Ok, so I spent some time this weekend installing aura bass shakers on my new Pembroke seats. I learned from
's install of buttkickers in his HTMarket seats (here
) that I needed to have the rubber isolation feet so I copied and ordered the same Penn-Elcom 2.5" diameter rubber feet from parts express link here
. This is an important requirement for the rest of my install guide not just for the isolation but because it raises the chairs a bit more than the original feet. We will need this extra height.
The Pembrokes (and presumably other HTMarket seats) have a wooden section on the seatback down near the floor. On the bottom of this seat section is the velcro for attaching the backflap of the seat. Some users have mounted the bass shakers to the outside of this wooden section. While this location would work just fine from a shaker perspective, I felt it was a poor location because the back flap cannot close properly and someone could hit the shakers walking by the back of the seat. This meant I wanted to install the shakers on the inside of the seat. Unfortunately the inside of the seat isn't a solid vertical surface. While it seems like the Aura's could mount here access to screw them down would be difficult and screwing into what I believe is 1/2" wood, it might that vertical placement would be very limited. I decided to mount the shakers to their own board, and devise an easier access method of attaching this new board to the existing structure. You can see what I've down in this rendering. The gray tone boards are what comes with the chair and then the wood/yellow toned board is the board I've added.
I decided to make my shaker board a little taller (vertically) than what comes with the chair so that I can shift the aura's lower to the ground. I found that with someone in the chair that there is very little clearance above the top of the wooden section to clear a bass shaker. Luckily, due the Penn-Elcom rubber isolation feet I had clearance at the bottom of the chair. So having this extra mounting height and with the shaker board mounted offset in the chair, and with the shakers mounted offset on the board, clearance is no concern. You can see that offset in this image.
To attach the shaker board to the chair I simply used L-brackets and drywall screws. For the bottom attachment on the bottom side I used some 1/2" spacers. I probably went overkill some on the number of brackets but the results is a very rigid and secure mounting. I don't believe any vibration energy is lost in the mounting and that it all transfers to the chair.
I put two shakers on each chair and there is room for a 3rd. There is not room for a 4th. Two are plenty of output I believe, but the auras do not have a flat response. In and around the mid-30 Hz there is a dip in output. A 3rd shaker would give headroom to EQ down to flatten the response. You may notice that I did not center the 2 shakers on the chair and that they are offset to the side. This is because I learned on my first seat that I installed on that if you keep it away from the arm of the chair, you get less rattle in the cupholder. The vibration in the chair does not feel offcenter to me, and I preferred this over hear the cupholder in the arm chair rattle a bit.