What is hi fi sound?

A good system in a good listening room can produce quite a convincingly real sonic illusion
 

How do we define hi-fi sound? Most audiophiles would say that we are trying to reproduce sound as close to the original as possible, so that if you were to close your eyes, you can imagine that you are hearing the real thing.

How close we can get to achieving this depends not only on the quality of the loudspeakers and electronics, but also on the fundamental limitations of the stereo and multi-channel formats that are currently in use. A good system in a good listening room can produce quite a convincingly real sonic illusion, and this is what we aim to achieve with naturally recorded acoustic music.

We are attempting to bring across the true tonal character of instruments and voices, their apparent locations in space, and to maintain this accuracy over a wide dynamic range. This is easiest to achieve with chamber-sized ensembles and soloists where the listening room is not too dissimilar in size to the recording venue.

It is harder to do with a full orchestra as we are trying to create the illusion of a concert hall space in a modestly sized listening room. Of course, we have to assume that the recording engineer is working in harmony with this process, and this is generally the case. So, when listening to classical and acoustic music on high fidelity loudspeakers, the main question we ask ourselves is: ‘Does it sound real?’

With studio produced music such as rock and pop the situation is somewhat different. This is music that is created in the recording studio and electronically balanced dependent on how it sounds when replayed through monitor loudspeakers in a studio control room. If the studio is well designed then a recording that sounds good in the control room ought to sound similar when replayed on a home audio system in a typical listening room. These recordings do not have an audio reference in the same way that acoustic music does; we rely on the recording engineer to create a sensibly-balanced product that will sound acceptable on a typical home audio system. There is still a general intention to record the sources as they sound naturally, such as amplified electric guitar, however it is common to use electronic effects to enhance what is basically a musical creation in the recording studio.

When recording jazz ensembles in a studio, for instance, it is common for the engineer to close mike the different instrument groups with a view to mixing them together to create an even harmonic blend when everything is combined. One group may be recorded with a ‘bright’ sounding microphone (or placement), and another with a different character to help them blend together in a pleasant way, even though their individual sounds may be somewhat different to what you would hear when seated in front of them.

So we need to bear in mind that the recording is not always representative of reality, and consider this when using studio recordings for the purpose of judging loudspeaker quality.

When it comes to movie soundtracks we also need to be very careful, as they are often closer to ‘effects’ than reality, and the sound quality of the voices often suffers owing to the way they are recorded and the processing that is applied to them. However, as with all genres, we collect together recordings that when used as a whole will tell us what we need to know about how the speakers are performing.