I recently grabbed a bunch of inexpensive 1.75" VC 1" exit compression drivers to test. Thought I would post some frequency response sweeps on the SEOS-15 others can see the basic response shape of the driver on that waveguide. Waveguide was unmounted, pretty much I set the CD on the floor pointing up dropped the waveguide on it and took sweep. Mic was semi nearfield, about 1-1.5' above waveguide. In a baffle you might see some change in the shape of the low end <1.5k but everything else should stay relatively close. SPL is not calibrated so don't use the measured as actual sensitivity, however the sweeps were level matched so you can compare relative levels between the different drivers. (1/24th octave smoothing) First DNA-360 as a reference ($79.50): PRV D280Ti-B ($39.99), Quit smooth above 2k, not sure what's up with that dip at 1k. I pulled it apart filed smooth the phase plug, added foam behind diaphragm, no change. Selenium D220TI-OMF-8 ($49.99) Dayton D250P-8 ($49.85) Dayton D250T-8 ($49.85)