NcHalfrican Posted July 5, 2010 Report Share Posted July 5, 2010 As the title says, I need someone to describe what the Bl/Bl curve is. Link to comment Share on other sites More sharing options...
arnold1992 Posted July 5, 2010 Report Share Posted July 5, 2010 motor strength, that's what I know RE se xxx 18d2 (4) Audioque 2200 (2) DC Power 270XP blue 3 C&D fr310 Stinger wiring CDT components Link to comment Share on other sites More sharing options...
NcHalfrican Posted July 5, 2010 Author Report Share Posted July 5, 2010 motor strength, that's what I know How does motor strength affect sound quality, cause from what I've heard a high Bl curve=better SQ. But thats the extant of my "knowledge" Link to comment Share on other sites More sharing options...
NcHalfrican Posted July 5, 2010 Author Report Share Posted July 5, 2010 Bump for knowledge Link to comment Share on other sites More sharing options...
NcHalfrican Posted July 19, 2010 Author Report Share Posted July 19, 2010 Bump, So does a higher BL rating make for a better sounding woofer? Link to comment Share on other sites More sharing options...
BJD3 Posted July 19, 2010 Report Share Posted July 19, 2010 Bump, So does a higher BL rating make for a better sounding woofer? Post it in Neo's noob thread? Anti Peel and Seal...lol You may be offended by the above. Don't take it personally, I'm just abrasive. 2002 Buick Park Avenue DC Level 4 M2 12 D2 Car Audio Bargain 1600.1 Eclipse CD3200 ~2 cubes @ 34 hz. Stinger Roadkill Expert Link to comment Share on other sites More sharing options...
HHR Ed Posted July 19, 2010 Report Share Posted July 19, 2010 Flat BL curve can be better SQ, but depends on so many more factors that are much more critical then BL. Example of a flat BL woofer is the AA SMD. Example of a high BL woofer is a DD99Z Ed Lester ShowtimeSPL Host Showtime Electronics Video MarketingMy old Build Loghttp://www.stevemead...08/#entry511451http://www.youtube.com/showtimespl 5 time dB Drag Finalist Last ride 2007 HHR, current dB 153.5 and bass race 149.4 dB. 153.0 dB on music New Ride, 2008 HHR SS. Build under way. Loudest score ever = 171dB 2009 dB Drag Racing, North American Points Champion Link to comment Share on other sites More sharing options...
NcHalfrican Posted July 19, 2010 Author Report Share Posted July 19, 2010 Flat BL curve can be better SQ, but depends on so many more factors that are much more critical then BL. Example of a flat BL woofer is the AA SMD. Example of a high BL woofer is a DD99Z How can you determine the Bl curve of a woofer off it's Bl rating, like 15.51 T*m. Link to comment Share on other sites More sharing options...
HHR Ed Posted July 19, 2010 Report Share Posted July 19, 2010 How can you determine the Bl curve of a woofer off it's Bl rating, like 15.51 T*m. A BL rating is simply its peak BL. The curve has to be mapped with the proper tools. The BL will change depending on where the coil is in the gap. Ed Lester ShowtimeSPL Host Showtime Electronics Video MarketingMy old Build Loghttp://www.stevemead...08/#entry511451http://www.youtube.com/showtimespl 5 time dB Drag Finalist Last ride 2007 HHR, current dB 153.5 and bass race 149.4 dB. 153.0 dB on music New Ride, 2008 HHR SS. Build under way. Loudest score ever = 171dB 2009 dB Drag Racing, North American Points Champion Link to comment Share on other sites More sharing options...
sundownz Posted July 19, 2010 Report Share Posted July 19, 2010 You will typically need a Klippel or DUMAX to measure the BL curve. You can assumme, though, that most overhung (long coils) at quite parabolic in nature... most under-hung have a flat spot in the center and then become parabolic. There are ways around this... Alpine flattens it out nicely in the new Type-R with some clever pole machine work: They machined in a bell shape inside the pole that flattens out the BL curve in the center -- here is an image from their patent: ---------- Some other examples below. First we have an overhung - the below is an approximation of the NS v.2 motor... very long gap / long coil design but still parabolic as it's overhung. As far as overhung goes the BL distortion is quite low as with the 71mm coil and 40mm top plate we achieve ~27mm linear one-way throw. * You see some of the coil sits outside the flux field and the flux is centered in the gap at highest level. ----- Next we have underhung - where you can immerse the coil in the peak flux field and it won't leave that area for some amount of stroke therefore giving you a small flat area before becoming parabolic. * One issue is the tall top plate and short coil tends to make the motors weak as there is poor flux utilization unless you use a giant magnet. ----- Now we have something really fancy called XBL^2 -- you have two gaps and the flux is steered around to immerse more coil than underhung and it also forces the flux out farther to extend the flat area of the BL curve. * Not the greatest example for SQ purposes as it's a big Neo SPL woofer... but you can see how the flux is broken up into two peak concentrations (dark blue areas) with some of the coil in each of those areas. The middle is no longer the strongest spot. As the bottom of the coil leaves the lower flux concentration it equally enters the top concentration so BL does not change for quite some time. These gaps can be stacked if necessary to achieve TONS of flat BL. - Jacob Fuller - Owner, Sundown Audio - Sundown Audio on FACEBOOK - Please DO NOT PM ME -- use my email address -- [email protected] Link to comment Share on other sites More sharing options...
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