Properly Integrating Tactile Transducers with Dirac ART?

[Cinema40]

Hey all,
My 5.4.4 HT setup comprises of 4 SVS SB 1000 Pros that are connected to individual sub outs of a Marantz Cinema 40 AVR. I have calibrated the setup using Dirac ART and am getting enough bass down to 20hz but want to experience infrasonic bass sensation (the rumble basically) without replacing the current subwoofers or adding additional ones.

The most used method is adding tactile transducers. The question is how do I connect it to my AVR, without messing with the overall subwoofer integration. My options are as follows -

1. Front Pair of Subs connected to a single subwoofer out. Rear Subs taking subwoofer out 2 and 3. Subwoofer out 4 configured as a tactile transducer in marantz settings and going to a dedicated subwoofer amp powering 4 tactile transducers. - Sub out 1,2 and 3 will be managed by Dirac ART, I don't know how the front two subs will be summed and if it can be done properly?
2. All 4 subwoofers remain independently connected but tactile transducers are added to one of the subwoofer outs using a Y RCA splitter. The AVR settings will not be changed and the subwoofer amp connected to the tactile transducers will be low passed to 40hz manually. - Infra bass bypass option will be enabled in Dirac Settings to allow sub 20hz content to be delivered to that particular subwoofer output.

What setup is recommended?

 

[Redacted]

I thought a tactile transducer vibrates solid objects and is not transmitting through air as such (as in the name).
If so, I don't see how Dirac will deal with it. And maybe low-passing them well below 40Hz seems a better idea to me if you are already getting 20Hz through your subs (a measured -3dB point or an assumption?)

Experimentation called for - let us know the findings.

 

[Cinema40]

I thought a tactile transducer vibrates solid objects and is not transmitting through air as such (as in the name).
If so, I don't see how Dirac will deal with it. And maybe low-passing them well below 40Hz seems a better idea to me if you are already getting 20Hz through your subs (a measured -3dB point or an assumption?)

You're right, I meant feeling that infrasonic bass sensation as it's a very costly affair to get subs that can move that much air. Also, I get 20hz flat in room as measured in REW. What i was wondering was if it's best to leave 4 sub outs to individual subs only with the transducer low passed on one output or dedicate 1 sub out to a tactile transducer and then run Dirac on 4 subs connected to 3 subwoofer outs remaining?

 

[Redacted]

Can't help with that! If I were trying to get that "infrasonic bass sensation as it's a very costly affair to get subs that can move that much air" I'd look at replacing a sub with one that can go really low, maybe 18" and 1kW? You say "costly" but 4 SVS SB 1000 Pros are not cheap! At least your mic for Dirac might pick it up, unlike a tactile transducer.

 

[Karls_speaker_works]

I have a Sonic Immersion VT200 Ibeam mounted across two floor joists just in front of my couch. I set the low-pass to 40Hz as any higher and it becomes actually audible vs, just shaking the room as I want. People seem to like that I turned the floor into a 150" "subwoofer". I use output #4 as it's dedicated to Tactile Transducer use. But you could do it using either option, can't help much there as I don't have ART.

 

[Keith_W]

The problem with tuning a tactile transducer: can't measure it acoustically. So you can't automate its timing with Dirac ART. You can't replace it with a subwoofer for the purpose of automatic tuning either, because the delay of the sub might not be the same as your transducer.

You could tune it subjectively, or you could try to jerry rig some kind of noise making apparatus that will be excited by the transducer. Maybe put a bell on it or something. Personally I would tune it subjectively, it seems the easiest. I would suggest using a short burst of a test tone to try to align the transducer to the sound.

1. Connect your tactile transducer and your main speakers to outputs L and R respectively. You will need some way to manually set the delays on the channel connected to the main speaker. I say main speaker, because I am guessing that the transducer will have more delay.

2. Set up REW's Generator like this. This will give you five cycles of 50Hz every half a second, which will simultaneously play through your main speaker and your tactile transducer. You may have to tune the settings so that it's easier for you.

3. Set the delays until the two tone bursts seem to coincide.

 

[Cinema40]

I have a Sonic Immersion VT200 Ibeam mounted across two floor joists just in front of my couch. I set the low-pass to 40Hz as any higher and it becomes actually audible vs, just shaking the room as I want. People seem to like that I turned the floor into a 150" "subwoofer". I use output #4 as it's dedicated to Tactile Transducer use. But you could do it using either option, can't help much there as I don't have ART.

