A friend just inherited a grand piano and wants me to remodel her living room to accomodate it. Where can I learn about the best materials to create good accoustics? How about the shape of the room? I can do a cathedral ceiling. Should I?
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Engineered rafters are lighter, straighter, and often have more room for insulation than dimensional lumber.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
There are a bunch of variables to consider. A bunch!
Anyway, there are a great many audio books that have super good information about accoustics. Most good bookstores should have decent Engineering/Audio section to check out. Accoustic behavior of a space is fairly complicated business. Do you want "flat", "bright", "dark", etc. the list kinda goes on and on. The most definitive source of information on the subject will be in The Audio Engineer's Handbook. It is a big, blue book costing upwards of $100. Unless you want to become a studio engineer anytime soon you should see if your local library has a copy.
Another idea would be to call around to local recording studios and ask if there are any engineers with some spare time that might want to make an extra hundred bucks. Have them come over and give you some ideas. If you happen upon a good engineer, he (or she) should be able to make some pretty good suggestions on the spot.
Marble floors would be a great place to start. Good luck.
Make it a "bright" room. You can always add curtains
and stuff to dampen it. You can't make it brighter
easily. Make the walls stiff. 2 layers of drywall.
A double-wall system with insulation between is good.
It will keep the room quiet and the house quiet.
HArdwood floors. Best not to have a square room.
That promotes standing waves and acoustical resonances.
Should be a BIG room. Angled corners, preferably a slope
to the ceiling. If you make it like a studio with anechoic
walls, the pianist can't hear his own sound. The ceiling
needs to be high. 10 feet is decent. A well-lighted room.
Lots of tall windows, but use glass that blocks UV well.
Don't want to trash the finish on a $50,000 Steinway.
This assumes the pianist is good. Really good. If not,
any nice room will do. They won't be able to tell the
difference. I've been playing for 40+ years. That's the
sort of room I like. But, even a bad amateur won't like ####10 by 10 room with 8-foot ceilings. About 12 by 20 is the smallest
you should consider for a grand piano.
Totally agree.
Thank you for the reply. A funny coincidence happened last night as I went to a party and met a guy who is an accoustical engineer for Boeing and his wife is a music teacher. "I love it when a plan goes together"
Here is a site that was posted on the old board (I believe) and that has at least as much information in it as anyone would probably need. Some other great stuff on the site, though definitely more engineering that rubber-hits-the-road.
http://www.nrc.ca/irc/bsi/85_E.html
Don
Thank you for the information.
I think you have some excellent advice to go on here. I looked up "piano" in my copy of the Handbook for Sound Engineers: The New Audio Cyclopedia and it only had an entry for microphone arrangements. The section on music rooms explains the science of reverberation time described by Sabine, and the Beranek rating system for concert halls. It talks about intimacy, liveness, warmth, loudness of direct sound and reverberant sound, diffusion, balance and blend, ensemble, and echo, noise, and tonal distortion. Your eyes glazed over yet? Effectively there's no practical info on how to build a room.
My Physics of Sound textbook has a table of average absorption coefficients for seval types of building materials at octave frequency intervals. Concrete and bricks is fairly reflective from 125 Hz to 4000 Hz. Glass is fairly absorptive at 125 Hz, becoming more reflective at higher frequencies. Plasterboard is absorptive up to about 500 Hz, then it reflects more and more. Plywood is extremely absorptive at 125 Hz, and starts being reflective around 2000 Hz. Carpet is inverted, absorbing the high frequencies, and not so much the bass. Same with curtains, but not as effective as carpet. Acoustical board is actually less absorptive than plywood at 125 Hz, but is hugely absorptive in the human speach range, which is sort of what it's for.
So therein lies the trick to determining the "best" building material. In your case, you want to know best for enjoying the piano.
My idea would be to think about a concert hall you like, even if it's just an old high school auditorium, and think of your music room as just the stage. Go with the guy that said hardwood floor, not marble. Concert stages are raised wooden floors. Direct contact of the vibrating object, like the piano makes a good impedance match to the floor, and then the entire wooden surface oscillates like a loudspeaker, moving the air. Just like the sounding board in the piano. That's made of spruce planks joined together. The pin block is maple. Maybe you could use one or both of those woods in your floor. It would be a conversation starter. If you're working on a slab, though, it's not going to be as loud. Maybe a floating floor? I don't know about the marble. It just seems too harsh. I'm just thinking of the sound of walking on marble in high heels. Click click. Put on some hard shoes and just go walk on different stuff until you find one that makes a sound you like. It will work with the piano the same way.
