One question has been asked time and again since the announcement of AAX:  “Why another format, why not VST or AU?” During a recent set of comments to our Why The Delay? article, we have had contributions from third-party developer Paul Neyrinck and AAX architect Dave Tremblay. You may have missed them in the comments section, so here they are in their own article. Paul Neyrinck writes…

“VST and AU are designed to only support Native and have no means of supporting DSP hardware. Only Steinberg can modify the VST format and only Apple can modify AU to add DSP support. AAX is designed specifically to operate as Native and DSP, similar to how the older Digi format supported RTAS and TDM.”

Avid’s Dave Tremblay continues….

“Paul’s answer is pretty succinct, as opposed to my long-winded answers. :) But I’ll echo it and add a little.

AU is clearly Mac Only, and we have a fair number of Windows users. So, it is out as a single format.

VST is a good format, but it doesn’t have the processing code isolated enough to run on DSP. So, Native only. It also take different stances with respect to coefficient generation and handling of automation, which we don’t think scales as well up to very large sessions.

Another thing that no one thinks about is that VST is a different plug-in format. The plug-ins are identified differently. Settings are stored differently. Automation is targeted differently. With AAX, we could design it to maintain compatibility with all legacy RTAS and TDM plug-ins, meaning that you can open old sessions, and even round-trip back to PT9 if you want. With VST, the data stored in our session isn’t compatible. How would people have responded to that!?!

We also want to remain an innovative company, and if you simply adopt VST, it doesn’t give you a lot of flexibility to innovate in your plug-in platform or in your engine that uses those plug-ins. A good example of this is a new type of plug-in we enabled for PT11, called AAX Hybrid. We added the ability for a single plug-in to process audio on the DSP and the Intel core simultaneously, using each processor for what it is best at. You can’t make those sorts of moves if you don’t own your format. Interestingly, you can also use AAX Hybrid to process audio in both the low latency and high latency engine threads within the same plug-in. Pretty cool, we think…”

Thanks to both Paul and Dave for helping us understand the reasons behind the new AAX format.