Nick wroteSo, given that the point I was questioning was that increasing the load resistance would cause a LOWER cross over frequency, you agree with me then?
Glad that's all sorted and we are ALL now in agreement.
So back to the speakers in question.
Yesterday I did the mods to the front baffles to replace the MA tweeters with the ribbons and also installed the L-Pad attenuators on the rear baffles. I am using the existing XO with no modifications. So the robbons are corssing over around 3.5kHz.
I always knew from the first moment I fired these up there was potential for a great speaker in the making. However in some respects and especially with the sibilence from the 1" silk dome tweeter with a max SPL of around 92dB and the overall speakers being 93-93dB efficient it was just asking too much of this tweeter in these speakers. I now believe this slight mismatch, with the tweeter, had been holding back what was (and now is) a great speaker stuggling to get out the boxes. However having said that they did sound rather GOOD. And I do mean GOOD in that incarnation.
But now with the ribbons in place I must say these have leapt up a notch in overall sound. They have he same deep quality bass, but Oh that midrange. So clear and detailed. I don't think I have heard better midrange from any other conventional box speaker. They do remind me in this respect to my venerable Quad ESL63's and 57's. But, the HF has now taken on a wow factor to add to the mix. Overall and with the little 300b SET's they do sound FANTASTIC (to my ears) and definitely the best speakers I have produced to date.
Here's a couple photos of the reconfigured driver set up in my listening room.