The maximum number of filters per channel is 10, up to a maximum of 60 / filter set. You want to do 15/channel and that simply isn't within the limits of MRC at this time. Keep in mind that you are dealing with time sensitive operations and it is likely that going beyond 10 filters/channel exceeds the ability of the DSP core to handle the calculation load in the time window allocated.

As for MTAT's suggestion, the problem with defining a filter target below your room's midband RT60 (which is what the default target is for filters) is that you tend to end up with subjectively too little bass as MRC tends to get too agressive. At least that's been my experience. YMMV.

Best,

Surround Music Fan/Computer Geek/Curmudgeon in training.
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