Looking at the compiler output, its possible to see the number of instructions per sample taken out of a maximum of 1024. The default project has two EQ blocks, the auto and parametric. When built, its used 740 out of 1024 instructions per sample (@48KHz sampling)
I am only going to use the auto eq so removing the parametric saves 124 instructions per sample. I left the nx stereo switch in place for some on/off testing of the eq (Removing the switch so its in-autoeq-out would save another 66 instructions (Every component here has a cost...)):
Set up the auto EQ with 14 filters each
Note, when you hit Design Filters button with this many, it takes a
very long time, like 20mins or so, to build the filters and it looks like its hung - be patient, have a cup of tea, let it finish, it'll display the Filters tab when done. If left and right is the same eq, you can save the completed EQ from one channel and load it in to the other channel.
With both channels complete, Link Compile Download then a quick look in the
compiler_output.txt file in the subdirectory created by the compilation:
Code:
Analog Devices Graphical Compiler Tool for Sigma DSP build date = 2008
Done Reading Nodelist ...
Done reading file,
Done Reading Parameter list ...
################## Summary ########################
(Note: Estimates are based on a 48 kHz sample rate)
Number of instructions used (out of a possible 1024 ) = 896
Data RAM used (out of a possible 2048 ) = 403
Parameter RAM used (out of a possible 1024 ) = 238
So, with the modified EQ section above to save some instructions,
15 filters per channel is the maximum you can apply which should be sufficient to fix most setups encountered by this amp (Its made a big difference to my terrible speaker set up
)
