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
"One must decide what listening position in the hall are you trying to re-create with your system"

That's a very good point that I suspect is often neglected.

THings sound a lot different depending on where you listen from. Getting this right and to your taste is a very valuable and free tweak.
And it would depend who and what is playing for me to no wear I would want to sit in the hall .
Hi Tmsorosk, may I ask if you are referring to acoustical "unplugged" music or electronically produced music as perhaps in a rock concert?

I go to classical concerts and recitals often (actually almost every week these past couple months) and I find that no matter where I sit, the concert hall sound is "warmer" than most stereo systems I hear (absolutely not at the dealers), including mine.

I can never hear that "Krell" and "Audio Research" kind of crystalline clinical sound when playing classical music
when I attend a live classical concert. I think that's their coloration to make it sound "wide open and airy" to attract a prospective customer has only 10 minutes or so at a stereo shop.

BTW in my opinion not all tube amps color its sound reproduction with warmth, and not all SS amps are cold and sterile (Pass XA....5 series and Paul Weitzel's TRL amps are solid state but they are warm sounding and I am sure many can agree with me)
Hello Johnsonwu... Most of the venue's we attend are JAZZ , not amplified . There has been times when we were so close that the horns would drive me back after a few songs , ya standing in the back . I'm not sure how loud the horn's were at that distance , I'dd guess over 100db , my ears rang for hours after . So now when I hear that we are going to a concert , I find out the particular's before picking out seat ticket's .
The liquid coherent sound that live music portrays I would not refer to as warm .
Whether it's tube or solid state the interpolation of warmth that equipment designers add to give a component realism can hardly be compared to what we hear live . Happy listening , live or recorded . Tim
Hi Bryon,

Another of your fascinating and thought-provoking threads, which expectably has stimulated some excellent responses.

The one thing that occurs to me that has not yet been mentioned, and which I think factors into "warmth" significantly, is hall ambience, or the lack thereof.

It seems to me that proper reproduction of hall ambience is a key factor underlying Learsfool's astute comment that
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.
And it strikes me as a key factor in achieving the "richness" that several other posters referred to.

Hall ambience, of course, was discussed at great length in your excellent "They are here" vs. "You are there" thread. Obviously its proper reproduction is highly dependent on the recording. I would offer the hypothesis that recordings that are lacking in "warmth," or "richness," or which tend not to sound "real," commonly have not adequately captured hall ambience.

If so, the obvious question is what to do about it. One approach, which iirc you offered in the other thread, is to try to adjust room acoustics such that they draw a reasonable compromise between adding some semblance of concert-hall acoustics to enhance the presentation of ambience in the case of mediocre or poor recordings, while not overshadowing the ambience that is captured on good recordings. Obviously there will usually be practical limitations to how effectively that can be done.

Another approach would be to try to adjust frequency response. But while emphasizing upper bass and lower mid-range frequencies, for instance, may to some rough approximation replicate the frequency response effects of hall ambience, that approach will be unsatisfactory IMO because it does not address the timing relationships between direct and reflected sound.

What does strike me as likely to be, in general, the most promising way of enhancing warmth and ambience on mediocre and poor recordings, without significantly compromising the reproduction of well done recordings, is the introduction of tubes into the system, as others have suggested above. The added dimensionality that is commonly attributed to tubes (that attribution being correct in my experience, although from a technical standpoint I have no idea why that would be so), and perhaps the relative emphasis that they may give to lower order even harmonics, seem to me to be the best way of achieving that balance.

Concerning where to put the tubes in the system, as you’ve no doubt seen there have been many debates on that question in prior threads here, with opinions sharply divided. FWIW, I am in the tube power amp camp. However in this case I certainly do not think that replacing your XA-30.5 with a tube amp would be the right approach. I say that partly because of the Pass amp’s outstanding reputation, but also because, assuming that the impedance characteristics of your 1027be’s are similar to those of the 1037be, the higher output impedance of a tube amp would result in increased treble emphasis and de-emphasized lower mids and bass, counter to what you are trying to achieve.

So I have no bottom line answer to suggest, beyond some of the suggestions that have already been made, but those are some thoughts.

Best regards,
-- Al