Heres my thoughts on this....
@Hugo
Being able to utilise frequencies in effects below 20Hz does not mean they need to always be at high output levels for them to bring benefits in sensations obtained. The user has to begin to learn or better understand what each frequency range can represent with the felt sensation different Hz ranges can offer. Also as I have illustrated at times, frequencies generate their own harmonics, so low Hz will generate more Hz with each harmonic. I learned a lot from just learning in building effects as to what can help bring for my own preference what I think are suitable sensations. Of course, some people may prefer something very different.
For example, take a car bouncing over the grass. or a bumpy part of track. It is possible to achieve a nice rebound type sensation that gives the user the impression of heave as the chassis is bouncing up/down and the user visually sees this on their display looking out their supposed windscreen.
I found using Shakeit with its "Left/Right Vibration" effect for (front & rear wheels) this with a setting utilising 30Hz - 3Hz operation it can indeed give a nice rebound type sensation for the chassis. Yet we still can have independent suspension based effects too.
Poorly Configured Effects & Settings = Bad Tactile (Even On The Best Hardware)
if the user does not generate/build good effects/settings with an excellent usage of important frequencies that help produce this rebound type sensation. Then it's likely the user will not get the same level of immersion and this can be the case with lesser tactile. They simply can't output effectively enough the suitable low frequencies so they miss the sensation or in some cases do not feel the full sensation someone else may indeed feel with hardware that can produce the lowest frequencies.
Leverage
How units are installed can also have a huge impact, as can isolation. Tests by users have shown that mechanical leverage can also be a factor as seen by the BK Gamer compared to the BK Mini or tactile placed on extended plates for leverage.
We even see this with the optional brackets for the "Earthquake" models. My own rig build will have each large BK unit use the "BK sofa" mount as an extended plate to generate some mechanical leverage. I will be testing 4 of these on the seat with the upcoming build.
Isolators below the primary installed surface will likely create a mechanical or vertical motion which may help to increase the output felt. Isolations main purpose, however, is to separate the desired tactile section from another. Obviously to limit reduce the mass/area the vibrations can travel to gain more effective energy distribution within the isolated section/area intended.
Moving Mass Theories
I am not an expert but I don't fully go with this perspective, which is often based on the size/power of unit in relation to the size/weight of mass it is installed to. Let me explain why, the amount of direct mass any of my units need to vibrate is not big at all and certainly much less than the "Sofa" or "Single Seat" based examples sometimes used by BK. They do this as an example to determine if a user should consider a small BK Mini, BK Advance or BK LFE sized unit.
For example, unlike a 3 seater sofa and a single unit installed to the center seat frame. I don't need the energy to reach to either end of its structure to the outer seats. What we are doing is different as firstly we are using multiple channels and each channel has its own duty or positional placement on the rig. Left/Right or indeed "Center" units can occupy the same "mass/section" be this the seat or pedal sections.
While I don't think its a major factor in this scenario. Some vibrations can also be airborne, with wave compression. They do not just need solid mass to travel. Anyone ever slam a door in a house for objects across the room react?
One of the most key elements I find for installation is that the primary energy of the installed unit has a PRIORITY to go into the "desired body region" in the most effective way possible. We want to control the path the energy will travel but also prevent it from going down or elsewhere away from the user's intended body region. The larger units have much heavier pistons, they are what is needed for the best energy with low Hz.
From my personal experiences, this does not, however, mean a small unit can perform just like a large unit if the small unit only has to vibrate a small structure or amount of mass. A small unit with its volume cranked will just become uncomfortable as its peak Hz determine its output character.
So this does not suddenly make it better for delivering under 20Hz by increasing its volume. You will find plenty of people who have tactile units directly installed to seats, (sides/back) etc and really they cannot have a closer or more direct installation to the user's body. Yet still, these cannot reproduce the lowest frequencies with the desired amount of energy as they just do not have the operating capabilities to do so.
I believe it really is more a factor of what the performance differences are between different units than how big or heavy a pedal section is on a rig or a "mass" contributing factor with multichannel tactile and in the way we are using tactile for sim cockpits. Clearly covered many times is how I disagree with placing tactile on 4 corners allowing the energy to spill into many other parts of the cockpits frame without even attempting to direct it more effectively to the intended body-zone region.
@Hugo do not rely on real-world vibrations to represent tactile immersion with sims.
I spent a long time evaluating how for example Simvibe used its V4-V12 options. Really it comes down to something simple. Utilising the usable Hz range to suit different cars RPM ranges, thats all it does and it has nothing to do with attempting to represent real cars.
Shakeit can deliver very nice RPM and Speed effects with LOTS of options to alter the sensations.
One key factor can be that if the engine overpowers other effects (even when placed on its own tactile units) then the net output experience felt is maybe not as good. This depends what sensations each user may want to feel. Engine is okay but some prefer to get more sensation for what the car is doing on the track. i dont see why this cannot also benefit motion rigs or with tactile let us bring more individual character in the felt sensations to different cars.
I do not see much use for Simvibe at this time with having tried Shakeit and having some idea in how its got updates to further improve it coming. Its simple, unless Simvibe has its own major improvements coming I dont see much use in using it for tactile when other alternatives offer things it doesnt and do things it does but also brings a much less frustrating UI.
