Didn't have time until yesterday to test. BUT, -- so far it is amazing!! Fats Waller's "Clarinet Marmalade" with Hammond organ (Bluebird c. 1938) was a great test. Plenty of shellac rumble, but Fats used the Hammond foot pedals and the bass goes down to about 30-35 Hz. Setting your unit on 25 Hz worked perfectly. More A/B tests to do, but I stand seriously impressed! When you remove the sub bass rumble (I like the 25 Hz setting), low frequencies come alive.

Clean, transparent, quiet. The volume difference between input and output is inaudible on mt system. The filter curves are great.

Don H., Jersey City, NJ
June 2010, via email.