I have two sets of all of the filters for the 846 so I have been modifying them out of curiousity. I have blue filters with no screen but with the dampening foam (very incoherent and shrill). I have white filters without the screen so just an empty tube (also rather shrill and materially brighter) and now black filters with the screen but with the foam carefully removed.
To my ears the black filters without the foam is actually brighter than the white filter. I would place the sound between no screen on the blue filter and the regular white filter. My first reaction is for those looking to add a little more shimmer to the top end and a slightly higher soundstage the black filter without the acoustical foam maybe the way to go. Call it the "white plus" filter.
I used as a reference the following songs "Can-Utility and the Coastliners" by Genesis in 16/44 FLAC, Riverside's "Second Life Syndrome" also in 16/44 FLAC and Porcupine Tree's "Anesthetize" in 24/48 FLAC.
After reading what you said I re looked everything over, as I loved the white filter on most tracks but felt it was just a little bright so after reading your post I took the white filter and as I had removed the foam from the black filter I inserted it into the white filter and it took just that slight edginess off please try it when you get a chance and let me know what you think if you hear what I hear then I think it may be a good combination.....