[net.audio] Strathearn ribbon drivers

band (02/18/83)

	Has anyone out there any experience with the Strathearn
	midrange/tweeter unit?  It seems to me they would be good units
	for the amateur to build around since, because they can be run
	nearly full range, careful tuning of crossovers and boxes is
	unnecessary. And, it is claimed by some, they are one of the
	best drivers around.

	Sooo, does anyone think they sound good enough to be worth the
	money? (For those who don't know, the drivers are expensive
	~$275-350/pair.)

	What is the driver's resonant frequency? I've been told 175hz 
	and 80hz.

	Assuming good, 'fast' woofers, what would be a good crossover
	frequency? One usually doesn't want to use a driver below it's
	primary resonant frequency so presumably the answer to this
	question is tied up with the answer to the last question.
	For the most coherent sound one would want to crossover at as
	low a frequency as possible but if the driver isn't up to it...

	How well damped is the driver? The basic mechanism is
	similar to Magnepan's but Magnepans ring badly, smearing the
	sound. If the Strathearn's magnets are strong enough (Samarium-
	cobalt anyone?) and the conductors dense enough then they might
	approach a true force over area type driver such as an
	electrostatic or a true ribbon driver (eg the Decca and Pyramid
	ribbon tweeters) where electromagnetic damping is very effective.

	Does anyone know of any similar midrange/tweeter drivers? Infinity
	uses one, the EMIN, in their top two models which I understand is
	made for them in Japan but is unavailable to the amateur builder.
	Are there any others?

	Let's hear it for roll your own audio!

			Peter Bandurian
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