Speakerbench....

Wolf

One of our own, and a person Jeff B said he respected and looked up to, Jeff Candy, and another known outside our community have designed a new web-based tool, and it looks good to me:
https://audioxpress.com/news/new-speakerbench-online-tools-for-assisting-in-speaker-design-calculations

Utilizing a double-delta-mass and semi-inductance, it seems a new valid tool in our arsenal.

ani_101

Thanks Ben... 

dcibel

FWIW this dual mass method has been included in REW since the 5.20 beta March 8 release:

Changes in V5.20 beta 24:

Thiele-Small Parameters

• The dual added mass method for Thiele-Small parameter estimation, developed by Claus Futtrup and Jeff Candy, has been implemented. This method provides a very accurate Bl estimate that is independent the driver impedance model and provides a "ZM*" model of the driver motional impedance around resonance, allowing accurate extraction of Mms.
• The driver motional impedance model has been changed to accommodate frequency-dependent compliance using the Ritter three parameter creep model

For more information, the AES article is here:

http://www.aes.org/e-lib/browse.cfm?elib=19366