I don’t think it is about adding filters.
It is about having better filters.
The assumption behind the DSP in Signalist HQplayers is that the PC, when programmed right, is a better platform for DSP due to its power and precision than the average DSP chip.
Wouldn’t be surprised if Matt shares this opinion.
DSP studio allows you to build an active crossover. The ultimate step is of course to remove the passive crossover from your speakers and make them true active speakers.
Likewise, if you have an up-sampling DAC e.g. one that up-samples all inputs to 192 kHz, it is possible that using JRiver for up-sampling has benefits sound quality wise.
Recently I listened to a Auralic Vega DAC.
It doesn’t use a DSP chip but a ARM processor to do the DSP.
I was surprised by the differences in sound between the various filters one could choose.
Filters are a beast, if they do no harm in the frequency domain, they do all kind of nasty things in the time domain and visa versa.
I do think more and different type of filters would be an asset for the DSP studio.
I would like to have a nasty 8 order filter. Beside the bit-tester we have a brickwall tester too!
A good read about filters:
http://www.audiosignal.co.uk/Resources/Why_do_equalisers_sound_different_A4.pdf