My home theater room has carpet over concrete. While my dual SVS CS+ 20-39 powered by a Samson S1000 will hit 117 dB peaks, I could cause structural damage and permanent hearing loss before feeling much bass through the concrete floor. With two rows of three Visteon home theater seats mounted on a wood base (1st row) or platform (2nd row), I decided to add Aura Bass Shakers about two years ago. Ultimately, I had three 25 Watt bass shakers on each row connected in series and powered by a Rotel 980BX amp. The bass shakers were cheap to buy and easy to power (my original amp was a used Sony receiver bought for $35). They added impact to the home theater experience and great bang for the buck. However, with a resonant frequency of 42 Hertz, they have little impact below about 40 Hertz and have poor transient response. Recently, the upgrade bug struck in the form of two Buttkicker LFE shakers and the BKA 1000-4 amp. The Buttkickers are power hungry with 1000 watts needed to reach their potential. The amp Buttkicker offers is up to the challenge delivering 2000 watts into the 2 ohm load of two Buttkickers connected in parallel. The Buttkicker specifications are a significant step up from the Bass Shakers with a resonant frequency of 9 Hertz. They offer excellent transient response, response below 10 Hertz and much greater impact than the Bass Shakers. I have also confirmed that adding sections of an anti-fatigue rubber mat to decouple the theater seats from the floor improved performance, as was observed in the review at hometheaterhifi.com. The Buttkickers need more careful installation than Bass Shakers, as the large moving mass can introduce strange groans and other noises if the supporting structure is not up to the challenge. In addition, isolation of the structure being moved is much more important than with Bass Shakers. My Buttkicker installation was about three times the cost of my Bass Shakers set-up. Are Buttkickers worth it? They were to me. After three days with the Buttkickers, I have now removed the Bass Shakers from my installation and plan to sell these. The Bass Shakers remain a great value, are easy to install and in my opinion add more than 50% of the tactile experience offered by the Buttkicker.