What is XBL^2?

[squeak9798 5,000+ posts]

Anyone have a link to details of MMAG?

I've never really read/heard very much about that topology. Just mentions here and there......

 

[Kyle_Keating 10+ year member]

Anyone have a link to details of MMAG?
I've never really read/heard very much about that topology. Just mentions here and there......

its very similar to xbl^2 but they break up the magnet and the gap rather than just the gap. fundamentally they linearize the bl the same way and have about the same efficiency doing so. Its of course difficult to compare, because MMAG breaks up magnets into two gaps where as XBL^2 uses one.

http://www.stepip.com/PublishedApps/MMAG%20copy.pdf

 

[squeak9798 5,000+ posts]

its very similar to xbl^2 but they break up the magnet and the gap rather than just the gap. fundamentally they linearize the bl the same way and have about the same efficiency doing so. Its of course difficult to compare, because MMAG breaks up magnets into two gaps where as XBL^2 uses one.

http://www.stepip.com/PublishedApps/MMAG%20copy.pdf

Thanks for the link.

That's how I assumed it functioned from the cut-away of the UL12 CA&E published with their review, but wasn't positive I had the details right.

 

[Ricci 10+ year member]

my point is, Dan W. is misleading about his accusations according to my analysis and im out to correct the record. I have debated this with him before and i will be publishing an extensive paper on this at some point. I'm not the only one to come up with this conclusion too. Steve Moray (former Bose engineer) did similar research completely independent of me and found nearly the exact same results.

http://www.s-m-audio.com/topologies.pdf

his model included a "well hung" motor which is simialr to a DD design or a 3HP /4HP motor

Oooh boy. Make sure I'm on the mailing list for that one Kyle! That should be good times. //content.invisioncic.com/y282845/emoticons/popcorn.gif.32dd9e22fd77e77bc3c907062768fcd2.gif

 

[Papermaker85 5,000+ posts]

BL linearity is there but BL is still lost. Not only are you taking steel out of the motor, but you are intentionally taking B out of the area that the coil is located the most....right where it straddles.
But the only linear BL approach that I know of that does not have some efficiency trade-offs is MMAG.

actually its not really a trade off, you ccan get just as much b as any other motor you just have to adjust the topplate height and coil length to suit your needs, it still offers the lowest inductance per xmax over any design not to mention you have a huge advantage simply by adding a sopper ring in the recessed gap between the two top plates lower inductance without lowering Q or BL... the biggest problem with hte older XXX was motor strength and power handling was limited for a given excursion, again easily adjusted by altering gap and coil height...