Newbie, 1st post.
Long-winded, but integrates two topics.
I bought a '98 37' Allegro bus (cat/allison), and was quickly shocked by the high level of bidirectional noise through the stock windows.
I have a background in professional acoustical design and sound engineering, so assessed possible quieting options.
Shy of making extensive soundproofing mods to the interior walls themselves, the thin glass is the weakest link for noise.
The most effective -and expensive- method would be to replace the glass with thicker, possibly laminated, panes. Any glass thicker than about 3/8" would be quieter than the surrounding walls, overkill. I was phone-quoted $300/per to replace the two rear bedroom windows with 1/4" glass (if I performed the window-frame r&r). However, I suspect that estimate would've jumped the moment the shop held the frames in-hand.
I also have an extensive art collection, and reflected how I'd really like to enjoy their company on the road as well. Given the limited open interior wall surfaces, I realized that the square-footage of the windows could be multi-purposed, simultaneously providing improved soundproofing and "gallery" surfaces.
The pics illustrate my solution: a vertical-sliding panel made of 3/8 decorative ply laminated with 1/2" celotex SDB (sound deadening board). Total material costs <200 sufficient for three window conversions. Skilied-labor intensive, as all worthy ends are.
I also improvised an "X" picture hanging system which permits artwork to be both roadworthy and "hot-swappable", gallery style. Virtually any piece can be swapped with any other hanging location, thanks to the matching geometry of the "X" mounting system.
50lb test fishing line. Eyehooks for the lower mounts, c-hooks for the uppers (see pics). The line is loop-threaded through the lower eyes, while the upper c-hooks can be rotated 180deg. to allow slipping-on the upper line-loop, then rotated upward to secure/tension the line.
Serviceably ingenius, I must say (lol).
I'm certain there's better ways to achieve the two objectives of soundproofing and art-surfaces, but that's the best my design hamsters could manage spinning in my cerebellum. Improvements most welcome.
(I rejected the option of a velcro X as both unsightly and weaker. Miles shall reveal how well the nearly invisible 50lb filament endures...)
PS- I CAN'T FIND THE TAB FOR UPLOADING PICS, BUT WILL UPDATE WHEN I HAVE TIME.