Equations of moton for a bass reflex loudspeaker

[wally50]

I am trting to derive the equations of moton for a bass reflex loudspeaker with two degree of freedom. anyone out there ever done this??

 

[Cliff_J]

This could be very involved since the system is modeled as an electrical fourth order filter. The speaker cone motion should (according to theory) show no movement near the enclosure resonance but varies because of non-linearities. The air within the port also has many non-linear aspects.

The work of Thiele and Small offered many insights into the very small signal level behavior, but at higher drive levels the complexities generally leave the modeling to devoted programs like LEAP that can accurately account for the non-linearities.

http://linearx.com/products/software/LEAP5/LEAP5_01.htm

Is this for a school project? Or for an application like sound reproduction. For the former, the AES papers by Thiele & Small from the late 60s (along with many others) offer tons of insight. For producing a loudspeaker, there are far cheaper and reasonably accurate software and the Loudspeaker Design Cookbook by Vance Dickason offers a simplified layman's approach to all aspects of loudspeaker system construction.

Cliff

 

[FredGarvin]

I would suggest looking at Art Ludwig's web site: http://www.silcom.com/~aludwig/index.htm

Art has a very extensive site on the physics of sound in regards to sound systems. He has some great information. He has a section devoted to system design that may answer your question:
http://www.silcom.com/~aludwig/Sysdes/Design_of_the_sound_system.htm

If anyone is ever interested in building a custom entertainment room or anything related, I HIGHLY recommend Art's web site!