The most significant difference between the E and G series SSL consoles is probably the G Series’ Bus Compressor which is possibly as famous as the rest of the console it originally came in!
So much has been said about this compressor and I’ve been of the opinion for quite a while now that the attention the SSL Bus Compressor receives can get counter-productive. Unlike the Fairchild as covered in this series under "F", I do have lots of experience with the SSL Bus Comp both in hardware and software. The word “glue” is used a lot when talking about this design and while I like this compressor, I do wonder whether describing it as “magic” might be raising expectations a little too much?
So what is all the fuss about? Well the SSL Bus Compressor is very transparent, it is this transparency which makes if appropriate for use on the master buss. I remember the first time I tried a real one and I have to say I was disappointed. If I hadn’t absorbed so much of the hype which has come to precede this unit as much as it does and had been allowed to discover its merits in the same way as the people trying it on those G series consoles in the 80s I think I would have taken to it far more quickly than I did.
I do now love the G Series Bus Comp. I love it because it is a very transparent and incredibly simple to use processor which, because of its limited feature set allows you to get on with mixing rather than agonising over the minutiae. Set it up, mix into it and keep an eye on the gain reduction. It's as simple as that.
Stuck On Glue
Compressing your entire mix is fundamentally different to channel compression. While heavy handed compression can be very appropriate on individual instruments or submixes, the space between no compression and too much compression can be very narrow on the master. The effect of good buss compression is subtle but very important. I dislike the word “glue” in this context. I think it's unhelpful. To me it has always suggested sticking things together, and if things are stuck together they can’t move. Movement is exactly what good buss compression should introduce. I prefer to talk about "interdependence". Compressing a track usually means that the loudest, most transient elements (often the kick and snare) affect the level of the audio between the kick and snare beats as they are modulated by the release phase of the gain reduction. With the attack time influencing the front of the kick and snare these two factors help give the impression of sounds affecting other sounds - the fabled “cohesive glue” of a good buss comp.
The G Series Comp is a VCA design with limited but well-chosen parameters. Compression ratios of 2:1, 4:1 and 10:1. Attack times ranging from very fast to moderately slow and as well as manual release times of up to 1.2 seconds, a multi-stage auto release is available and works brilliantly. The release time increases based on the length of the peak and this multi-stage behaviour is so benign that I use almost all of the time in master buss duties.
Tips For Use
As a transparent compressor designed for subtle use on the master, the squishy excesses we all enjoy so much when test-driving a compressor aren't really the point of this comp. That is well covered elsewhere, for example the Elysia Mpressor. Top tips for anyone new to using buss compression would be to use the compressor from the beginning of the mix (the track in the video below is unmixed and the buss compressor is inserted right at the beginning of the mix process). The gain reduction of your compressor will fight against your fader moves and the (hopefully) subtle changes in level the buss compression introduces will mean that if you strap a compressor across your master after mixing, you'll probably end up mixing it again to address these changes. The second tip would have to be to aim for between 1-3dB of gain reduction on peaks unless you have very clear reasons why you are compressing harder than that.
See the UAD SSL G Series Bus Compressor in action in this video where I demonstrate its use on a master, a drum buss and on some test tones to illustrate the effect compressing drums has on everything else in the mix. Thanks to Linden Hale and Luke Goddard for the piano and drums respectively on the jam session recording used in the demo.