Spider separating was what I was told it was.....from years of running it too hot.
New driver is good, sub calibrated level with speakers.
one PC12 Plus and one PC13 Ultra here, in a 9 x 9 x 16 ft. room with a narrow door (30 ins.) to the kitchen, for a total of approx. 3000 cu. ft.
first i bought the 12, but found the sound not quite to my liking when reproducing peaks in movies like WOTW,
so i bought the 13 Ultra to supplement it.
now i have first rate SQ and they seem to be loafing all the time.
Freq. Resp. is flat down to 10 Hz.
once, i cracked open a bedroom door before listening to WOTW, and at the end of the movie,
the door was open a full 18 inches...
Sarhento and Bass addict, first, you should check my signature in order to have some info on my installation.
check this one first: http://www.blu-ray.com/community/gallery.php?member=Gelli
Once there, you'll see a chart showing a Hz by Hz Frequency Response made at the MLP.
the measurements were done exactly where my ears are positioned, which is the same i used
for Audyssey calibration.
i don't know exactly what makes the response so strong below 16 Hz.
it is most probably caused by many factors.
the measuring instrument i used has a flat Fr. response setting); meaning
no low frequency attenuation in the measurements.
one thing that isn't told is that the smaller sub is tuned at 16 Hz
and the larger one at 10 Hz:
for a given signal, the output of the smaller sub has been decreased to compensate
for it's lower max. output capability, in order that when both subs are driven hard,
the smaller one is not overloaded. i tuned for a difference of about 5 dB between the two.
i've tuned the 13-U like this:
2 ports blocked;
filter set at "sealed".
in the AVR config, after Audyssey calibration, the subs are set to play 3 dB hot, for a flat-to-the-ear response.
playing the loudest movies at reference level or Cameron Carpenter's Revolutionary on SACD, i never hear port chuffing from
the subs, and no distortion that i can hear.
before tuning this way, i asked Jack Gilvey for his opinion about this way of doing it,
and he answered: "I’d go with a 3-4 dB difference between the two as the PC13-Ultra will have at least that much advantage. Should be an outstanding setup! :)".