Why are you dead set on Neodymium magnets? Also, I would say the Revels are fairly power hungary. Having owned both the M20's and the F30's.
You never said what your budget was.
You never said what your budget was.
More powerful magnets = more accurate sound in theory. Not concerned about the so-called Revel power issue. This is one of these "I heard on the internet one time..." kind of statements. Heard them with 20 tube watts, powered by Manley, Heard them with more than a hundred powered by Arcam. Better with the Manley. Interesting about the Gallos. I hadn't considered them. I'll put them on the list. My budget is not more than $3200-ish + bookshelf speaker. I have seen the JM LAbs Utopia Be's for around this used.
Bose has a very active development division, and they use Neodymium magnets...
Hey, I'm not dissing Neo magnets; I use 'em. But the advantage of Neodymium in most applications isn't strength; in most cases a ferrite magnet can be just as strong if it is designed well. The sonic advantage of Neo is reduced flux modulation under dynamic conditions, and less temporary flux loss as it heats up. Another advantage is smaller size and lighter weight. On the downside is added expense, the possibility of permanent demagnetization if it is severely overheated, and faster heating due to reduced mass. In addition, a good ceramic motor with demodulation rings (also called shorting or Faraday rings) can easily have less flux modulation than a Neo motor - unless the Neo motor also has such features.
So, it's a trade-off. Frankly I think there are other factors that are a lot more important than the magnet material.
On the subject of a small company that employs a top-notch engineer to design their speakers - that's not a bad approach in my opinion. It's much more cost-effective to rent the brains you need only for as long as you need them. A manufacturer really doesn't need a permanent staff of rocket scientists in order to build excellent loudspeakers.
Revel is in a rather unusual and perhaps almost unique position as part of Harmon International. They have ready access to the rocket scientists, and president Floyd Toole is a leading researcher in correlating subjective preference with measured performance. JBL (another division of Harmon) was one of the pioneers in high quality ceramic magnet motors incorporating Faraday rings, and they still make some of the best motors in the industry.
Last year I was working on a loudspeaker design and heard a significant lack of clarity with a particular custom 12" woofer that had been built to my specifications. Much to my dismay, an off-the-shelf 15" woofer I had on hand exhibited far better clarity in the vocal region. The difference was, the 15" woofer had a Neo magnet with Faraday rings; my custom 12" woofer had a Neo magnet but no Faraday rings. So I'm convinced of the importance of high quality motors.
In the book "Audio Transducers", Earl Geddes lists several sources of driver mechanical and electrical non-linearity and he ranks variation in BL (flux) as the most audibly significant.
I'm embarassed to say that I don't know very much about the specific magnet assemblies used in most commercial loudspeakers. Eben, Alon, and Thiel come to mind as manufacturers who use drivers with very high quality magnet systems. Looks like the little Revel M22 does as well. So do two of the lines I sell. Audiogon member JohnK uses drivers with incredibly high quality motors in his commercial offerings.
A couple of questions, if I may...
Would a compact floorstander be a possibility? Also, how important is sweet spot width vs excellent imaging for one?
I have heard so many people reference that Geddes book, I must read it. There are also so many myths about speakers in particular, so much sales double speak, and so many issues that have as much to do with construction as what's used in the wave producing device, not to mention the actual wiring/crossovers. With box speakers it really is like creating a musical instrument.
Not concerned about the so-called Revel power issue. This is one of these "I heard on the internet one time..." kind of statements.
Actually it's not. I've owned two pairs of M20's and one pair of F30's. It has nothing to do with what I heard on the internet. It has to do with personal experience. And me saying that Revels require more than average power to sound their best.
Of course the Manley sounded better than the Arcam. If you are going to compare power ratings, compare two of the small quality level.
Most of Earl's "Transducers" book is over my head, as it's pretty math-intensive. But he lapses into English often enough that it's still useful to the likes of me.
In my opinion the more accessible and in many cases more useful book of his would be "Premium Home Theater - Design and Construction". Don't let the title put you off - it has sections on small room acoustics, psychoacoustics, and loudspeakers that are well worth the price of admission.
Earl was working on a book specifically about loudspeakers aimed at hard-core hobbyists like you & me (okay I'm a dealer too, sometimes), but unfortunately it looks like that project is on hold due to lack of available time.
Earl does consulting work all over the world, and is an example of an audio rocket scientist who could be hired to design a pair of speakers for a company that couldn't begin to afford putting him on their payroll. Vance Dickason and Alan Hulsebus are others.
In your latest post, I think you have hit upon the central issue in loudspeaker design in noting all the myths that have arisen. In my opinion the core questions are: What really matters? And next, how does one best accomplish what really matters?
One of the things that makes loudspeakers so exciting (to me at least) is the wide range of opinion and product arising from differing answers to those two questions. By coming up with better answers, it's possible for a small company to do an end run around some of the big boys.