The classic spot to first use a tactile transducer, or bass shaker, on a racing simulator is directly under the seat. Most third-party tactile feedback software packages however can support multiple output channels with the ability to send different “data” to each channel. Two supplementarily locations to mount a transducer are directly behind the seat or directly under the pedals. Either or both of these additions can greatly enhance immersion, and depending of the Sim or feedback software, improve your lap times.
Rear Seat mount:
Mounting to the rear of the seat is an option if you have a hard shell type seat made from resin or fibreglass type material. You’ll need a stiff seat shell to be able to transmit the vibration to your body, rather than getting lost in the seat itself. Additionally, the goal should be to locate the transducer as close as practical to the “edge” where the seat-back and seat-bottom meet, this will be stiffest location of the shell and better transmit the vibrations into the seat shell. In the picture below you can see the use of a Clark Synthesis TST329 Gold Transducer mounted in this fashion.
When configuring the output to the Rear Seat transducer this is a great location to turn on “gear change” impacts as you’ll really feel in throughout your butt and spine. For the TST329 I have found that ~80Hz works well as it is fairly “rapid” and still has high energy. This is also a great spot to utilize engine vibrations, especially if you already use them under your seat, as you can set up engine “harmonics” between the two transducers – this takes a bit of time tweaking but really improves immersion.
Mounting to the pedals directly is not typically possible, but rather you would mount to the deck plate that the pedals are mounted on. A metal deck would be ideal but a plywood deckplate would work as well. In the picture below a TST239 Silver Transducer is installed under the pedals and directly to the supporting metal deckplate. This is a very stiff arrangement and the higher power Gold Transducer was deemed overkill for this application.
Your feet are surprisingly good at sensing vibrations. If your software supports road texture or bumps this is a good location to send that data. As the front the wheels would be the first part of the vehicle to the “see” the texture/bumps it is natural for your brain to first expect the input at your feet (front). This is also a great location to map braking lock-up (or pre-lock-up) if your software supports that output. As your braking foot will be applying pressure directly to the brake pedal during lock-up, the vibrations will find their way directly into your braking foot!
Comments on transducer choice:
You will notice in both applications discussed above that more than one “data” stream/type was being sent to each transducer. It should also be noted that gear impact and road bump data are typically discrete high energy output, while engine vibrations are generally low impact, but sustained continuous vibrations. My experience with many different transducers types/brands over the years has been that while the high wattage “bass-shaker” type transducers work ok for impact type situations, they lack fidelity/precision for other feedback (i.e. brake lock-up). While the low power (~50W) type foreign transducers can sometimes handle the fidelity/precision, they cannot be used for high energy feedback, as doing so will overheat or permanently damaged quickly. The Clark Synthesis transducers chosen for this application were selected specifically for their ability to both handle high impact as well as fidelity/precision and sustained vibrations without overheating.