The ButtKicker unit has been reviewed by many publications, including ours. It is a great product, no question.
The original product was big and weighed 16 pounds. Although it has since been lightened to 11 pounds (renamed the LFE), it's still pretty heavy. The reason is the steel cylinder inside that does the shaking. It's heavy too, since a reasonable mass is required to shake a chair, with one of us sitting in it.
The main problem with such a big heavy shaker is that it can be difficult to find enough room inside a chair or couch to mount it.
Guitammer has solved that problem with the introduction of the LFE Kit. The kit includes the LFE shaker, an 1,100 watt power amplifier to drive it, associated cables, and a mounting platform that holds the shaker on one end, with a couch or chair leg sitting on the other end.
To install the kit, you mount the LFE shaker on the platform (bottom right corner of the photo above), using the included bolts. The LFE sits on the end with the hole. At the other end of the platform, there is a round rubber pad. This is where the couch leg goes. I found that the shaker is so powerful, it is necessary to place the leg of the couch as close to the end of the pad nearest the shaker. Otherwise, the platform would flex and rap on the floor.
The platform has rubber isolation feet on the bottom, and there are additional rubber feet (supplied) that go under the other three couch legs. This keeps the couch level.
The processor subwoofer output is fed to the power amplifier, using the included Y connector to split the signal (so you can supply your subwoofer as well as the shaker with one subwoofer-out), and the power amplifier output is connected to the shaker. The original ButtKicker had bare wire termination. The LFE has jacks that accept spade lugs. The included cable has bananas on one end and spades on the other.
Most people have their couch across the room from the hi-fi rack, so you would need a long RCA cable to connect the sub-out on the processor to the shaker power amplifier input. We also had on hand the new ButtKicker RF Link, which provides a wireless connection for shakers and subwoofers. I used the RF Link for the LFE Kit, and it worked perfectly. No ground loop hum and no long RCA cable to put under the rug.
The LFE shaker and amplifier combo had more than enough power to shake the entire couch. I found that I only needed to turn the amplifier volume control up about 1/3 of the way to get a completely satisfying effect. Now the word "satisfying" is a subjective thing that will be different for everyone. But to put it in perspective, I have four Velodyne 18" servo subwoofers in my home theater, and I love deep powerful bass. So, I can't imagine that anyone would not find the LFE to deliver enough tactile sensations in their movie experiences.
I invited some neighbors over to watch Amadeus, and I did not tell them the shaker was attached to the couch on which they were sitting. You should have seen their faces at the opening scenes of the movie, which has very intense music.
Of course, the most fun will be had with action films, such as Pearl Harbor, and just about anything with Schwarzenegger or Stallone.
The amplifier is rated into 2 Ohms, so you can add a second shaker at the other end of the couch if you like, both powered by the one amplifier.
Lastly, again, I can't say enough about that RF Link. It is one of the coolest accessories to come along in years.
For those consumers who wanted to buy a ButtKicker shaker but could not figure out a way of attaching it to their couch or chair, the problem is solved with the LFE Kit. For $599 (this is less than the price of the original ButtKicker), you get everything you need to move your home theater pleasure to a new level.