| A measurement question? [message #756] |
Fri, 20 August 2004 05:25  |
wunhuanglo
Messages: 912
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
|
Is running a fixed frequency through a loudspeaker and measuring amplitudes (or relative amplitudes) at the harmonic intervals an appropriate way to assess speaker performance? Specifically, I'm wondering if I can appropriatley assess the second harmonic "distortion" of a dipole by feeding the speaker say 50 Hz at 80 dB and measuring the level at 100 Hz? Is it that simple?
|
|
|
|
|
|
|
|
| Re: Harmonic distortion Thanks! A follow-up, please? [message #759 is a reply to message #758] |
Sat, 21 August 2004 00:51  |
Mike.e
Messages: 471
Registered: May 2009
|
Illuminati (1st Degree) |
|
|
Check in your local library for audio technical books.I had one with a picture of the B&W Re % and db,no because db are log scale.
"Distortion is higher at 20 Hz than at 30 Hz even though the displacement is the same. This is a curious result. The fundamental drops 40log(30/20) = 7 dB, as expected. The 2nd and 3rd harmonics, though, remain at nearly the same sound level, as the voice coil swings through the same range for each of the excursion dependent non-linear parameters. Thus the distortion percentage increases"
-I dont think so-
|
|
|
|
|
|
| Thanks, mike [message #761 is a reply to message #760] |
Sat, 21 August 2004 06:34 |
wunhuanglo
Messages: 912
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
|
I probably would have remembered about the log relationship somewhere in the 22nd century; thanks for the reminder. I had downloaded a copy of Speaker Workshop some time ago but never got around to exploring it. Guess I will now. Thanks again.
|
|
|
|
Posting Rules
Members
Search
Help
Register
Login
Get a T-Shirt!
