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Revisiting speakers vs headphones in light of BACCH and Smyth Realiser

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I am planning to buy a complete ultra high end audio system, however I'm still not decided which route to take.

Option 1: Headphones like Stax SR009S or Abyss Phi Tc with a Smyth Realiser or the BACCH4MAC software

Option 2: Speakers like Genelec Ones or D&D 8C with the BACCH4MAC

Which would result in higher overall sound quality? I assume it is a given that something like the Stax SR009S would outresolve any speakers. HOWEVER, and this is the most important question...

How closely can a Smyth Realiser or the BACCH4MAC, when used with headphones, mimic the sound of a BACCH-ed speaker system? Emphasis on BACCH-ed speaker system.

As far as I am aware, in the demonstrations of BACCH for headphones and the Smyth Realiser, non-BACCH-ed speakers were used. As I understand it, BACCH or Smyth make the headphone listening experience indistinguishable from listening to conventional (non-BACCH-ed) speakers. However, if we make it a level game and use BACCH with BOTH speakers and headphones (or Smyth instead of BACCH with headphones), which come on top?

Maybe even someone from Theoretica could chime in and tell which option they recommend for optimal performance?

Thanks.
 

maverickronin

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Depending on your prefrences, one possible issue with the headphone setup is bass impact.

Even planars like the Abyss with decent amount of moving mass couple to you head won't give you the full body bass impact of speakers so you'll end up needing to cross the headphones over to some subs if you want them to be as close as possible to speakers.
 

Theoretica Appl. Physics

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Apologies for not catching this thread earlier (we have been busy with the release of BACCH4Mac 9.5).

The Smyth Realizer has no way of emulating a pair of BACCH-ed speakers. First, in order to emulate BACCH-ed speakers you would need to make the impulse response measurements (needed to produce the headphones filter) with the BACCH filter on, so you would need BACCH4Mac, but even that will not work as the BACCH 3D Sound process consists not only of a Finite Impulse Response (FIR) filter for crosstalk cancelation (XTC), which, in principle, could be measured by an impulse response measurement system (although not easily, as the filter requires a true stereo (aka 2x2) convolution) but also a proprietary mono correction algorithm than cannot be captured by an impulse response measurement.

With the BACCH-hp module of BACCH4Mac, you make an IR measurement with in-ear microphones and head tracking (a process not unlike that the Smyth Realizer requires) and the BACCH-dSP application then automatically produces, from the same measurement, two filters that are applied in series. The first is a head externalization filter that allows emulating those speakers over headphones (that filter plays the same goal as that produced by the Smyth) and the second filter is a BACCH filter for crosstalk cancelling the (headphones-emulated) speakers. For listening, BACCH-dSP applies these two filters in series to the input audio, along with the the mono correction process, to emulate BACCH-ed speakers. At any time, the user, if he so wishes, can bypass the BACCH filter with a click of a button and hear an emulation of the speakers (non-XTCed), which would then be equivalent to what the Smyth Realizer does.

In other words BACCH-hp does what the Smyth Realizer plus gives you the additional option of projecting the perceived sound in 3D space — not having the soundstage anchored at, and limited to, the (headphones-emulated) speakers as in regular stereo listening.

An additional advantage of BACCH4Mac over the Smyth Realizer is that head tracking is done optically (and very accurately) via a regular webcam (or the built-in webcam in your laptop) and therefore does not require that you wear anything on your head in addition to the headphones.

We generally advise not to think of systems like BACCH-hp or Smyth Realizer, as wonderful and magical as they are, as replacements of the audiophile speaker listening experience (for reasons that include that mentioned by maverickronin) but rather as a way to emulate that experience when you are constrained not to turn on your speakers (someone is sleeping nearby, or you are on travel away from your system). No matter how good your headphones are and how accurate the emulation is, the sensation of sound waves hitting you in the face and body, which adds much to the “being there” realism, is in the realm of speakers and real life sources.

I hope that this explanation is helpful.

Please feel free to reply here, and/or write to us at [email protected] if you have more detailed questions.

Regards,
Buddy
[email protected]
 
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RayDunzl

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Blumlein 88

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Apologies for not catching this thread earlier (we have been busy with the release of BACCH4Mac 9.5).

The Smyth Realizer has no way of emulating a pair of BACCH-ed speakers. First, in order to emulate BACCH-ed speakers you would need to make the impulse response measurements (need to produce the headphones filter) with the BACCH filter on, so you would need BACCH4Mac, but even that will not work as the BACCH 3D Sound process consists not only of a Finite Impulse Response (FIR) filter for crosstalk cancelation (XTC), which, in principle, could be measured by an impulse measurement system (although not easily as the filter requires a true stereo (aka 2x2) convolution) but also a proprietary mono correction algorithm than cannot be captured by an impulse response measurement.

