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
Bryon, Re Room treatments/tuning, like everything else in audio, ain't a Sunday walk in the park with a pretty girl.

Depends on what you are trying to change to create 'warmth'. In this post I will assume that 'warmth' means unemphasized highs with or without a corresponding wide but small boost in the lower mid-range thru to the upper bass. Room dimensionally induced issues? Set up issues? Equipment selection issues? Treatment selection absorption/dispersive panels, traps, etc, all of which require careful selection given the source of the 'problem' are critical.

For example, excessive sounding highs can be caused by equipment types or positioning relative to reflective surfaces. They can be controlled/reduced by speaker location, orientation, or using sound dispersion or absorption panels.

But, as in the case of absorption panels, a common type of treatment recommended and used by audiophiles, if the materiel used covers a broader frequency range than needed, i.e. you need to knock down a 5K peak but use materials which are absorptive down to 1500k you will have dulled down an otherwise well balanced mid range. This might enhance the sound of the lower mid range/bass to some folks but not to all.

Conversely if you have an upper mid-range peak, a very common problem in speaker and electronics, and you try to damp it with absorption materials you loose the highs as well as the mid-range peak. For me that removes specific absorbers from the list of possibilities unless you can figure out how to compensate for the unwanted change. And so it goes with a just few room treatments but set up problems as well as speakers and electronics share the same issues. How to get balance in your room? Even the experts often can't get it right.

So, to my point (finally). Tubes. If you have speakers appropriate to your room and to tubes in the first place, and these speakers have a reasonably good sense of 'natural' resolution, by using tube equipment and carefully using (rolling) tubes therein to get you to your sonic goals, you can tame common HF problems and even add some bass /lower mid range boost (that warmth you are looking for?).

The possibilities with tube equipment seem as endless as the frustrations experienced by many in the implementation of tubes, especially by those who aren't all that dedicated and like quick fixes, or miracles. One of the things that I would always recommend because of the learning curve involved is to keep it simple, even knowing that ultimately someone might want an all tube system. For example, there are quite a few good integrated tube amps now and are an excellent place to start as opposed to introducing separates and making a mixed system.

And, FWIW, realizing that there exists those who will vehemently disagree, with ss stuff you are excluded from changing its sonic signature significantly, keeping it off the horizons for adventurers. Wires and little black boxes can only do so much.

But I digress and apologize for going off point and getting on a box with such simple observation
Many feel some speakers are "warmer" sounding than others.

I have always tended to attribute this to tonality, ie the relative balance of frequencies with warmer speakers tending to have less emphasis on treble or higher frequencies relative to midrange in general.

I'm wondering do different speaker designs handle harmonics differently? that would seem to be the case if harmonics is the main factor in determining warmth.

Most discussion of harmonics I have read tend to be about how different amplifier technologies deal with harmonics.

But what about speakers then assuming some speakers are inherently warm and others less so, which I believe to be the case.
Mapman, FWIW, I agree with your first two sentences. I think tonal differences in speakers can easily be effected by enclosure design, speaker selection, and crossover design.

Except for those speakers which have been intentionally designed to use its natural resonance frequencies to enhance a tone, the speakers 'harmonics' would not greatly affect its frequency response so much as its resolution.

For example, if the cabinet had an unsuppressed resonance frequency of, say 350hz, it would likely sound muddy/boomy, not natural at all, and something I think a designer would want to avoid like the plague.

In the context of this thread I think 'harmonics' is a term referring to the overall tone of an instrument and how it is replicated in the recording or playback process, something that it best appreciated with the choice of a violin, guitar, piano, etc, which all have sound boards which resonate and create complex sounds (harmonics) resulting in a natural tone. Not a warm tone, not a cool tone, a natural tone, the signature of the instrument itself, and not the recording or playback process. That tone is what it is. That is what I think when I use the term 'natural'.

Personally I'm not comfortable in referring to speaker designed tone, hall acoustics, or home room acoustics as 'harmonics' in the same sense as those of instruments.
hi newbee:

i think you have described the concept of warm, in your first paragraph in a previous post.

however, would you say that a dip in the highs and a peak in the upper bass and/or lower mids, is amore specific description of warmth ?

if so, warmth is a coloration--an audible deviation from a flat frequency response.

a basic issue is whether warmth is a coloration.

as 9i have said, when listening to musicians playing instruments which are unaplified, does the word warmth apply ?

i think not, i suspect that what people mean by warmth is accuracy of timbre. when an instrument does not sound real, there usually are errors in frequency response.

it would be interesting to find out rrobert harley's definition from his famous book (i don't remember the title).

the easiest way to achieve warmth , other than room treatment is equalization, but there is a cost to using this approach. i had suggested a deqx or tact in a previous post, these devices operate in the digital domain.
Hi Mr T,

As I have said in a post previous to the one you have quoted, my only hope when I listen to recorded music is to hear something that sounds natural, consonant with that which I would experience live. My live experiences leave me with little choice when selecting components for my home system but to tune a system which might be called warmish, especially in the upper bass/lower mid's and a little dip between 2 and 3K hz. I do not seek a reduction in the high frequencies. To me my choices only compensate for the prevailing design critera used by so many speaker and electronic's manufacturers, as well as more than a few recording engineers that better serve the stereo format and goals than the music itself. Just think how music could be better served if soundstage was no longer an issue. In stereo the engineers rely on multi-mic'ing to create the stereo effect and the sound of a live event is lost.

For example, most live music, except for very close seating is mono in form which is amplified by the horn shape of the stage and enlarged by the hall acoustics. If you can ever find one, try a properly set up binaural recording and see how much the stereo soundstage collapses into a large, well defined, mono sound field.

FWIW, just my POV. But I don't think I can help you with your conclusions.

Call that sound colored if you will but to me it has the potential to occasionally remind me of something I heard live, and at worst covers a lot of 'uncolored' sin perpetrated in the name of 'audio'.