OT: Radio Playout

But then you add-in the 10pm to midnight John Peel slot, and the Friday Rock Show, and the Saturday afternoon (while sport was on Radio 2 medium wave) chunk, and Sunday evening after the Top 40 and it tots up to quite a lot of hours......

Quite true! A radio station has to decide whether it wants to cater for the minority of hi-fi buffs, or the majority of listeners in cars or in other non-ideal environments - other rooms in the house, with a single speaker tranny playing, doing the hoovering, in a noisy office etc.

I was listening to one station in Leicester today, that played the Darkness "I Believe in a thing Called Love" followed by a 90s track whose name I forget... the 90s track was inadudible!! Some stations just do not have any idea. I want a nice, constant volume - when I listen to Winamp and all my MP3's, I use a DSP dynamics processor plugin, and believe me, the thing is compressed and processed to absoloute f**k. And in my opinon, it sounds bloody great.

Hi-fi buffs should use their CD players.

We're talking about two completely different sorts of compression here.

The discussion started talking about digital compression, that is a technique to reduce the number of bytes PCM audio data occupies. In it's best form, this sort of compression does not affect the sound at all. It allows the storage of more music on a hard disk, or permits the usage of a slower digital link between locations that are using a digital audio link. In terms of playout systems, it is this sort of compression that is being used less and less nowadays due to cheaper hard disk costs.

The second type of compression that this discussion has veered round to is essentialy an analogue technique (although there's no reason why it can't be done digitally via a DSP) that reduces the dynamic range of the music by increasing the gain in quiet bits and reducing peaks. This technique came into radio around 20 years ago. Clear advantages are smoothing over the overall sound, very handy when in a car especially. However the main reason it was introduced and is still a very importatnt part of a radio station's transmission chain nowadays is that it can make a station sound "louder" than its competitors.

Hope that clears it up!