Interesting also that the crossovers are 24 db/octave. This helps reduce power to the drivers but also offers excellent vertical response. That is, you can sit or stand up and still hear an excellent frequency response without destructive interference in the crossover regions. An approach rarely seen in passive crossovers. This shows they are leaving nothing to disturb the carefully chosen horn designs. |
Analysis Audio Planar Ribbon speakers use a first order crossover at 600 Hz. Arion Audio Apollo speakers use fourth order filters at 120 Hz. If the drivers and system are designed for it and the drivers have the headroom it can work very well. There are very many things that have to be taken into account. For example our Arion AMT drivers are mechanically damped so they are able to follow complex wave forms which is exacerbated by the extended range they must reproduce. I have enjoyed DD67000s on many occasions. A wonderful speaker by many accounts. I'm sure the engineers at JBL did their homework and met their design objectives. |
My Electro-Voice main speakers are crossed at just over 600Hz to a large format midrange/tweeter horn (2" exit) that runs up to 17-18kHz. An important takeaway here is that the Constant Directivity horn controls directivity all the way down to the crossover point to the woofers (dual 15", vertically aligned), even lower, with a very uniform dispersion pattern at the crossover. Slopes are 36dB/octave L-R throughout, actively configured, and the mains are high-passed at ~85Hz for subs augmentation below. The EV DH1A compression drivers used here are built to withstand a crossover point at 500Hz 12dB/octave for pro cinema use, but I find they sound better crossed just over 600Hz, and with the steeper slopes. They’re an immensely well-sounding and powerful speaker system. |
JBL talks about their drivers in their white papers. They are capable of covering this range. The 4” compression driver in the S9900 shows some non linear breakup above 10k but The 4” driver in the Everest is beryllium and probably addresses it. Also the ring driaphrams in the M2/4367 are also show to eliminate the breakup. I think cutting out the center removes the breakup and adding two brings back the surface area needed for SPL/heat reduction. With all that being said I think the D1 driver (used in M2, 4367, SCL-1) is about cost reduction as they needed a cheaper driver for the pro market as the exotic metal driver have to cost a tone and the pro VTX line array has 3 D1s per box, times how ever many you want 10,12… more…
Anyway the 4367 has the cleanest mids and highs I have heard to date, really special. I have never heard the other top models but based on them being made by the same designer I would imagine they are all pretty great. white paper here.
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@erik_squires . Interesting research-- AES preprint 3207 by Oohashi et al. claims that reproduced sound above 26 kHz "induces activation of alpha-EEG (electroencephalogram) rhythms that persist in the absence of high frequency stimulation, and can affect perception of sound quality." |
