Dave's Speaker Pages
Raw Measurements - Tweeters
Measurement Dates as Indicated on Graphs
The measurement pages available here are provided as representative examples of raw drivers that are (or were) readily available to the DIY hobbyist, with a few exceptions such as my hybrid tweeters. They are quasi-anechoic SPL measurements taken on a large flat baffle with accompanying impedance measurements that were mostly taken unmounted. Each driver has a downloadable set of measurements for SPL and impedance beside the graph. These contain only the on-axis response for SPL and free air measurements for impedance.
Details of my test/measurement hardware and software can be found here.