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
Learsfool you wrote; "As I have tried to explain, the actual overtones do NOT change"....and; "Al, you are probably correct about the amplitude of them (overtones) changing". If they change amplitude, they change the sound and waveform, change is change. If a musician strums an open chord on an acoustic guitar, then the musician places his hand on the bridge and strumms the same chord it would sound different because the frequency and amlpiude of the overtones have changed due to the damping effect of the musicians hand. It's basic acoustics.

All halls, venues, rooms have thier own sound.
http://classicalmusic.about.com/od/concerthallsvenues/ss/bestconcerthall_6.htm

Often they are modified to improve thier sound.
http://www.saflex.com/pdf/Saflex%C2%AE%20Acoustic%20-%20Chicago%20Symphony%20Orchestra%20Hall.pdf
02-16-11: Unsound
"...While other hall effects might sound cool". Yes, but I would think that's more likely in small, highly reverberant halls, and not as likely to happen in typical concert venues.
02-16-11: Almarg
I can't remember ever being in a hall in which the instruments sounded "cool," in the way that they can on some recordings.

My apologies. I wasn't very clear in my last post. When I used the phrase "hall effects," I intended to refer to the acoustical characteristics of recording spaces that might or MIGHT NOT be a concert hall. In other words, I intended "hall effects" to simply mean "acoustical effects," and I should have said as much.

What I was trying to express was the idea that 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.

Bryon
If a space can't support or leaks the lower frequencies, and at the same time reverberates or enhances the higher frequencies, though not typically likely to happen, I would suspect the results would be "cool".
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.