What is a "warm" sound?



What does it mean for a sound to be warm? What does a sound need to have to be "warmer" than other?

We often hear this associated with analog systems. "analog warmth", "the warmth of vinyl". What is it? Is it something that can be measured and analyzed? Is it something people say when they don't know how to describe what they hear? Is it something else?

Anton dB

Posted 2015-03-01T18:40:07.850

Reputation: 3 839

This question has also been discussed in sound SE: http://sound.stackexchange.com/q/29926/6631

– Anton dB – 2015-03-23T16:56:24.953



Most widely applicably,

  • A warm sound - whether a note, voice, song OR a warm-sounding hi-fi system - has plenty of lower frequencies, compared to the amount of high frequencies (but not all lows - that would sound more 'muffled' or 'muddy').

  • when talking about individual sounds (like individual notes), more harmonic partials (like a piano or guitar), fewer inharmonic partials (as found in a bell). This might be seen as less relevant to the warmth people find in systems, but it's possible that some sound reproduction systems that add some subtle harmonic distortion are seen subjectively as warm; certainly a sound recording/reproduction system that was adding aliasing artefacts (which would not be integrally related to fundamental frequencies of notes) might sound more 'brittle' or 'harsh'.

slightly more subjectively,

  • a sound that is somwehat complex and has a 'natural', shifting frequency spectrum - think a string section, as opposed to a single cycle repeating buzz or bleep sound.

  • we tend to find warmth in sounds that are steady in volume and other characteristics. Think of a late night radio presenter's gentle, compressed voice.


Posted 2015-03-01T18:40:07.850


Would you say that "warmth" and "analogue warmth" concepts are similar in that sense? Also, could you dive into the more controversial aspects too? That'd be very interesting, even as a side note. – Anton dB – 2015-03-01T19:18:46.233

@JCPedroza do you mean analogue like a moog, or like a record player? or either? – None – 2015-03-01T19:33:59.493

Both. Any sound produced, reproduced, or affected by analogue means. Analogue synths, analogue playback devices, analogue effects, analogue signal paths. Are you familiar with the "analog warmth" concept? It comes up regularly in analog vs digital discussions. – Anton dB – 2015-03-01T19:45:04.760

Analogue synths : most typically low pass filter designs (so there's your 'more lows'; they often have oscillators that produce simple waveforms (essentially harmonic partials) that can yet be detuned or PWM'd to give a natural complexity; sometimes the pitch instability in the oscillators adds to this. Also the distortions in certain filter designs add extra harmonic distortion that accentuates this complexity (As well as adding more harmonics!) – None – 2015-03-01T19:52:25.730

Interesting! But it doesn't really answer the question. Maybe you are not familiar with the "analog sound" concept? In a different subject, what are the more controversial aspects you didn't include in your answer? Maybe you can include them as a side note? – Anton dB – 2015-03-01T19:55:26.493

1Vinyl / Cassette : again, often less aggressive high end than a digital system; some distortions that may occur with turntables and tape systems will tend to produce extra frequencies that are harmonically-related to the music. – None – 2015-03-01T19:56:27.830

I'm aware of the dynamics of analog systems. I was asking if you think "analog warmth" and "warm sound" concepts are directly related. I was not asking what is "analog warmth". Sorry for the confusion. – Anton dB – 2015-03-01T19:58:31.443

1So yes, in both cases I think it's relevant. I'm sure there's plenty of placebo affect going on too - a preference for "real" analogue over "virtual" digital. I will have a think what I meant by 'controversial' - maybe it wasn't the right word! – None – 2015-03-01T19:58:45.467

1@JCPedroza I think some of our comment messages above were cris-crossing. Anyway I think 'warm' is used in a lot of different contexts to describe a bunch of different things by different people who may not be perceiving the same thing anyway... so I have tried to stay in the centre of the topic. – None – 2015-03-02T07:18:22.527