With the BACCH-hp module of BACCH4Mac, you make an IR measurement with in-ear microphones and head tracking (a process not unlike that the Smyth Realizer requires) and the BACCH-dSP application then automatically produces, from the same measurement, two filters that are applied in series. The first is a head externalization filter that allows emulating those speakers over headphones (that filter plays the same goal as that produced by the Smyth) and the second filter is a BACCH filter for crosstalk cancelling the (headphones-emulated) speakers. For listening, the BACCH-dSP applies these two filters in series to the input audio, along with the the mono correction process, to emulate BACCH-ed speakers. At any time, the user, if he so wishes, can bypass the BACCH filter with a click of a button and hear an emulation of the speakers (non-XTCed), which would then be equivalent to what the Smyth Realizer does.

In other words BACCH-hp does what the Smyth Realizer plus gives you the additional option of projecting the perceived sound in 3D space — not having the soundstage anchored at, and limited to, the (headphones-emulated) speakers as in regular stereo listening.

An additional advantage of BACCH4Mac over the Smyth Realizer is that head tracking is done optically (and very accurately) via a regular webcam (or the built-in webcam in your laptop) and therefore does not require that you were anything on your head in addition to the headphones.

We generally advise not to think of systems like BACCH-hp or Smyth Realizer, as wonderful and magical as they are, as replacements of the audiophile speaker listening experience (for reasons that include that mentioned by maverickronin) but rather as a way to emulate that experience when you are constrained not to turn on your speakers (someone is sleeping nearby, or you are on travel away from your system). No matter how good your headphones are and how accurate the emulation is, the sensation of sound waves hitting you in the face and body, which adds much to the “being there” realism, is in the realm of speakers and real life sources.

I hope that this explanation is helpful.

Please feel free to reply here, and/or write to us at [email protected] if you have more detailed questions.

Regards,
Buddy
[email protected]
It looks like you are with the people who make BACCH.

It is great to have someone from that to take part in our forums.

You might want to put something in your profile so everyone knows you are connected with BACCH. Let's us know when we are getting answers about things straight from the people involved in making/designing something.
 

Sal1950

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I am planning to buy a complete ultra high end audio system, however I'm still not decided which route to take.
.
If your going to spend ultra high end money, why not put together a Multich-Atmos system so you can play real multich-immersive recordings?
 

q3cpma

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I don't know about quality per se, but since the vast majority of music is produced on speakers, I expect speakers to give the most neutral and consistent performance across genres and productions.
The real question is: will the room (inc. physicial and digital room correction) be good enough to beat the "roomless" headphones?

Personally, call me when there's an UNIX version; it shouldn't be that hard to make a CLI version, as MacOS itself is almost POSIX compliant, so the GUI is the only thing that should go.
 
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Theoretica Appl. Physics

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It looks like you are with the people who make BACCH.

It is great to have someone from that to take part in our forums.

You might want to put something in your profile so everyone knows you are connected with BACCH. Let's us know when we are getting answers about things straight from the people involved in making/designing something.

Done. Thank you for the advice.
 

Theoretica Appl. Physics

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What's the cost of entry into the world of BACCH-3D these days?

Or a demo?

https://www.theoretica.us/dealers.html

Nothing close to me.

The pricing for BACCH4Mac is shown in the Editions table near the bottom of the BACCH4Mac webpage.

The Intro Edition was created to provide an entry level software-only BACCH solution.

BACCH4Mac Intro is an excellent way to explore BACCH on your system. Many BACCHers use the Intro Edition as a stepping stone towards the Audiophile Edition while some are happy to stay at the Intro level and enjoy BACCH without head tracking and customized BACCH filters.

BACCH4Mac Intro relies on the u-BACCH module of the BACCH-dSP application at the heart of all the BACCH4Mac editions. The u-BACCH module (where the “u” stands for “universal”) produces u-BACCH filters, which give 3D sound over loudspeakers (with no head tracking) based on the user's input of quick tape measurements of the listening geometry. u-BACCH filters come close to the performance of regular BACCH filters (the latter rely on acoustic measurements using the BACCH-BM, or BACCH-BM pro, in-ear mic) if the loudspeakers are well-matched in frequency and phase and they have good phase coherence.

To learn more about u-BACCH module of BACCH-dSP look for that module description on the BACCH-dSP webpage.

