Linn Komri loudspeaker Manufacturer's Comment
Editor: Thanks for a most professional review. Yes, the Komri is a very difficult load. This is a side effect of the 4k array being operated as a four-way passive system. It requires a power amplifier capable of operating into a low impedance. The cabinet was engineered to be extremely dead, as measured, hence some of the weight. The upper bass driver has a first-order crossover so, as measured, it slightly overlaps the bass-system rolloff. Any more than a first-order high-pass on this driver introduces an excessive rate of phase change, and this slight overlap has been found to give the best overall response.
The measurements and conclusions about the response and dispersion through the midrange and treble regions are very astute. The Komri is obviously not a conventional loudspeaker, and the measurements therefore will not be the same as a conventional configuration would give, particularly around the mid/treble regions. After much listening and measuring, the Komri arrangement was optimized to give the most pitch-accurate, natural behavior in a real room. This, as explained in the text, is a combination of direct and indirect reflected signals. Only our ears can put all the pieces back together again.
The supertweeter rolls in at about 13kHz and extends to the ultrasonic. The above-axis suckout is due to the slight overlap between the tweeter rolling off and the supertweeter rolling on. Using the supertweeter at a relatively low frequency gives its smooth dispersion and fast response through the top of the audioband, rather than reserving it just for ultrasonics!
As suggested, the waterfall graph shows reflections, not resonances. Careful engineering eliminated resonances.—Brian Morris, PR manager, Linn Products