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balanced mode radiator (BMR) speakers

Note: why is this in the headphone forum? Can this be moved to the speaker forum?



I've been researching small surround/atmos speakers mysel the past month or so, the Minx's in particular, searching desperately for measurements.

I finally found some of the smaller Minx12 in a youtube video:


View attachment 347497

Please note the super-squished scaling, but I mean, it could certainly be worse. Honestly, better than I expected; the overall trend is fairly flat. At 45 degrees, it's actually a little more linear, and you can see just how wide these things radiate.

View attachment 347498


It's barely changed below 10khz.

Given decent EQ, a sub, and a small listening space like many apartment theater setups(mine), I can see these being quite pleasing. I'm also curious about using them for digital piano setup. I have the iloud MTMs but find myself wanting even wider dispersion to better replicate the feel of a real piano.

Curious to see how the larger minx22 fare. Half tempted to buy one just to measure it...

Edit: Just so we're clear though, here's that measurement on closer to Amir's typical scale, which is itself more squished than I'd like:

View attachment 347500
It really is amazing what these drivers are capable of. The Philharmonic speakers use a ribbon above what, 4k? 3k? And I would never second guess them, but this dispersion really does break all the rules. Note also that the dips are in the same place off axis - you could equalize this for greater linearity.
 
It really is amazing what these drivers are capable of. The Philharmonic speakers use a ribbon above what, 4k? 3k? And I would never second guess them, but this dispersion really does break all the rules. Note also that the dips are in the same place off axis - you could equalize this for greater linearity.

Not only that, but in Erin's test of the Philharmonic BMRs, the frequencies roughly covered by the BMR driver seemed to show less compression than either the woofer or tweeter...

1707159511629.png
 
Hey, is anyone besides Tectonic even MAKING BMR-type drivers? Is there anything that isn't like 82 dB sensitivity?
Cotswold Sound Systems

Founded by ex-Wharfedale/Celestion/NXT employee, Graham Bank.

I spent a lot of time with Graham when working at NXT licensee, Amina Technologies.

The Cambridge Audio products use Cotswold drivers.

The 4” BMR sounds excellent and doesn’t need a tweeter. From memory the directivity narrows in the upper mid and widens again in the HF. But as a compromise it’s terrific from a single drive unit. Subjectively I always thought it sounded wonderful.

The 2” unit is also excellent, although massively helped that it’s already small enough to have reasonable dispersion.
 
It really is amazing what these drivers are capable of. The Philharmonic speakers use a ribbon above what, 4k? 3k? And I would never second guess them, but this dispersion really does break all the rules. Note also that the dips are in the same place off axis - you could equalize this for greater linearity.
Philharmonic are using it in the pistonic frequency range though, demonstrating it's good as a conventional mid.
Erin tested the little tectonic driver here:
https://www.erinsaudiocorner.com/driveunits/tectonic-elements-tebm35c10-4-miniature-bmr-driver/
Also tested a DIY speaker using it, crossed over low (~200Hz IIRC) so you can see what the directivity looks like. It's not the smoothest.
https://www.erinsaudiocorner.com/loudspeakers/lcm_nearfield_monitor/
 
considering the technical specifications of these speakers, could they be used for a pendant speaker project, certainly not for hi-fi music but to effectively provide sound to small environments in a simple and minimally invasive way?
 
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