Overview:
The 15H 52 12 06 SDKM is a mid-range from the AudioTechnology C-Quenze series.
The best part of energy during development was put into refinement of the performance in the midrange area. All the materials used, were picked to obtain the trust worthiest midrange reproduction. The drivers are extremely fast and move without any dynamic compression due to the mechanical construction.
Customers are able to make adjustments regarding the T/S parameters as well as the physical parameters – FX. Voice coil winding height, magnetic gap height and magnet sizes. This is an unique possibility for DIY:ers.
The features such as: SD system, Kapton voice-coil former and under-hung motor structure is available in the C-Quenze drivers. Hexacoil voice coil winding technique is used.
The high ventilation factor through the centre pole piece, under the rear suspension and the perforation to the voice coil, are naturally kept intact, enabling the moving system to accelerate without any compression.
Note! The 15H 52 12 06 SDKM has an over-hung voice-coil made of Kapton. Drivers with Kapton voice-coil former often perform a more detailed midrange with higher dynamic and less coloration and distortion. It also has a special mid-range surround which helps eliminating the cone-edge resonance seen in the 15H mid-woofer version.
AudioTechnology spec sheet: C-Quenze_15H 52 12 06 SDKM
T/S Parameters:
Very close match between sample 1 and 2. Slightly higher Fs and Mms than manufacturer’s specification.
(click on picture to zoom)
Impedance:
(click on picture to zoom)
Free air impedance measurement:
Sample 1 = Green
Sample 2 = Blue
A perfect match between the two samples. Note the very flat impedance response.
Frequency:
Frequency measurement conditions:
The mid-range is measured mounted on a baffle with the following conditions:
Baffle size: (WxH): 33×20cm (baffle edge round-over r=19mm)
Driver position: Flush-mounted on center-line with driver unit centered on the baffle.
Mic position: 1m distance, on-axis (horizontal measurements). Frequency response valid down to 270Hz.
Smoothing: 1/24 octave smoothing applied.
0deg on-axis
Sample 1 = Blue
Sample 2 = Red
Nice consistency between the two driver unit samples. Very smooth frequency response with no signs of cone-edge resonance frequency dips or cone break-up peaks. Slightly rising frequency response from 3.5kHz.
0deg = Blue
15deg = Red
22.5deg = Green
30deg = Blue
45deg = Red
60deg = Green
Frequency measurement summary:
Very smooth frequency response and the mid-range can be used up to 3-3.5kHz without any issues.
Distortion:
Measurement setup:
- Mid-woofer near-field measurement at 15cm
- Frequency Range Mid-woofer: 200-10000Hz
- Baffle size WxH: 33×20cm (baffle edge round-over r=19mm)
The distortion measurements are done in near-field and the amplifier output level was adjusted for each driver so that the fundamental is 85dB, 90dB and 95dB at 1m. This setting simulates normal, medium and high listening levels.
85dB @ 1m (click on picture to zoom)
Left: = Sample 1
Right: = Sample 2
90dB @ 1m (click on picture to zoom)
Left: = Sample 1
Right: = Sample 2
95dB @ 1m (click on picture to zoom)
Left: = Sample 1
Right: = Sample 2
Distortion measurement summary:
Low odd order harmonics, but the harmless second order harmonics increases with higher SPL. This is a very low distortion mid-range that shouldn’t be crossed-over higher than 3-3.5kHz.