size and shape

[Don Mannino]

Gregory,

The full name is "Anechoic Chamber."  Kawai has a very large one in Japan (as does Yamaha, I'm sure!).

You can demonstrate very easily how the acoustics of a room interfere with sound and affect the volume. Hook up a tone source to your stereo, turn the balance knob all the way to one extreme or another, and play the tone through the one speaker. Now move around the room - the volume changes dramatically as your head passes through areas of wave cancellation or reinforcement. Higher frequencies have smaller distances between dead spots, and reverberant rooms have wider variations in volume than absorbent rooms.

When you consider the affect of the room acoustics on a single frequency coming from a small source, then you will see why an anechoic chamber is the only accurate way to study complex sound coming out of a piano.

I have heard of sound analysis software for computers which attempt to factor out room acoustics - but I don't believe they are really that good at it. The last name I heard for it was the initials MLSS.

Some Universities have anechoic rooms that can be used if you know the right people (like the school piano technician?). The biggest problem you might have is making sure the floor will support a piano - the floor is made from wire mesh, with sound absorbent panels below, so most anechoic chambers will not support a piano, and placing plywood on the floor would greatly affect the sound.

Good luck!

Don Mannino RPT


> >I have designed a very detailed study but need some assistance, in
> >understanding what I may get first.
> >
> >1. Using the PianoDsic system, I can nearly completely 
> control the volume of
> >each note, by ear.
> >
> >2. Drawing a radius around the piano, I can place the digital decibel
> meter on
> >the radius and monitor changes in volume of the piano.
> >
> >Question: what room "type" would be best suited for study?
> >			A. size
> >			b. shape
> >Is there a room with known, proven characteristics to rule out room
> acoustics?
> >
> >I did some work for CBS when they owned Steinway, did a tuning in a
> >room...well it was like being in space.
> >
> >Hey anyone need a spare tin foil hat?
> >
> >Gregory