Hi guys - I wrote a very long post last night, only to discover that I could not post it, for some reason. The discussion has meanwhile left me far behind, but it has been a very good one. Obviously, the main problem here is terminology. As Newbee politely pointed out, some of you seem to have a misconception of what "harmonics" or "overtones" are, and my attempts to define it were obviously unsuccessful. I refer you to any book on acoustics. Hifibri in particular has misconstrued what I have been saying about them, and I give up - there is a reason why I am a musician, and not a writer, LOL (Hifibri, if you want to email me through the audiogon system, I can try to explain to you why your guitar example is not quite correct). I am in agreement with what Al and Newbee have said about harmonics in general.
What I will say is that I think I do finally have a handle on why you all think that frequency response is a major part of warmth. The terminology was holding me back - partly some people's incorrect usage of it, but also and mainly the differences between the meaning of certain words when used in the context of a musician's performance as opposed to the attributes of an audio system's "performance." The only quibble I still have with this discussion is with the importance many of you are placing on minute changes of amplitude in overtones within a musician's timbre as being the major factor in a perception of "warmth." (I am NOT denying that this is a factor) Overtones are inaudible to 99.9% of us. Changes in their amplitude, therefore, would not be heard independently from changes in amplitude to the main frequency actually being sounded. Harmonics do of course have to do with the "warmth" of the timbre, but the musician has no control whatsoever over specific harmonics within the overall timbre. Nothing the player does can isolate a specific harmonic and change it's amplitude - all harmonics will be affected by anything happening to the main frequency being sounded. Let me give a couple of examples.
If I sound the same tone with the same amplitude on two different horns in the same room, the differing "warmth" of the instruments will have everything to do with the alloy of the metal used in constructing the instruments, as well as the difference in the way the horn is designed (not to mention the differences in execution of the same design). Assuming that a strobe tuner is present so we can be sure that the two tones are of exactly the same frequency, the harmonics will be exactly the same. And if the frequency is off by say a cent or two, the harmonics will be proportionally off as well, and this extremely slight difference would not be perceived by 99.9% of us, anyway. You would perceive perhaps a great difference in the "warmth" of the two horns, but it is not because of harmonics. Same if I play the exact same frequency and amplitude in two different rooms on the same horn. They WILL sound perceptibly different to everyone, but it is because of the acoustics of the room, not because of overtones. One more example - two different recordings made of one note in the same room (with a different mike placement for each, or very possibly with the same mike placement) will also sound different. One may sound "warmer" than another, but again not because of harmonics.
Bryon, you are definitely on the right track here: "some acoustical environments, whether a recording space or a listening space, can CONTRIBUTE to the perception of warmth, while other acoustical environments can DIMINISH the perception of warmth. The fact that most concert halls - being highly acoustically designed environments - contribute to the perception of warmth is something I do not take issue with. I was merely trying to point out that LESS WELL DESIGNED acoustical environments might diminish the perception of warmth. Two things seem to follow from that observation. First, for recordings that lack warmth, the acoustics of the recording space might be a factor. Second, for systems that lack warmth, the acoustics of the listening space might be a factor." Change the first word from "some" to "all," and change each use of the words "can" and "might" to "will". Despite all the best acousticians know, it is impossible to predict exactly what the hall is going to do to the overall sound. These factors and others mentioned in other posts (the audio equipment itself, in particular) have a great deal more to do with "warmth," IMO. |
Hi Bryon and Al - Al, you interpreted my comments exactly right, and clarified/elaborated them nicely with your discussion of hall ambience. Bryon, I am not so sure, though, that it has as much to do with distance from the performers in the hall, other than to state that to be too close is not ideal, as the sound will definitely be brighter. And sound does generally travel up and back in a good hall, so that the "nosebleed" seats in many halls are actually the best ones. However, the latter is not always true, often mezzanine seats, or seats in the middle to the back of the floor are best (as long as they are not under an overhang, then they are definitely the worst).