While Theoretica has a network of dealers around the world for its standalone BACCH-SP processor (who are happy to give demos of the BACCH-SP), the BACCH4Mac product is sold directly by Theoretica through its webpage. One great thing about the BACCH4Mac Intro Edition is that you would can get 100% refund within 14 days of purchase if you decide not to keep it. Therefore not only you can have a BACCH demo whenever you want, but you can have one with your own system in your own listening room with the assurance of a full refund return policy. (The return policy of the other editions, stated at the bottom of the BACCH4Mac webpage involves a restocking fee as the package involves hardware and an in-ear microphone that must be refurbished after return.)

Buddy
[email protected]
 
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RayDunzl

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Thank you.
 
OP
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Apologies for not catching this thread earlier (we have been busy with the release of BACCH4Mac 9.5).

The Smyth Realizer has no way of emulating a pair of BACCH-ed speakers. First, in order to emulate BACCH-ed speakers you would need to make the impulse response measurements (needed to produce the headphones filter) with the BACCH filter on, so you would need BACCH4Mac, but even that will not work as the BACCH 3D Sound process consists not only of a Finite Impulse Response (FIR) filter for crosstalk cancelation (XTC), which, in principle, could be measured by an impulse response measurement system (although not easily, as the filter requires a true stereo (aka 2x2) convolution) but also a proprietary mono correction algorithm than cannot be captured by an impulse response measurement.

With the BACCH-hp module of BACCH4Mac, you make an IR measurement with in-ear microphones and head tracking (a process not unlike that the Smyth Realizer requires) and the BACCH-dSP application then automatically produces, from the same measurement, two filters that are applied in series. The first is a head externalization filter that allows emulating those speakers over headphones (that filter plays the same goal as that produced by the Smyth) and the second filter is a BACCH filter for crosstalk cancelling the (headphones-emulated) speakers. For listening, the BACCH-dSP applies these two filters in series to the input audio, along with the the mono correction process, to emulate BACCH-ed speakers. At any time, the user, if he so wishes, can bypass the BACCH filter with a click of a button and hear an emulation of the speakers (non-XTCed), which would then be equivalent to what the Smyth Realizer does.

In other words BACCH-hp does what the Smyth Realizer plus gives you the additional option of projecting the perceived sound in 3D space — not having the soundstage anchored at, and limited to, the (headphones-emulated) speakers as in regular stereo listening.

An additional advantage of BACCH4Mac over the Smyth Realizer is that head tracking is done optically (and very accurately) via a regular webcam (or the built-in webcam in your laptop) and therefore does not require that you wear anything on your head in addition to the headphones.

We generally advise not to think of systems like BACCH-hp or Smyth Realizer, as wonderful and magical as they are, as replacements of the audiophile speaker listening experience (for reasons that include that mentioned by maverickronin) but rather as a way to emulate that experience when you are constrained not to turn on your speakers (someone is sleeping nearby, or you are on travel away from your system). No matter how good your headphones are and how accurate the emulation is, the sensation of sound waves hitting you in the face and body, which adds much to the “being there” realism, is in the realm of speakers and real life sources.

I hope that this explanation is helpful.

Please feel free to reply here, and/or write to us at [email protected] if you have more detailed questions.

Regards,
Buddy
[email protected]

Thanks a lot for the informstive reply. Really appreciate it. Do you think that it would be possible to combine BACCH-ed open back headphones with a subwoofer or perhaps something like this https://subpac.com/ to get the visceral body impact?

Especially the Subpac intrigues me greatly. While I could soundproof a room and get a great speaker system if I wanted to, the headphones + subpac route appears to be by far the more convenient and cheaper one.
 

Theoretica Appl. Physics

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We have no experience with the Subpac system at Theoretica nor do we know anyone who has tried it with headphones (which may not be too surprising given that it is a product yet to be released). Although the idea of combining such hardware with headphones is intriguing, and may well lead to a fun experience, we are very skeptical that such a system could come near, in sheer realism, to listening to a pair of full-range, phase-coherent, low-distortion speakers with a custom, i.e. individualized, BACCH filter.

Moreover, in order to create a BACCH-hp filter that believably emulates the sound of speakers in your room you would need physical speakers in the first place, and ideally have the impulse response measurements (needed to produce the BACCH-hp filter) done in the same room (of course you could emulate someone else’s speakers in someone else’s room).

This is why, as I stated in an earlier reply to your post, we look at headphones-based speakers emulation systems (such as the BACCH-hp or the Smyth) as a convenient alternative to speakers-based listening, when the latter is prohibited by environmental constraints or lack of access to actual speakers, and not as a perfect replacement to speakers-based listening.

