Reading an inductance plot

[arc2v]

Attached is an inductance plot of one of my dayton drivers. http://www.partsexpress.com/pe/showd...number=295-366


Overall shape looks good except for two things. Something weird by the peak and a little bump at 1800 Hz.

I've seen people identify potential problems from these. What am I looking for? Are the bumps from breakup, distortion, or something else?

Measurement was done in Speaker Workshop using an MLS signal.

I plan on trying to repeat the measurement tonight, as well as do the second driver I have of the same type. I'll overlay the "ideal" response as well.

All help appreciated!
AC

[Svante]

Originally posted by arc2v
Attached is an inductance plot of one of my dayton drivers. http://www.partsexpress.com/pe/showd...number=295-366


Overall shape looks good except for two things. Something weird by the peak and a little bump at 1800 Hz.

I've seen people identify potential problems from these. What am I looking for? Are the bumps from breakup, distortion, or something else?

Measurement was done in Speaker Workshop using an MLS signal.

I plan on trying to repeat the measurement tonight, as well as do the second driver I have of the same type. I'll overlay the "ideal" response as well.

All help appreciated!
AC

I suppose you mean an impedance plot?

I don't see the attachment though, but a nudge in the impedance curve at such a high frequency usually means that there is a cone break-up there. Mostly, but not always, this means that the driver should not be used at those frequencies.

[arc2v]

DOH! You are right. My coffee had not kicked in yet this morning when I typed that message.

Impedance, that's what kind of plot it was.

That follows that the breakup is starting there.

I had the crossover there before I tested it (thinking that it could play higher without distorting). It sounded great everywhere except right at the crossover where it got that ultra-harsh sound. But only at that exact frequency. When breaking in the speakers I could listen for an hour to music and not hear the effect at all, then one note or voice hit right there and OUCH!

It did not seem to attach so I'm trying again.


Also, moderators, if one of you could change inductance to impedance in the subject, I'd appreciate it. Thanks.