[tactile] DSP amplification vs non-DSP amplification + software EQ

[ferdiaz]

Hi there people,

This is my first post here, so my apologies if this question has been asked already. I haven't been able to find the answer, even though I have been reading about this topic non-stop for the last two weeks. My apologies if that's the case!

Anyway... I have just joined because I am in the process of building my first sim rig, and tactile is a topic that has got my attention (and in which way!). I very much prioritize immersion, so this is one of the areas I want to dive a bit deeper and invest a bit more.

I have been reading a lot these last days about the benefits of DSP. It is now clear to me that by being able to fine tune individual frequencies, it allows us to optimize the experience and/or prevent problems - such as the Buttkicker piston pang. This is well understood, and I definitely see the advantage.

However, the delta in price between DSP amplifiers and their non-DSP counterparts is not negligible: the extra features must be paid for.

Considering that depending on the setup, we might end up with more than one (or even two) DSP amplifiers, we can quickly observe the divergence in price between a DSP and a non-DSP setup.

So the question I have is: would it make sense to build a setup based on non-DSP amplifiers (which are considerably cheaper), and instead, do the EQ tuning on the software-side, so that the problematic frequencies are not even sent via the output of the audio interface?

By delegating the EQ to the software, we won't need to replicate the EQ capability on each amplifier, which leads to a much simpler and consolidated setup. I would consider this as a classic example of component simplification... however, I suspect that I am missing something here, so that's why I come to query you guys...

What would be the disadvantage of software EQ + non-DSP amplification?

Thank you very much for your answers, and again, sorry if this topic was already covered!

Cheers

 

[blekenbleu]

What would be the disadvantage of software EQ + non-DSP amplification?

Disadvantages are mostly limitations and quirks of Windows and whatever software EQ is chosen.

Thank you very much for your answers, and again, sorry if this topic was already covered!

Check what RacingMat is currently sorting:

First thing first, let's try Parametric Equalization before purchasing a DSP hardware with APO EQ

 

[ferdiaz]

Disadvantages are mostly limitations and quirks of Windows and whatever software EQ is chosen.

Check what RacingMat is currently sorting:

Interesting, that's more or less what I had in mind. My current very theoretical potential setup consists of the following:

• 4x Reckhorn BS-200i
• 1x Behringer EPQ304 to power the 4 transducers above
• 2x BK LFE
• 1x Behringer NX3000 (non-DSP version of NX3000D) to power the two BK above
• Outputs consolidation via a dedicated audio interface (Behringer UMC1820), corrected via software EQ and fed into each of the amps above

Again, this is all very theoretical at the moment. I definitely need to keep reading and gathering information. But it's gratifying to realize that what I had in mind wasn't completely wrong. Thanks for the link, much appreciated!

It would be interesting to explore whether introducing this additional layer of software equalization would lead to some nasty effects (cracks, dropouts, latency, etc.). Equalization shouldn't result in too much overhead... but we're dealing with real time audio here, and based on my previous experience with the ASIO driver implementations from different vendors, I believe that all these factors are a very real risk.

 

[dwightyone]

Sometime in the next week or so I'm going to experiment with APO as an attempt to reduce piston slap. Will be interested in your view of how if all panned out for you.

 

[RacingMat]

What would be the disadvantage of software EQ + non-DSP amplification?

yes, clearly the windows softwares configuration!

I'm currently writing a topic on this matter and it's not an easy way... [Tactile] tutorial Simhub + Equalizer APO + Peace but manageable

DSP amps are a really appealing way if you can afford enough units for all your transducers.

 

[blekenbleu]

My current very theoretical potential setup

So long as total channel count <= 8, then a single 7.1 sound card
with Equalizer APO is relatively easy to wrangle in Windows.

 

[ferdiaz]

Thank you all for the replies!

I am very curious and looking forward to your experiment @dwightyone.

So all in all, the biggest hurdle with this approach seems to be the software. I had (most likely wrongly) assumed that the learning curve to configure the DSP equalization via "Behringer NX Series edit" would be somewhat equivalent to doing the same adjustments via APO (or any other similar Windows EQ).

I need to read a bit more in detail your post @RacingMat, there's plenty of interesting information there. Just curious... is APO the go-to choice for Windows equalization in the community? Or is that just your personal choice, resulting from testing a number alternatives?

@blekenbleu the idea behind the Behringer soundcard is flexibility. I have a couple of other projects, which are music-related. So far, I have been using a 4x4 audio interface... but I've been meaning to upgrade for a while. This could be the perfect opportunity to do that, since I could be using it both for the music projects and the sim racing rig. Also, because it comes equipped with 10 output line channels, it would also allow me to add extra transducers down the road.

 

[Mr Latte]

Sometime in the next week or so I'm going to experiment with APO as an attempt to reduce piston slap. Will be interested in your view of how if all panned out for you.

As most people use entry-level or budget transducers.
Including the BK Mini or BK Gamer series

I'm curious, what can be achieved with a decent soundcard EQ lowering the 31Hz band (for piston issues) and using the crossover on Simhub or a BK Gamers own amp to then fade out, higher Hz output (helping to lower heat generated).

