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
Well, the Audiogon site seems to be a bit fickle when it comes to hyperlinks. So here's the definition from J. Gordon Holt, the man who probably put this language in our lexicon:
"warm The same as dark, but less tilted. A certain part of warmth is musical sound."
"dark A warm, mellow excessively rich quality in reproduced sound. The audible effect of a frequency response which is clock-wise tilted sound across the entire range so that the output diminishes with increasing frequency. Compare "light".
"light Lean and tipped up. The audible effect of a frequency response which is tilted counterclockwise. Compare "dark".
Hi Mapman - Before I owned the Focals, I owned Dynaudio speakers for several years. They did have a warmer sound than the Focals, as you point out. But ultimately I concluded that their "house sound" is somewhat too colored for my tastes. I have not heard the Confidence line, however, which might change my mind about that. I have heard the Sapphire, which was pleasing, but a bit underwhelming for the price. I know lots of folks love the C1, but I can't get past its looks, which is shallow of me, I know.

This all raises another question I've been wondering about, namely: Is there an inherent advantage in warm speakers with neutral electronics or warm electronics with neutral speakers?

I have a slight bias toward the latter - warm electronics with neutral speakers - but it's based on nothing more than the intuition that warm speakers diminish resolution more significantly than warm electronics. I guess that's based on the suspicion that the source of warmth in electronics - harmonic distortion - is inherently less destructive to resolution than the sources of warmth in speakers - uneven frequency response, underdamped drivers, driver coloration, and cabinet resonance. I am happy to be wrong about any of that. If I am wrong, and if I choose to pursue greater warmth, then I will have to consider other speakers. Unless...

I should mention at this point that I'm also considering modding the crossovers in my Focals, with the hope that it might increase the perception of warmth, or at least diminish the perception of "coolness." Johnsonwu, who posted above, has already given me some good advice about this type of mod. But I don't want to proceed until I'm pretty sure I'm going to keep the speakers, since it might affect the speaker's resale value.

Lots to consider.

Bryon
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.
@ Learsfool: Careful with Cary. That's the foggy yet non-linear sound which I couldnt deal with. Prima Luna varies from model to model, some are pretty good, some are thin and beamy.

@Bryon: worry not about the mod, if you extract the stock cap carefully you can always fit it back in with no issues.
If the old caps are professionally put back in it with care will not affect the resale value, at least IMO
It's the $$$ on labor and the expensive cap that you will lose.

I may sound like a broken record but dont change out the amp. Borrow a tube preamp from someone and try.
02-11-11: Learsfool
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.

MUST NOT...TALK...ABOUT...CAN'T...STOP MYSELF...

Ok, I'll break my own self-imposed moratorium on discussions of neutrality just long enough to say...

RE: "ADDITIONS"

I never assumed that warmth, as heard at the listening position, is NECESSARILY an "addition." To state the obvious, what is heard at the listening position is both the recording and the playback equipment. If you hear warmth at the listening position, it may be coming from either or both.

If the warmth is on the recording, and you hear it at the listening position, then the playback system is accurate with respect to warmth. Hence it is not an "addition." If, however, warmth is NOT on the recording, but you still hear it at the listening position, then the playback system is NOT accurate with respect to warmth. In this case, warmth is an "addition" to the signal introduced by the playback system.

Having said that, I have recently come to believe that some "additions" to the signal introduced by the playback system, while inaccuracies relative to the recording, may nevertheless be MORE accurate relative to the live event. That is because, both deliberately and accidentally, the recording process often REMOVES characteristics like warmth from the recording. Hence the ADDITION of warmth by the playback system actually makes the sound at the listening position closer to the sound of the live event. That was the point of my first post on 2/8.

RE: "COLORATIONS"

If the playback system adds warmth to the signal, then in terms of accuracy to the recording, it is a coloration, understood as a consistently audible inaccuracy introduced by the playback system. But again, the addition of warmth to the signal may NOT be a coloration in terms of accuracy to the live event, in circumstances where the live event was warm, but the warmth was removed during the recording process.

RE: "ADDITIONS" + "COLORATIONS"

The addition of some playback colorations, like warmth, can be a way of hearing at the listening position, a sound that is more accurate to the live event, even though it is less accurate to the recording.

And, FWIW...

This is an adjustment to, but not an abandonment of, the position I took on the neutrality thread, where I suggested that efforts to maximize neutrality (i.e. the absence of playback colorations) tended to make a system more enjoyable, at least to me. I have reached the point where my efforts to increase neutrality by removing audible playback inaccuracies have ceased to result in greater gains in enjoyability. I now feel that the introduction of a SLIGHT playback inaccuracy, in the form of additional warmth, might make the system even more enjoyable, by expanding the range of recordings that sound excellent on the system.

Bryon