Knowing very little about the physics of sound, does using a thinner
tube as opposed to a larger diameter one, make the tube have a
narrower " bandwidth " ?
See: http://www.fonema.se/qpipe/qpipe.htm
Since the primary loss component of an "organ pipe" is friction along
the wall, a larger diameter tube will have lower losses and thus higher
"Q".
73,
... Joe, W4TV
On 2/20/2017 9:51 PM, Dean L wrote:
This whole topic is very interesting to me. Very ironically, just before
this topic got started, I was thinking about qrp hall of famer, Rick
Littlefield's, Ham Radio magazine article Mar 89', featuring a resonant cw
speaker.
It was built using a solo 16 cup and a small 700hz transducer.
I put it on my to do list, back in 89'... nearly 28 years later I FINALLY
sent Rick an email asking if he still had any of these little speakers
left, after so many years... A few days later I had a package from Rick
with a couple of the little speakers!
The generosity of old school hams never ceases to amaze me.
I have a question for those in the "know"--
Knowing very little about the physics of sound, does using a thinner tube
as opposed to a larger diameter one, make the tube have a narrower "
bandwidth " ?
How would on increase the Q of the device ( if that's even possible)?
I'd appreciate any input. TIA
72
Dean/K2WW
On Feb 18, 2017 8:09 AM, "jrquark" <[email protected]> wrote:
The confusion here is a common one, closed vs open ended resonators,
especially if one looks at the poorly explained graphs in most physics
texts.
The speaker, attached to one end of the pipe, is not the closed end, it is
open, since it drives the air particles at that end, and that makes it a
displacement antinode, where the particle displacement is maximum.
Jim - K7BIE
On Feb 17, 2017, at 9:43 PM, Joe Subich, W4TV <[email protected]> wrote:
A cylinder with a speaker in one end and open in the other is an "open"
cylinder (open pipe). It is a *half wave* in air which means the
formula uses 2f instead of f.
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