These loudspeakers should best be placed on sturdy stands and tilted back about 5 to 10 degrees (depending on listening height) with the tweeters just above ear-height. This also how the measurements were taken. Playing with the amount of toe-in lets you find the right balance between top-end clarity and image size. The distance between the rear of the cabinets and a wall should be at least 20cm's, preferably a little more. By varying this distance you can adjust bass-weight to your personal situation.
After you have finished building these loudspeakers give them a few weeks of normal use to settle in. When first connected they will sound a bit on the bright and lean side and the image will tend to stick to the loudspeakers. This is quite normal and is the case with any new loudspeaker. After a while the sound will grow, become warmer, more spatious and will extend at both frequency extremes. Once fully burnt-in these loudspeakers will sound extremely neutral with very good seperation and spacing of the image. Everything is realistically well defined from top to bottom and has a nice long-term listening character. I found these loudspeakers to perform well with a large variety of source equipment and amplification, they just grow as the quality of the equipment grows with them.

Above left: frequency curves of the midwoofer without crossover (red) and with crossover (blue); frequency range 200Hz - 20kHz; vertical range 50dB - 100dB, subdivision 2dB's.

Above right: frequency curves of the tweeter without crossover (red) and with crossover (blue); frequency range 200Hz - 20kHz; vertical range 50dB - 100dB, subdivision 2dB's.

Above left: individual frequency curves of the midwoofer (blue) and tweeter (green) and the summed response of the finished system (red) with corresponding acoustic minimum phase; frequency range 200Hz - 20kHz; vertical range 50dB - 100dB, subdivision 2dB's. The crossover point is centred at about 2250Hz with the drivers crossing at a perfect 6dB's below the summed response.

Above right: summed response of the finished system (red) and the summed response when the polarity of one of the drivers is reversed (blue); frequency range 200Hz - 20kHz; vertical range 50dB - 100dB, subdivision 2dB's. The reverse polarity measurement shows a very deep reverse null indicating an excellent phase tracking between the two driver units at the crossover-point!

Above left: summed response of the finished system in the horizontal plane; on-axis (red); frequency range 200Hz - 20kHz; vertical range 50dB - 100dB, subdivision 2dB's. The output level is within +/-1dB over the whole range!

Above right: summed response of the finished system in the horizontal plane; on-axis (red); 15 degrees off-axis (blue); 30 degrees off-axis (purple); 45 degrees off-axis (green); frequency range 200Hz - 20kHz; vertical range 50dB - 100dB, subdivision 2dB's. Diffraction on the baffle edges create an increase of off-axis energy - this loudspeaker sounds best when it is pointed at the listener.

Above left: Cumulative Spectral Decay of the finished system; frequency range 200Hz - 20kHz; vertical range -30dB, subdivision 6dB's, time window 4 milliseconds.

Above right: Burst Decay of the finished system; frequency range 200Hz - 20kHz; vertical range -30dB, subdivision 6dB's, time window 20 periods.

Above left: Impedance plot (black) with corresponding electrical phase (purple) of the finished system; frequency range 10Hz - 20kHz; vertical range 40 ohms, subdivision 4 ohms. A healthy 8 ohm nominal load with the port tuning frequency at 58Hz. Impedance minimum 6 ohms at 220Hz.

Above right: Burst Decay of the port measured directly in front of the rear-firing port; frequency range 20Hz - 20kHz; vertical range -30dB, subdivision 6dB's, time window 20 periods. Maximum port output at 55Hz. Port noise around 1kHz that disappears completely when measured from the front (see the above Burst Decay of the finished system).