My FR driver is 8" size, I have till now simulated over 7 woofers of 12", 15" and 18" including eminence, seas, Ahuja using Basta, but none of them have a better response on the low end compared to this Soviet era driver based on published data.
This intrigued me a lot and I want to discover if it's really true and hence building one. I will be following a minimalist approach for this as I don't have much h building experience with OBs. Will be fully trusting the simulator as of now.
I do have a pair of Bolton 10" woofers with me, but their SPL is suite low.
I don't have much personal experience with OB outside of hearing some but I also would second what Shafic says. 8 inch wide bander is unlikely to give satisfactory bass weight in an OB. My limited understanding is one needs something larger like 12" woofer with sufficiently high Qts of at least 0.7 to work in OB, to work along with the wide band driver.
Do check out this thread.