Morel Fat Lady Loudspeaker (TAS 209)

Are We There, Yet?

Is it really over when Morel’s brand-new $32k flagship speakers, The Fat Ladies, sing?

That’s the bold promise of this wittily named arabesque of a three-way, four-driver floorstander from Israel and Great Britain (by way of British speaker designer Russell Kauffman), but before I even start to answer the Big Question I have to point out that Morel is certainly pulling a fast one in another regard: The Fat Lady ain’t fat. In fact, she’s a surprisingly demure (13" x 50" x 17"), strikingly attractive, sensuously curvaceous bit of modern sculpture, molded out of fiberglass, epoxy resin, and carbon fiber, without a single straight line in her body.

Morel says she was modeled to look like a musical instrument—and with her modernesque, slimmed-down-doublebass-like profile, she does. Like a musical instrument, she also has no internal damping. Instead, her high-tech chassis was specifically designed to “sing along” with the drivers in a “controlled” fashion—and, thanks to the superior damping properties of the materials it’s made of, to stop singing as soon as the drivers stop. The drivers, in turn, were specifically designed, developed, and fine-tuned to the cabinet.

Like Focal, Morel has a leg up on most other speaker-manufacturers in that it not only builds speakers but also builds and markets very high-tech drivers, and The Fat Lady uses bespoke ones: Two 9" cabon-fiber/Rohacell composite cones for the bass (with integral one-piece domes and double-magnet hybrid neodymium/ferrite motors, 3" long-throw aluminum voice coils mounted externally, copper-insulated center pole pieces, and diecast aluminum baskets); a 6" cabon-fiber/Rohacell composite cone for the midrange (with integral one-piece dome, hybrid neodymium/ferrite motor, 3" long-throw underhung aluminum voice coil mounted externally, copper-insulated center pole pieces, and a diecast aluminum basket); and 1.1" hand-coated soft dome for the treble (with pancake Neodymium magnet motor and underhung aluminum voice coil). Frequency response is claimed to go from 20Hz to 22kHz and to measure an impressive +/-1.5dB from 40Hz to 18kHz (I will validate this claim in a few paragraphs). I assume the speaker’s distortion numbers must be commensurately impressive, though none are specified. Sensitivity is rated at 88dB. With a nominal 4-ohm speaker like The Fat Lady this usually means that sensitivity is actually 3dB lower than its rating. Not here, however. If anything The Fat Lady seems a bit higher in sensitivity than its specification, as I could drive it (without distortion) to very loud levels with a lot less gain than I’m used to from Magico M5s. Like the Nola Baby Grands, these speakers will rock the house with considerable ease (indeed, Morel claims that The Fat Lady can handle peak power of 1000W, which would result in SPLs that would drive me not just out of the room but out of the neighborhood).

Without a doubt, the Morel drivers, both in The Fat Ladies and also those modified for use in other ultra-high-end speakers, are exceptional. In talking to Morel’s Russell Kauffman—who is an extremely interesting, intelligent, experienced, and quite obviously gifted speaker-designer (and also a just plain nice man)—I learned a good deal about the Morel drivers and the way he is using them. For one thing, Morel’s midrange and tweeter drivers are not designed to behave in an entirely pistonic fashion; instead, they have been deliberately engineered to allow for a certain amount of controlled flexibility at various points in their diaphragms, so that their “break-up” modes, though potentially more audible in the passband, will in actuality be “self-cancelling.” What this means—if I have it right—is that when one part of the driver’s diaphragm “breaks up” by going out of phase and linearity at a certain frequency another part of the diaphragm simultaneously counteracts this phase/linearity shift by “breaking up” in the opposite phase-direction and to the same degree of non-linearity at the same frequency (or frequencies); thus, the sound of break-up is said to be instantaneously cancelled out.

(To understand why “break-up modes” are important, you might want to take a look at my Magico Mini II review in Issue 179 and my Magico M5 review in Issue 196. In a nutshell, when a midrange driver, for example, is crossed over to a tweeter, the midrange cone doesn’t stop playing immediately, no matter how steep the crossover slope. In fact, it continues to play—albeit at a much reduced level—well out of its passband into the treble frequencies where it starts to behave non-pistonically or non-linearly and distorts. The very low-level distortion of this midrange’s “break-up”—which is what this non-linear out-of-passband behavior is called—gets added to the sound of the tweeter it is crossing over to, subtly roughening up the sound in the treble. Breakup modes may appear to be esoteric, but I’m here to tell you that the difference between the sound of speakers in which the break-up modes of the drivers have been optimized and the sound of speakers in which they haven’t is quite audible.)