Recording a cymbal from different mic positions (with audio)
7 important microphone types that you should know and the benefits of each
The new Apple HomePod smart speaker - what difference will it make to your mixing and mastering?
How to get started quickly in home recording
Who should be responsible for the fade at the end of a song - the producer, mix engineer or mastering engineer?
Can you hear the difference between a square wave and a sine wave?
Are 18 bits enough for tech metal? [with audio]
Q: Why do I have to record acoustic guitar twice?
New vs. old guitar strings: Part 3 - The case for conditioning your guitar strings
Is it time to reinvent the physical mixing console?
Subscribe to access our latest, up-to-the-minute articles with hints, tips and adventures in audio in the weekly Audio Masterclass Newsletter.
There are lies, damned lies and statistics, according to the saying. At an even lower level of truthfulness are audio specifications.
We could be talking about any item of audio equipment, but let's stick to the good old power amplifier. In this day and age it's easy to produce the equivalent of a piece of wire with gain, is it not?
Well, it depends how you look at the specifications. The main problem with power amplifiers occurs when the signal crosses the zero volts boundary, exactly halfway between the positive and negative excursions.
At this point, the current switches from being delivered by an npn-type transistor to a pnp-type 'complementary' transistor or vice versa. Inevitably there is at least some slight mismatch and this causes 'crossover distortion'.
Still, distortion of this type is at a low level compared to full signal output. As a percentage, it could be as low as 0.03%. But remember that this is a percentage of full output level. Your amplifier is not going to be working as hard as this all the time.
Expressed as decibels, this equates to around -80 dB (-80 dBFS) in comparison with full output level (0 dBFS). But what about when the level drops to something rather more quiet - say -60 dBFS, which is still perfectly audible?
Now the distortion is only 20 dB below the signal level. Express this as a percentage and you get the mammoth distortion figure of 10%!
So just consider that when the music gets quiet and peaceful, a full 10% of what you are listening to could be pure distortion. Yurggh!