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August 14, 2020, 06:59:14 PM

Author Topic: Jager crossover frequency spec  (Read 791 times)

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Offline Paul Joppa

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Re: Jager crossover frequency spec
« Reply #15 on: July 29, 2019, 06:41:26 PM »
PJ, in my limited experience, Beaming is an issue when ever I cross woofers near the upper end of their useable range. The upside is these designs often are very good on axis (but lose coherency off axis). 2.5 way TMMs are generally not very good in the near-field because the “sweet spot” is not focused in a location for near-field listening and floor bounce is hard to control. Would the Jaeger, perhaps, be a good near-field TMM? The bass response of the speaker might be too much for a small room (10x15x8), but that could be adjusted, perhaps? The straight forward Beaming has me interested since these cones are wool. Beaming with metal cones tends to be obnoxious, but with softer materials it can be used constructively, especially in the near-field.


For what it's worth, when I said "beaming", I was just referring to the interference between the woofer/tweeter at crossover (the driver centers are about 1.6 wavelengths apart at crossover), and ignoring the difference in acoustic path length. So it's just the vertical beaming.There ought to be a theoretical null at -18 degrees and another peak at -40 degrees, but the beaming of the woofer probably reduces that substantially. At least, that is the thinking that went into this design.

The bass is tuned on the assumption that the amp damping factor is around 2.5 which is typical for zero-feedback SET amps (Kaiju is 2.8). If the bass is too much, you could plug the ports and get a sealed box; volume is about 1.1 cubic feet for each woofer - the cabinet is divided into two independent chambers. That gives, very roughly, 45Hz resonance at QT 0.65 with an SET, or QT 0.45 with a high-damping amp. I imagine that would work well in a smaller room, but we have not tested this, so YMMV!
Paul Joppa

Offline joepiecuch

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Re: Jager crossover frequency spec
« Reply #16 on: July 30, 2019, 02:33:45 AM »
I work sometimes with a finish carpenter who's a music lover and who has been talking a bit lately about getting into speaker design; I'm going to suggest he read this thread to get a sense of the depths of what he does not yet know!

Offline Doc B.

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Re: Jager crossover frequency spec
« Reply #17 on: July 30, 2019, 11:39:10 AM »
I was at a trade show several years ago where I had been talked into showing our electronics with someone else's speakers. The manufacturer was a contractor. The cabinets were beautiful looking and IIRC the price was $80K. When we had a Q&A session the manufacturer asked me to field the technical questions about his speakers (which I was experiencing for the first time) because he had no clue how they worked.
Dan "Doc B." Schmalle
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Bottlehead Corp.