Build Report: Tactile Immersion in Motion

[ScreaminBejesus]

I'd just built what seemed to me the perfect immersive racing platform. What had started off as a modest attempt to dust off an old hobby had turned into something of an obsession -- messy, mismatched, and ridiculously inadequate at first, but now finally coming together.

After years of disuse, I'd pulled an old Thrustmaster wheelstand, wheel base, and pedal set out of the basement, plopped it down in front of a large screen television, sat myself in a comfy chair and gone racing.

I'd had an on-again-off-again interest in SIM racing since the early nineties, culminating in the release of GP Legends, which I'd played with a wheel bolted to my computer desk. That's about as far as I'd gotten in terms of hardware. But even I could recognize that this whole setup left a lot to be desired. It was of course annoying to have the stand slide out from under my feet under even light braking, to have only minimum feedback from the wheel and no resistance from the pedals, and to endure the 60Hz television refresh rate. I was having fun, but wanted more. So I started out on a project that I thought had reached its pinnacle before this thread even starts.

Over the course of the next four of five months, I took a jagged path through a stand just rigid enough to support a direct drive wheel, a better chair that still had to be strapped to the stand once I added a hydraulic brake pedal, eventually forcing a decision to build an 80/20 cockpit, install a proper racing seat, add a motion platform, belt myself in, and put on a VR headset. It was everything I had imagined it could possibly be and was responding beautifully to my efforts to dial it in.

Then, on a whim, I decided to try out one of those Buttkicker Gamer2 packages. I honestly thought it was a gimmick and didn't expect it to add much to the immersive experience. Even so, despite my already low expectations, I found it singularly unimpressive. Almost every other step I'd taken in this process had not only shown promise, but delivered a substantially improved experience. This thing just did nothing for me at all. I sent it back almost immediately.

Still, the idea of adding tactile stimuli made sense to me. Although that specific product in that particular configuration on my individual platform had not delivered, I couldn't stop turning over in my head that it could be done right and in a way that wouldn't just add a bit of rumbling noise, but would complement the immersive experience of motion and VR. I soon discovered the exhaustive tactile immersion tread and began a correspondence with @Mr Latte that has transformed my thinking about what it should be possible to achieve. Without his guidance, I'm sure I would have given up on this idea.

This thread will chronicle my efforts integrating tactile stimuli on my platform. It may take me a while to cover everything, but here's the plan: After describing my starting point and some of its idiosyncrasies, I'll outline my objectives, general philosophy, specific hardware choices, challenges I've faced and solutions discovered for isolating the 80/20 frame and motion platform while conducting stimuli to the body, explore a few dead ends that haven't worked for me but may be instructive for others, and finally look at software configuration and tuning, which I've only just begun to explore.

 

[ScreaminBejesus]

Thanks for your comments. I’d followed your work with great interest and learned a lot from the experience you have shared.

After installing the NLRv3, I’d already raised the steering column as high as it could go, so was glad to find a solution that could add isolation without having to raise the seat.

The 1/4” plates are quite stiff and don’t extend far, but I’m sure do still produce a different effect than you’d get from mounting directly beneath the seat. You mention rocking and I think it’s significant that the NLRv3 puts the seat on a stiffly sprung universal joint, so the transducers are able to push it around in a way they could not move a seat more directly fixed to the frame. That effect may be greater the further the transducers are from the pivot point.

I have a second LFE on order so that I can experiment with two of those behind the seat. But it won’t arrive for a couple of weeks, so in the meantime I will push ahead with the original plan.

A couple of points give me pause about replacing the Advance units. First, each single LFE and Advance was already individually as strong as I could have wanted in delivering convincing engine, rpm, and gear shift sensation. In fact, I had to dial those effects back to avoid being overwhelmed. Secondly, while mono effects will be shared between the underseat BK and back-of-seat TST, the stereo effects will come primarily from the BKs on the seat rails alone, with some help from the higher frequency Dayton units at the shoulders and knees. From the measurements I’ve run so far, it looks like better crossover points may be found with the Advance/Dayton units in stereo and LFE/TST for mono. But I will experiment with that to confirm once the second LFE arrives.

