Hi,
I did a sine sweep and that revealed lots of problems with these drivers.
first the second harmonic is nearly as loud as the fundamental below 1000hz.
You can hear it singing above the fundamental. My 291's with symbiotik's produce nice whole tones.

Further there is an array of all sorts of noises that occur at very low level. this explains why guitar chords were fuzzy. Very strange. they are brand new drivers. and both exhibit nearly identical characteristics. It is a shame they have to go back. To bad too because i feel I will never be able to properly comment on the performance of this driver.

But I do feel that the driver is too slow. As I noted in my first post, you get spoiled by the sheer speed of the aluminum. I mean, there are comments out there about the loss of speed going from aluminum to Pascalite, so going to a rolled suspension does not surprise me now. But like most things you have to experience it first hand to tell.

My goal was for a warmer mid with little change in the top end. Afterall, I roll these off above 3500, I did not expect the loss of transparency. At good volume, vocals were fuller and warmer, but the the tradeoff on speed and transparency is not worth the gain at the bottom.

Yes, I am of the mind that if you really want to experiment with the phenolic, you need to find a good used or NOS 290. Not so much because it is bigger or more robust though , but just that it is vintage, and likely made with more care.

Hope that is helpful
Kevin
010311