What is “warmth” and how do you get it?


Many audiophiles set out to assemble a system that sounds “warm.” I have heard several systems that could be described that way. Some of them sounded wonderful. Others, less so. That got me wondering: What is this thing called “warmth”?

It seems to me that the term “warm” can refer to a surprising number of different system characteristics. Here are a few:

1. Harmonic content, esp. added low order harmonics
2. Frequency response, esp. elevated lower midrange/upper bass
3. Transient response, esp. underdamped (high Q) drivers for midrange or LF
4. Cabinet resonance, esp. some materials and shapes
5. Room resonance, esp. some materials and dimensions

IME, any of these characteristics (and others I haven’t included) can result in a system that might be described as “warm.”

Personally, I have not set out to assemble a system that sounds warm, but I can see the appeal in it. As my system changes over time, I sometimes consider experimenting more with various kinds of “warmth.” With that in mind…

Do you think some kinds of warmth are better than others?

Thanks for your thoughts.

Bryon
bryoncunningham
02-06-11: Almarg
“Woodiness,” “body,” etc. are for example certainly important aspects of warmth, and their successful reproduction involves capturing the fine detail and harmonic balance of the instrument. That in turn can be expected to be compromised as distance increases. On the other hand, massed strings, to cite another example, can sound overly bright at close distances. As was noted above, high frequencies will be attenuated more rapidly as a function of increasing distance than low and mid frequencies.

This is a good point, Al, and it makes perfect sense of the idea that, in at least some cases, warmth increases as the distance of the listener to the live event increases. That would explain the correlation you observed between recordings with ambient cues and those with warmth. On the other hand, it also seems to suggest that, for smaller scale performances, warmth might DECREASE as the distance of the listener to the live event increases. So maybe there is reason to believe that a common characteristic of warm recordings is that the distance of the microphone to the live event is “proportional” to the scale of the event being recorded. That idea makes a lot of sense to me.

Also, reflected energy will be subject to frequency response contouring as a result of both the greater distance it travels before reaching the listener or the mic’s, and the acoustic properties of the reflecting surface. Finally, and perhaps most significantly, summation of reflected energy with directly captured sound will result in comb filtering effects.

The first of these points is more or less what I meant in the OP by item #5, which I called “room resonance,” but would probably more accurately be called simply “room acoustics.” Having said that, it never occurred to me that comb filtering might be a detriment to a system’s warmth. That strikes me as a plausible idea, since the destructive interference of comb filtering effects could conceivably result in a kind of "harmonic thinning,” which might very well be experienced as a lack of warmth. An insightful observation, Al.

Bryon
Once again, more proof of the need for a better audiophile vocabulary; one which, if it is to have any real meaning, needs concensus. A good place to start is, ironically, outside the audiophile world; in real world vocabulary. How often do we say something like :"Joe Toob is a warm person", or "John Fett is not a very warm person, he is cold". When we say these things, are we referring to anything having to do do with frequency response? Probably not. We are probably referring to wether a person is amiable or not. I think the term warm, in the audio context, is being misused, and has more to do with a components ability to draw you in, and let you get involved with the music. Frequency response certainly plays a role, but I think more impotant in determinng a component's "amiability" is the texture of the sound it makes. This can be independent of perceived brightness, or darkness. I have heard components that sound way too dark, and thick through the midrange, but are also very dry sounding. Conversely, I have heard some that I would consider way too bright sounding, but are also very liquid sounding. Texture. Micro dynamics ability is the other key factor. That is where a component's ability to convey a performer's expressive qualities lies; the warmth of the performance.

Music that approaches the sound of a live performance is, by defintion, warm. The sound of live music runs the gamut as far as wether it sounds shrill, bright, dark, etc. It is the human element that makes it warm, or not. What gives music that hard to describe texture, and dimensionality is the human body attached to it.
hi almrag:

so, you are saying that a tube amp would have a ddifferent freequency response than a ss amp, when driving an electrostatic speaker.

would you expect the difference to be as much as 5 db difference at frequencies exceeding 3 db, or what difference in spl would you expect and at what frequencies ?

how might the frequency response change if the amp was a hybrid (tube input stage), such as the aria amp, designed by mike elliot ?

i have quad esls and am considering the aria wt 100. it has a tube front end and bi polar transistors.