 

[Mr Latte]

Keep up the good report, with using the Crossover with +12dB for the "output level"
If the LFE is not feeling substantially stronger then try increasing the front dial on the amp (source input) to 1pm or even 2pm positon. It will make quite a difference when the output level is this high.

It also depends on what gain level you have for the individual effect, so it's finding a balance between these 3 factors. Note that, +12dB may cause issues when you have multiple effects using the same low Hz as when this happens it also increases the dB for repeated frequencies, so do allow for some headroom just below your optimal.

Note that if the soundcard is at a 50% level (as we are using the amp to boost) the LFE piston is more than 3.5x heavier than that with the BK Advance is, so it might need more juice to really pump that low-end.

Use the curve to boost the desired Hz range and use the EQ to reduce specific Hz peaks from that implemented curve. Or use EQ to boost higher based Hz. Obviously some are typically lower in dB with the curve/slope being used. Although as you may find BK models are not great at bringing more detail with higher Hz even with EQ boost added.


Keep experimenting and enjoy the journey in finding optimal settings for each unit...

 

[ScreaminBejesus]

Today I mounted the LFE in its target location under the seat. This is considerably further forward than most underseat mounting I have seen. In addition to dividing mono effect frequency ranges between this and the TST329, I also aim to experiment with fore/aft separation.

It’s secured with four buttonhead M6 bolts and two diameters of fender washers to spread the load.

Here is the view from below:

In this position, it presses against the spring-loaded wire that secures the Sparco seat cover. I have some surgical tubing on hand in case that starts to buzz.

 

[ScreaminBejesus]

With all of the transducers and exciters mounted in their intended positions, I began this week the process of determining ideal crossover and EQ settings. I began by performing these tests outside of the game environment, using Tomasz Saynalski's tone generator, which I highly recommend, before moving on to refine these settings in-game using SimHub profiles previously shared by @Mr Latte. Testing with pure tones allowed me to characterize the transducer’s frequency response curves and establish a good starting point, but studying the in-game effects with harmonics and overlapping layers has been an essential step in dialing in these settings.

Although these results are, to a large extent unique, to my configuration, I'm hoping they may be helpful as a reference point for others. The high pass filter settings should be pretty standard as these were constrained mainly by the internal limitations of the transducers (to avoid piston slap, for example). Notches in the mid-range EQ were chosen mostly to avoid resonance with the seat or elsewhere on the rig. The low pass filter settings will depend on what other transducers you have, how wide a range you need to achieve with each one, and how much audible output you can tolerate. I'm going to spare you all the reams of data I collected to arrive at these settings, but I'd be happy to discuss that in more detail if there's interest.

Before I’d even gotten started, I discovered that I needed to alter the positions I’d chosen for the Dayton Audio DAEX34EP-4 exciters. I’d tried to hide these under the seat covering, which had seemed like a good position. But there they vibrated against the cover’s retaining wire and I also discovered that they did not make good contact with my body when actually racing. The positions shown below worked much better.

This required a bit of cable management and maybe eventually, if I ever settle on a permanent configuration, I will drill some holes and use some grommets to run the cables internally, but for now, these are out of the way and relatively tidy.

I had honestly not expected much from these Dayton Audio exciters. They are only about 6cm in diameter and 40 Watts, but their performance was seriously impressive. Out of the box, they could vigorously shake the whole seat in the 40 to 50 Hz range and with a little EQ work, they deliver a solid response from under 30 Hz to almost 200 Hz. Since they turn the seat into a speaker, their effectiveness depends on having a solid seat. But if that’s what you are working with, and you are able to complement them with one or more large transducers for lower frequencies, I would highly recommend these exciters as a relatively inexpensive, easy to mount, versatile, and remarkably effective way to deliver focused stimulus to specific regions of the driver’s body. I will be very surprised if I don’t end up adding a few more.

