Okay! Testing done!
(Technically not done at 1W, but was done at 1M from baffle to mic)
I ran 4 sweeps in total: 2 as OB, 2 with the back cup mod.
Sweeps were done, on axis, 500-20,000 Hz using REW with 1/24 smoothing.
Here's the test baffle/waveguide, with a dynamat product on the back to reduce resonance of the plastic.
Deep cup results:
Red: Stock Neo3 Orange: GRS-3
Green: Stock Neo3 Blue: GRS-3
I'm honestly impressed, they both measure well. And quiet consistently to one another, esp in their OB/dipole config!
Tho I would say that the Neo3 does fare better in the deep cup tests, but for OB the GRS-3 doesn't appear to be a bad option, and can easily get you down to 900HZ
In the sweep, there are other minor sweeps near the end, where I would say that the Neo3 does sound clearer imo, but the difference is pretty minor, and for the price is a pretty nice way to go.