Distortion measurements:
I’ve done distortion measurements on the driver units used in the design. The measurements are consistent with my research and listening tests of the loudspeaker driver units.
Both drivers perform very well and especially the tweeter impresses me a lot. Considering the listening and measurement performance, the tweeter is a real bargain.
The distortion measurements are done in near-field and the amplifier output level was adjusted for each driver so that the fundamental is 85dB at 1m and 90dB at 1m. This setting simulates normal to medium-high listening levels.
The tweeter is very low distorting and it appears to have “copper” in all the right places in the motor design. With a proper filter design, this is one of the few tweeters that actually could work together with an 8” woofer in a 2-way. It can be crossed-over as low as 1.2kHz, if used properly.
The mid-woofer has the expected cone break-ups at 10kHz and 13.5kHz. These break-ups show up in the 3rd harmonics at 3.3kHz and 4.5kHz and at the 5th harmonics at 2kHz and 2.7kHz.
The active cross-over I’ve been using while breaking in the drivers is crossed-over at 1750Hz. My listening tests confirms that it’s a rational cross-over point. Together with a properly constructed notch filter, I wouldn’t use this driver higher than 2kHz in order to deal with cone break-ups properly. Somewhere between 1.7-2kHz seems doable.
For measurement details see:
Distortion measurements – Dayton Audio RS28F-4
Distortion measurements – SEAS E0021 W12CY001