Now, on with the measurement results...

Edit: I was asked about the cable clips in these photos. Here is a link to the ones I am using. Similar ones are available from a lot of different sources. These happen to have 3M VHB backing tape, which is convenient.

 

[ScreaminBejesus]

Let's start with the BK4-4 Advance transducers. These units are mounted just behind the seat rails and are intended to carry stereo effects. At higher frequencies, I had planned that these same effects would be carried by the DAEX exciters, so I can afford to be restrictive on the low pass filter. But once I began working with the in-game RPM effects, I ended up using the exciters to complement the large central LFE for those effects instead. So I may need to revisit how best to deliver higher frequency stereo effects.

Both BK4-4 Advance units were tested together and with identical settings, with the sound card output set at 50%, the tone generator output set at 100%, and the NX3000D knobs at 12 o’clock. I found these transducers to be very effective over a range from 3 to 40 Hz, with the strongest output between 6 and 35 Hz. However, gain had to be carefully controlled below 10 Hz, so to be safe, I have limited this signals with the high pass filter.

Despite physical isolation of the seat and transducers, output from the BK4-4s in the region around 25 Hz resonated with the wheel support platform so had to be curbed. I boosted the signal around 80 Hz slightly to achieve a more uniform decay of the tail at the high end. There are a few other hot spots in the mid range where I made adjustments to achieve a smoother sweep of output across frequencies at higher gain volume levels.

I have so far not changed these settings on the basis of subsequent in-game testing, but I have also done very little testing with stereo effects so far. So these values may well be modified. I should also mention that I have two additional LFE units arriving tomorrow and may end up setting the BK4-4 Advance transducers aside for another purpose.

 

[ScreaminBejesus]

The BK LFE and TST 329 are run from the other Behringer NX3000D amp. The LFE, running as Channel A, has its phase offset by 180 degrees since it has been inverted. The TST, running as Channel B, has its peak limiter is set at 150 W.

These two transducers were intended to share responsibility for mono effects with the LFE covering output below 40 Hz and the TST covering output above 30 Hz. But, as I mentioned below, the Dayton Audio exciters proved so effective and the ability they provide to let the RPM effects gradually rise up through the body proved so compelling, that I’m rethinking this now.

The LFE's response curve was very similar to that of the BK4-4s. Its high pass filter also limits output below 10 Hz, though more of that gets through than on the small Advance units. Based on the pure tone testing, I had decided to apply a low pass filter to limit the TST unit‘s output above 150 Hz, as shown below, mostly to avoid a range that seemed more audible than tactile.

However, once in the game, I discovered that the audible output was less distracting than I’d anticipated and the higher frequency tactile more evident, so I opened them up as shown here:

EQ tuning for the LFE was more straightforward than it had been for the BK4-4s, in part I think because of its mounting position under the seat and consequent greater isolation. I did end up notching out some signal around 30 Hz where the unit is particularly strong and bumping it up around 80 Hz, as I had done for the BK4-4s. This is pretty close to the EQ @Mr Latte has recommend for the LFE.

The TST has a remarkably wide range and easily conveys sound in the audible range, so I wanted to make sure to keep its output below 200 Hz. Within the 30 to 200 Hz operating range, the attenuation I applied was mainly to avoid resonance with other parts of the seat area.

 

[ScreaminBejesus]

The four Dayton exciters run through a Behringer EPQ304 amp which lacks the DSP features of the NX3000D. I drive it from an external USB audio card so that I can control the signals in software with the EQ APO software tool available here. I'm sure there are more sophisticated ways to use this tool, but I just used its graphic equalizer to shape the overall signal going to the amp.

