Menu
Forum
What's new
New posts
Live Activity
Search forums
Members
Registered members
Classifieds Member Feedback
Car Audio Discussion
General Car Audio
Car Audio Build Logs
Car Audio Equipment
Subwoofers
Speakers
Amplifiers
Head Units
Car Audio Help
Wiring, Electrical and Installation
Enclosure Design & Construction
Car Audio Classifieds
Car Audio Classifieds
Car Audio Wanted
Classifieds Member Feedback
Gallery
New media
New comments
Search media
SHOP
Shop Head Units
Shop Amplifiers
Shop Speakers
Shop Subwoofers
Shop eBay Car Audio
Log in / Join
Test
Forum
Search
Search titles only
Search titles only
Log in / Join
Search
Search titles only
Search titles only
What's new
New posts
Live Activity
Search forums
Members
Registered members
Classifieds Member Feedback
Menu
Reply to thread
Forum
Car Audio Equipment
Subwoofers
What is XBL^2?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="Kyle_Keating" data-source="post: 5328573" data-attributes="member: 582385"><p>Jacbo, You're 100% right about "it steers" it around, i think you meant to say "B" not BL, <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite7" alt=":p" title="Stick out tongue :p" loading="lazy" data-shortname=":p" /> and yes, it conserves the flux lines, but it also couples with 50% less lines in the total gaps so............in my calculations (i wrote software to do this using FEA motors i designed) i was not able to get more "BL" from any XBL^2 model i measured. in fact, i have a hypothesis that any linear motor must sacrifice BL... worded a little differently of course.</p><p></p><p>my models of XBL^2 include two solutions that are pretty convincing. I FEA'ed three motors. An overhung, and then two XBL^2 motors. One with 50% shorter and 50% lighter coil and one with 50% shorter coil with double the turns (same mass and resistance the overhung)</p><p></p><p>The results are as follows: the first XBL^2 motor has aprox an 27% BL(0) loss. Very large! the second had about a 9% BL(0) loss. Both gap widths were corrected for each coil. The first xbl^2 model used the same gap as the overhung (say # of layers on the coil) the second XBL^2 motor has a larger gap for the larger coil. the second model was much better in terms of coupling but still lower that our overhung, and the inductance of the system exceeded that of the overhung because of the extra coil in the gaps. Sure you can put a shorting ring in the notch in the gaps on either side, but you can do the same for an overhung coil with an undercut t-yoke which is basically what the XBL^2 t-yoke is. putting a shorting ring directly in the active GAP and winding it is going to reduces sensitivity the same for either XBL^2 or overhung, its a wash.</p><p></p><p>about the linear stuff, sure, the overhung has higher BL, but its still a non-linear method, the XBL^2 is a linear method, so there is the trade off. XBL^2 has lower distortion. But XBL^2 also has a difficult time correct for asymmetry about the x axis. variable coil solutions can in fact easily correct for this without having to use a very high extended poll piece. I have found that most XBL^2 motors i have modeled have higher xmax on the down-stroke. This can be corrected with a carefully designed motor im assuming.</p><p></p><p>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.</p><p></p><p><a href="http://www.s-m-audio.com/topologies.pdf" target="_blank">http://www.s-m-audio.com/topologies.pdf</a></p><p></p><p>his model included a "well hung" motor which is simialr to a DD design or a 3HP /4HP motor</p></blockquote><p></p>
[QUOTE="Kyle_Keating, post: 5328573, member: 582385"] Jacbo, You're 100% right about "it steers" it around, i think you meant to say "B" not BL, :P and yes, it conserves the flux lines, but it also couples with 50% less lines in the total gaps so............in my calculations (i wrote software to do this using FEA motors i designed) i was not able to get more "BL" from any XBL^2 model i measured. in fact, i have a hypothesis that any linear motor must sacrifice BL... worded a little differently of course. my models of XBL^2 include two solutions that are pretty convincing. I FEA'ed three motors. An overhung, and then two XBL^2 motors. One with 50% shorter and 50% lighter coil and one with 50% shorter coil with double the turns (same mass and resistance the overhung) The results are as follows: the first XBL^2 motor has aprox an 27% BL(0) loss. Very large! the second had about a 9% BL(0) loss. Both gap widths were corrected for each coil. The first xbl^2 model used the same gap as the overhung (say # of layers on the coil) the second XBL^2 motor has a larger gap for the larger coil. the second model was much better in terms of coupling but still lower that our overhung, and the inductance of the system exceeded that of the overhung because of the extra coil in the gaps. Sure you can put a shorting ring in the notch in the gaps on either side, but you can do the same for an overhung coil with an undercut t-yoke which is basically what the XBL^2 t-yoke is. putting a shorting ring directly in the active GAP and winding it is going to reduces sensitivity the same for either XBL^2 or overhung, its a wash. about the linear stuff, sure, the overhung has higher BL, but its still a non-linear method, the XBL^2 is a linear method, so there is the trade off. XBL^2 has lower distortion. But XBL^2 also has a difficult time correct for asymmetry about the x axis. variable coil solutions can in fact easily correct for this without having to use a very high extended poll piece. I have found that most XBL^2 motors i have modeled have higher xmax on the down-stroke. This can be corrected with a carefully designed motor im assuming. 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. [URL="http://www.s-m-audio.com/topologies.pdf"]http://www.s-m-audio.com/topologies.pdf[/URL] his model included a "well hung" motor which is simialr to a DD design or a 3HP /4HP motor [/QUOTE]
Insert quotes…
Verification
Post reply
Forum
Car Audio Equipment
Subwoofers
What is XBL^2?
Top
Menu
Home
Refresh