A vaulted ceiling is nice just because it increases the reverb time. The sound takes longer to travel up there, and then longer to get back to your ear. Unless the room is the size of a concert hall, though, that time is still so small as to be fairly imperceptible. You needn't go nuts and do a mahogany barrel vault or something. The phase distortion from standing waves is only noticeable with really long delays. You can try to make the walls and ceiling surfaces not parallel if the room is truly huge. Or you can also get a good effect if you put the piano in a room by itself that's barely big enough to hold it, or even an alcove. Sheetrock walls and ordinary low ceiling, raised hardwood floor, and the sound will just really build up in there, like a shower. It will be loud. That would be fun if your friend just wants to play by herself.
The other benefit of putting the piano in it's own little place instead of out in a big room is protection. Put it out of the way and people won't tend to put their drinks down on it. If you put it on a raised platform, it stops you from whacking it with the vacuum cleaner. Use a dust mop on the wooden platform. Plus if you can keep the piano out of drafts and drastic changes in temperature, it will stay in tune longer. Another reason to stay away from windows besides the finish on the wood.
Good luck!
B
A concert hall or recording studio is designed to
convey the sound of the performer to the audience or
microphones without distortion. It is NOT designed
to allow the performer to hear their own performance.
Many halls I have played in allowed the audience to
hear the slightest whisper yet were so dead on stage
that you could not hear your own performance at all.
Ignore ALL the data on concert hall design. That is not
what you want to do here. A recording studio is totally
dead. You also do not want that.
A grand piano fires the sound sideways relative to the
performer. As you sit facing the keyboard, the right
wall should be hard and reflective - double drywall.
Ceiling ideally should slope upward from the right
to left, highest on the left wall. Left wall covered
completely with drapery, wall in front of you likewise.
Wall in back should be hard. This will probably give
the best compromise between a practice room and small hall.
Floors should be hardwood. You can always add some rugs
if the room is too bright. Much tackier to lay bits of
wood on the carpet. Best if the back right corner is not
90 degrees. Should be a larger angle. What you are trying
to do is create a room without resonance, that allows sound
to travel from one part to the other but has minimal reverb.
You want the angles so that standing waves cannot form, which
would make dead spots. The piano should be about 1/3 of the
way from the right wall- not in the center. Should be maybe
1/3 of the room length away from the back wall. Some
experimentation may be necessary to find the best place for
the piano. If you want to play stringed instruments, sit
facing the right hand wall. Not a bad idea to have a raised
platform for the performer. Not so necessary for a piano since
the sound source is higher, but a good idea for other instruments.
I've been playing for 40+ years, including Kennedy Center and
a good few smaller places. Also been an engineer for 30 years.
Ignore the books mostly. Very academic stuff. As far as ####practical guess, this is it.
Wow! That's very specific and excellent information! I need to save that in case anybody ever asks me about piano playing spaces. I'm sorry I gave incorrect advice about thinking of the stage. I suppose that was pretty stupid. I wasn't feeling good yesterday and I was just in here killing time on the computer. I started out on the right track telling him that there's nothing useful in the books, though, then I just went skittering off. My experience with acoustics is mostly from helping Dr. Patronis work on auditoriums and sound reinforcement systems. I've been on the stage at the Fox in Atlanta and the Grand ol' Opry, but that's not Kennedy Center! I was always listening to pink noise through the sound system or a swept sine wave, never playing music. Wrong experience.
I always struggled just to be average as a student, so I wouldn't much claim to be academic, either. But if I'm no academic, then I'm WAY no musician! I'm just a housewife with an Applied Physics degree and a onerous project I'm distracting myself from. Pressure treated lumber, yuk. I'm ready to finish that and get back to making my new bathtub enclosure into a subwoofer. I'll try to restrain myself from giving any more lame advice.
B
There actually is a lot of good info in the books
if you have the budget to do a real design, and if
the size of the space deserves it. But, my experience
in this and other acoustical subjects has proven that
the theory is often far from the practical solution.