I was surprised by the remarkable range and strength of these small exciters. Output made a clear impression as low as 25 Hz, reaches a peak intensity in a band from 37 to 43 Hz before dropping off around 60 Hz. With pure tones, no vibrations are perceptible above about 150 Hz, but the untamed output is audible throughout the range of the human ear. Based on initial measurements and an interest in keeping some of that low end for a smooth overlap with the BK4-4s, I sought to eliminate anything above about 150 Hz.

In subsequent in-game measurements using RPM effects, I discovered that I could extend the EQ to allow these cover transducers to cover a range from just over 25 Hz to around 200 Hz.

 

[EsxPaul]

I've spent the weekend finishing up the build (hope I've wired this all up correctly ) and I'm hoping to work through some initial setting up during this week.



My main concern now is that I don't cause damage to anything. I'm thinking that I should set up the configuration in the NXedit software, then move to the online tone generator before attempting to fire up any games.

Before I move to the tone generator, should I install SimHub and configure all of the channels in order for online test tones to be directed to each unit in turn?

I would imagine that I should then take notes of the frequencies that feel good/bad as a reference for what will need boosting or cutting later further on in the setting up process.

 

[ScreaminBejesus]

@EsxPaul, if you start with flat EQ, zero gain in the crossover filters, the sound card volume down, amp knobs at noon, and adjust in small steps, I don’t think you are at much risk of damage.

I used the test tones independent of SimHub just by directing Windows to send audio out to the appropriate sound card. As far as I could tell, this output is only “stereo aware,” so I had to make sure the exciters/transducers I wanted to test were plugged into the primary L/R output of the sound card I’d selected. Swapping around the plugs is a bit of a pain, but not a burden since you’ll be testing this equipment one channel at a time in this mode. Obviously, the in-game testing will give you much more flexibility to select and combine channels at will.

I didn’t find a way to send tone generator output through SimHub, but maybe others can chime to let us know if this can be done. I do know that some have created a kind of tone generator within SimHub by linearly assigning frequency output to RPM, but I didn’t want to be adjusting frequency with my foot, so didn’t pursue that path.

Yes, you will want to take notes. I started by sweeping through frequencies from 1 to 200 Hz, taking three sets of measurement for each channel. One where I looked for the lowest volume at which I could perceive any output at each frequency; a second where I found the output at each frequency clearly and distinctLy; and a third to find the limit beyond which the output became distorted, the transducer showed evidence of being overdriven, or other parts of the rig started to resonate. These peaks lead me later to my EQ adjustments.

 

[Brutal Deluxe]

Yep, very good advice above from @ScreaminBejesus . Just start off with low volumes as mentioned and you won't cause any damage. Great work on the cable management, looks really clean!

 

[JohnBeardmore]

Thank you for the detailed practical write up. It is nice to see the theory put into practice and read about the set up especially the tuning of the frequencies.
I can now see the advantage of having the EQ on the Behringer.

 

[ScreaminBejesus]

Testing the slippery slope effect

 

[Mr Latte]

Plenty of power now


Queries with gain levels?
Can give you another test to try
Create a different amp profile but lower the dB into negative gain.

Keep this flat at first and determine with the current soundcard/amps knob positions (50% & 12pm) at what minus value can you still feel the frequencies. Test different frequencies to determine how far below 0dB can you feel their activity.

For example, do you feel to
-5db or -10dB or more?

You can try this with and without the same PEQ settings but it will help you determine how much of the curve you have been using below 0dB that you still actually will feel from the tactile being used.

From settings shown above:
Do you feel Channel A 80Hz at -5dB
Do you feel Channel A 100Hz at -10dB

What will you discover with different frequencies at these negative values?
What is the lowest felt dB and what is the peak felt dB for each 10Hz band, how does it differ with the BK LFE?

This would be a good test to do to compare all the BK models.

With your current DSP profile and also with using a flat/negative gain mentioned above.

What happens if you now turn the amp to 1pm or 2pm keeping the soundcard still at 50%?
What happens if you now turn the soundcard to 60% or even higher with amp at 12pm?

