Bass shakers have come down in cost over the years but still there a few models or newer models that are bit pricey for pre-made ones.
There is other option diy made ones as this has been talk for a few many years. Basically modifying a simple 6.5" or smaller speaker into a bass shaker that would give a same results. I have some spare ones to make some myself but got no way of really hiding them on my x6 Irwin rocker seats expect attached underside of the seat bucket.
Google main page links to diy bass shakers if anyone cares to try this and save a few £$-bob or two.
https://www.google.co.uk/search?q=jbl+control+series+list&ei=HGZBVYHqJIvaavDBgKAK#q=diy+bass+shakers+
If one has the same bass shaker transducer and providing each home owner had the same sofa/couch well maybe the two can standardize their shakers and agree with what ever film or music they are playing at same db level on AVR?
Also bass shakers are POWER EATERS like "Audrey II"
Feed me amp, feed me now. They'll eat the watts and get hotter and hotter until...
Next you'll have The Towering Fried Shaker.
I ran some sine wave must be around 25Hz 30Hz for a few minutes and the top of the Aura was getting warm like a radiator. Well at least they'll keep you're asses warm during the wintertime like car heater seats do. No really you'd need to run it to point of voice coil burning out due to exceeding each make/model normal tolerance levels.
Its best to get the most shake vibration with the less wattage db input.
I have tried many placements with my Dayton "Puck" to get the most vibration with little input being feed to
"Audrey II" I which I had Audrey II amp "feed me" lol.
Pre-made ones I have been skeptical until I bought x6 affordable Dayton Puck that are thee smallest.
A year or so ago now I brought a pair one by one over the weeks to try inside my Irwin rocker seat buckets.
Got the electrical drill out and marked the holes and took a few seconds to drill each hole.
A bit long but that is all I had at the time and need to go down the diy store and size up with one I have for a shorter one but same width nut/screw.
I tried the Aura on the floor and it was no, "go for launch" it was eating/heating up due to more increase I was given it so I knew type of flooring that is wood more less for lower seating raiser and the back riser no point in me going any further.
I tried underneath underside of the seat bucket but that was bit of weak spot oddly thou may seem but running all the manual frequency sweeps on REW up/down. No go I'm afraid.
I went for inside the seat bucket and its an almost close tight fit. The seat cushion and springs compress down and I can feel the springs are on top of it. But for anyone else I doubt they would even twig on there's shaker right under their ass.
It isn't impossible to place a microphone on the seat and set the gain levels so it reads the frequencies displayed on the RTA that part isn't impossible to see. But takes lots of patience.
There is another way I not yet looked into. I have two THX pro crossover/monitors and I can easily set up two and have one to monitor my in-room speakers as I can monitor Processor sound/frequency and more as well as Amplifier returns and monitor that all on TrueRTA or Spectrum Lab.
I can set them up so I see the Amp returns for example monitoring centre channel in-room and the bass shaker on another monitor but I'd need to set-up a fancy inexpensive way to check without having to swap monitor output lead/s or set up a stereo or duel Mono, so I can see what in-room level is and bass shaker is like.
Another simple way is to use
No not Sharon Stone, even thou she does move my Earth, with the shakers.
I can more less hear were the in-room even with subs and if sub can't shake the seat at 60db give it up. Might as well use less sub bass as too much and its only matter of time, until one ends up with tinnitus with show-off at 120 + db more.
In the real world bass sub bass doesn't press on our bodies on daily basis sorry bust all you're sub bass bubbles, but only certain things will be felt.
When we walk about we feel some great sub bass but I bet most here won't even give that a second nature thought.
You feel it in feet to legs though the body. If you want to hear that "GRAVITY" sub bass "thump, thump"? That is easy. Earplugs place them in and the walk about or handle some objects and you hear and inner-ear in-head cavity sound of lows it does sound very annoying.
In a car you feel the engine the gear shifting changing the pitch of engine and the speed mind you keep it at 30MPH or 55MPH don't want to get pulled over and handed a ticket.
I notice great sub bass for £3.98 on bus. I love public transportation. But it can be really annoying. If its a badly tuned engine the noise can easily reach 100dbC sounds like several random sine waves playing and will do you're ears in after 20mins, feels like stepping out of decompression chamber, when getting off the bus.
But if I wear earplugs that I keep in my wallet. I have nearly 80 earplugs. I can feel the vibration on the bus in the seat back seat rest and my feet on the floor. If I lift my feet up off the floor, the vibration feel reduces a little bit. I'm bit of human sound recording. I can remember some events/experiences and that is great it can be used as type of reference.
Even Mr.Scott noticed the out of phase of the ships engines, but couldn't at the time put his, finger on it as to the why?
I know it doesn't make sense but the feel of the sub bass is wrong.
I have even tied glasses with water in them in the armrests of the seats and watched the water ripple with a film or sine wave.
Also are bodies are made up of so much % of water and these factors may play a part in what we feel or can strive to feel. But give it up if its not gonna happen at comfortable db level then you're asking too much and damage to hearing.
Films don't have nowhere near close to explosions, really please. The purpose of bomb is to spatter body parts all over walls and floor and they all sound and have different frequency range and level.
Get a real firework and set off in the basement home theatre without earplugs and you'll know what tinnitus will sound like then. But cover you're faces don't want that pyrotechnics blinding you also and face looking black with smoking hair.
I've generally have played safe with my shakers and after reading many on other forums where theirs went up in flames of glory. That is gonna cost hundred/s every time.
Also can fit audio limiter/compressors to them to relax the higher peaks and increase on the smaller vibrations if that tickles anyone's fancy?
I just set mine with individual blends of LCR on their own fader that I use on basic 6ch mixer. I give a little blend of LEF.1 so it won't over taxi the driver to bottoming out or looking like...
Overcooked chicken.
A basic manual frequency sweep with button pressed down 10Hz sweeping upwards.
LCR rumble from TOS STAR TREK "Balance of Terror" region 2 DVD DD5.1. when the outpost on the asteroid is totally obliterated. I liked the rumble I played it three times.
The brighter yellow is the higher peaks no LFE.1 during the scene its mostly played over LCR with milder lows on the surrounds. There is some LFE.1 that reaches past 20Hz on later scenes.
Another way of creating a vibration shake while seated with nothing playing. Hold arms up a little bit and make a fist and shake you're arms. Now that is some personal feeling sub bass shake you'd feel over you're arms and face and body.