to enhance each other.  But that depends on the assumption that the two violins are exactly the same distance from your ear.  From a different location the sound would take longer for the more distant violin to reach your ear, and there might be some locations where the two violins would appear to be exactly out of phase and would cancel entirely.  Averaged over all locations in the concert hall, the variations cancel out and you get the same acoustical power, for N violins, N watts.

Of course, it is quite possible that the section will sound stronger when playing in tune.  Your ear is not a microphone, so it is quite plausible that a well defined frequency source would cause a stronger auditory response than a poorly defined frequency source.  I suspect the explanation is something different.  When the section is playing out of tune, each player is fearful that von Karajan will hear him playing of tune and have him put in front of a firing squad (or sent to the Berliner Staatskapelle).  Therefore each player plays more softly.

[M forever]

Sounds good, but unfortunately, things are way more complex in reality than you seem to understand. You need to do a whole lot more reading up on that subject. There are many books available about that, and probably a lot online, too. In any case, you shound't hold public lectures about it since you don't really understand it.

And what's with those idiotic comments about Karajan and the Staatskapelle Berlin? BTW, the Berliner Philharmoniker produced a sound with an enormos dynamic range from extremely soft but defined to extremely loud but full and unforced. They weren't afraid of Karajan hearing them play out of tune.

Is this board completely the domain of idiots now? Aren't there any more people left with whom one can actually have a good discussion?

[scarpia]

Sounds good, but unfortunately, things are way more complex in reality than you seem to understand. You need to do a whole lot more reading up on that subject. There are many books available about that, and probably a lot online, too. In any case, you shound't hold public lectures about it since you don't really understand it.

And what's with those idiotic comments about Karajan and the Staatskapelle Berlin? BTW, the Berliner Philharmoniker produced a sound with an enormos dynamic range from extremely soft but defined to extremely loud but full and unforced. They weren't afraid of Karajan hearing them play out of tune.

Is this board completely the domain of idiots now? Aren't there any more people left with whom one can actually have a good discussion?

So you want to go on record with the statement that the Berlin Philharmonic violin section can violate the conservation of energy?  I knew they were good, but I didn't know they were that good!

[71 dB]

Whether you have 16-14-12-10-8 (total 60) or 18-16-14-12-10 (total 70) doesn't make any noticeable difference in sound pressure level

You are right about that M. When you double the number of player (60 => 120) you get theoretically about 3 dB higher sound pressure level which isn't that much subjectively. The difference between 60 and 70 players is less than 1 dB meaning it's barely noticeable.

[M forever]

So you want to go on record with the statement that the Berlin Philharmonic violin section can violate the conservation of energy?  I knew they were good, but I didn't know they were that good!

I am going on the record with the statement that you don't understand these physics. You have read a thing or two and now you think you understand it all, but you don't. You have a very simplistic idea of how that works and how acoustical energy is dispersed through a room. Since there is so much reading about that readily available online and it would take a long time to explain that to you, you can read up on that yourself and then come back.
You also don't understand the practical effects this has on music making. There is no reason you should lecture about that. Nobody here can gain anything from reading your nonsense.

[scarpia]

You are right about that M. When you double the number of player (60 => 120) you get theoretically about 3 dB higher sound pressure level which isn't that much subjectively. The difference between 60 and 70 players is less than 1 dB meaning it's barely noticeable.

3db is a factor of two in power, exactly what you'd expect.  The issue is that human hearing is roughly logarithmic in its response, which is perhaps what you mean.  I also wouldn't say that 1db is insignificant.  Sometimes when I'm listening increasing the volume by 1db is the difference between sound that is totally satisfying and sound that is not quite it.

I am going on the record with the statement that you don't understand these physics. You have read a thing or two and now you think you understand it all, but you don't. You have a very simplistic idea of how that works and how acoustical energy is dispersed through a room. Since there is so much reading about that readily available online and it would take a long time to explain that to you, you can read up on that yourself and then come back.
You also don't understand the practical effects this has on music making. There is no reason you should lecture about that. Nobody here can gain anything from reading your nonsense.

I can assure you that I am qualified to comment on this topic.  If these books you keep talking about have any merit they can't have anything in them which would violate the conservation of energy, which is what I am invoking here.

[M forever]

Man, just how slow are you? Conservation of energy as a basic fact does not contradict in how many different ways acoustical energy gets propagated and dispersed in a room, and how different wave patterns interact with each other, how the sound waves generated by instruments or voices interact with each other, how sound travels through the room and how all these phenomena are experienced subjectively. You obviously have no clue how complex that subject is. Like I said, go read up on that. There is no point in wasting time to explain that to someone as ignorant and arrogant as you present yourself here.

[scarpia]

Man, just how slow are you? Conservation of energy as a basic fact does not contradict in how many different ways acoustical energy gets propagated and dispersed in a room, and how different wave patterns interact with each other, how the sound waves generated by instruments or voices interact with each other, how sound travels through the room and how all these phenomena are experienced subjectively. You obviously have no clue how complex that subject is. Like I said, go read up on that. There is no point in wasting time to explain that to someone as ignorant and arrogant as you present yourself here.

As I mentioned in my first post, it is clear that subjective or physiological factors in human hearing can affect how loud the section appears, depending on their tuning and other factors.   But I'm quite certain that conservation of energy constrains all of the other things you mention.  What is most obvious, though, is that you don't do well when someone doesn't agree with you.