 

[ScreaminBejesus]

Despite the shock of returning to work after three weeks off, I did manage to find some time to begin testing tactile effects within a real SIM environment this week. Rather that share data that would, in any case, be unique to my own specific hardware, I’ll instead set aside some time this week to review my process, which should be more generally useful to others and consists basically of divide, conquer, reassemble, refine, and repeat.

But I will also want to share some struggles I’ve been having with an idea to run all of the SimHub effects out to my DAW software, analyze and process them there, and then send them on, in real-time, to the tactile amps. I tried all sorts for virtual routing software, most of which sort of halfway worked, but none to my satisfaction. So the next step will be to break down and repurpose this RME hardware interface from my bass amp rig.

I realize this is complete overkill that could not possibly be justified on its own terms. But I’m not playing the bass anymore and it’s been a couple of years since this interface has gotten any use, so ... why not put it to good use? Here is the interface specification.

 

[ScreaminBejesus]

Plenty of power now


Queries with gain levels?
Can give you another test to try
Create a different amp profile but lower the dB into negative gain.

Keep this flat at first and determine with the current soundcard/amps knob positions (50% & 12pm) at what minus value can you still feel the frequencies. Test different frequencies to determine how far below 0dB can you feel their activity.

For example, do you feel to
-5db or -10dB or more?

You can try this with and without the same PEQ settings but it will help you determine how much of the curve you have been using below 0dB that you still actually will feel from the tactile being used.

From settings shown above:
Do you feel Channel A 80Hz at -5dB
Do you feel Channel A 100Hz at -10dB

What will you discover with different frequencies at these negative values?
What is the lowest felt dB and what is the peak felt dB for each 10Hz band, how does it differ with the BK LFE?

This would be a good test to do to compare all the BK models.

With your current DSP profile and also with using a flat/negative gain mentioned above.

What happens if you now turn the amp to 1pm or 2pm keeping the soundcard still at 50%?
What happens if you now turn the soundcard to 60% or even higher with amp at 12pm?

I don’t currently have the BK Advance on the platform, so won’t be able to compare it directly with the LFE, but the tests you’ve requested are similar to the ones I reported earlier, except that the amp gain, rather than the sound card volume, is being adjusted to find the threshold of perception. But I’ll try this with the transducers that are on the platform to see what it can tell us.

 

[Mr Latte]

Nice hardware indeed.
If you know how to use all that then this should be a breeze for you.

I don't think the virtual software routing is good for low-frequency multi-channels like we are using. Latency may indeed also become a factor and channel crosstalk interference when more channels are used. When I looked at it a couple of years ago I had issues with it and knew it wast the solution for what we are needing. I don't know if the software for such has improved but really dedicated hardware options will be the best route.

Part 1
Very few "Sim Racers" will want to go into the whole realm of using a DAW and the learning curve that requires as well as time/effort needed to properly make use of its features and additional plugins such can bring. Of course a person already familiar with using such its easier.

Into the Deep?
Some of the below is going to go over people's heads. Again few will have experimented much with this side of tactile immersion and with Simhub. I myself still have things to learn and improve on but will share my thoughts.

I have, several times over the general tactile thread mentioned how easy it is to use iPad and compatible interfaces with apps like AUM. Its so cool and simple. Plugins like Fabfilter Q3 will bring advanced features for control (like dynamic EQ) that could improve on what is possible with other options. More real tests would help determine how each option compares or what suits the user but a multichannel input interface with this iPad approach via AUM would not need DSP on the amps or soundcard. So this can give you DSP functionality from the iPad and applied to all the channels you want it on (each with own settings). This bypasses the issue with NXD USB only able to work on a single amp at a time. I have yet to determine what I want to do but we could still use the wattage limiter or crossover/filters on the amps and just use the better dynamic EQ with ProQ3 via iPad and the audio interface.

