Measure Clamp Concept Implementation

Loudspeaker Impedance Measurement Stand/Clamp

We all (should) know that it is better to measure the Thiele/Small (T/S) parameters of a speaker ourselves, rather than rely on manufacturer specs which deviate from a little to "are you kiddin' me?".

By collecting the speaker's varying impedence over a frequency range, we can calculate many of the required parameters. The clamp I have built is simply an attempt to hold the driver firmly while the impedence measurement is carried out. The aim is to minimise reflections and reduce vibrations that can affect the accuracy of the measurement.

Conceptual Design / Requirements

  • Must be rigid to prevent movement of the driver during measurement
  • Must hold the driver 3 feet in the air
  • Must have a clear path around the driver to reduce reflections
  • Must firmly hold up to a 12" driver

This was the first conceptual design, scrapped for being overly complicated. Since my plan involved using mild steel, I did not want anything to carry the magnetic flux away from the driver motor by gripping it. I could have used rubber, or wood for the grip, but I also wanted the clamp to firmly hold up to a 12" driver, and I didn't think this clamp would do it well.

Cenceptual design 2. Use the basket to hold the driver, that's what it's there for! Nothing touching the magnet, and looks like it will firmly hold large drivers too.

Copyright © 2006 Vikash Chauhan. All rights reserved.