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.