As to the question of whether or not something recorded in a studio can be "warm," that is a much more interesting issue. The studio itself is of course a very cold, dead space. I would say that the vast majority of the time, studio recordings that sound "warm" have been altered with digital reverb, etc. - studios are the playgrounds of the engineer, for sure. And while Al may be right that close miking can result in some good studio recordings of certain instruments, this is IME not usually the case - normally close-miked recordings of acoustic instruments do not sound very good, if by good we mean "real." This, to me, is sort of equivalent of sitting too close in a concert hall. I guarantee you that whenever an engineer puts a mike too close to an instrument, the player tries to move it as far away as he can get away with. |
I would like to comment on one thing that Hifibri said - while I agree with pretty much all of the rest of the post, I would disagree with this part: "Recording studios can and usually are 'warm', dead maybe, designed to lack reverberations to control the sound, but not usually characterized as cold. Great pains are taken to control studio acoustics. "
Great pains are usually taken indeed, but almost never to make it "warm." In fact, quite the opposite - the engineers want the room to be as dead as possible, as they want to totally control the sound not only of the room itself, but even more importantly (and objectionably, to us musicians), of the actual instruments/voices. This is true not only of small studios, but also of the big studios in Hollywood and London. Some very famous musicians truly detest what some engineers do to their sounds in the studio, including in the top movie studios.
By the way, this does not necessarily mean that the resulting sound is bad; but although it may have cool effects, and the recording itself made and edited and mixed very well, it usually has very little to do with what the musician actually sounded like (although for the vast majority of pop singers, for instance, this is actually a very good thing, and they love it).
Also, this is not to say that the studio cannot be made to sound more like a real performing venue - once I had the pleasure of playing with an orchestra I was in with Georg Solti in Abbey Road studios (it was a one-off rehearsal in a training orchestra), and most of the deadening treatments in the room were pretty much removed for the purpose. And this is sometimes done for big budget films where the score is an even more than usually important part of the film. But what I am saying is that this is never done for the overwhelming majority of studio recordings - if they wanted it to sound like a concert hall, they would record in one. Usually, the room sounds so cold and dead that it is actually hard to hear your fellow musicians - the sound dies almost as soon as it leaves the instrument. Of course, normally there is a click-track going on in earphones you are wearing anyway, so there is very little sense of ensemble in any case. And of course, it is usually a much smaller ensemble than a full orchestra, but that just gives the engineer that much more control over his production.
Bryon, some of this also relates to your Recording Accuracy/Event Accuracy thing. Obviously, I am almost always much more interested in the latter than the former, with the type of music I perform/listen to. But if one listens either entirely or at least primarily to electronically produced music, then all of the above is nowhere near as big of a deal (if not practically irrelevant!). It is certainly a hell of alot easier for engineers to manipulate the sounds of electronic instruments exactly how they want to. |
Hello Hifibri - I guess I am still struggling with your use of the term "warmth", after reading your latest post. You seem to be equating "warmth" with the sound of the instrument itself, not merely as a characteristic of it. For a musician thinking about his sound, the "warmth" of it has nothing to do with the frequency being produced, but has to do with the "color" of the sound, or in audio terms, proper reproduction of timbre, not frequency response. Now of course, if a system has frequency response issues, it probably won't resolve timbre correctly, so I guess I can see why you would directly associate the two. However, I would still maintain that you can have a system that measures very well in the frequency response that still sounds very cold (or doesn't resolve timbre correctly) - I have heard many of them in dealer's showrooms - so that is why I do not equate "warmth" with frequency response. Harmonic structure does come much closer to my conception.
Your definition of "air" is also different from how I have sometimes seen the term used here before - some on this board seem to associate that term exclusively with high frequencies. I like your definition better, and I agree that it is a separate thing from "warmth," though it will have a huge effect on the perception of it. |
Lots of good posts here! @Bryon - Johnson is correct that many currently produced tube amps are not warm at all. In fact, the trend seems to be the opposite. Many companies are now making much more high-powered tube amps, so people don't have to change speakers to use them. In that respect, it makes sense. However, with the added power comes added brightness and a loss of warmth. Johnson's Audio Research example is a good one, another American company doing this is Rogue Audio. If you want a modern tube amp company that has a warmer sound, I would suggest PrimaLuna or Cary.