The problem with tuning a tactile transducer: can't measure it acoustically. So you can't automate its timing with Dirac ART. You can't replace it with a subwoofer for the purpose of automatic tuning either, because the delay of the sub might not be the same as your transducer.

I think my question may be wrongly understood by the way it's been worded. I am *not* looking to calibrate the tactile transducer using Dirac ART, but rather want to know which method is best to add tactile transducers to a system that's already been optimised by dirac ART. Like would i get a worse result if a y splitter is used for ART because a dedicated sub out is used for adding tactile transducers or not?

 

[staticV3]

You'd ideally need a fifth "clean feed" LFE output from your Cinema 40, before Dirac can do its MIMO beam forming.

That then you could tune by hand to match the acoustic output, ideally with a miniDSP 2x4HD and BassEQ to get proper infra.

I don't think the Cinema 40 can do it though.

Tapping into one of the four regular Sub outputs for the tactile transducer would be rather janky. Not least because Dirac agressively high-passes them at 20Hz.

 

[Cinema40]

You'd ideally need a fifth "clean feed" LFE output from your Cinema 40, before Dirac can do its MIMO beam forming.

That then you could tune by hand to match the acoustic output, ideally with a miniDSP 2x4HD and BassEQ to get proper infra.

I don't think the Cinema 40 can do it though.

Tapping into one of the four regular Sub outputs for the tactile transducer would be rather janky. Not least because Dirac agressively high-passes them at 20Hz.

Would the infra-bypass option not be enough to get that signal to the transducer?

 

[TheKoC]

You could do something with Dirac ART for PC and channel routing in a DAW there, but with the integrated AVRs at I don't see a good solution.
Best would be to petition Dirac to integrate a "this channel is a bass shaker" option in their software, but that will take time if it happens at all.

 

[staticV3]

Would the infra-bypass option not be enough to get that signal to the transducer?

Even if it did, the Sub output from ART is FIR filtered to cancel acoustic modes.

Playing that signal back on a bass shaker is suboptimal.

What's more, without BassEQ in the chain you'll hardly get any infra bass out of the shaker anyway as most soundtracks are high-passed at 30Hz.

 

[Devnull]

Mirror the audio to the zone 2 line level outputs. Then drive the bass shakers with the line outputs

 

[DenonMate]

Mirror the audio to the zone 2 line level outputs. Then drive the bass shakers with the line outputs

If Mainzone and Zone 2 get the same audiosignal there could be a downmix to 2-channel PCM also in the MainZone? Dolby Atmos could be lost.

 

[Devnull]

If Mainzone and Zone 2 get the same audiosignal there could be a downmix to 2-channel PCM also in the MainZone? Dolby Atmos could be lost.

No. Zone 2 gets down mixed, the primary zone doesn't get touched

 

[Cinema40]

Mirror the audio to the zone 2 line level outputs. Then drive the bass shakers with the line outputs

Is there a guide that you can share on how to do that?

 

[DenonMate]

This is from the x4700 manual. As far I understand it you have to set Zone2 or 3 to source to get the MainZone processing untouched. If you set it to a specific source (the same as mainzone) the mainzone signal gets downgraded. But the manual is not perfectly clear at that point.

(Thanks. To use the Zone 2/3 for shakers is a very good hint. Never thought about it. At the moment I use a Y-cable to split the audyssey processed subout2 signal for the shakers going into a minidsp2x4hd.)

And there is no EQ of the signal from source to Zone2/3? That would be great.
Further I guess Zone2/3 RCA output is the same Frequency Range at the lower end as the subouts = down to 3 or 5 Hz?
Since Zone2/3 gets the full range signal you need an external LPF (in the amp with dsp or minidsp or …).

 

[ThELiZ]

I do this very setup. Here’s how I set it up:

I have 4 subs in my rectangular room. One in each corner of the room. I have 4 sub outs, but I want to use ‘sub out 4’ as a tactile channel (so Dirac ignores it during calibration). Your Marantz will have an option to set sub out 4 as a ‘tactile output’.

In order to use my 4 subs, I have to decide which subs are best to combine as one virtual sub (so I can free up sub 4 output). For me, this could have been either my front two or rear two, both of which have similar responses when measured individually. You can either use a Y splitter afterwards to present as one virtual sub, or use miniDSP (which I highly recommend for being able to adjust timings of the tactile device to the subs - but you may get lucky and they may fire at the same time and seem coherent).

