AudioTechnology C-Quenze_15H 52 12 06 SDKM Measurements!
The next driver measurements to publish for the Sequence Three – Grand Reference loudspeaker design is the AudioTechnology 15H 52 12 06 SDKM. This is the pure mid-range version of the 15cm AT driver.
The mid-range is an over-hung version with a special mid-range surround for optimized frequency response. Measurements for the under-hung mid-woofer can be found here: AudioTechnology C-Quenze 15H 52 06 13 SDK
If we compare the two different versions we can see that the mid-range version both have a more linear frequency response as well as lower distortion throughout the mid-range drivers usable frequency range.
Blue = 15H 52 12 06 SDKM (mid-range)
Red = 15H 52 06 13 SDK (mid-woofer)
Note! The SPL is normalized. They don’t have the same sensitivity.
The dip in the frequency response at 1.25kHz for the mid-woofer version caused by the cone-edge resonance is completely eliminated with the specially constructed surround of the mid-range driver.
To be honest, this dip in the frequency response is more of a cosmetical nature rather than technical, since it doesn’t have a large impact on the sonic performance of the mid-woofer.
The mid-range is perfectly usable up to about 3-3.5kHz and my goal is to use it up to 3kHz +/- 200Hz, where it’s crossed-over to the RAAL 140-15D ribbon tweeter.
Simulations, measurements and listening test will determin which filter topology to use, LR2 or LR4? If it works I would like use a shallower sloped filter e.g. a second-order LR, since I often think such filter topology sounds better if it can be done properly.
Time will tell what’s possible and feasible. 🙂
Left: = 15H 52 12 06 SDKM (mid-range) @ 1m 90dB
Right:= 15H 52 06 13 SDK (mid-woofer) @ 1m 90dB
As can been seen the distortion is higher for the mid-woofer version when tested at medium-high levels.
To sum up!
This mid-range driver from AudioTechnology delivers top notch measurement performance without any surprises as nasty cone break-ups, odd frequency response or distortion problems.
I think the mid-range will complement the RAAL 140-15D perfectly!
For further detailed measurements see: AudioTechnology C-Quenze_15H 52 12 06 SDKM