@sobek can be digitally efficient, when he wants to be… 
I, on the other hand… 
You want the lemma for why he’s correct? 
I was just admiring this terrifying efficiency in communication. Why waste words or give more information than needed. 0 or 1? 1.
Testing, testing… Is this thing on…?
This was a test wav in the SimShaker module. Output at 100% and the amp at about 50-75%.
The black cushion is one of those 2” fitness pads. I use one in the SimBox seat, with a little latex foam ontop.
The amp is a bit noisy. Anything one can do about that? It’s not too bad. I can live with it. It’s not that high pitch whine of the JetSeat motors.
Now…where to put the pucks…? 
The amp noises, etc…I think its all just part of the sounds in the jet! Or perhaps use sound suppression headset?
Yeah, you’re not wrong.
Sitting in the cockpit at work is incredibly noisy, even with the engines off. The dead silence that occurs when we shut the external and battery power off gets me everytime…
Yeah, I said I was done with Sea Stories but this one is applicable…
On USS GUAM, steaming out in the Virginia Capes, in the middle of the night they suffered a lube oil leak down in engineering and had to shut the steam off to the main engine, which also cut it off to the SSTGs (steam turbine electrical generators). The EDGs (emergency diesel generators) didn’t kick in as they should have and the entire ship went literally cold and dark…or perhaps I should say cold dark and silent. All the ships noises-especially the ventilations fans-stopped.
I immediately woke up from a deep sleep and shouted to my roommate who was the Main Propulsion Assistant - the #2 engineer.
He answered back “I hear it” - meaning that he didn’t hear anything! 
Wow, betting it never even gets that quiet in port! I’d figure ventilators would at least be running on pierside power.
Absolutely. If you think about it, a navy ship is just a bunch of steel airtight/watertight rooms…without pretty much constant ventilation, you’d suffocate! 
What is the power of your amp, watts? Just curious. I’ve never heard an amp make that whining noise before, however, a) my amps are below 300w (single channel) and, b) haven’t had a stereo system in decades 
Huh, yeah I’ve no idea what that noise is.
160W each channel.
I did some testing of puck locations today.
I decided to put two in the lower back and two in a strap, beneath the seat cushion.
I cut holes in the alu cover of the seatback.
This position will have two of the the pucks vibrate directly against the lower back cushion.
That cushion is rather thick, but it is also compressed when I’m in the seat…
We’ll see how it goes.
I made a rubber strap for the lower pucks.
It’s the same material as the seat bottom itself.
I know the recommendations say to mount the pucks to the structure. The two rear pucks are mounted to the alu skin of the seat back, but that will flex some. Those pucks vibrate directly into the lower seat back cushion.
The lower seat pucks vibrate directly upwards into the bottom cushion.
Let’s test it and see how it works out…
Partial success…
Couldn’t feel the bottom pucks at all, but the lower rear pucks gave good vibes.
They ran quite hot though. Could it be because they vibrate directly against the seat cushion…?
So, maybe I’ll put two pucks in the upper seat back segment, as that seems to work well.
But I really would like vibrations from the bottom…
Maybe move the lower pucks to the thigh supports, per my initial idea…?
I have mine mounted directly to the mdf structure of my seat mount, no flex or give anywhere, and the vibrations transmit nicely through the seat cusions. I’m afraid mounting them on the alu skin will diminish the effects somewhat, as it will use the energy to flex the skin?
Edit: That seat is looking mighty good, nice work!
Yeah, probably, but those mounted on the skin were the ones I could feel.
The new ones are mounted to the structure via a 2mm alu plate. Very little flex in that one.
Trial and error is the name of the game… 
And half of the fun really 
Testing the new placement…
I dunno, guys…
I can hardly feel the thigh pucks, and if I turn up the power, so I can feel them, the whole frame starts resonating. One of the pucks starts ticking badly as well. I dropped one of them on the floor. Maybe that’s the one?
And all the pucks get really, really hot! So hot that I can’t touch them after a minute or two.
That can’t be right?
So, a resonating frame, noisy amp, hot pucks and hardly any vibration is the results after a few days of building and testing.
Right now it looks like this project goes the way of the JetSeat…
Edit.
What if I put the pucks in series? The Amp has 4ohms per channel. Two 8 ohm pucks in parallel is 4 ohm. Two 8 ohm pucks in series is 16 ohm. Would that help with the heat?
The pucks touch the cushions. Is this a problem? Should they operate in free air and only touch the frame at the mounting points?