Once I’ve freed up sub out 4, I connect my tactile device to that. Then run Dirac calibration (it will ignore sub out 4).

After cal is complete then you need to adjust the volume and timings of the tactile device to suit. Your AVR will let you adjust your crossover slope of the tactile, but not the timings. That’s where I use the MiniDSP.

I can write this up better on my pc better tonight. It’s making me feel a bit sicky doing this on my phone!

 

[Cinema40]

I do this very setup. Here’s how I set it up:

I have 4 subs in my rectangular room. One in each corner of the room. I have 4 sub outs, but I want to use ‘sub out 4’ as a tactile channel (so Dirac ignores it during calibration). Your Marantz will have an option to set sub out 4 as a ‘tactile output’.

In order to use my 4 subs, I have to decide which subs are best to combine as one virtual sub (so I can free up sub 4 output). For me, this could have been either my front two or rear two, both of which have similar responses when measured individually. You can either use a Y splitter afterwards to present as one virtual sub, or use miniDSP (which I highly recommend for being able to adjust timings of the tactile device to the subs - but you may get lucky and they may fire at the same time and seem coherent).

Once I’ve freed up sub out 4, I connect my tactile device to that. Then run Dirac calibration (it will ignore sub out 4).

After cal is complete then you need to adjust the volume and timings of the tactile device to suit. Your AVR will let you adjust your crossover slope of the tactile, but not the timings. That’s where I use the MiniDSP.

I can write this up better on my pc better tonight. It’s making me feel a bit sicky doing this on my phone!

I understood it completely. Thanks for the help!

 

[GusTheCat]

I did this a different way earlier this year. Here’s my post from another forum describing what I did. My tactile platform is there for <20hz signals only. I believe that Dirac will not be applying eq at these frequencies (but could be wrong).

I first tried ezBEQ Christmas 2024 but didn't stick with it as my system was still in flux. As of this week, I now have everything in my system configured exactly as I'd hoped. In terms of bass, that means:

• 4 subs on discrete channels connected to a Denon A1H, using Dirac ART
• 1 tactile bass platform with negative delay offset to the subs of 17ms (meaning that tactile response is in sync with the audible bass)
• ezBEQ loading BEQ profiles via a Raspberry Pi, onto 2 miniDSP 2X4 HDs
• Control of ezBEQ using a custom application (heavily inspired by GoWatchIt) which will load BEQ profiles upon playing a movie in Plex and includes a feature to fallback to non sound format matches for a movie or load a generic curve if the movie isn't found. This is installed in Docker running on my NAS, alongside Plex

I spent a while considering how best to connect everything and perform EQ etc and landed on the following:

1. Each of the 4 sub outs from the Denon is connected to an input on a MiniDSP 2X4 HD
2. On 1 2X4HD, I routed input 1 to output 3 for use on the tactile platform. On this channel I applied the required EQ (I like a subtle effect so went for a low LP filter with a steep roll-off - 20hz I think?).
3. After some experimentation I landed on 17ms as the negative delay required to synchronise the subs and tactile platform. I then applied this delay to all 4 sub output channels on the MiniDSPs, but not the tactile platform
4. Ran Dirac calibration - I have a MLP focused set of 9 measurements and a wider 'front row' set with 17 measurements.
5. During Dirac ART configuration, I ensured that I checked the option to pass through low frequencies below the cut-off of (I think) 20hz.

I watched Dune Part 2 last night and everything felt and sounded great.

I did try a different setup which involved using 1 of the 4 sub outs as a dedicated transducer channel and then using 1 sub channel to drive 2 subs with a minidsp DDRC24 used to split the signal and pre-apply DIRAC to them to make them work well as a pair before then running Dirac for the whole system. I prefer what I did as described in the quote above best.

 

[Sheng]

Recently, I’ve been adding bass shakers to my X6800H-powered 7.4.6 home theater with Dirac Live ART. I used a Y-cable to split the signal from my most powerful sub to the shaker amp. I was initially worried that using a non-native signal would ruin the tactile experience, but it turns out I worried for nothing. I installed four shakers on my wooden two-seater, and the movie-watching experience is absolutely phenomenal now.
I also experimented with giving up one sub channel to use the X6800H’s dedicated tactile transducer output instead. However, the 3-sub + shaker setup couldn't compete—the overall bass performance took a noticeable hit compared to running all four subwoofers.