I'd like to ask for recommendations on how to best support convolution where you have a different file for each sample rate.
Should we just support some naming convention, like adding " (44.1 KHz)", " (48 KHz)", etc. to the end of the filter files? Or should the configuration file contain a list of filters? Or something completely different?
Thanks for any help.
Hello Matt,
a full convolution setup can be quite complex. Imagine a multi-channel multi-way setup including some additional crosstalk mix (e.g. adding some channels to a subwoofer output but also crosstalk cancellation). You may like to create a wav-file including all the filters for a given samplerate. But this also may become difficult, as the sequence of channels in a mutli-channel wav file does not necessarily correspond with the sequence of filters/outputs.
Thus it is IMHO best to handle each filter in a separate file in native format, e.g. double format, or as wav file (double precision is also possible).
By default Acourate creates crossovers and correction filters as dbl-files (but wav is also possible). For stereo applications the names are given as XO1L44.dbl, XO1R44.dbl, XO2L44.dbl, XO2R44.dbl, XO3L44.dbl ... and Cor1L44.dbl, Cor1R44.dbl, Cor2L44.dbl ...
For multichannel applications it makes sense to use corresponding abbreviations like C=Center, BL=Back left, BR=Back right, LF=low frequency, SL=Side left, TL=Top left ...
So a filter name like Cor1BC44.dbl can easily be identified as a filter for a back center channel.
So we have some classification:
a)
XO = crossover filter
Cor = correction filter
XTC = crosstalk filter
b)
1, 2, 3, ... -way identification, e.g. 1=bass driver, 2=midrange driver, 3=tweeter in a 3-way setup
c)
L, R, C, LF, BL, BR, SL, SR ... = multichannel identification
d)
44, 48, 88, 96, 176, 192, 352, 384 = samplerate
Especially d) can be used for an automatic search of filters depending on samplerate.
Of course it is not mandatory to follow such a specification of filenames. If MC will interprete a configuration file then a user can arbitrarily defines his own filenames. Then it is the user's responsibility to define the names, to set up the config file and to assure that the filters are available.
Configuration files as XML have become quite fashioned today. BUT IMO these files are difficult for human editing. So a file like the VST Convolver config file or an old-fashioned ini-file is better to read, edit and understand.
BR
Uli