Some interfaces now support wifi, those that do, then let you control the audio interface from multiple options. iPad/iPhone /Android Devices/ PC/ Mac and also Midi-controllers. Personally I see benefits with monitoring multiple channels more on a full DAW. As you could have multichannel spectrum analyzers being viewed on a 4K screen. Handy for in-depth study or just looking impressive.

AUM on iPad and with certain plugins, however far exceeds the user interface with simplicity and control of channels better than most DAW software. AUM as I also shared can be controlled by a midi controller. Making it easy to adjust gain levels or pans for stereo mixing as well as mute channels. With AUM you load a saved profile and bang, you're ready to go all channels within easy control via your touchscreen or connected midi controller. You just program how the midi-controller operates and this is simple to apply in AUM.

Your unit is compatible so worth looking into using with its own app and AUM.
iPad touch interface may be handier than traditional DAW software on PC/MAC for what you need to do here.


The Mix
The problem you will run into is that SimHub already lets us create/place the effects mix we need per-channel for each transducer. It also supports unlimited soundcards so we have no real limitations with the number of channels we can use.
Therefore we don't need to really create a "mix" within a DAW.

It would be possible to mix the "Game Audio" & "Simhub Effects" within the DAW which I think you are really interested in. Yet in some ways, it may be best to consider comparing and having the option in using dedicated tactile for both sources or limit what effects you are mixing with both sources for a transducer to generate.

We can expand engine character and immersion with this but having RPM/SPEED/GAME AUDIO all incorporated on a single channel, well I will let you discover your own findings what happens. Another factor is if we increase the sensation of the car's engine/transmission along with sensations for increased engine strain and speeds how do we still maintain the felt sensations of other effects, particularly directional based effects when these mono based effects are already swamping the seat?

These are factors that only testing and experimenting with will let the user determine the best course of action. Also how/what installation of tactile they might use. There is a reason why I went the path I did with my own build but to the average person having so many tactile units looks absurd. in one sense it is but not when we use different units for specific performance benefits and that's one area my own build will highlight how we over-come certain factors.

Is Feel Alone Enough?
So you need to discover and test different options as your experiences or findings may differ to mine. However when you are routing everything into a DAW then you can visually monitor all frequencies from both sources. This is a huge benefit as you can then see what happens when you create different effects using different frequencies and can visually see as well all the plugins you may use in how then the mix or output of these would be going from the DAW interface onto the amps and transducers.

We can only do so much in tuning by feel alone, so yes for advanced users with the experience it is possible to take things further with this approach regards how well your tactile can operate. We can then discover how using harmonics and matching effects with specific frequencies can enable groups of effects to work better when combined. We then also can determine by testing what effects we distribute to other channels/units to help with our bodyzones to feel, rather than a single unit sending multiple layers of effects into one installation/path. This being the "less is more" limitation but as I have said one we bypass with the BK/Exciter concept and installation approach.

Bodyzones / Seats / Materials
You already are getting an idea of how the same effect but coming from different units or indeed units installed in a different location (body region) may vary in its felt sensation. This alters the flow of that effect into the seat but will be a user preference. The beauty is we can easily create effects that may be distributed to different channels saved in different profiles. This is also one way from testing I believe we can help the feel of cars vary so that we bypass the boring sensation that lots of cars engines feel the same as most users rely on the same effects using traditional methods and installations like Simvibe restricted us to.

Being Creative With Effects
It's worth experimenting with how/where effects you use what channels they operate on.
Be it that they are static to specific channels or we introduce ways to have an effective transition from one channel/body location to another. This is possible by using delay and altering the sensitivity in which the activity of that channel for a specific effect layer is used.

Ive tried to be creative and will continue my own tests with this when I get back to having a rig with tactile installed. It brings options and uses the idea of the concept well but also pushes how Simhub can be so much better than other tactile software.

 

[Mr Latte]

Part 2

Hardware Outputs
Typically with music a DAW is used to combine many instruments/source inputs into a 2 channel audio mix. We however are not doing that, we are wanting a high number of individual channels with potentially specific effects placed on these.

