How to install bass shakers (aka buttkickers) without screwing into your couch

Mikorist · Januar 7, 2012

So I have always wanted to give bass shakers a try, in my apartment it just makes sense, plus it sounds like a cool idea. However, the couch isn't mine, and by that I mean If I so much as put a single screw hole in the bottom of the couch my girlfriend will murder me. So I came up with the idea of a tension based brace. Similar to an adjustable shower rod I concocted this brace using the following materials all found at your local home repair warehouse:

[*]1 2inx6inx8ft piece of lumber (I bought pine but whatever is cheap should work) Depending on the size of the couch you may need a longer 2x6

[*]1 pack of bulk felt furniture padding

[*]2 3 in x 3/8 threaded rods

[*]6 3/8in bolts

[*]4 3/8in washers

[*]1 3/8 in whole saw

[*]drill

[*]saw

[*]2 bass shakers

[*]14 ga speaker wire

Optional

[*]2 3/4in whole saw

[*]speaker terminal

The first step is to measure the distance between the inside edges of the couch. Next you will need to cut off a 2in section of the board to act as the mobile side of the tensioning device (the small piece of wood). You will need to account for this piece of wood, the additional distance caused by the threaded rod and by the felt padding. I hat to cut the main board twice, I left extra the first time and then was able to measure the exact distance needed.

After cutting the wood to length, divide the small board in thirds length wise and in half height wise (see picture below),

where the lines cross is where you will need to drill the 3/8in hole. Use a piece of masking tape to mark off the depth of the drill bit and drill both holes 1.25in deep. Repeat this on the large board as well.

Next thread all 3 bolts onto a threaded rod and place a washer on each end. Place this setup in between the two holes you drilled in the boards and repeat. The final setup is shown below.

You can now use the bolts to extend the size of the opening, increasing the length of the board and creating a tight fit. Be sure to watch the edges of your couch for flexing, if you over tighten the board you could break the side board of your furniture. Once the board is tight you can add on the bass shakers.

If your couch has cross braces that now meet up with your adjustable brace, this is where I mounted my bass shakers, I will have to move them around and test the best location but this seemed like a good place to start. I used the tip of the 3/8 whole saw to start the screw holes after marking them with a pencil and using the bass shaker as a template.

As I am just testing the location, I temporarily held the speaker wires together by twisting them and covering them in electrical tape. Once I find the optimum position I will use butt splices and staples to secure the wire. I have my bass shakers ran in series, as they are each 4 Ohm, running two in series will create a 8 Ohm load on my amplifier, which is the recommended amount for my model. see the image below for my wiring setup.

Once you have the bass shakers wired up you will need to wire up the audio source. You have two options and both require a mono RCA cable (subwoofer, digital coaxial or composite video will work as well). You will also need a RCA Y-adapter with one female jack and 2 male plugs.

If your receiver has a "zone-2" you can setup the bass shakers without even buying another amp. All you need to do is pick a source (I used Cable/Sat) plug the two rca jacks from the y adapter into the input, and plug the single end into your subwoofer plug. (My receiver has 2 subwoofer plugs, if yours does not you will need a male to 2 female rca adapter)

You can see the Y-adapter (grey monster cable) is plugged into an input, and the black braided single RCA cable is plugged into the subwoofer output. You then need to select "Zone-2" on your remote and set it to listen to the input you have selected. For initial setup you should set the speakers to a normal listening volume and adjust the "zone-2" volume to control the bass shakers alone. After the initial setup, changes in volume will affect you speakers, subwoofer and bass shakers, keeping the ratio of shake to noise locked in.

After I find the sweet spot for both the adjustable board and the bass shakers on the board (I might try bridging the couch width wise) I plan on painting the board to match the couch, adding a speaker terminal that can accept banana plugs, and routing the wires above the board so they are out of sight.

I adjusted the location of the cross brace today (It was all the way against the back of the couch). I moved the brace to the very middle of the couch and WOW what a difference. I also tightened the bolts more then before. Before, you could only feel the "shake" in the most bass intensive scenes. Now you can feel the bass in the soundtrack, in the blades of a helicopter, etc. I also adjusted the volume of my subwoofer and turned it up just a little, I think hearing the bass makes the shaking sensation feel more natural. And finally I set the crossover on my receiver to 90hz, (up from 80hz) and turned down the actual subwoofer to 80hz. (I tried setting the receiver to 100hz as well but there was too much shaking going on.

After using this setup for a few weeks now, I can say it was one of the best investments I have made. It was not expensive, it did not take long to make, and most importantly, I can watch movies with the bass shakers on high and the sub on low, without bothering my neighbors.

I went into this project to invent a way to make the bass shakers comparable to the Butt Kicker LFE kit, which includes an isolation foot mount for the shaker, which allows for installation without putting a single screw into the couch. I think I found the answer.

Here is what the final outcome was:

The first step I took to make the brace look better was to cut the 2 3/4 inch hole for the speaker terminal. I chose to place the hole in the side away form the brace to reduce the stress on the main board, and because I thought it was aesthetically pleasing

I wish I had taken the time to sand the board and then apply a coat of primer... but I didn't.

After cutting the hole for the speaker terminal I applied a single coat of Krylon "Leather Brown" satin paint.

After the paint dried, I installed the speaker terminal which involved four screws and very little effort.

(The dog wanted his toys in the photos)

I then slid some 1/4in heat shrink over the speaker cable leads coming out of the bass shaker, and shrunk the shrink with a hairdryer.

I used the 3/8 in hole saw to make two holes right next the location where the shakers were to be installed, I used 2 RG-6 Feed-Through Bushings (which I accidently purchased 50 of instead of 5 (they were $.99, but didn’t state that was the price for a 10-pack) If you want any of the bushings contact me and you can have them for the cost of shipping.

Once I tapped the bushings in the hole, I screwed down the bass shaker:

Then came the re-wiring, I still wired the shakers in series, but made sure to tidy up the cables. I started out at the speaker terminal, and used nail in cable clamps to keep the speaker cable inline.