Below 20 HZ Notes/Instruments

You might want to check out this list of "Top 30 Bass CD's"

http://www.oakland.edu/~djcarlst/basscds.htm

Even if you cross over at 21 Hz you will still tend to blurr the imact of the SC-V's on music. The ears sensitivity increases enormously as the tone goes from 21 to 42 to 63 to 84 based on the Fletche Munson curves. This effect will be magnified by half wave length standing wave room modes.

You didn't say what kind of room treatment and placement you have but it also takes very careful placement to not just load the room. I used a RTA to first position the speakers and then the Sigtech to align them for very smooth low bass. You can easily ear the difference on good organ and electronica recordings.

If you just want the explosions to jolt your house, these niceties don't really matter

I also own SC-V's. I listen to a fair amount of organ and electronica which are the only instruments with fundamentals below 27Hz. I use a Sigtech and with a realtime analyzer measure my Sigtech corrected Dunlavy's flat to 22 Hz with very decent output at 16Hz due to room placement. (Try the Dutoit recording of the Pines of Rome with a 16HZ pedal on the final track).

I've tried several Subs and have found that they detract from the Dunlavy's for music reproduction. I only use mine when we set up the room for dance.

I'll dig out another list of low bass CD's that I only have on paper. As for acoustic instruments it is pretty much a few pipe organs to 16HZ. The extended double bass and contrabassoon bottom at 27Hz. However the big Bosendorfer grand piano has a unique musical "rumble" below 32Hz due to resonating strings tuned below the end of the keyboard. A few years ago I had the chance to use an RTA on one and there was a fair amount of sound in the 16-32 HZ range but not enough to require any kind of sub woofer on top of the Dunlavy SC-V's

Lots of electronica these days has sub sonic electronic drums

Here is the list. I got it from Dr. Hsu of Hsu Subwoofers.

Telarc CD88097 Michael Murray at the Organ in Davis Symphony Hall

Telarc CD80146 Star Tracks II

Philips 412 619 Saint Saens Organ Symphony (16 Hz instead of the usual 32 HZ)

Dorain 90117 Mussorgsky’s Pictures at an Exhibition played by Guillou on the Tonhalle Organ. A must (19Hz)

London 410 164 Prokofiev Alexander Nevsky. Cleveland, Chailly. Bass drum at around 25Hz

Argo 417 159 Hindemith Organ Works, Argo 414 420 Mendelssohn Organ works. Peter Huford. Very loud 19Hz notes!

London 410 145 Respighi Pines of Rome. Dutiot, Montreal 22Hz organ pedal in the Pines along the Appian Way.

RR 58 Pomp and Pipes Tracks 4 and 9 sub 20Hz

Laser Light15 Virgil Fox Franck’s Piece Heroique. Sub 20 Hz