[WerTicus]

I'm about to embark upon my second DIY set of speakers and I have decided to utilise only the best of the best.... the GeerS EvE II design modified for:

..the 12m4631g00 from scan speak at 8ohms with 89db sensitivty for midrange (2.5" insead of a 6.5" for absolute clarity of mid range)

I want to match this to the 1" ring radiator r2904-700000 from scan speak. With 4ohms and 94.5db sensitivty.

So I had a brilliant idea and decided that if I used two mid ranges in each speaker then I could wire it to be 4ohms and also increase the overall sensitivty... hence making the cross over simpler and perhaps negating the need to attentuate the tweeter.

Additionally I would use a couple of 6.5" woofers for the bass in each speaker (instead of the one 8") (yet to decide which but probably the carbon fiber ones)

My question is this....



What will be the sensitivty of two 89db speakers working in parrellel?  Am I right in guessing it would use twice as much power and therefore be 92db? Or would I have to measure them to know that answer?

Also would I be losing some quality (probably from the point of view of the amplifier) by reducing the ohms rating by wiring in parellel? Perhaps since they will be identical drivers I could improve the output quality by using a series configuration and getting 16ohms?

thanks!

[cadmaniac]

The Scan 12M is a 4-ohm driver, and mine measured with a sensitivity closer to 90dB.  In parallel; nearly 96dB would result, but impedance would be 2-ohms (maximum: that ridiculous tweeter is also 4-ohm)!

It really is an excellent midrange, though; smooth and clear, with a fairly flat response.  I use it in a 4-way coz it is pretty small (and I like very high SPL).

Tony Gee is working on a very promising 3.5-way, with the 7000, 12M, 18W/8531 & Seas 10" metal woofer:  http://home.hetnet.nl/~geenius/Diary.html.  If I wasn't hip-deep in my own acoustic lunacy; I'd copy his design & be done with it.

[WerTicus]

Some cataloge I have lists it as a 8 ohm but I see that your right as the scan speak site has it as 4 so that makes things a little trickier

hrmm thanks for the link to this tasty article