How necessary is APO or DSP for various budget transducers?

Guys, before doing all this look at your effects and tell me what Hz you use for effects on the tactile you own? Keep in mind the Hz applied is not the only Hz generated.

Do consider that DSP on units, if you are getting the best from them using 25Hz-60Hz for effects? In some cases, people may feel decent output in 30Hz-80Hz, even that as an example is only a 50Hz usable range. Better Tactile is not just about DSP, installation, and isolation are very important to the quality of feedback you will feel. DSP is about tuning that further. It won't make a bad installation good.


Personal Opinion:
The main benefits of the DSP based PEQ and Crossover is beneficial to help boost the low bass (sub 20Hz) energy as much as possible for the large BK. This can make a BIG difference.

To then reduce certain Hz amplitude for installation/reverb issues, controlling the troublesome Hz only. Lastly to control the audible hum/noise from units like the exciters and TST units that work really well with harmonics from generated effects way beyond 100-200Hz that you cant feel on most other models of transducers.

You might find APO a lot of hassle for limited benefits depending on what transducers you are using as to what extra performance or improvements in tuning it, might give you back. Also just keep an eye out for potential latency issues. It may have improved or be more specific on certain cards or PCs.


@ferdiaz
Note also that DSP on the Behringer amps is only $50 or £30-£50 (price varies) over models without it. That is an absolute bargin considering you get wattage limiter, phase control, crossover, 8 band parametric EQ, a dynamic EQ, easy to share saved configuration profiles with other owners with a easy on the eye user interface.

If someone really wanted to save a bit then as stated many times on the forums the NX1000D will happily power 2x large BK LFE or Concert. The benefits of such an amp are its great to power smaller BK that a user may currently own (and of course control them well) but at the same time ideal for such a user that may want to upgrade to a larger BK or large Eathquake Q10B. The amp fully supports 2ohm, 4ohm, 8ohm transducers. They are recommended not just for their DSP abilities.

The NX3000D is probably the most purchased amp, with its additional wattage for large BK owners and as such you get the DSP so no need for a software-based solution for the BK and other amps for them can cost more without DSP. Those that buy the NX4 without DSP are fools, sorry but its true. Somebody could fit an extra amp in or place a rig on wheels with storage below the rig. I say that as often the excuse is "I only want space one amp takes up."

The topic of debate, maybe you guys will shed light onto?
Is it worth applying software based DSP to budget or entry-level units, that in the vast amount of cases are being powered by cheap non DSP amps and as highlighted with very narrow operating frequency ranges?

Advice, for an interface but with plenty of channels. The Behringer XR18 is one of the best value. You can use their Android /iOS app or an even better unofficial one to control it wirelessly via tablet or phone as well as with its own PC software. No real need for DAW but one of those will bring more options for pro audio plugins if desired.

Good luck

 

[RacingMat]

Just curious... is APO the go-to choice for Windows equalization in the community? Or is that just your personal choice, resulting from testing a number alternatives?

I looked for free alternatives (by curiosity) but I didn't find any!

Before dreaming on ideal configuration or buying stuff and stuff, software DSP PEQ is a good first step for me.
I can evaluate how effectively the piston bottoming is affected by PEQ, how difficult it is to setup the software
how complex becomes my rig (accumulation of softwares like Simtools or FlyPT mover, Simhub, Simucube, Streamdeck app, Steam...)
and hopefully I gave up the Reverb G2 trial with StreamVR, Mixed Reality Portal , Mixed Reality Portal for SteamVR.... the GPU setup...

I have not answers yet, as I'm following the long road that @Mr Latte is speaking about: testing the transducers, report measures, see what I really gain and what I really need.

 

[Mr Latte]

The 1st thing to do is use effects in Simhub (not just sinewaves via tone generators)
To determine what Hz values you feel from the transducers and amp owned.
What is the lowest felt value, the peak values, the highest values the person can use?

With the various effects Simhub does not output just pure tones. So using pure sinewaves from various generators to evaluate a transducer isn't fully applicable for the usage case scenario we are using them. Better to test from within the source.

Note down the frequencies you currently use for the effects you run with.
It appears some of you are trying to use/apply methods relating to improving the lowest bass and highest bass frequency ranges for models that do have performance benefits with these frequencies. Like the large BK to the Exciters or TST units.

The typical common/budget transducer does not generate these lowest/highest bass frequencies adequately anyways. So the benefits of using APO or other DSP on entry-level and common budget (bandwidth-restricted) transducers will also limit any potential gains.

 

[blekenbleu]

the learning curve to configure the DSP equalization via "Behringer NX Series edit" would be somewhat equivalent to doing the same adjustments via APO

That part is true; on a guess, APO may be easier. One challenge in Windows is routing multi-channel audio,
e.g. from SimHub to Equilizer APO to appropriately configured Windows audio device drivers.

the idea behind the Behringer soundcard is flexibility

So long as Windows handles it gracefully, that looks like a nice piece...

Just curious... is APO the go-to choice for Windows equalization in the community?
Or is that just your personal choice, resulting from testing a number alternatives?

