I understand that using 2 identical speakers in parallel will give a 6dB increase compared to the single speaker due to the doubled surface area and the resulting doubling of amp power. I also understand that using 2 speakers in series will give a 0dB increase compared to one speaker. Sigfried Linkwitz provides proof for this here: http://www.linkwitzlab.com/faq.htm#Q21. Unfortunately, his math is a little bit too vague for me to plug in some real world numbers and fully digest the equations. I'm hoping somebody can help me with this. There are generic rules of thumb out there (3dB for doubling cone area, 3dB for doubling power, etc), but I'm hoping to dig deeper into the physics behind these rules of thumb so that I can better understand it and how it would apply to different speaker configurations. I'm ok with the electrical side of things, but on the mechanical side of things, like the relationships of cone velocity with respect to voltage and current and the relationship to cone area and output, etc.

Thanks for the help.

Thanks for the help.

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