Questions about my Dual Showman 15" JBLs

[Hamilton]

In '70 I saw Jack Cassidy with Jefferson Airplane use two Dual Showman Reverbs with his Guild bass and the tone was jaw dropping.

[hardtime]

I used D130Fs in homemade Showman cabnets seven nights a week for years (bought them in 1962), they are still perfect. Those gummy edges really worked.
I thought I would update with 140s, it all also required an amp about 4 times larger for about the same output. Check the the output of the two and you will see why.