Greetings and Happy New Year. As a former Dunlavy owner I found that removing the grill cloth improved the sound even though supposedly they were designed to stay on. Recently I got the hair brained idea of removing the cloth that covers the M3 Turbo S', so I laid the speakers face down on a few pillows and unscrewed the screws holding in the speakers. Took a few minutes, very easy, then I lifted the speaker up with one hand so that it hovered over the cabinet and removed the cloth.
While removing the screws I noticed that they look like standard 1" sheet rock screws. Hummm. Then I got the hair brained idea of replacing them with brass screws, so I went to Lowes and bought a 50 pack of #10 x 1 IN Hillman solid brass phillips screws for about $6.50. Before I replaced the speaker screws I also had lying around part of a sheet of "db Neutalizer" which from Herbie's website says "Ideal for component chassis damping and loudspeaker applications". These I had already cut into half inch by half inch squares from another project, so I used them as washers and drilled a small hole in the center of the damping sheet squares and threaded 32 screws into 32 half inch squares. I then replaced on screw at a time, setting the torque on my drill to sixteen, as that seemed to be fairly tight. The brass screws are slightly larger than the rock screws so they were a bit harder to drive in which may have been a good thing.
OK, on to the listening test. I had used a mediocre recording of Beethoven's quartet #132 as both violin and cello make it easier to discern fullness in those areas and indeed there was an improvement. BUT, as I moved on to other recordings I kind of had a WTF moment and I was trying to figure out what was different in a very pleasing, very involving way. Now this was yesterday, so I reserve the right to renege on the jaw dropping improvement, but to my ears the soundstage opened up, the bass is fuller, the highs are more crisp and defined but also more relaxed. The PRAT factor (pace, rhythm, forgot what the A is

, timing) got huge.
Two days ago I was playing spinning wheel (blood sweat and tears) on vinyl and with the cloths off,(no screw tweak yet) I noticed a small but noticeable improvement in clarity and cymbals, etc. But with the new screws in I really was blown away with what I was hearing, as the jump factor and musical involvement improved dramatically.
There is another possible reason for what I was hearing, as I have an EL34 tube amp and the Sophia Electric EL34 tubes (highly recommended if you want to spend the bucks) take up to four hours to sound their best. So I would attribute maybe 20% of what I was hearing to an improvement in sound from tube warm up, and the other 80% you can attribute to placebo factor if you think I'm full of s**t. Hopefully, what I heard yesterday will continue and I urge any others that can handle a screwdriver to try their luck.
It would be interesting to try this tweak with some FoQ product, but for now YMMV, but I'd be interested in that Xmas reply "do you hear what I hear". Thanks for listening.