Testing time guys & gals....
Last evening I had a few hours to really put this stacked mass of drivers to the test and it passed with A+'s....
I cranked the gains to max on the amps (750 to 900 watts per sub cabinet). I pulled the stacked subwoofers about two feet from the inside corner of the walls to help with the radiation of the sound waves for optimal room gain.
I started out with a Telarc SACD of Michael Murray's Dupre-Franck-Widor organ music performance at St. Sulpice, France. I followed that with Eugene Ormandy's Philadelphia Orchesta with Michael Murray at the Organ at Syphony Hall, Boston, another Telarc SACD. The organ's low end is one of the lowest in the musical instrument scale and cranked up, my pants, shirt, and everything that wasn't glued or nailed down shook, and was as clean as it could be expected.
I went on to Frederick Fennell with the Cleveland Symphonic Winds. This SACD has a lot of march music and kettle drums. I wasn't disappointed with this one either. Very clean and crisp. The kettle drums sounded like they were in the living room.
I could have listened to it all night but had another one of my favs to check out......
How about Joe Satriani's Live in San Francisco...a small change in music format. I like most music except, rap, country(except for a couple of artists), and the new dance pop culture.
This is a two disc DVD set and I was again blown away with my low end and SPL. His performance was really cookin on disc one, and when we got to the fifth song, Borg Sex, the living room blew apart. It was an awe-inspiring "actual" reproduction of the concert. There are tons of low end bass in this song, and it went into a few other rifts with extremely low and clean bass.
I had to jump up and grab my rat shack SPL meter and at the subs, I was pegging about 118 db and in the center of the living room at the seating area, with the combined speaker arrangement I was listening to 120 dbs of pure clean music. My main Rotel amp/processer is a 100 watt high current model and it was set to 72 on the gain with more headroom. It goes up to 81 or 91 wide open. I also had the two QSC 1450 sub amps bridged and maxed out and never clipped, and a cheap KLH 100 watt amp for the center back B & W DM 303's.
With the Joe Satriani, and Michael Murray's performance, the bass was so good I don't know if you could have felt a transducer under your chair at the levels I was listening.
If I ever take on another subwoofer project, I'll again sacrifice the extra hundreds of dollars for the passive radiator design. It has it's own clean sound without the port noises I spoke of at the beginning of this thread and they deliver as promised.
Many, many thanks to Michael Grynick and his efforts to work with TC Sounds to produce such a fine performing driver with excellent follow up tech support and prompt emails.
Mike