Finally, there is an important factor that I forgot to mention in my earlier post, and that is the importance of having a pair of actual speakers in your visual field to look at (or to at least to be conscious of their visual presence) for the head externalization to be robust. Without real speakers in front of you, there is a well-known psycho-acoustical tendency to head-internalize the sound during headphones-based speakers emulation. This important fact may not be often mentioned by people eager to sell you a headphones-based speakers emulation system, but can be attested to by anyone who owns such a system.

A robust headphones-based speakers emulation system, therefore has the following requirements,

1. A good high-fidelity head-externalization filter (such as those the BACCH-hp or Smyth can produce).

2. Accurate head-rotation (yaw) tracking (the Smyth does that using a head-mounted device, while the BACCH-dSP app does it with a webcam)

3. Real speakers in the visual field (to use for measuring the impulse responses needed for making filter, and to look at, at least intermittently, during listening)

4. Either a transparent pair of open headphones, or, if you must use closed headphones, an individualized equalization filter produced from a measurement of the HpIR, which is the headphones impulse response measured at the entrance of the ear canals (both BACCH-dSP and Smyth can do that through a measurement that involves wearing the headphones while the in-ear microphones are in your ears). This equalization step is often not necessary for open headphones due to the associated low value of the acoustic impedance between the headphones transducers and the entrance for the ear canals.

5. If you wish the emulation to be 3D, and not of just regular stereo speakers, then a final requirement would be an individualized XTC filter (e.g. a BACCH filter for speakers).

I hope the above is clear and helpful.

Regards,
Buddy
[email protected]
 
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OP
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Moreover, in order to create a BACCH-hp filter that believably emulates the sound of speakers in your room you would need physical speakers in the first place, and ideally have the impulse response measurements (needed to produce the BACCH-hp filter) done in the same room (of course you could emulate someone else’s speakers in someone else’s room).

Interesting. I know that with the Smyth Realiser, you need to do this - measure speakers in order to then emulate the experience of listening to those speakers. You can make measurements in different rooms with different speaker systems and get different results/listening experiences, and Smyth ships the product with I believe two pre-installed options.

However, with BACCH, isn't the purpose of the filter to remove the speakers from the equation completely?

Why should you need to measure speakers, emulate them with headphones, and then run a filter to remove the experience of listening to the speakers you measured?

Couldn't there be a way to create 3D sound with headphones directly, i.e. bypassing the step of measuring speakers?
 

Theoretica Appl. Physics

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nteresting. I know that with the Smyth Realiser, you need to do this - measure speakers in order to then emulate the experience of listening to those speakers. You can make measurements in different rooms with different speaker systems and get different results/listening experiences, and Smyth ships the product with I believe two pre-installed options.

However, with BACCH, isn't the purpose of the filter to remove the speakers from the equation completely?

Why should you need to measure speakers, emulate them with headphones, and then run a filter to remove the experience of listening to the speakers you measured?

Couldn't there be a way to create 3D sound with headphones directly, i.e. bypassing the step of measuring speakers?

The BACCH-hp module (which is part of the BACCH4Mac Audiophile+ Edition), like the Smyth Realizer, does indeed require measurements to be done with actual speakers and your actual ears. Only then you could capture the needed components of your individual HRTF that are essential to making the head externalization believable and robust.

We do have another technology called VLS (Virtual Loud Speakers) that requires the BACCH-3dm module of BACCH-dSP Pro (BACCH4Mac Pro Edition). BACCH-3dm is a powerful 3D mixer but also allows making both BACCH and BACCH-hp filters with virtual speakers and a virtual head (using pre-measured HRTFs). Essentially, you would use the BACCH-3dm mixer (which is described on this page) to place two virtual speakers (actually perfect point sources) anywhere you wish in 3D space, choose the dimensions of a (shoebox-shaped) room, the materials of the walls (which control the absorption and early and late reflections), and select a pre-measured HRTF (a set of 10 are provided but you can add your own in the SOFA format if you have it). BACCH-dSP then allows you to make both BACCH filters (for XTC) and BACCH-hp filters (for headphones-based speakers emulation) for that virtual system and apply it to emulate that system over headphones. This VLS technique has the advantage of giving you a lot fo latitude to tweak things without worrying about actual hardware but it is not as foolproof as the regular BACCH-hp or Smyth method of emulating real speakers in real rooms and for your own head. Moreover VLS is an advanced pro tool that requires (aside from the cost) some knowledge of, and experience with, spatial audio concepts.
 
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I think I understand now. You need your own personal HRTF for the BACCH-hp to work optimally.

