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Thanks for the feedback. It seems that most of the other designs using this driver cross at 2.5 Khz or lower which is the Seas recommended upper passband. However, I suspect that this was done because of passive XO constraints, since the frequency-response of the driver looks smooth until about 3.3 KHz or so. If I follow this guideline and set the XO to 2.5 kHz @ 100 dB/octave, I'll be down ~65 dB with an XO at the driver resonance. What about the low-end, with my subs? Since I use them in an array ...
Previously, I have adjusted the XO between the SS and LCY drivers between 1.5 and 2.2 kHz, but have never found a particular setting to be leaps and bounds better than another. Guess I need to listen longer and/or more carefully. Or perhaps the SS drivers are more forgiving, and it just doesn't matter. The impetus for raising the XO to 3KHz was to avoid a driver transition within the "critical" 1-3K region, a band in which human perception is reported most critical. However, the consensus view, with ...
Rick, how would the portion of the distortion curve in the Seas data sheet plot which increases linearly at frequencies below 130 Hz affected by a high-pass filter? It seems that you're implying that there is some modal coupling between the upper-frequency breakup modes and this distortion increase at the low frequencies. Nothing in the distortion plot seems indicative that this linear distortion increase is an intermodulation effect from any of the numerous modes that appear at frequencies beyond 1.8 kHz.
In principle, to fully correct these in the amplitude and time domain will work IF the driver is truly minimum phase by itself, and IF we compensate each one of these issues individually. How many tuned notch circuits are you willing to implment in your passive or active crossover?
Here we go...the post with re: to the W18 and implementation that sums it up succintly and better than anywhere else I have come across.Jon Marsh's comments on various implementations of the Excel W18 driverShort answer: 1400hz = best xo point, 1800hz = bang for buck xo point, 2400hz = popular but suboptimal point.
You're dead on Jim. Even with DEQX, it's still a balancing act. It would be nice to get a 16Hz-20+kHz speaker with near perfect dispersion and distortion characteristics, but even with DEQX, you really can't get there. I think you could do it with a 4-way though. I've spoken with Jack at NHT at length and I can tell that they labored over every option and combination til they finally had to make the best compromise possible for a 3-way, 3-driver system. You can overcome some stuff with added driver ...
I think that is why JM & SL both write off using ribbon tweeters and use some of the more robust 1 1/8" tweeters. You have done a nice solution with the Carnelian, et al by using the morel dome in between to avoid problems with compromises of top end of the midbass and bottom end of the ribbon or Hiquophon.