I also make violins and assorted stringed instruments.
I have probably 10,000 pages of books and articles on
the acoustics of violins. Equations, spectrographs,
vibration mode diagrams, radiographs, you name it.
But, you can combine all that erudite research and
you still CANNOT produce analytical criteria for either
making a "good" instrument or evaluating whether one
is actually "good". You simply must listen and judge.
Halls have been built with the most sophisticated analytics
that sound like garbage. HAlls have been built with no
analysis that sound wonderful. My personal guestimate is
that the solution I offered will sound fairly good.
I could trot out assorted credentials and whatnot, but then
I'd have to charge the same exhorbitant fee that you would pay
for the same advice elsewhere. Don't make it square. Don't
use carpet, except for a couple throw rugs. Don't put the
piano in the middle. That's about 97% of it.
One of the more interesting threads I've read in a while. Wish I was building something I could use the info for. Subwoofer bathtub? Please elaborate, if you feel like killing more time...
-DW
When I finish it and test it I'll start a new thread. My physics professor at GA Tech suggested I try a direct method using a Bass Shaker made for bolting to the bottom of home theater seats or video game consoles. I have found people online that say they found those on clearance for $8. I have to start haunting the car stereo stores I guess. If that method proves the notion is good, but the quality isn't there, we can measure the volume and do a lot of calculus and come up with the right driver to do it the conventional way. First I want to see if it's even a good idea. I had this notion that it would be relaxing to lie in a hot bath with headphones on with corresponding low notes transmitting directly to the water, and therefore to me. It might just be alarming or unsettling. I'm going to wait and see.
I'm also planning to HEAT my cast iron tub. I don't want to shake loose my heater with low bass. I might have to just pick one luxury.
B
Hell, I'd go for the base - You can always add more hot water...........(-:
My palm reader says tarrot cards are a crock
You might want to consider coupling the high end into the water, too -- ultrasonic cleaning....
;-)
-- J.S.
> I can do a cathedral ceiling. Should I?
Absolutely not. Avoid any concave curved surface like the plague. They reflect sound to a focal point. That can put the ratio of direct to reflected sound upside down. We had to shoot in a Greek Orthodox church once that had a ceiling like that, and ended up looping the whole scene. The church had a PA system with little speakers all over the place, because there was no other way you could understand what was being said under that reflective vault. (and not because it was in Greek ....;-) )
For recording, you want a relatively "dead" room -- one with mostly absorbtive surfaces, and non-parallel surfaces. In particular you'll notice that the big glass booth windows are generally angled way down. That's because you want to record the music, not the room. Reflective surfaces and the distances between them are what give a room its character. There's something strangely depressing about an acoustically dead space, which is why it's called "dead" rather than "clean" or "pure" or something like that. So, you want some reflective surfaces, which is what makes things tricky.
Try going to a variety of acoustic spaces -- an open field, a small bathroom, an underground parking garage -- and in each one clap your hands loudly once, and listen to the sound as it bounces around (or doesn't). Try different places in each space, and see how they differ. Sound travels at a bit over 700 MPH, so larger spaces mean longer echo paths, and longer delays. Some rooms have more variation from place to place than others. For instance, the little Foley stage we built about five years ago is extremely quirky in that way. They've got it mapped out, and set up different effects in particular places depending on the acoustic quirks of the room.
Acoustics is a vast and difficult subject, so difficult that even major concert halls are sometimes so f***ed up when they're first completed that they need major re-work. And artists treasure the ones that got lucky and came out sounding good.
-- J.S.
Hi, John-
Excellent posts. Another source for help with acoustics for the piano room would be to check with a high-end audio store (NOT a big box) for someone on staff. Perhaps easier and less $$$$ than an acoustic engineer.
You're so right about how the acoustics will make or break a concert hall, for the performers as well as the audience. Yes, been some big faux pas happen. Opera performance is particularly demanding in terms of the venue's acoustic quality. The last thing in the world you would ever see is operatic voice enhanced with microphones/amplification, at least for purists, which is what opera inherently is. The hall must adequately support the voice, with no coloration or distracting reverberation. Engineers are paid a lot of money to sweat these details in concert hall design.
Ken Hill