Equalizer APO has significant community support,
and it has been both more stable and less obtrusive in operation
than alternatives tested and used over 30 years.
Important to me is synergy with Room EQ Wizard, which I intend to apply for haptics,
having good experience with it in home theaters.

Keep in mind the Hz applied is not the only Hz generated.

That is one place that contact microphone experiments hopefully apply.
FWIW, your concerns echo those among audiophiles;
where commodity audio equipment are developed largely based on measurements
made using single frequencies, rather than listening to music.
On the other hand, when single frequency measurements are bad, other results are not great.

Rather than depend on specific equipment capabilities, anything that can be accomplished using free
(and preferably open source) software with commodity hardware at least allows results to be more widely duplicated.
FWIW, I also liked the XR18 for live performances, but lack experience using it with Windows

 

[Mr Latte]

Using APO for movies or music is one thing.
Applying it to price-conscious owners of budget tactile and amps with Simhub is another

You have yet to show the results of your "pickup" and verify its accuracy or use it has with improving tactile.

As stated before, quality audio tools will show the accurate output of what frequencies are being generated from Simhub as a source. Not the operational noise of the transducer and what its installed onto.

 

[ferdiaz]

Before dreaming on ideal configuration or buying stuff and stuff, software DSP PEQ is a good first step for me.

Completely understandable. Besides, this approach, if working, scales very well. By decoupling the EQ functionality from the amplification, you can first design your software (APO) equalization setup/profile, and then amplify the result with whatever you have at hand.

As mentioned, price is one factor leading me to investigate this approach... the other big factor, is flexibility: this approach allows me to begin by setting up my environment using budget amplification (or whatever is laying around at home), and later to upgrade to a higher quality device without having to touch the EQ. Just plug and play.

So long as Windows handles it gracefully, that looks like a nice piece...

Agreed. I'd expect this to be the case, but it definitely needs to be tried and tested. My 4x4 Tascam interface shows the 4 output channels in Mac (I don't have Windows at home yet, though I have already pre-ordered a PC to build my rig). I'd be surprised if it wasn't the same in Windows. After all, audio devices with a 7.1 setup do show their channels correctly... so the Behringer interface "shouldn't" be much different... But as mentioned before, this must be tested and confirmed.

Advice, for an interface but with plenty of channels. The Behringer XR18 is one of the best value.

Thanks for the suggestion. Though I am a bit confused. Doesn't this device support 18 input (rather than output) channels? Isn't the goal to split the signal in X separate output channels (one for each BK/transducer), rather than consolidating X separate channels into a single signal? Could be that I haven't read the spec correctly, though. I am checking this:
https://www.behringer.com/product.html?modelCode=P0BI8

Note also that DSP on the Behringer amps is only $50 or £30-£50 (price varies) over models without it. That is an absolute bargin considering you get wattage limiter, phase control, crossover, 8 band parametric EQ, a dynamic EQ, easy to share saved configuration profiles with other owners with a easy on the eye user interface.

If someone really wanted to save a bit then as stated many times on the forums the NX1000D will happily power 2x large BK LFE or Concert.

I agree that a difference of ~50 EUR is negligible when considering how much we are getting compared to the non-DSP amp. Yet, if confirmed that the same behavior can be achieved via software with the same degree of quality, then I'd find it hard to justify getting the DSP version. I agree that "it doesn't hurt having it", but yeah... budgets aren't unlimited, and every little corner that can be cut within reason makes a difference. By the way, I am not sure whether prices have changed recently, but the NX1000 and the NX3000 seem to be quite close in price now. Thomann.de is reporting the following prices today:

• NX1000: 172.62 €
• NX3000: 182.78 €
• NX1000D: 211.39 €
• NX3000D: 248.32 €

Thank you all for chiming in, and for the enriching conversation. It's much appreciated. I wish I had already all the gear, so that I could test this out and report back... this will have to wait a bit unfortunately.

 

[blekenbleu]

My 4x4 Tascam interface shows the 4 output channels in Mac (I don't have Windows at home yet,
though I have already pre-ordered a PC to build my rig). I'd be surprised if it wasn't the same in Windows.

Oh my, you may be in for a treat. I am redeploying an obsolete PreSonus AUDIOBOX USB that is plug-and-play on macOS...
on Windows, if a coordinated sequence of software installation and USB connection steps is not precisely followed, all bets are off.
Similarly for e.g. Logitech G29; if plugged to USB before installing Logitech's software, controls get misconfigured and not easily recovered.

achieved via software with the same degree of quality

I forgot to note, by avoiding a round trip of ADC and DAC, software DSP can be of higher quality.
Some hardware DSP is implemented without floating point, which can also be problematic.

 

[ferdiaz]

Oh my, you may be in for a treat. I am redeploying an obsolete PreSonus AUDIOBOX USB that is plug-and-play on macOS...
on Windows, if a coordinated sequence of software installation and USB connection steps is not precisely followed, all bets are off.

Gotta love a challenge!

 

[Mr Latte]

Look no mics

Revs On Rainbow Road


Currently testing rig isolation solution but also how to apply specific Hz elements for RPM characteristics over the RPM range. Lots of single-digit low bass in this example.