On the Avid Blogs there's a very interesting interview by Derk Hagedorn with Nathan Eames from Sonnox about the company's history and approach to designing plug-ins. It is well worth a read especially following on from UBK and Kush Audio's decision not to continue with AAX DSP plug-in production.

Nathan recalls that the first plug-in, the Oxford EQ, was very well received by Pro Tools users...

I remember at demonstrations in the UK people were impressed and saying, “Wow. This is unlike any other EQ we’ve heard. Somehow it doesn’t sound digital, it’s not harsh or brittle, it just sounds very transparent and musical.” Essentially it sounds exactly like the console as it’s the same algorithm. In fact, [nine-time Grammy winning engineer] Mick Guzauski had an OXF-R3 console which he obviously knows very well, having mixed many platinum Sony records on it. He uses the Oxford plug-ins and finds it hard to tell the difference. I think that’s what sets Sonnox apart from many other plug-in brands that primarily emulate existing gear. Don’t get me wrong—they do a fantastic job at it. There are many great emulations out there of classic hardware. But at Sonnox, we’re not trying to emulate a piece of classic analog outboard. They were always digital algorithms, and we’ve just taken that code and moved it to a different platform. So when you buy an EQ or a Dynamics plug-in, you’re literally buying the same channel strip from the original million-dollar console.

Derk asked Nathan about Sonnox's design philosophy...

Our design philosophy, I would say, is to create the highest fidelity audio plug-ins that sound very clean and transparent—that’s what we’re known for. What’s interesting is that a lot of people are using analog emulations in conjunction with our plug-ins. So you’ll quite often see some classic hardware emulation plug-ins on a channel, adding some color, and then the Oxford Dynamics plug-in after that to compress and transparently level a vocal or something That’s what we went for when we designed the SuprEsser. A lot of people, especially at the professional level, wanted de-essing that you don’t hear. That’s really the whole point of de-essing, isn’t it? You don’t want to hear it. You shouldn’t be able to tell that there’s a de-esser on the channel—it should just be completely transparent and natural sounding.

Later on in the interview Derk asked about the SuprEsser DS plug-in designed for live use...

The original SuprEsser came out in 2008 and it was native only for technical reasons. It’s quite a complex algorithm—lots of heavy code. And when we tried to port it to TDM, the DSP didn’t fit in the chip. With the new HDX chipset, that all changed, so the SuprEsser DS is an AAX DSP-only plug-in included in the LIVE Bundle focused specifically on de-essing. We wanted to design the highest, best-quality de-esser that we could while keeping it completely transparent. It’s got some convenient functions in there, like “auto-tracking” for example. When mixing vocalists with wide dynamic ranges, they might be singing quietly in a verse so if you set a fixed threshold to take care of S’s in the verse, you’ll have a problem when they start belting the chorus. They’d be essentially crossing the fixed threshold by a lot more, so a lot more de-essing would be applied, which could sound a little bit unnatural. So with auto-tracking, SuprEsser DS will follow the average input level and apply the cut proportionately.

If these excerpts have whetted your appetite then hop over the Avid Blogs and read the full interview.