TDM plugs vs. VST/RTAS and so on

[Compression Records]

I've often wondered if the processing of non-TDM plugs is inferior to that of TDM plugs. I recall reading that it's actually the opposite (RTAS or VST plugs actually process better because of a higher resolution issue). Can anyone say with certainty? Thanks.

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Marco Marinangeli
Magelic Productions, Inc.
Compression Records
http://www.compressionrecords.com

[Corey Shay]

I wish Waves would clarify this, but I think in the case of their TDM vs RTAS plugins, the TDM plugins like Ren EQ, L1, and C4, are 48 bit double precision dithered back to 24. I believe the RTAS plugins (C4 I know) don't have double precision. But I really can't speak for other plugins. I think its all up to the developer. Native, VST or RTAS plugins have the capability to be of higher quality than TDM plugins because they are not limited by the power of a single DSP chip. I think for the most part this is not exploited because it would choke a CPU pretty bad still.

[Zeus]

Well, if I have understood correctly the TDM data bus is 24 bits wide. This does not, however, prevent plug-ins from using a higher bit depth internally, like 48 bits in Waves Ren EQ and Comp. Of course, the plug-in has to chop off the remaining bits when coming back to the TDM bus, but I guess that with proper dithering this is not too bad...

[Zep Dude]

This is a topic that almost seems taboo. Rarely does one get a satisfying answer. At the recent Digiworld I asked a few developers this question. There were varied answers, but the consensus seemed to be that, it depends on which type of processing you're doing. One develper, to the best of my memory, said that time based effects like reverb, chorus flange are better implemented on native (RTAS, VST) and that non-time based effects like EQ and Compression are better implemented on TDM (assuming that they are using all 48 bits). Digidesign EQ's and compressors do not use 48 bit internal and therefore, as one digi rep confirmed for me, their plugins are identical between TDM and RTAS.

This is pure conjecture, but based on these answers, there might be a difference between the native vs TDM versions of something like the Waves Renaissance EQ (which uses 48 bit for TDM but by definition could only use 32 bit for native).