[M forever]

Conservation of energy has nothing to do with the various patterns and effects of different forms of wave propagation which lead to enormously complex results. That has nothing at all to do with the total amount of acoustical energy in the room, but rather with how it moves about the room and how it reaches the listeners.

This is not a subject on which people can "agree" or "disagree". It is a subject of either you know how complex it is or you don't. You don't.

Like I said - READ UP ON THAT. Since you don't understand it, your contributions here are just disinformation and spam.

[scarpia]

Yes, it is well known that in any discussion the person who becomes more abusive is the one that is right.  Makes things a lot easier to figure out.

[M forever]

Ah, the well tried passive-aggressive "I am so hurt now" tactic. "All I wanted to do was to make a smart-ass comment even though I don't really understand the subject, and you are so mean for pointing that out. Boohoo!"

Still doesn't help you to grasp the subject at hand though.

So you wasted much time googling like crazy for an explanation of the very complex phenomenon of sound wave propagation and acoustics based on *just that one basic formula*. But I told you before it's way more complex than that, didn't I?

Your time is better spent if you invest it to READ UP ON THAT. I would have given you a few basic tips to make it easier to understand, but since you are so obnoxious, I won't waste my time with that.

[scarpia]

No Boohoo's here.  I assure you your are causing me nothing but amusement.   

Now, scold me again for not reading all those books that you supposedly understand.  I've not seen any sign of insight, except is so so complicated that you couldn't possible explain it to me, which is very convenient for you.

BTW, conservation laws, such as the conservation of energy in a radiation field, simplify things like this, they tell us that no matter how much complication is introduced, there are certain lines that can't be crossed.

[M forever]

Part of the answer is already contained in your own writing here:

If the two violins are at exactly the same frequency, it is theoretically possible for them to be exactly in phase, in which case the waves would add coherently, causing them to enhance each other.  But that depends on the assumption that the two violins are exactly the same distance from your ear.  From a different location the sound would take longer for the more distant violin to reach your ear, and there might be some locations where the two violins would appear to be exactly out of phase and would cancel entirely.  Averaged over all locations in the concert hall, the variations cancel out and you get the same acoustical power, for N violins, N watts.

[scarpia]

Very mysterious!   

Part of the answer is already contained in your own writing here:

[Bonehelm]

The explanation given here violates the laws of physics.  You can think of each violin as a sound source like a loudspeaker that produces a certain acoustical energy.  If violin A produces 1 watt of acoustical energy and violin B produces 1 watt of acoustical energy, then there are 2 watts of energy going into the room.  It doesn't matter if they are playing at exactly the same frequency or not.  If the frequencies are different then the two acoustical waves will not stay in phase, there will be a "beat" or variation in volume for a given listener as the two waves shift in and out of phase, but the average energy is the same 2 watts.  If there are N violins, then all of the beats will average out and you will hear the effect of N watts, regardless of the tuning. 

If the two violins are at exactly the same frequency, it is theoretically possible for them to be exactly in phase, in which case the waves would add coherently, causing them to enhance each other.  But that depends on the assumption that the two violins are exactly the same distance from your ear.  From a different location the sound would take longer for the more distant violin to reach your ear, and there might be some locations where the two violins would appear to be exactly out of phase and would cancel entirely.  Averaged over all locations in the concert hall, the variations cancel out and you get the same acoustical power, for N violins, N watts.

Of course, it is quite possible that the section will sound stronger when playing in tune.  Your ear is not a microphone, so it is quite plausible that a well defined frequency source would cause a stronger auditory response than a poorly defined frequency source.  I suspect the explanation is something different.  When the section is playing out of tune, each player is fearful that von Karajan will hear him playing of tune and have him put in front of a firing squad (or sent to the Berliner Staatskapelle).  Therefore each player plays more softly.

I'm a high school student and I can already tell that you are wrong. You cannot measure energy with the unit "watts"...watts is for power "P", which is a measurement of how much energy is transferred every second. "Joules" is the ONLY correct unit for energy, no matter what form it is, be it vibrational fields, sound, heat....

[scarpia]

You are correct, that was a typo, the violin would be described by amount of power going into the radiation field.  The use of watts is correct, and I should have referred to it as a power, or as energy per second, not energy.

I'm a high school student and I can already tell that you are wrong. You cannot measure energy with the unit "watts"...watts is for power "P", which is a measurement of how much energy is transferred every second. "Joules" is the ONLY correct unit for energy, no matter what form it is, be it vibrational fields, sound, heat....

[71 dB]

Are you people arguing about two violins being out-of-phase to each other and cancelling each other away? I'll try to bring some sanity to this:

Efective out-of-phase canceling can happen only when the two violins are very close to each other relative to the frequencies radiated by the instruments. In case the violins are 1 m away from each other, efective canceling can happen way below 100 Hz, frequencies that violins do not even radiate! In fact, it's impossible to place two violins close enough. If the violins were close enough to each other and they canceled each other out the violins would change the acoustic radiation impedance of each other so that all the power given by the violin players would transform into idle power. That means no acoustic power disappears anywere since no real power can be created in the first place under these conditions.

In real world, the violins are too far away from each other. In these conditions we have a complex radiation pattern. In some directions the violins cancel each other away (completely or partially) and in some other directions the violins enforce each other. If we integrate the power in all directions we get the correct result, 2 x the power of one violin.

In real world we have also a room/hall with reverberation were the violins are played. The radiation pattern will therefore be smoothed for all listeners.