Alan
Does this mean you are moving your system into the office area we all looked at?
Does this mean you are moving your system into the office area we all looked at?
Bookshelves behind speakers for absorption/diffusion?
- Thread starter sleepysurf
- Start date
Help Support MartinLogan Audio Owners Forum:
sleepysurf
Well-known member
Exactly! I'll end up with a combo of both... 2' x 2' angled absorption on the bottom (as bass traps), and mix of books, CD's, and small absorption squares on shelves above, "tuned" it to my sonic taste.
Nope! Just adapting the Family/Listening Room to serve everybody's needs. Stay tuned for the transition!
sleepysurf
Well-known member
sleepysurf
Well-known member
I'm forging ahead with the bookshelves project, but unfortunately cannot do the front projection home theater. Having a stealth drop-down screen is no problem, but turns out, there is no way to mount a projector at the proper throw distance, without using a long rod from the cathedral ceiling (behind the ceiling fan). That would look like cr*p, so I'm putting that part of the project on hold until some later date, when we'll consider adding ceiling cross-beams, which could incorporate both the drop-down screen and a projector mount.
Glad to hear you are moving forward with the bookcase/diffusior/absorber project.
Are you going to build a place for the screen and wiring now so you won't have to alter the bookcase later?
Keep us up to date with the progress.
Are you going to build a place for the screen and wiring now so you won't have to alter the bookcase later?
Keep us up to date with the progress.
sleepysurf
Well-known member
My cabinet guy just came over for final measurements. My bookshelves should be ready for installation in a week or so. The unit will be walnut, with a lattice design on top, matching the center cabinet sliders. The flanking bookshelves will be 24-1/8" inside diameter, to accommodate absorption panels (and/or diffusion panels), along with books, in whatever combination I find best. The unit/shelves will only be 9" deep, so I'll still have plenty of "air" behind the Summits (see attached drawing).
As an interesting side note, my cabinet guy turns out to be an audiophile himself, and is currently constructing his own listening room/home theater! He's gathering a bunch of McIntosh gear (? speakers), but focusing on room acoustics first. After demo'ing my setup today, I think he might consider ML's (and a Squeezebox setup) down the road!
As an interesting side note, my cabinet guy turns out to be an audiophile himself, and is currently constructing his own listening room/home theater! He's gathering a bunch of McIntosh gear (? speakers), but focusing on room acoustics first. After demo'ing my setup today, I think he might consider ML's (and a Squeezebox setup) down the road!
Attachments
sleepysurf
Well-known member
My cabinet guy said he can easily add a drop-down screen, at a later date, on top of the current design (it would first pull out like a drawer). We also discussed another idea of adding some large A-frame beams spanning the cathedral ceiling cross-wise. The front one would hide the screen, a middle one would hold the projector mount, and a rear one would hold surround speakers (near the back of the room). That idea really piqued my interest, but will need to be put on the back burner for now.
That was an awesome idea incorporating the panels in the bookshelf. I bet most people won't even know they are tucked in there unless you tell them (I am sure you will hear a difference though).
sleepysurf
Well-known member
My cabinet guy installed the bookshelves unit yesterday. His woodworking skills are incredible, evidenced by the intricate lattice design he recreated (matching the center console sliders). I'm starting off with 2' square panels angled in the bottom section (for bass trapping), and will stagger books on the shelves directly behind the stat panels, to see how diffusion works. The shelves are designed so I can optionally still use my two 4' panels, if that proves best. I now have endless possibilities for acoustic "tweaking" by combining acoustic panels, books, CD's, etc. I'll eventually use my XTZ Room Analyzer for final tweaking, but need to address some reproducibility issues with that device first. I've attached a sneak peek of the unit thus far.
Attachments
sleepysurf
Well-known member
Another update. After a week of listening, I'm quite amazed by the bookshelves/diffusion effect! Firstly, despite the asymmetry of my room (open arch/door front right, sliding glass on left wall), my soundstage is now perfectly centered (was never this good), and twice as deep. That was a complete surprise! I was also surprised by the degree of SPL boost. I expected things to be slightly louder (vs. using absorption), but once I dialed in the speakers, they were ~20% louder, and a bit brighter than I prefer. On a whim, I hung my 4' tall absorption panels behind my wall-mounted HDTV (see pic). That helped dampen the brightness a tad, probably by eliminating the reverb from sound bouncing between the wall and cantilever-mounted TV. Fortunately, my wife begrudgingly accepted that non-WAF addition. I also changed the 2' square absorbers to be fully upright at the lower front sections of the unit, with 9" of dead space behind them for better bass trapping. The bass is now even tighter, but I'm thinking of adding some cotton batting behind the panels to see if I can eke out further improvement. I'm still not done tweaking, but can honestly say this combo acoustic/decor upgrade has had the greatest impact on my soundstage since getting the Summits. I know that absorption, absorption, and absorption is commonly preached by many on this forum, and I fully understand the logic. However, if you already have a somewhat dead room, and are able to pull your speakers out at least 36-40" from the front wall (which is how far mine are out from the bookshelves), don't underestimate the power of diffusion for improving the imaging, attack, decay, and overall energy, of your ML setup!
Attachments
sleepysurf
Well-known member
As pointed out to me in another forum, the books in my setup are probably acting more as absorbers than diffusors. Thus I'll call this upgrade the WAFAbFusor bookshelves.
sleepysurf
Well-known member
Diffusion vindicated!
FYI, the Absolute Sound has a free download of Robert Harley's System Setup Secrets... http://media.avguide.com/excerpt.pdf
It's a superb reference, excerpted from his highly regarded Complete Guide to High-End Audio. Of note, he specifically addresses the issue of absorption vs. diffusion for dipole speakers, as quoted below..
After an additional two weeks of extended listening with my "Acoustic Bookshelves" I wholeheartedly agree. Think I'm gonna don my flamesuit and change my Username to AAA (the Anti-Absorption Advocate)!
FYI, the Absolute Sound has a free download of Robert Harley's System Setup Secrets... http://media.avguide.com/excerpt.pdf
It's a superb reference, excerpted from his highly regarded Complete Guide to High-End Audio. Of note, he specifically addresses the issue of absorption vs. diffusion for dipole speakers, as quoted below..
Last edited:
Ethan Winer
Well-known member
There's nothing wrong with diffusion, but it needs to be good diffusion for best results. A shelf full of books is not a real diffusor, as you know from watching my video All About Diffusion.
--Ethan
sleepysurf
Well-known member
There's nothing wrong with diffusion, but it needs to be good diffusion for best results. A shelf full of books is not a real diffusor, as you know from watching my video All About Diffusion.
--Ethan
True, Ethan. However, at least in my room, the bookshelves work exceedingly well. I haven't noticed any appreciable difference if the books are staggered depth vs. all lined up, so I'm likely getting a combined effect of absorption and diffusion. Bottom line is I just wanted folks to know that bookshelves are a viable option, particularly for those of us dealing with WAF issues.
