The End of Analogue - Is analogue multitrack recording dead? (part 2)
I dont think anyone is in serious doubt anymore that digital recording is better than analogue. Some people will say that analogue has its own special sound which is certainly true. These people probably also prefer vinyl records to CD and black and white television to colour. I would say that while it would be nice to have these old sounds available in an effects rack (along with the gritty distortion of optical sound on film), it is not appropriate - unless you specialise in the musical styles of a bygone era - to apply them to everything you record. 16 bit digital audio is a much more transparent information channel, even if its not perfect yet. By the way, if you want to see how bad some digital convertors are, record a sine wave tone onto your DAT and slowly reduce the level to zero. Now play the tape back, and as the tone diminishes, increase the monitor level to compensate. If the convertors are good then you will hear a noise building up which is smooth and even in character. On cheaper machines the noise will be harsh and gritty - not very nice at all. If the sine wave itself starts to become harsh then the convertors are not as linear as they ought to be. Youll probably hate digital after you try this!
Even when working at its best, 16 bit recording is not always ideal. One day, digital recording will be 24 bit and very close to being absolutely linear (free of distortion within the 24 bit limit). When that day arrives well probably rediscover analogue and apply all the techniques learnt along the way to create an even greater argument! For now, 16 bit digital audio is considered perfectly good enough for domestic stereo listening providing all the bits are used. But 16 bits are not quite good enough for mixing to stereo in the studio because you have no margin of error - its virtually impossible to get full value out of that very last bit and drive the signal all the way up to 1111111111111111 without going over the top at all. 16 bit multitrack is definitely not good enough because each time you double the number of tracks you mix together the noise goes up by a theoretical 3dB. This means that sixteen tracks of 16 bit recording will mix together to give the equivalent of 14 bits, in the worst case situation. The signal to noise ratio of the mix would in theory be 82dB rather than the 96dB (in theory once again) of each individual track. So to be compatible with 16 bit stereo standards, a sixteen track digital multitrack machine should record to 18 bit resolution.
It should be evident that sound quality-wise, digital recording is not perfect. But even so, I would still confirm my absolute certainty that its a damn sight better than any current analogue format other than Dolby SR noise reduction used on machinery of a full professional standard. This last option can give 16 bit digital a fright, but only at a very considerable cost. As I shall be pointing out shortly, a digital multitrack recorder with A to D and D to A convertors of reasonable quality such as the Alesis ADAT is easily superior in sound quality to narrow gauge analogue machines such as the Fostex G and Tascam MSR models. Its not the fault of the analogue machines or their designers, its just the way things are.