@Newbee - excellent post about decay. Agree 100%. This is one of the major reasons why many of us musicians prefer tube amps.
@Hifibri - I think we are still not quite understanding each other. You wrote "If live music were only composed of primary frequencies this statement would be true; ‘For a musician thinking about his sound, the "warmth" of it has nothing to do with the frequency being produced, but has to do with the "color" of the sound, or in audio terms, proper reproduction of timbre, not frequency response.” However, live music is not just primary frequencies but a combination of lots of different overtone frequencies that create harmonic structure, warmth, tone, and timbre."
There are a couple of problems with this. First, there is no such thing, if we are speaking of acoustic instruments, as live music composed only of primary frequencies. That could only happen with electronically produced (and then electronically altered) music. Second, when a musician alters the "color" of his sound, this does NOT change the frequency, including the overtones within the sound - these overtones are determined by the frequency being produced, not by anything the player is doing. Now if the player's tone is not pure (is a little or a lot unfocused), this can mess with the overtones that are produced, as the intonation will be off. But usually only jazz musicians sometimes deliberately "bend" notes in this way on purpose. This isn't done in classical performance. I am talking about much more subtle changes of timbre. But the main point is that the musician cannot change the natural overtones produced by the frequency being played. This can be done to a recording of an acoustic instrument electronically, of course (something that digital processing is frequently guilty of) but that is not what we are talking about here.
@ Bryon again - I know we hashed this out on your neutrality thread already, but I still cringe when I read someone assuming that "warmth" must be an "addition" or "coloration." I still vehemently disagree with this. For me, again because of the types of music to which I listen, if "warmth" is not present, that is a definite "subtraction," and therefore an inaccuracy. Measurements be damned! :) I guess this has alot to do with your question about caring more about reproduction of the recording or the actual event. |
Hi guys - Hifibri wrote in his last post "By changing overtones you change the shape of the wave and the resulting sound." As I have tried to explain, the actual overtones do NOT change.
Al, you are probably correct about the amplitude of them changing, I would need to get out my acoustics books to make sure. However, since these overtones we are speaking of are not audible to the vast majority of even highly trained ears, changes in their amplitude then would not be audible either, and they would be very minute in any case (though some would argue that this does not mean the brain wouldn't perceive the change somehow). The actual amplitude of the total sound of course has a far greater effect on the waveform. You bring up a very interesting question, though. How a musician's subtle changes in timbre affect the waveform is something I would need to look up (certainly these changes obviously effect the waveform somehow) - but I am not sure that my books go into that much detail. What I can say is that there is no way a musician can deliberately change the volume of a specific overtone in his sound, so even if you are completely correct, there is unfortunately no practical application of this for actual live performance.
Regardless of what the answers to these questions are, things like what Al terms "hall effects" have a MUCH greater effect on the perception of "warmth" (Unsound is perfectly correct in his last post), and the recording itself has an even greater effect. The design of the audio equipment also has much to do with it - for instance, to bring up Onhwy61's point, many designers of digital processors routinely omit all harmonics above the range of human hearing, claiming what the ear can't hear it won't miss. Many of us beg to differ, and it has been proven that the brain can detect frequencies above what the ear can hear. LOL, am I now getting dangerously close to arguing against my point? This is a fascinating discussion, indeed. |
Hi Bryon - perhaps Al can weigh in on this and correct me if I am wrong, but I'm pretty sure harmonics couldn't truly be "added," (they are of course all already present in the timbre) though digital reverb would be an example of an "addition" that would certainly affect the perception of warmth. Overtones can be and are sometimes removed by digital processing.
Perhaps a better word to describe what you are speaking of would be "emphasizing." Atmasphere has posted quite informatively about these types of issues, talking of even or odd order harmonics being emphasized by the design in different types of amps, and whether or not the designer is thereby following the "rules" of human hearing. This is very similar to the way the acoustical environment affects the timbre, except the designer of a piece of audio equipment I suspect has alot more control over his end result than an acoustician does.