While your mixer can support loads of input channels, the restriction is often the number of output channels a unit offers. Some hardware units with RTC will let you expand the number of outputs via additional box but this again is more money.

On a lot of hardware mixers, I could be wrong but 8 output channels is often the number supported.
So we need to get clever as how can we double that?

Latte Vs Layers
The answer is within how we create the effects to contain the low bass and detailing for both types of units. Then by using the DSP crossovers of the NXD we create a split for units like the BK / TST. By using suitable crossovers we now send only the lowest Hz to the BK unit and the primary detail to the TST unit. The same approach is possible with the exciters if we then are using DSP with them. Ahh, one reason why I have shown people affordable DSP options for exciters.

We just are being more resourceful within the effect layers created for the operation of both units and reducing the clutter within Simhub.

This way we also reduce the number of individual effect layers in Simhub. So while its possible to have individual layers and effects for BK and then individual effects for TST or Exciters we soon get to a point that the software becomes a mess. The "Advanced Tuning" menu shows all the layers for all effects (Output Mixer) and all soundcards. This becomes a real mind screw trying to keep track of each effect layer for each soundcard and channel you want that effect layer on. So with this approach, we avoid all these factors in Simhub. I have looked into both options but on my own build, I have too many transducers to keep each unit as an individual channel and it was better to have Simhub also easier to manage. This is also less time needed in making changes in tyring to balance effects gain levels and blending them to desired preference.


Okay So Duplicating Channels
This is easy to do with various hardware, so basically you have your channels with their effects from Simhub, we duplicate each channel so that we can send individual outputs for BK / TST / Exciters and even for monitoring purposes. We then just control and adapt the output to suit each device or its role/purpose within the DSP path for each amp powering each channel. This way the tactile unit gets only the Hz we want it to output and effects are spread over the body locations not restricted to single installation points as commonly done.

We then can further tune the output for the intended transducer and the users own installation via the DSP at the final stage on the amp, not at the point or within the DAW itself. The only drawback here is our spectral analysis is prior to this but we know what is going to the amps and how the amps crossover filters/EQ will be handling those frequencies and we already know the best performing frequency range we want each unit to use having determined and applied crossover curve/filters.
These then and the DSP, in general, should be set and forgotten once tuned.

This is why I use the HA6000 for real-time adjustments as we can make changes on the fly per channel to each unit but control the operational limitations of each unit by the amps DSP settings. I found it easier to do that on a hardware device like the HA6000 than have to go back and forth over a DAW to make simple EQ/PAN adjustments for a mix. Also while I may use a monitor specifically for Simhub being able to just adjust the HA6000 (bass/treble) is easier and less tedious than adjusting several effect layers volumes in Simhub. Will see in real-world practice how each option goes, both options are nice to have.

Drawbacks?
Could get costly with all the cabling needing in routing everything with the approach I have taken.
Depends on the price of cables used but could be a few hundred if using decent brands but all comes down to the number of channels you are using.

Pro Performance
This is how and why I use "Dual Role" and from the creation of the effects to design the effect layers to contain the low bass and detailing on the same channel within Simhub. Then split this so that the BK and the TST output the frequencies they (as very different devices) work best with. Thus you exceed the operational performance limitations a single unit has but you also now benefit with the "peak performance" being achieved on each unit and with both units combining to produce the channel output to the body region intended. For exciters we can place them on their own channels with their own layers. In some cases just using frequencies that are harmonically matched or an octave higher than some layers used for the BK/TST. Again this becomes something we discover in the creation of the effect and trying different approaches as in what to use for the exciters to complement the other transducers used or for individual sensations or roles.

Pushing Boundaries
I don't know of anyone that follows this approach with Simhub but it is a crucial element of my own builds usage with tactile.
It is also costly to do and very hard to come up with an installation that makes it possible or even work. My own seat as mentioned before, will use 6x large BK and 4x TST combined with 6 exciters for specific reasons based on past tests. I will see how well it all comes together soon but look forward to maximizing the options that installation and this approach brings.

