How to calculate the BL of driver
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
 12th October 2006, 03:50 PM #1 p_eric   diyAudio Member   Join Date: Jul 2006 How to calculate the BL of driver Hi, I am a rudimental guy of driver.I want to know the BL of driver by calculate,who can tell me How to calculate the BL of driver,thanks! BL=B*L(TM) But how to confirm the L,thanks!:
 12th October 2006, 08:03 PM #2 Svante   diyAudio Member     Join Date: Feb 2004 Location: Stockholm L is the length of thread that is exposed to the magnetic flux density B. The unit is tesla*meter or newton/ampere (which is the same thing). Calculating Bl from B and L is typically only possible for the loudspeaker manufacturer, we other deadly people measure it as the force factor, ie we run a current through the coil an detects the force generated in one way or another. __________________ Simulate loudspeakers: Basta! Simulate the baffle step: The Edge
 12th October 2006, 08:10 PM #3 just a guy   diyAudio Member   Join Date: May 2006 I don't know how to do it but WINISD does. Assuming all other driver parameters are correct, enter what you have into WINISD and it will fill in the blanks.
 13th October 2006, 02:05 PM #4 claudio   diyAudio Member     Join Date: Feb 2002 Location: Italy Hi, knowing the T/S parameters BL=2,51*√(Fs*Re*Mms/Qes). __________________ ______________________________ My Home Page: www.claudionegro.com
 13th October 2006, 03:42 PM #5 p_eric   diyAudio Member   Join Date: Jul 2006 Thanks all, I know that the BL may pass some softwares to obtain(eg finemotor or spead), but if know that the magnet of the driver and a specification of voice coil only, how to beg the BL, have the in general use formula? Thanks! I am a primers of dirver designs, so want to know whether there is such formula can beg the BL. Execuse me, my English is not good, hope your apprehensibility the meaning that I say, also hope to get the help of everyone, thanks!
 13th October 2006, 06:12 PM #6 Ron E   diyAudio Member     Join Date: Jun 2002 Location: USA, MN http://www.diyaudio.com/forums/showt...936&highlight= Bl is just the magnetic field in the gap times the length of wire in the gap. The fringing field may be approximated, but because of it there is no simple formula. At the link above you may find a driver design spreadsheet that I made. __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Armaments, universal debt, and planned obsolescence--those are the three pillars of Western prosperity. —Aldous Huxley
 13th October 2006, 11:00 PM #7 GM   diyAudio Member     Join Date: Jun 2003 Location: Chamblee, Ga. Greets! Cool! Thanks for sharing! GM __________________ Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
 14th October 2006, 03:57 PM #8 p_eric   diyAudio Member   Join Date: Jul 2006 Dear Ron E , Thank you for your help,Your document of Excel is very good, very practical, thanks!ˇˇHowever I want to know that how "Rms" is obtain, the "BL" calculates through this formula of( Res=( BL)^2/( Rms+2 Rmrses) that arrive the "Res" and is how to beg? Hope your help, thanks! Eric
 15th October 2006, 12:33 AM #9 Ron E   diyAudio Member     Join Date: Jun 2002 Location: USA, MN Rms is a characteristic of the spider and surround and the voice coil former material. It is a lumped measure of the mechanical losses in the moving system. It is a material characteristic which must be measured, although there are general trends... Conductive formers have a higher Rms, as generally do heavier surrounds. Each of these has an individual contribution, and when lumped together they constiitute Rms. As Rms increases, it causes a lower Qms and a lower impedance peak. I'm not sure what you are asking in the last bit with the formula? Are you working on an electrical impedance model/simulation? __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Armaments, universal debt, and planned obsolescence--those are the three pillars of Western prosperity. —Aldous Huxley
p_eric
diyAudio Member

Join Date: Jul 2006
Dear Ron,

Thank you for your help, the material of the vibration system affects to the Rms very greatly, especially the voice coil former affects to the Rms biggest. The demand writes in the Rms concrete value in your document of Excel, I want to know that how you are makes sure what this be worth
Thanks,

Eric
Attached Images
 001.gif (8.0 KB, 256 views)

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Holton Precision Audio         CSS         Dx Classic Amplifiers         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post The Paulinator Subwoofers 2 21st May 2008 01:00 PM Yassen Solid State 1 9th May 2007 08:59 AM bogdan_borko Solid State 3 18th January 2006 10:15 PM Antonio Tucci Tubes / Valves 0 8th October 2004 12:25 PM GP01-Fb Multi-Way 0 24th April 2003 03:33 PM

 New To Site? Need Help?

All times are GMT. The time now is 01:40 PM.