And yes, I would say that tube designs are certainly "warmer," speaking very generally, than solid state designs, therefore sounding more lifelike. I'm just saying that there is a whole lot more to do with that than amplitudes of individual harmonics within the overall timbre - again, these harmonics are inaudible to far more than 99.9% of us. |
Hi Al - thanks for weighing in on this. However, I think you are incorrect when you say "Harmonics can, and to some degree inevitably will, be INTRODUCED by the system in the form of distortion products." (My emphasis) Your own examples that follow are all examples of what I was speaking of in my previous post - what you call enhancing certain harmonics via distortions (and they are good examples). However, ALL natural harmonics are always present in the natural timbre, so you can't introduce a new overtone that wasn't there before, though you can distort (or even remove) it. This is what I was trying to say in my previous post. If this statement is indeed incorrect, please explain.
One other point - in your violin examples, yes, those overtones are of course part of what make differences in timbre. However, each individual one is indeed indistinguishable from the others to the ears of at least 99.9% of humans. It is not possible to tell which of those overtones are the ones that are different, in your example of two different playings of the same note on the same instrument. If I played the same note twice, at the same volume, on my horn, you would not be able to tell me which individual overtones were affected and how, and this is doing you the credit that you would be able to hear the difference in the timbre between the two at all - a great many audiophiles would not, especially if I tried to the best of my ability to make them exactly the same. And in the same case, it would have to be a VERY bad recording/system indeed that would distort them so much so that most people could hear it. These sorts of differences are MUCH more audible live and at very close range than they are on a recording. |
Hi Al - you wrote: "If you are saying that any note produced by any instrument will naturally and invariably contain frequency components of non-zero amplitude at ALL harmonic multiples of the fundamental (lowest) frequency component of the note (and I don't know whether or not that is true), then yes, that would mean in a literal sense that the system cannot INTRODUCE a harmonic that isn't already there."
Yes, this is exactly what I am saying. All of the harmonic overtones of a sounded frequency are always present in the timbre, so electronic distortion cannot introduce or create new harmonics, it can only distort those already present.
About your last statement: " For a given volume, fundamental frequency, and envelope I can't envision anything other than differences in harmonic structure that could account for differences in timbre, tone, or the basic character of the note." This is a strange statement. The basic difference in timbre between a flute and a violin, to use your example, is that one is made of metal and one is made of wood, not to mention the fact that their sounds are created in a completely different manner as well. This is obviously the largest factor in the difference in timbre. Without going into the science of it, waves produced by a string behave very differently from waves produced by a tube. A tube with one end closed behaves differently than one open at both ends, and conical and cylindrical tubes behave differently as well. Side holes in the tubes have their effects as well, of course. Not to mention different types of wood or metal alloys used in the instrument's construction, which have very great effect on the timbre.
Another important thing to point out is that although some of these various timbres are more acoustically complex than others, the overtone series for all of them is always the same - it doesn't matter what instrument is creating it.
As a side note, the flute happens to be one of the purest instrumental timbres, and the oboe is one of the most complex. This is the reason that the oboe gives the A to tune the orchestra - it's complex tone is more easily audible.
Last, another word on the audibility of these harmonics. Sometimes, it is possible for the brain to concentrate on an overtone of the tone sounded, if this frequency has already been sounded, so that the ear is aware of it. For instance, if a piano sounds A440Hz, and then the A an octave below (220Hz), it will be easier to attempt to hear the A440 overtone within the sounded A220Hz tone. This takes some training, of course, especially if one wants to try to hear more difficult overtones. There are some people who have claimed to be able to hear as many as 27 different overtones, but the vast majority of researches seriously doubt this claim - 5 or 6 at most, and that for a very highly trained ear indeed. Those types of experiments are fascinating.
Best regards to you as well, Learsfool |
Hi guys - Kijanki, you make a very good point about jitter (and explains yet another reason why digital has never sounded as good as analog for me), and the intermodulation distortions. I guess I thought that jitter had more to do with timing, but I suppose that it would indeed produce harmonic distortion as well.