 

[Mr Latte]

I don’t currently have the BK Advance on the platform, so won’t be able to compare it directly with the LFE, but the tests you’ve requested are similar to the ones I reported earlier, except that the amp gain, rather than the sound card volume, is being adjusted to find the threshold of perception. But I’ll try this with the transducers that are on the platform to see what it can tell us.

There is no way the BK Advance will perform to a similar output with the sub 10Hz when we take each unit to its operational peaks and account for the difference in piston weights. We want of course to have it operate just below this peak. So an LFE/Concert well within its operational peak should outperform with low frequencies a BK Advance at its peak output.

Regards adjusting volumes, on
A) Simhub Soundcard Output Level
B) Amp Input Level
C) Amp Output Level

Having a good balance is important, as we can avoid distortion or help to better control clipping. Some effects in Simhub can cause clipping (Shift). We dont want the input level to be coming into the amp too hot. So A & B need well balanced. It is good to have some margin here but we want that margin to be at the effect control level. This is why if we have the soundcard volume only at 50% we can adjust it higher if desired for different sims. Also we want the ability to change increase/decrease specific effects gain. So that the strongest effect is still within the operating levels that feel good but the majority of effect layers will not need tweaked that often.

Its easier to find a good balance and then increase the amp dial up to 1 or 2 o'clock positions via (B).
This way you don't have to go to different amps connecting each USB to bring up the software individually for every amp and then alter (C). So its best not to have this at max +12dB to allow for some headroom being applied from either (A/B).

Increasing (C) however will have more impact than (A/B) as by increasing the output from the amp this is likely to have more impact on how your crossover filters and EQ alter the output.

You may find your own approach but getting a sweet balance with some degree of easy applied +/- is a good thing to have yet still know what the gain limitations are before introducing problems or overdriving the tactile. We want the balance so the lowest Hz has the energy they need yet the 40Hz mid-bass is not overbearing and at the same time the higher Hz are well-controlled but we feel their addition with the harmonics being generated.

Much of this comes just with daily usage and experimenting with settings but so many people over-drive their tactile seeking more (slam) energy of peak Hz instead of a more balanced or detailed feel/sensation from all the frequencies that are being generated.

 

[ScreaminBejesus]

Thanks very much for your feedback, @Mr Latte. I got sidetracked from my software configuration. Having started out on a path I thought quite reasonable of taking one effect at a time, one layer at a time, and one transducer/exciter at a time, I soon determined that four exciters were not going to be enough. I wanted to be able to divide stereo effects left and right, but also deploy other effects in waves from knees to shoulders. I thought briefly about adding four more exciters in series, but quickly realized that I wanted the flexibility to be able to place each effect exactly where I wanted. So I got a second EPQ304 and another truckload of cables. While waiting for those to arrive, I also decided that I wanted more control over the output signals than I could figure out how to get from EQ APO, so set out to see if their was some way to put my DAW in the signal path between SimHub and the amps. After struggling with various software bridges and virtual cables, I remembered that I had an RME UFX hardware interface sitting idle in my old bass rig. It has twelve independent analog input and output channels, so seemed like a perfect fit for this project. So I ordered yet another truckload of cables. Today, I am pleased to report that I got it all set up, confirmed the mapping of channels from SimHub through the audio cards, in and out of the UFX interface, to the four amps, and finally to all of the rumbling parts. So now I am essentially back where I was two weeks ago and ready to again start shaping effects. One important step forward is that I now have real time visibility of the full spectrum of signal I’m sending to each transducer and can see exactly how multiple outputs are combining. I now also have a convenient way to filter and inject any game audio to any combination of transducers and exciters. So the next steps should be quite interesting. More soon. In the meantime, here’s a shot of my massive collection of cables.

 

[Mr Latte]

And so the fun begins....