Do you thing something like this https://www.genelec.com/aural-id
could work too at the highest level? You mentioned that the BACCH VLS is not foolproof. However, if I loaded my personal accurate HRTF into BACCH VLS, could I get an optimal result?
 

Theoretica Appl. Physics

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I think I understand now. You need your own personal HRTF for the BACCH-hp to work optimally.

Do you thing something like this https://www.genelec.com/aural-id
could work too at the highest level? You mentioned that the BACCH VLS is not foolproof. However, if I loaded my personal accurate HRTF into BACCH VLS, could I get an optimal result?

Yes, loading you personal HRTF in the BACCH-3dm mixer and using that to make a VLS BACCH-hp filter will definitely improve the result. It would address the first of the 5 requirements I listed above. BACCH-dSP will also take care of Requirements 2 and 5. You would still need to adequately address Requirements 3 and 4 (especially 3).
 

phoenixdogfan

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Depending on your prefrences, one possible issue with the headphone setup is bass impact.

Even planars like the Abyss with decent amount of moving mass couple to you head won't give you the full body bass impact of speakers so you'll end up needing to cross the headphones over to some subs if you want them to be as close as possible to speakers.
Or use a tactile sub.
 
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Yes, loading you personal HRTF in the BACCH-3dm mixer and using that to make a VLS BACCH-hp filter will definitely improve the result. It would address the first of the 5 requirements I listed above. BACCH-dSP will also take care of Requirements 2 and 5. You would still need to adequately address Requirements 3 and 4 (especially 3).

Thank you very much for your detailed answers. One more thing that interests me is what headphone in particular would you recommend for optimal speakers emulation. I know the HD800 is widely used for 3D audio, and Stax models are held in high regard too (also by Smyth Research). In your experience, which is the absolute best one to use with BACCH?
 

Theoretica Appl. Physics

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While we generally shy away from recommending specific brands, I can say that all the open headphones we have in the lab, which include the HD650, and the Stax SR09, work nicely with BACCH-hp.
 

phoenixdogfan

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Apologies for not catching this thread earlier (we have been busy with the release of BACCH4Mac 9.5).

The Smyth Realizer has no way of emulating a pair of BACCH-ed speakers. First, in order to emulate BACCH-ed speakers you would need to make the impulse response measurements (needed to produce the headphones filter) with the BACCH filter on, so you would need BACCH4Mac, but even that will not work as the BACCH 3D Sound process consists not only of a Finite Impulse Response (FIR) filter for crosstalk cancelation (XTC), which, in principle, could be measured by an impulse response measurement system (although not easily, as the filter requires a true stereo (aka 2x2) convolution) but also a proprietary mono correction algorithm than cannot be captured by an impulse response measurement.

With the BACCH-hp module of BACCH4Mac, you make an IR measurement with in-ear microphones and head tracking (a process not unlike that the Smyth Realizer requires) and the BACCH-dSP application then automatically produces, from the same measurement, two filters that are applied in series. The first is a head externalization filter that allows emulating those speakers over headphones (that filter plays the same goal as that produced by the Smyth) and the second filter is a BACCH filter for crosstalk cancelling the (headphones-emulated) speakers. For listening, BACCH-dSP applies these two filters in series to the input audio, along with the the mono correction process, to emulate BACCH-ed speakers. At any time, the user, if he so wishes, can bypass the BACCH filter with a click of a button and hear an emulation of the speakers (non-XTCed), which would then be equivalent to what the Smyth Realizer does.

In other words BACCH-hp does what the Smyth Realizer plus gives you the additional option of projecting the perceived sound in 3D space — not having the soundstage anchored at, and limited to, the (headphones-emulated) speakers as in regular stereo listening.

An additional advantage of BACCH4Mac over the Smyth Realizer is that head tracking is done optically (and very accurately) via a regular webcam (or the built-in webcam in your laptop) and therefore does not require that you wear anything on your head in addition to the headphones.

We generally advise not to think of systems like BACCH-hp or Smyth Realizer, as wonderful and magical as they are, as replacements of the audiophile speaker listening experience (for reasons that include that mentioned by maverickronin) but rather as a way to emulate that experience when you are constrained not to turn on your speakers (someone is sleeping nearby, or you are on travel away from your system). No matter how good your headphones are and how accurate the emulation is, the sensation of sound waves hitting you in the face and body, which adds much to the “being there” realism, is in the realm of speakers and real life sources.

I hope that this explanation is helpful.

Please feel free to reply here, and/or write to us at [email protected] if you have more detailed questions.

Regards,
Buddy
[email protected]
And the Bacch can capture a 24 channel Atmos or DTS-X surround system, like the Smyth A16?
 
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