Al, I do understand now much more where you are coming from, thanks very much! I will have to read up on these types of electronic distortions some more. When I took a graduate level acoustics course, it was geared (as was the very fine textbook which has always been my main reference ever since) to performing musicians and live acoustics, not recordings and electronic equipment. In fact, I am not sure that purely electronic distortions were discussed at all, I will have to look that up. I have never been one to judge audio equipment by the specs, anyway, so these types of things have never held much interest for me. This discussion has certainly got me curious, though!
I will have to check out the article you linked when I have some more time to give it serious attention. Just reading over your quotes from it, it seems like very good info. The text I mentioned goes into great detail about all of those issues mentioned. If you care to look it up, it is entitled The Musician's Guide to Acoustics, by Murray Campbell and Clive Greated, and was published by Schirmer. I do see, getting it out, that the last couple of chapters discuss electronics briefly (I think mostly from the perspective of electronic instruments rather than audio equipment, though), but the book is basically about acoustic instruments and how they behave, and how the room affects them. So my knowledge of acoustics is much more in that line, things that affect live performance rather than recording playback.
What is particularly interesting to me is your discussion of different amplitudes of the harmonics having such a big effect. I am starting to come around, but it would be good to find some info on that in particular. That would certainly seem to be one of the biggest differences between live and recorded sound, then, and probably a much bigger difference than I have thought. Thanks so much for sharing your knowledge - between you and Atmasphere in particular, I have received quite an education on this site. |
Hi guys - great posts. @Kijanki - thanks for the jitter discussion. And yes, timbres of instruments are extremely complex. It makes for fascinating reading; the book I mentioned before is a great place to start - non-musicians would have no problem with any of the terminology, from what I remember of it.
@Kirkus - thanks for the great post! I had a girlfriend in college who was doing alot of composing in the electronic music studio, and was actually quite frustrated by the bewildering array of options. It was a very overwhelming experience for her. To be honest, I'm really not very enthusiastic about any form of electronic music - while I appreciate it, I just don't care for the timbres. But you are probably right that that would be a good source of info.
About your last paragraph on poor tone production affecting tuning - what you say is basically correct, and it does go for brass instruments as well. An unfocused sound will also not necessarily be flat - the pitch actually fluctuates quite a bit, and can be sharp just as well as flat, which is a very interesting phenomena. Uncentered might be a better description of what I mean specifically here - the pitch is wandering out of the player's control, and it doesn't just move in only one direction when this happens. Pitch tends to raise, for instance, particularly when the player is straining. Overall, though, the timbre of a very unfocused sound will be dull (which is why it often sounds flat even when it may actually be sharp in pitch), weaker, and often airy in the case of wind instruments. There will also be lots of "fuzz" on the edge of the sound. Some jazz musicians cultivate this type of sound for expressive purposes, and bend the pitch quite a bit. This is where the old tuning joke "close enough for jazz" originates. Another example would be of a brass player with alot of "edge" to the sound - they may sound very loud up close, but "edge" will not carry out into the hall very well on it's own - there must be a good core to the sound.
As Mr. Tennis brings up, though, how all this relates to what audiophiles call "warmth" is another question. Even if "warmth" is called a "coloration", I think Bryon is right in asking is this a bad thing? In the case of an orchestral recording, equipment that makes the sound "warmer" is almost certainly also making it more lifelike, or as Bryon would put it, faithful to the original event. I for one don't care how a piece of equipment measures, or if it is "neutral." For me, equipment that is usually described as "warm" almost always sounds better than equipment specifically described as "neutral." And then there is the recording and how (and where) it was done. To me, these are still huge factors in the perception of "warmth," despite my education I have here received on electronics, and my realization that they do manipulate harmonics quite a bit more than I understood. |
Hi Bryon - for me, assembling a system that sounds "real" is automatically also going to be a system that sounds "warm." I suspect this is true for the great majority of audiophiles out there, especially those whose reference is live, unamplified acoustic music in a good performing venue (I am assuming, for instance, that this is what HIfiman means by "acoustically neutral," but I could be wrong). A good performing venue is "warm." I have never heard a system I would describe as "cold" or "harsh" that I could also describe as "real." Hifiman also speaks of the "inherent warmth of real instruments", which is certainly true, and I would also add the human voice to that. Though an actor may make his voice sound as cold as possible, there are extremely few instances where a singer would do so. Even HIP groups that don't use vibrato still have a natural warmth to their string tone. I really don't care how well a high-end system may measure, if it doesn't sound real/warm, and IMO/E, way too much high end equipment falls short. As for technical reasons why, I am certainly nowhere near as qualified as many others on this board to answer that; but this does put me in mind of something I read I think last night in a different thread where Atmasphere said, and I am probably badly paraphrasing here, that designers often have a choice between making equipment that measures well, and equipment that obeys the rules of human hearing. Perhaps he will weigh in on this thread.
