Morten has bought a pair of demo Coolbacks for his system which has been passively divided until
this “upgrade”. The loudspeaker system is 3-way in 2 boxes reminding a bit of Wilson’s Watt/Puppy.
The bass driver is a 10” Audio Technology Flexunit in vented enclosure. The “satellite” box also has
a 5” Flexunit with capton voice-coil former and the tweeter is a classical ScanSpeak D2905/9700 driver.
The source is Rega Curca pre-amp, Micro Seiko turntable and a modified Pioneer DVD-player.
Bass/mid is crossed at 250Hz 24dB/oct. Linkwitz-Riley. The mid is low passed already at 700Hz with
a 1.order with baffelstep compensation in mind. Then again the tweeter is high passed as high as 4kHz
also 6dB Butterworth and phase reversed. The actual crossover point is 2400Hz. Some room resonances
have been damped some 6dB. The midrange has a breakup around 4kHz which has been damped with a PEQ
attenuating 6dB. All of these settings are done according to datasheets, already gained knowledge
of the drivers/boxes/room and finally through extensive listening.
Comments from Morten in an E-mail:
"Despite the fact that measuring the system will improve the sound further there have been a great
improvement compared to the passive filter. The bass is clearer and with much more correct body to
the instruments. The mid now has more direct access to the recording and the same applies to the tweeter.
As mentioned the final refinement of the equipment is yet to be done and this will probably improve the
homogeneity of the overall sound even further - but for now there is already more pleasure in listen
to my old records."
And over the phone:
"Before activating the loudspeakers I wasn’t too happy about the reflex enclosure because of little control
and muddy imaging – BUT now it’s controlled and plays with ease and I’m satisfied with the bass boxes being