I thought the Fried Model H was a <very> good speaker but I thought the big IMFs sounded tubby and wooly--nice highs and mids but the bass threw me off. These were my impressions at the time, I haven't heard these speakers since they were new.
I thought the Fried Model H was a <very> good speaker but I thought the big IMFs sounded tubby and wooly--nice highs and mids but the bass threw me off. These were my impressions at the time, I haven't heard these speakers since they were new.
I thought the Fried Model H was a <very> good speaker but I thought the big IMFs sounded tubby and wooly--nice highs and mids but the bass threw me off. These were my impressions at the time, I haven't heard these speakers since they were new.
The IMF designs were more heavily stuffed in the last fold of the T-line compared to the Fried designs.
Having the last fold of a T-line too heavily stuffed will cause impedance peaks in the lower frequencies
This could account for Tom's observation as a tubby wooly sound.
The Kef B139 was not the beast choice for use in a T-line.
This driver has a heavy cone mass and large Vas which made it best suited for a closed box.
I think you might be thinking of a different driver Jim, everything I've read about the B139 states that it has a lightweight cone, which is part of why it bottoms out in t-lines.
I agree it is not the best t-line driver out there, but there is a reason it was used in transmission lines.
Area is Albuquerque, New Mexico...
IMF RSPM MK IV for sale today on ebay (no affiliation). Not sure of reserve price. Possibly nicest set of these ever seen other than when they sold new decades ago. Mentioning as someone near Meridian, Idaho can pick up, or he will ship (expensive). Maybe these are selling from an Ak'er, or hopefully an AK'er will get them. These need no work at all, which is a blessing and the best way to go; what we all wished was ours; the tops may have some water spots only. Beautiful condition. No bids so far, he opens at $10 with a reserve. If anyone gets these here, let us know how you like them.
Tom, the MkIIs had a little different rock wool formulation, and the Hs were quite, quite good.
I picked these up from an estate sale where I submitted a low bid. Didn't hear anything for two months, and then suddenly got a call out of the blue asking if I still was good for paying the bid amount. Other than being in San Diego and the speakers being in St. Louis, I was good to go and a friend picked them up the next day.
They are supplanting a pair of Thiel Cs1.2s in the family room, to my wife's dismay, but I really like the bass. They aren't nearly as bloated as the AR3s were in the same spot, but not as nimble as the KHorn bass. The best part is I can't hear the box, and they are more efficient and hit heavier than the Vandersteens that were under consideration.
Hope an AK'er gets 'em.