I don't think it makes a lot of difference since the "boxy" sound from having speakers in a cabinet is more likely to be at slightly higher frequencies -- maybe 300 to 1000 Hz.

Just a minute....

M60s are about 3 feet tall, for round-trip distance of 6 feet...

Speed of sound is 1130 feet per second, so 6 feet corresponds to about 1130/6 = 190 Hz. Should be a peak around 180-190 Hz (1 wavelength), a dip around 90-95 Hz (roundtrip = 1/2 wavelength)...

... plus lots of dips and bumps at higher frequencies controlled by the width of the M60 openings and size of the VP150 openings etc...

Only issue I see is that if you do end up with a dip in the 90 Hz range on either M60 or VP150 (is the VP150 opening about the same size as the M60 opening ?) you could lessen it by moving the crossover freq up to 100 Hz or so.

I would start at 80 like everyone recommends, though...


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8