I was always wondering about them .
What benefits do they have over "normal" speakers?
How do they sound vs normal Speakers ?
Do they need different room treatment than that used with normal speakers ?
Are they worth their high price ?
I'm an MBL fanboy, always wanted the 101 model, way too rich for my blood, and ended up with one of their stand mounted omnis - the MBL 121 (now discontinued).
I've written a lot about owning the MBLs so I will try not to get too detailed.
First, as to value, that's of course up to the individual. I think that if any speaker can lay claim to being higher priced, the MBLs are certainly one of those brands. They really are unique, and a product of original and proprietary design and materials almost all the way through. Not saying they justify their super high prices...but I can't imagine any of their speakers not being quite expensive all things considered.
As to their benefits: wide sweet spot in terms of even tonality, maintaining some level of imaging off axis, as well as a similar tonality off axis. The sweet spot is always of course the best for image focus/accuracy. But they were always fascinating to own, the way they didn't really change sound when you got up and walked around them.
The rest of the benefits I guess are in the eye of the beholder, as to whether you like the omni presentation.
Sound vs normal speakers? I've had quads, all manner of box speakers large and small, and like any audiophile have heard a gazillion different speakers. The MBLs "disappeared" as apparent sound sources and cast a 3 dimensional soundstage and imaging like no other speaker I've ever encountered. As we know reproduced sound doesn't normally sound indistinguishable from "real." But the MBLs often, for me, reduced that gap more than most speakers. On most good box speakers, put on a recording of a solo guitar and, yes, it can appear "right there" hanging in space between the speakers with nice clarity. Ditto for on a panel speaker. But the MBLs just took it a step further. It just sounded like a guitar had appeared in the room, in 3 dimensional space, with a sense of the instrument carved out in space that goes right 'around' the instrument. Hard to describe, but in comparison the average box speaker presentation sounds a bit more like a sonic image that is flatter, pasted against a flat background.
It made it often more effortless to get that "listening in to the recording to live voices and instruments" vibe. And if it were only an imaging trick, it would have neato, but not nearly enough to get me to want an MBL. But I found, when well dialed in, the timbral beauty and realism and sense of accuracy was almost second to none, at least as I perceived it. I've never heard such natural ultra fine grained detail - I could hear the flesh of fingers on classical guitars, not in a "hyped up" way but in the way you can just hear that if you care to listen, with someone playing right in front of you. The speakers reproduced different instruments with such specific and recognizable texture and timbre, the exact sound of a classical guitar string, vs an acoustic guitar, the sparkle of the piano keys in the upper registers, the distinct metallic "blatty" quality of horns played hard, the skin of a bongo, the wood of a wood block....I've rarely heard such surprising and believable range of instrumental tone from a speaker. It mesmerized me.
Treatment? I have a room that can be a bit on the "damped" side. I can make it livelier or more dead. I found I liked the MBLs either way, more reflections would make it sound more "live and in the room," less reflections brought out the recorded ambience/added reverb more. Ultimately I liked a balance that sounded in between - life-like vividness, but without it sounding like instruments had been crowded in to my room, but rather that the recorded acoustic/reverb took over my room and I could hear "in to the recording."
Also, I found imaging focus to be quite good in my room, not this exaggerated diffuse imaging that so many audiophiles seem to claim is endemic to omnis.
