Wooden blinds vs cellular shades for acoustics

Standard old school advice for large window acoustical treatment seems to be "heavy draperies". Some cellular shades (Hunter Douglas, Bali) have high factory-rated NRC (0.60 or better). That's about the same for what little I've found for draperies.

Recently, I heard that partially-open wooden blinds are best for acoustics, acting through diffusion, rather than absorption. Opinions? Experiences?

Well....assuming most rooms will have 1 wall of large window coverings unless you bought a church like Arlo,that is indeed an interesting question.Being it is part of 3 other walls[usually] it will be next to impossible to comment adroitly.Soundwaves like diffusion and absorbtion to varying degrees depending on the total area with whats there.For instance I have a wall of windows,8'x20' covered by shades which I move up and down according to the Sun.I have not found a difference yet as to there height though I havent been listening/looking for one.If I do I will remember this post perhaps and thank you for opening my ears,cheers,Bob
I have three windows on the left side of my room that measure approx 34x60 ea so in effect the windows dominate that wall. I previously had cloth vertical blinds and recently replaced these with solid wood shutters.
Sonically, I feel it is an improvement compared to the verticals. It is also possible to make some adjustments to the presentation by different orientations of the wood slats. It is not a major change, subtle but noticeable. I don't know how the shutters would compare to standard drapes or other types of blinds. I feel I made the right choice. I will post updated room photos in a couple of weeks once new carpet is installed.
I have wood blinds behind my speakers, never experimented with partial opening, unbelievable! Will have to try this weekend.

Closed, they are reflective, it will be interesting to note the amount of added diffusion when partially opened, something I've been looking for. It does seem that the diffusion properties would be somewhat limited by the window behind being in such close proximity to the wood blind. In the summer the storm window can be pulled out, I suspect the added space behind would increase the diffusive properties. I also have cellular shades on one side wall, these absorb sound, however, not to the extent of my Echobusters.
I was where you are going to be in regards to your carpet.When that goes in all else will be majorly overshadowed.In my place it was a good thing as I am in a condo.If I had my own place I would go with wood floors,YMMV,Bob
I've treated my main picture window and smaller sides with wood shutters,(solid, no slats). Made a huge difference over blinds or drapes. I bought unfinished ones from Lowes, staind them to match my other wood surfaces, then treated them with larch resin to try and give them the best reflective surface I could find, sonically much better than regular poly. It's great. Look up mother of tone website and you'll see what I'm talking about. You can get the varnish from Sinopia. Also, since glass is not our sonic friend, I'm using Marigo dots on the windows, and it is a fantastic tweek. That might interest you as well. Good luck. If you really want to make your room sound great, it's worth it.
I'm having a problem with a 5'x6' standard double glazed window (1/8" glass). The sucker rings at midrange frequencies. Yech! I've tried putting powerful 2" magnets on both sides to keep it from resonating (little help), I have thick velvet curtains with backing on them in front (still rings). The people who install plastic films on windows doubt it would help. I'm talking to the window people about getting laminated glass replaced in - but that will likely be costly. I don't know about the Marigo dots - can't imagine they would be much better than the magnets. This could be an expensive fix, as the glass they use is thin enough to be like a drum membrane.
Peter_s, is the window mounted inside a frame? If so, I wonder if inside-mount blinds (high-NRC cellulars or partially-open wooden) would reinforce the curtains sufficiently to stop the ring.
I have a window wall measuring 8'x 18' opposite my speakers with four panels of metal mini-blinds. I alternate the blinds panels with slant-up and slant-down hoping to break-up and redirect reflections.
I've also placed several 2" squares of DynaMat on each of the four double-pane windows in hopes of reducing glass vibrations.
I have no idea if this works although it sounds reasonable that it should.
Hi again, yes, the dynamat is a very cheap alternative to the marigo dots...it did work on my windows. I bought mine off ebay, cut it into 2" circles, and placed it an inch out from the corners in every corner. It works. The Marigo's do a much better job, don't ask me how, you should call the Marigo guy, he's doing great business, he seems to have hit on a very successful product. plus, money back guarantee. look at his website, or check the review on 6moons. I still have skeptical friends,(who have issues in general) but me and my friends with ears are totally sold. I would think it's a much better alternative either way than getting new windows. I did, but not because of that, replaced 110 yr old ones with new ones, and the dots improved the new glass as well. If you like your glass, its sealing properties and all, just get dots.
I have used partially open wood blinds for years and this is a good start, but I have cellular shades over the sliding glass door and this is a better midbass/bass trap and allows for high dB listening without a standing wave. In addition, I have a coffee table in front of the couch, between me and the speakers and I covered the bottom of the table with foam egg crate and this is another great bass trap, and is not visible. I use this under all furniture I can get to until the bottom end is tame. Wall tapestry is another good tweak if needed. Too much though and the bass will be thin, pinched and dry overall. Tuning a room is the art to fabulous sound....Jallen
Being a natural material, wood makes a good insulator and acoustic diffuser. Here are some more interesting tips about wooden blinds http://www.articlesnatch.com/Article/The-Ins-And-Outs-of-Wooden-Blinds/1084597 . Hope this helps
Anyone else have any experiences they want to share with adding Dynamat, Marigo dots or something similar to windows or glass surfaces in their listening rooms?