In shops that sell televisions, they often play some sort of ‘showreel’ of spectacular scenes; you know the type of thing: ultra-detailed night time cityscapes, ultra-saturated lizards, ultra-contrasty arctic wildlife, and so on. You realise that it is impossible to see any real difference between the televisions with these scenes. They are ‘impressive’, but only at the most superficial level of what a television can display. Basically, any modern television can display them, with the only differentiators being size and absolute brightness. It always seems to me that the only way I can tell if a TV is any good is to watch a local news programme or something like that – not zero ‘production values’, but something that is relatable to everyday life.
Does something similar happen with audio?
When writing this post, I vowed to myself to search for a report of an audio show demo track, and to use the first track I came across as my example – of course I would have quietly forgotten that vow if it hadn’t illustrated my point fairly well, but as it happens, I think it does. The track is by Malia, and is called I Feel It Like You.
Absolutely no criticism is implied of the track, nor its production which is exemplary for this kind of music. But as an audio demo track?
Listening to it on my laptop, it seems to me to be an ‘in-your-face’ studio recording, built from a fairly sparse assemblage of pristine layers, each of which has been processed, compressed and equalised. The vocals are crystal clear and close up, mixed with a carefully-balanced amount of ‘Large Hall’ reverberation. The backing features plenty of detail, with lots of staccato, sampled(?) percussion rhythms and bass.
I think that this track would sound superficially impressive on any system – it even sounds good on my laptop.
What it is missing, if you ask me, is any connection with the organic, natural acoustics we encounter every day. It is like those uber-detailed images used for TV demos; the sound is highly-detailed and everything is at peak contrast and saturation. Such tracks are very common in audio demonstrations.
An alternative staple of audiophile demonstrations is ‘jazz’… I’m not sure what the appeal of this is (as a demonstration). I suspect it is because it often seems like an antidote to over-production – although jazz can still be over-produced. But again, as the potential customer, I don’t think it is telling me very much about the system’s capabilities. Old recordings of jazz are like grainy monochrome pictures, and modern recordings are still showing a ‘scene’ that is ‘smokey’ and sepia-toned (which I am sure is the intention). The style of music and the instrumental line-up (e.g. continuous brushed snare..?) means that I am often not hearing clear delineation between the instruments nor much in the way of transients and dynamics. (Or maybe I just don’t like jazz particularly and cannot engage with it, in which case ignore my objections…).
Just looking through some of the tracks that I might ‘demo’ my system with, one thing strikes me: they usually feature a bit of ‘messiness’. They may, or may not, have been put together in a studio using overdubbing, but the individual layers are a bit raw, organic, and recorded from a bit of a distance, so the room’s natural acoustics are audible. This possibly masks a bit of the pristine detail, but there’s enough there to verify that the system can do detail, anyway. When a short sound stops, and the reverberation remains, the contrast between the two can be particularly revealing. In photographic terms, the image covers all shades of grey and there’s still detail in the shadows; it’s not pushed into excessive contrast, nor selected or processed to be super-detailed. I am not even advocating massive ‘dynamics’ most of the time, which some people cite as proof of a system’s chops. As I will mention later, there are some specific classical tracks that might be played in order to put the system’s dynamic capabilities beyond doubt, anyway!
My favoured demo tracks are not just a single mic recording of a school concert, of course! They have been put together with some high ‘production values’.
It is worth perhaps listing the aspects of the system we might want to show off, or listen to if we are thinking of buying it.
- frequency response: it is good if the track covers a wide spectrum of frequencies with equal weighting – not just bass and treble. A problem with many a system, would be fixed bumps and dips in the frequency response. These are almost impossible to hear against a recording that also has fixed bumps and dips in its ‘frequency response’. For example, a solo voice or a string quartet, or a piano. All of these are generated by resonant systems characterised by a formant, or a group of similar formants. Some studio recordings are also augmented with fairly aggressive parametric equalisation of the individual layers in order to make them sound even more detailed. It is only when we hear many different natural musical sources playing in varying combinations that we assemble enough ‘simultaneous equations’ to work out whether the system is neutral or not.
- bass: of course we want to demonstrate this! Deep organ notes, kick drums, symphony orchestras in natural acoustics are going to show this off well. The best bass does not have ‘one note’ quality; it engages somewhat with ‘room gain’ in order to extend all the way down to below audibility; it starts and stops quickly, hitting you in the chest (the kick drum will show this). In other words, sealed not bass reflex…
- distortion: a sine wave would show up harmonic distortion, and several musical sources all playing at the same time would show up the resulting intermodulation distortion. A single voice will not really show it, nor percussive sounds. A choir would probably be a pretty good demonstration of low distortion, as would a symphony orchestra playing a varied selection. Less good would be girl-and-guitar, a string quartet, or a ‘world music’ drumming ensemble.
- imaging: the really great demo, in my opinion, is when the stereo speakers produce a complete 3D audio ‘scene’. It may be an “illusion” as some people are very keen to point out, and not a perfect holographic reproduction especially if the recording was created with multiple mics and overdubs in a studio, but it is very compelling. Some classical recordings are made in purist fashion and do create a very convincing sense of 3D space – not just left-right imaging, but also a sense of distance. Imaging depends at least on low distortion and accurate correlation between left and right speakers, implying (I would say) a requirement for accurate reproduction of phase and timing. Some people would claim that absolute reproduction of phase isn’t important as long as both channels are well matched. I think this is special pleading based on the performance of traditional systems; I sometimes think that the people who are very keen to ‘dis’ imaging probably have very expensive systems based on valves, vinyl and passive crossovers…
- power: achieving high volume isn’t usually a problem, but we want the system to behave uniformly well at all volumes. I suggest that the way this would be made obvious would be when a musical performer or ensemble plays continuously and naturally between quiet and loud – with minimal dynamic compression being applied. This is different from demonstrating a system playing a less dynamic recording with the volume control low and then high. As the Fletcher Munson curves show, there is only one volume at which we perceive a sound with the correct frequency response: its natural volume. If the system does something peculiar as the volume increases, it will be much more obvious if we are listening at a fixed volume that is closer to the ‘real’ volume at which it was recorded.
Of course, recommending tracks is a bit pointless, because the track’s ‘demo’ qualities are combined with musical taste – and I think you need to like the music in order to engage fully with what you are hearing and to know how it’s going to sound with ‘your’ music. Nevertheless, here’s a few tracks out of hundreds that I tentatively suggest would reveal a system’s attributes (no accounting for Youtube’s sound quality) and are the sort of thing I would want to listen to in order to get some idea of whether a system was any good.
Sufjan Stevens, Jacksonville – not a familiar act to me, but this track is ‘big’, has great bass and enough rawness to hear that the system sounds ‘natural’.
Elton John, Rocket Man – a beautiful, rounded studio recording with a great sense of space (so to speak).
Neil Young, Double E – very simple rock track that doesn’t sound over-produced.
Khachaturian Symphony Number 3 – a *massive* symphonic recording with huge pipe organ and 15 trumpets (apparently). If you play this loud, the end is very loud!
Arvo Part, Credo, for Piano Solo, Mixed Choir and Orchestra – possibly some of the most dynamic, contrasting classical music you will encounter.
(Maybe these classical performances are a bit too dynamic for everyday listening, but if you really want the demo to show what the system is capable of..!)
A less intense classical recording with some great imaging, space and some revealing bass is this one:
It’s An American in Paris by Gershwin, performed by the LA Philharmonic under Zubin Mehta – not sure if the Youtube version is the same as the CD version I listen to.