Thought you guys might be interested in this also:
Linky: http://forum.elitecaraudio.com/showt...threadid=99719Originally Posted by cheapboy on ECAGot my Koda 8's today, pulled them out of the box and starting playing some 20hz sine waves through them to soften up the suspension. I cranked the drive level to 17.5Vrms and noted that although there were some loud mechanical noises and distortion was clearly audible, that I don't believe I saw more than roughly 1cm of forward excursion. Push/Pulling with both hands on the cone after break-in also gave me the impression that 19mm of 1 way forward xmech may seem a bit exaggerated on the unit I received, or perhaps I'm just blind.
Pics of the driver:
Nearfield+Farfield frequency response:
(note: breakup modes in the nearfield were also shown to be present at 1m)
I also compared non-linear distortion between the Focal 8w5411, a 12" tc2+, and the Koda 8... all at 1m, unbaffled, in free-air. The results were surprising in that the Koda 8" had about 5-15db higher 2nd and 3rd order distortion combined between 40-300hz than the Focal 8", at about 8Vrms referenced to the Koda 8" @ 40hz.
A subjective listening test using the tc2+ as a reference (note: it also measured considerably lower distortion than either 8" which is not surprising) also gave me the sense that the tones being played through the Koda 8" were not as pure as that of the Focal 8". A slight "shrillness" to the tone could be heard, although below 100hz it was difficult to say. Also, when driven to nearly their mechanical limits at 40hz, I have to mention the Koda was noticeably louder than the Focal unit.
I had some pretty high expectations for the Koda 8", and I was left a bit dissapointed with their non-linear distortion performance at moderate levels and the mechanical excursion of the unit, especially given such a large surround.
FWIW, here is a FFT of a 20hz sine wave, 13.8Vrms for the Koda 8" and adjusted for the Focal 8"... although they're very close in distortion performance, the Focal is really at it's physical limits at this point and there are some very loud mechanical noises coming from it. The Koda 8" is making some noise, but not close to the level of the Focals which are obviously being overdriven.
I still feel that I need to run further tests to really see what's going on however. The Koda clearly outclasses the Focal 8" at the highest drive levels where mechanical noises become an issue, but within their range of quiet operation, it would seem that the Focal 8" betters the Koda 8" between 40-300hz. At this point I'm just a bit confused, especially given the remarkable performance of the Koda 10".