Variable tension apparatus for transducer analysis

[thadman]

I'm interested in building a ribbon loudspeaker in my free time over Christmas break and would like to drive it directly. Following the resolution of some meetings with faculty in the engineering department, I might be able to gain access to the Universities Laser Vibrometer and Anechoic chamber for measurements (and comparison with the RAAL 140-15D).

I've conducted significant research within the AES E-Library as well as my Universities research library with regards to ribbon transducers. Only a few articles have been published, and of those, very little research regarding the behavior of the membrane was conducted.

Assuming I can get access to the Universities measurement equipment, I'd like to do testing on a variety of transducer alignments, specifically low and high compliance membranes.

Haphazardly clamping the membrane does not appear to possess the rigor necessary for a scientific analysis of transducer behavior.

To achieve an accurate correlation between experimental and simulated results, it will be necessary to apply a very specific, measurable force at the ends of the membrane.

I'm not sure how/where to build/purchase/acquire access to such a specific machine...or even what to google. If any users could provide help with regards to the aforementioned topic, I would be very appreciative.

Thanks,
Thadman

[skeptic43]

You might try looking into tensile testing equipment like that made by Instron
http://www.instron.us/wa/product/330...g-Systems.aspx

They and others can measure very small stress and strains on strips of materials down to very low levels.

A tweeter ribbon is a narrow long strip of matal.