I just chatted with the guy selling these 2 single 15". http://cgi.ebay.com/Bass-Speakers-2...ageNameZWDVWQQrdZ1QQcmdZViewItem#ht_500wt_975 From what I understand, they are 8 ohms each. He is local and I could buy a bass from him as well. I am under the impression that he is underpricing them badly. I have 2 options: buy and flip, or tell him.
The SROs date to the late '60s-early '70s. They had very limited excursion and, while great guitar drivers, weren't much on bass, even by 60's standards, being seriously outclassed by the JBL K/E140 and Altec 421. I'd pass.