Warmth - what is it? How do you get it? Will we feel warmer if we huddle together?
It would be interesting to find out when the concept of 'warmth' in audio was first introduced. Probably when the first icy winds of transistor electronics began to blow across an entirely valve landscape sometime in the 1960s. We began to feel a certain chilliness in our recordings that led us to want to wrap them up in warm winter woolies so they wouldn’t catch their death of cold. Later in the 1980s, temperatures plummeted further towards absolute zero with the introduction of digital technology.
Listen to a typical 1980s recording made purely with digits and transistors and icicles will start to grow from your nostrils. And then in the 1990s, people realized that living in the audio equivalent of the Antarctic wasn't really such a clever thing to do. They started making equipment with valves again, and although the rush back to analogue recording wasn’t exactly breakneck, tape simulators and emulators started to appear on distributors' shelves. Now we can have all the warmth we want - but is this the equivalent of a central heating system which raises the temperature without adding too much subjective warmth and coziness to a living room, or should we be looking for the audio equivalent of a roaring log fire in the hearth?
Few would doubt that modern digital audio is incredibly accurate, and between the output of the microphone and input of the loudspeaker hardly anything changes other than the amplitude of the waveform. Some people can hear differences, many say they can but probably can't. Most probably accept that what we have is accurate enough for the purpose of satisfying the consumer (although I don't deny the need for 'professional headroom'). But what is accurate isn't necessarily right or desirable.
In earlier generations of audio equipment, engineers and producers had to accept that the technology of the time changed the signal, often drastically. Consciously and subconsciously, this became part of audio culture. Consumers came to expect what a recording would sound like, which inevitably led to an expectation of what a recording should sound like. Likewise, engineers and producers always imagined that they were striving for better accuracy in recordings, hence demanded better and better equipment until we had equipment that came within a tiny fraction of a percent of the limits of the measurable response of the human ear. Somewhere along this timeline a threshold was crossed where objectively better equipment didn't give us subjectively better sound.
So we look back with fondness at the old equipment. It might have been starved of facilities but it certainly had the sound, and still has if in working order. We describe the sound as 'warm', probably for want of a better word, but what do we really mean when we talk about warmth? Is it a measurable effect that can be replicated in any desired strength and variation? Or is it something so elusive and fugitive that one day we have it, the next day not, and we are left to wonder where it has gone?