Product Review - ButtKicker Low Frequency Shaker - February, 2000

John E. Johnson, Jr.

Introduction

Have you ever noticed that most product names don't really tell you what the products are, let alone what they do? When Secrets was at this year's CES in Las Vegas, our booth was just down the corridor from another booth that was rocking and rolling with "Apollo 13" demos all day. One afternoon, I became very curious as to what they were selling. The booth itself was no larger than ours (10' x 10'), and there was a big screen TV and a couch that was sitting on a platform. When I stood on the platform to see what was going on, I felt a surge of low frequency energy. I was experiencing the ButtKicker, a name that says what it is and what it does.

Behind the couch, mounted to the platform, was the unit itself, a 7" x 7" football-shaped device. However, you would not want to try kicking a field goal with this football, as it is solid metal, weighing in at 16 pounds. I sat on the couch for a few minutes and watched the movies, feeling like I was in an amusement park ride. In fact, the ButtKicker has been used in amusement parks for quite a while. It is just now being marketed for home use. I was so impressed with the new sensation for home theater, I asked Mike Holliday (Home Theater Sales Manager for ButtKicker) if I could get one for review. He said, "Sure," and handed me one to take home.

Hardware

While other brands of shakers use a voice coil, the ButtKicker uses a magnetic steel piston that is suspended in a chamber surrounded by an electromagnet. Since the piston weighs 3 pounds (voice coil systems weigh much less), it takes a very powerful amplifier to drive the unit. In fact, the specs say 350 watt minimum, and it has to be an amplifier that will handle 4 Ohms. Not only that, but one is asking the amplifier to output mainly low frequencies with all that power. So, what kind of an amplifier should you use? Mike Holliday suggested something like the Carvin series of touring amplifiers that are used by rock and roll bands in concerts. They are powerful, they are made for low impedance drivers, and they are not very expensive. I chose the Carvin DCM2000, a two-channel power amplifier, which will deliver 2,000 watts into 4 Ohms when bridged. If you buy it at the same time with the ButtKicker, they will sell the DCM2000 to you for $557.95 plus shipping. Direct from Carvin, it is $619.95 plus shipping ($1,295 list). You will need an RCA-Phone Plug adapter, since the Carvin does not have RCA inputs.

The ButtKicker was too big to mount inside my Lazy Boy recliner, and I also wanted to be able to use it with my couch, so I bought a 24" x 48" x 3/4" pressboard, covered with white Melamine. This gave me a surface that looks nice and would let me put my recliner on top of it, and I can slide it under one end of my couch. The 24" circular recliner platform fits perfectly on the board (see photo below).

I placed the ButtKicker at the rear of the board and my recliner on the front. I positioned the kicker so that I could rotate the chair as much as possible without hitting the kicker. Then, I marked the spots for drilling inside the mounting brackets. The bracket holes will not fit 1/4" bolts, so you have to use some that are slightly smaller. In this case, I used some that were 1" in length. With countersinking on the underside, this allowed me to keep the nuts on the underside within the 3/4" thickness so that they would not protrude.

I attached a set of banana plug/jacks to the two 12" wires that exit the kicker. This lets me run the cable (14 gauge) from the amplifier to wherever the kicker is being used in the room, connecting to it with banana plugs. If I had run it under the rug, I would have been limited to putting the kicker wherever the cable came out of the rug. When I am not using the kicker, I just put the cable on top of the Carvin amplifier.

I decided that what I really was interested in was to have the shaker operate in the subterranean area, so I connected the subwoofer output from the receiver (using a Y connector for having the sub out also go to my subwoofer) to an Audio Control  Phase Coupled Activator (PCA). It is a $200 gadget that is just made for something like the ButtKicker. The PCA creates sub-harmonics, so if the input has a 40 Hz signal (typical action movies have this), the PCA creates a signal at 20 Hz. By turning the PCA level control most of the way up, the output has its sub-harmonics at a much higher level than the original signal. This way, I send mostly the really deep sub-harmonics to the ButtKicker, and I don't have someone's voice noticeably shaking my recliner.

I found that the subwoofer output from my receiver was just not enough to fully drive the Carvin, so I ended up using an old preamplifier (Parasound) to boost the voltage. The final circuit was Receiver Subwoofer Out - Phase Coupled Activator - Preamplifier - Carvin Power Amplifier - ButtKicker.

ButtKicking . . .

Although the Carvin will output 2,000 watts when bridged, I could get it to clip. This is testimony to the tremendous demands placed on it when driving the ButtKicker with the PCA and some heavy duty action movies. Taking the PCA out of the circuit will reduce the demand, because you won't have so many 20 Hz sounds, but I highly recommend using the PCA. It is really an awesome sensation when you have very low frequency signals shaking your chair. For example, I used the DTS version of "Daylight", and the scene where all the cars are crashing in the Lincoln tunnel made my heart race. Of course, that particular scene is one shake after another. For other movies, where the shake can be sudden, I was literally startled out of my seat.

If you have it cranked up all the way with a constant action movie, the ButtKicker will get pretty hot, and so will the amplifier. Don't even think about using an old receiver to drive the ButtKicker, as the receiver would just go into orbit. Remember, you are asking the amplifier to drive something that will lift the piston, the platform, the chair, and you, off the floor. It takes a lot of power to do that. The kicker does have a thermal protection circuit, so if it shuts down, put the Stallone film on pause, and go get some more popcorn while you wait for it to cool off. The Carvin has a noisy fan, but it is necessary when driving it hard, so you might have to put it behind the TV on the floor.

You can, if you wish, mount the ButtKicker sideways to give you earthquake sensations, but since California has plenty of these without adding some electronic ones, I decided to opt out here. I am just now getting over having nightmares from the 1989 quake that had cold sweat running down my face while I sat paralyzed with fear in my dining room.

Since DD and DTS are here, and we are all starting to get a little restless, we are asking, "OK, what now?" Well, here is the next thing to fire up a completely different part of your cerebral cortex. And you don't even have to waste time trying to figure out what it does after reading its name.

- John E. Johnson, Jr. -

� Copyright 2000 Secrets of Home Theater & High Fidelity
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