Incidentally, part of the above is another instance of confusion that results from the use of the term "neutral." :) |
Hi Bryon and Hifibri - both of your last posts have fascinated me. I did not realize that audiophiles used the term "warmth" in quite the way you both describe - specifically, equating warmth with the body of the sound, as Hifibri put it, or with the frequency response/harmonic content of it, as Bryon put it. To me, the body of the sound is quite separate from the "warmth" of it, though of course it will have a significant effect on the perception of "warmth." And certainly "warmth" is not equated with frequency response in my mind. I won't go into it in any boring detail here, but musicians work very hard on the relative "warmth" of their tones depending on what sort of passage or what composer we are playing. We work for as many different shades of color we can get, and all of these would have varying degrees of "warmth." So I guess I am using the term much more in the sense of "color" than you are (another reason why I strongly dislike the negative connotations in the use of the audiophile term "coloration").
Hifibri, you are correct that we are basically in agreement, then, if I have understood your post. However, I would still argue that a recording studio or other "dead" space will most certainly have a very significant effect on the perceived "warmth" of the sound. In such a "dead" space, no matter how "warm" a tone the player creates, the fact that it almost immediately dies away has a huge effect on the perceived "warmth." This would have nothing to do with frequency response or harmonics, but the "deadness" of the space. You are correct, of course, in what you say about the anechoic chamber, but I think it should go without saying that no one would ever want or expect music to be either created or listened to in such an environment. So I of course agree with your ending - if it sounds good, do it! This, of course, will be different for every individual.
So yes, Bryon, I would argue that a "dead" listening room is indeed a detriment to "warmth." In fact, I think we have actually had this conversation in a slightly different context elsewhere. As we all know, the same equipment can sound very different in different environments, and this is the biggest reason why, IMO. |
Hi Bryon - loved the beginning of your post. :) I think we are actually in agreement here.
@Hifibri - yes, re-reading what I wrote, that is a little confusing, for which I apologize. Basically, this is the part that is the important part: "the main point is that the musician CANNOT (emphasis added) change the natural overtones produced by the frequency being played." In this quote: "Now, if the player’s tone is not pure…this CAN (emphasis added) mess with the overtones…musicians sometimes deliberately bend notes on purpose." the word "overtones" is not what I meant to use - I meant to say frequency, though this is pretty badly worded period.
Without going into a very technical discussion of sound waves and how they are formed inside a brass instrument (to continue your example), a brass player is manipulating frequency and creating different waveLENGTHs when he "buzzes" his lips as the air moves through them and into the instrument. Where this frequency is on the natural harmonic series determines the waveLENGTH. These natural harmonics are of course fixed, as are the resulting overtones in the sound, which are determined by these fixed natural harmonics. It isn't possible for the player to manipulate these. If the player is "lipping" too much or too little, or "blowing" too much or too little, this inefficiency results in the tone becoming unfocused in some way, changing the waveFORM, but it does NOT change the frequency or the waveLENGTH, and therefore does NOT change the harmonic content. The dynamic level, or amplitude, makes subtle changes to the waveFORM, and any subtle "color" changes the musician may make to a note (such as the jazz trumpet player "bending" a pitch) also change the waveFORM, but NOT the harmonic content.
So the point I am leading to here is that changes in "warmth" are NOT related to frequency or harmonics or overtones whatsoever. I hope the above is clear, there is a reason I am a musician and not a writer! So to speak of "warmth" in a system as something to do with frequency response seems wrong to me, and I am trying to understand this association among audiophiles. |
