[sdiy] Re: pentode power amp circuit

[metasonix]

>There are many things that contribute to a speaker driver's efficiency.
>Size of the cone is one part of it, but so is the material the cone is made
>of as well as the cabinet its mounted in, the biggest misconception in that
>being that ported cabinets are more efficient than if sealed.

Hah?

>As far as driver itself though, boils down to the mass and tension of its
>diaphragm in relation to the signal driving the transducer, and the use of a
>ferrofluid lubricant or not.
>But there are 15 inch drivers out there that are a hell of a lot more
>efficient than headphone speakers.

Excuse me? Does the term Thiele-Small ring any bells?

Efficiency is a complex business. You want efficiency, the 
best way is STILL with a horn. Or headphones. The loudness of
the wave hitting your eardrum is what matters! So, headphones
are the ultimate. Even average ones need only 400 mW to achieve
painful sound levels.



uncle eric
metasonix.com