Thought experiment; Imagine taking a megaphone in order to shout out clearly over longer distance. But, as a requisite condition, you must hold a dense pillow 1" from the mouth of the megaphone! You see, the rules are such that the gap between the pillow and the megaphone must be maintained.
THAT, my friends is the equivalent illustration to the design choices used in the old Model F! I did the foam removal, and I'm not going to talk about the potential for asbestos. As I say with other sensitive maneuvers, IT IS A DO AT YOUR OWN RISK ACTIVITY. So, let no one say I told them to remove the foam inside the Model F, not without pointing out their responsibility to acknowledge potential issues. I am presuming the old foam would likely have properties that might militate against safety today.
Now, on to the great news! IMO, this speaker has been resurrected! I'm WAY more excited about it now that when I said it was sublime. The removal of half the foam has allowed the driver to work as it should! The indistinctness, lack of high end sparkle, muted, weak bass was all really getting to me! For a design that was supposed to be all that it was not doing it.
It had to be at least in part due to the foam. You don't take an open moving driver and stuff thick material 2" away from it, and not expect the driver to choke! This speaker is a study in the convergence in the '70's of a brilliant, innovative driver, and at the same time awful construction methods that absolutely killed a LOT of the speaker's potential. It's hilarious that such a loser move with foam reduced this wonderful driver to a pathetic performance.
Well, NOT ANY LONGER! Now, the driver is acting as I would expect, a MUCH closer approximation - as would be expected - to the HHR Exotic model that I have heard. That was a big part of the frustration with continued listening; it just was not great. It was big soundstage, and that was about all worth praising. Now, the speaker has indeed come alive! Now, the driver sounds as it should, with respectable sparkle as well as spaciousness. The top to bottom frequency balance is commendable, though not SOTA. The soundstage is FULL now, not anemic and struggling to expand. The dynamics are SO much improved. The driver does not sound squelched, but has pop, and the bass is a big bonus, as the cabinet half full has a great, solid and powerful bass response!
There are so many insights from this to be gained, including not to hold an older/vintage speaker as sacrosanct, such that it would not be improved from futzing with it. Another lesson is that a designer might be brilliant, but the conventional aspects of speaker making of the day can reduce what would be an even more brilliant design. Yes, of course, the standards have changed; that's part of the reason I was not accepting the performance. Free air motion of the driver is SO important, and without the back force of the foam blocking the driver's operation, this IS A RESURRECTED SPEAKER!
Now, it's not a charity case, but an authentically reasonable selection for listening to as a quality transducer. These speakers probably within a fairly short period of time would have been on the way out - somewhere. Now, they will stay, because this one change has brought a cascade of positive changes, and the driver is operating closer to my expectations.
With this final fix, the restoration is a big success! Now, beyond a shadow of doubt, this IS the best $400 speaker I have ever owned! It now may take its place longer term alongside my other speakers, and because it has been resurrected to play with above respectable levels of sound quality, it will be used in rotation.
Have I overstated my conclusions? No, I have not. This was a roller coaster of changes, thankfully most of them leading to a more favorable result. Had I been too timid to rip into the foam, treating it as though it was sacred material, this never would have resulted in my finding deeper pleasure in them. But, as it is, speakers that are not mostly cutting it need to be reassessed, and I do not care whether it is iconic or not. NOW it performs along the lines of what I expect a great omni to perform.
Conclusion? YEEESSSSSSS! I now have a vintage speaker restored to a quite respectable sound quality level, and I am most gratified that I futzed around with it to make it happen!
Now, to give some balance, are these suddenly replacing my other reference speakers? Of course not, but neither will they languish as an also ran, nice idea project that failed. That's where they were heading before I motivated to try the foam removal. They will be a pleasant alternative, and a respectable one, to build systems for enjoyment, and even for reviewing. The change has been good enough, I feel, that they can be used occasionally for reviewing. Prior, I wouldn't have dreamed to do so.
WOW, what a difference removing the pillow makes!!! Again, those with older model F's are not being told what to do, and consider your bravery if you want to alter this iconic speaker. But, performance is SO important to me that this was THE solution to the speaker's foibles.
Now, I think I am done. The restoration is acceptable to me, the performance as good as I was hoping. It has solidly moved along the spectrum from "sublime" quite a bit closer to sensational. No, not drop jaw on floor, but much closer. I now consider it a brilliant move on my part to seek the affordable fix, and to trust my instincts in regard to pushing the speaker further along. I am SO happy I did not accept the weaknesses, but made better things happen. BTW, note that this all happened without burn in. I am an advocate of change to systems, a system builder, and that is a fundamental reason why I ended up with a positive outcome. Waiting would have done nothing to address the fundamental issues, and being active has gotten me a very nice vintage speaker redone performance-wise within a couple weeks of return from repair. BIG, BIG WIN! This has been the singular best turn with a vintage product I have had, but then again, I was more aggressive about altering it than I have with other vintage gear. Nice lesson learned, with all upside. :)
