I posted numbers for the hardware and plugins I'm using:
When I use rePhase with the OpenDRC-DI and the 2x2 Plugin, I set 6144 taps, at 48kHz and it works. See page 2:
https://www.minidsp.com/images/documents/Product Brief-OpenDRC-DI.pdf
When AcourateDRC builds a filter for the OpenDRC-DI, it uses 6144 taps (
https://www.minidsp.com/images/documents/Product Brief- OpenDRC 2x2 plug-in.pdf - says 6148, might be a misprint, or maybe a newer version(?)
An empty filter in the "OpenDRC 2x2" plugin:
b0 = 1,
b1 = 0.0,
b2 = 0.0,
...
b6141 = 0.0,
b6142 = 0.0,
b6143 = 0.0
With a filter assigned by AcourateDRC:
View attachment 15972
View attachment 15970
When the Dirac firmware is loaded into the OpenDRC-DI, the device operates at 96kHz, and I don't know anything more about it, except it locks it into useage with Dirac and costs more.
That's a different plugin, for 8 channel out? Available memory in the Sharc would be allocated differently.
When I run the 2x4HD with the "MiniDSP 2x4HD" plugin, there is a pool of 4096 taps, allocable among the 4 output channels, defaulting to 1024 for each output channel, and it runs (unverified by me) at 96kHz.
View attachment 15969
I don't know the Dirac details, being disinterested in Dirac after running their demo and looking at the price a couple of years ago.
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Although the Sharc chips in the different devices may be similar, the way it is implemented/programmed is determined by the firmware/other hardware in the device into which it is installed.
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An "FIR tap" is (my definition) a memory slot for a music sample, a memory slot for the FIR Filter Value to be applied to that slot, and whatever other programming/memory is needed to make it work, from the pool of memory in the Sharc.
I suppose there is another pool of taps/memory allocated for the PEQ/IIR/crossover/compressor/or biquad values on various devices, but I'm ignorant of the particulars.
These (and other?) factors determine the number of taps per channel available from the same/similar Sharc chip in different device configurations.