[MichaelJames99]

Have you checked out the sennheiser gx1000 headphone processor? There are some binaural demos of it on youtube. Its $200

Trying to figure out what Inputs it takes? I am not using this with a computer.

 

[cachi]

Trying to figure out what Inputs it takes? I am not using this with a computer.

Sorry, didnt realize it doesnt take optical input. I think it practically requires a computer.

 

[MichaelJames99]

I have a computer that I can use to power it. But I would need something that has an optical input or hdmi input or some other input

 

[Sordel]

So, while we wait, I have nothing that does surround processing for movies from my Bluray or DirectTV.. anything fairly cheap that I can buy to make due until this gets done? Something under $500
Maybe the creative sounds X7?

Just to check: you're happy with your amp and surround speakers but just need a decoder?

 

[MichaelJames99]

AKG712 headphones. My Headphone amp is Musical Fidelity XCan v2..its pretty old but seems to do a good job. Just need a stand alone headphone surround processor that will take an optical or hdmi input. I was using a Creative Sound Blaster Recon3D..before it blew up for movies. It was just ok and used an optical input. Not great. I was powering off a laptop that was next to my Marantz AV7702 Preamp Processor. The Marantz has a Virtual mode for headphones, but its not very good. (this is what I am using right now)

 

[castleofargh]

I have some questions, and a few remarks.

Does that mean you measure the HRTF for 1024 directions, and that for each ear? For the moment I assume that is what it means.
By the way: what is the maximum angle between 2 adjacent points in that case?

Actually if it measures 16 speakers at 5 measurement points (5 lookangles to interpolate between for headtracking/derotating), that would be 80 per ear, 160 total.
Also for one individual pair (one speaker, one lookangle, for the 2 ears) beware that in fact that for that specific lookangle the full HRTF (all directions, an infinite number) is respected: reflexions and reverberations from any direction are captured including the HRTF filtering they underwent. This holds for all the speakers, and all the measurement points. So when during the simulation you look for example straight forward (the zero degree measurement point), at that moment the simulation of all the speakers and the room is "accurate" in the sense that it is not in anyway compromised by lack of having a 1024/2048 point HRTF. Only at the moment that you move your head inbetween the measurement points and the Realiser starts interpolating then there could be (and probably will be) inaccuracy in that same sense.

A little detail: When you do a personal measurement with the Realiser you are actually capturing a PRIR (Personalised Room Impulse Response), not a BRIR (although it would be a BRIR for someone else). Indeed you can not extract the personal HRTF from that, but the personal HRTF is fully respected in the sense that I descibed above.

Note that in the approach of capturing an isolated HRIR and combining that with an isolated room response later, to make that "accurate" you should somehow make sure that all refexions and reverberations undergo the proper HRTF filtering belonging to the many different directions they are approaching the ears from. Is this incorporated in what you desribe in the following quote?

the half stargate(don't know how it's called ^_^) we often see used to capture HRTF, has like like 60 or even more tweeters on it, so it's relatively fast to reach a thousand points. I've seen a bunch of 50*25(horizontal*vertical) measurements for dummy heads, but I've also seen measurements in increments of 15° or 20° for example. and of course, we're very clearly limited in angles while using a pair of headphones sited in a chair. so a great deal of points in a full HRTF have no value for our intended use. I was a little surprised that the calibration was done with so few positions at first, but thinking about it a little, I didn't feel like it was worrisome. now of course it's a serious limitation if the plan is to use the A16 as a measurement tool to do something else. using the A16 to measure stuff, while it would most certainly be trivial for Smyth to allow for it, it's clearly very limited as is, and I doubt they'd be interested in giving us tools to free ourselves from the A16 ^_^. although I absolutely plan to record the output while looking right in the middle and make myself some impulse to get the most customized crossfeed+reverb in the world while using a headphone on the go. it's too bad we can't really used that to calibrate IEMs, but I'm not sure my ears would agree to the in ear mic+ my pair of etymotic .

 

[Richter Di]

Have you checked out the sennheiser gx1000 headphone processor? There are some binaural demos of it on youtube. Its $200

Thanks. Tried the demos but didn’t like it. Sounded a bit artificial. Sorry.

 

[pfzar]

Hello all, http://resource.isvr.soton.ac.uk/FDAG/VAP/html/nmh_hrtf.html a bit of reading and images to an example of one type of rig.

Acoustic measurements are typically every 5deg, some comparisons have been done to evaluate the difference between 512per ear and 1024 per ear. 512 is rather good, and yields good results at the cost of DSP overhead.

The term PRIR is still only rated to the Smyth product, as such is does not translate to a portable dynamic rendering engine.

When one is convolving HRTF with Reverb and reflections they are taking into account the interactions with the various points in space and the relationship to Left and Right ear.

Tweeters are not used for capturing a HRTF, typically something that is more broadband.

https://www.princeton.edu/3D3A/HRTFMeasurements.html

Some of my ongoing work about binaural rendering can be found here.
http://www.aes.org/e-lib/browse.cfm?elib=19310

 

[jgazal]

(...) I was a little surprised that the calibration was done with so few positions at first, but thinking about it a little, I didn't feel like it was worrisome. now of course it's a serious limitation if the plan is to use the A16 as a measurement tool to do something else. using the A16 to measure stuff, while it would most certainly be trivial for Smyth to allow for it, it's clearly very limited as is, and I doubt they'd be interested in giving us tools to free ourselves from the A16 ^_^. (...)

AFAIK, the limitation is for real time content decoding. Smyth may allow in the mid term two A16 with master/slave head tracking and third order ambisonics. You can measure as many points as you like:

(...)
This screen shot shows the virtual room speaker set up menu for the selected preset. Each of the inputs can be assigned any virtual speaker from any PRIR file the user has stored in the A16, on the micro SD card, or, if connected to the internet, any PRIR or BRIR file the user has in their account in our Realiser Exchange website. This is a major improvement from the A8 which could only load entire PRIR files to presets.
(...)
http://smyth-research.com/downloads/additional_KS_info.pdf

If they don’t encourage users to measure more points, it might mean that they don’t beleive users will go that extra mile (to feed more coefficients in the interpolation algorithm) or that they don’t need to go that extra mile (apparently at least one user, @dsperber, is convinced with the Realiser interpolation performance).

This is Smyth view:

I agree completely and that’s why I think future acquisition of HRTF with biometrics has an edge over PRIR’s. (...)
You’ve got me there, particularly having in mind the efficiency of the interpolation algorithm. You have to hear it by yourself. Nevertheless, here is what Professor Smyth says about you apprehension:

SMYTH SVS
HEADPHONE SURROUND MONITORING FOR STUDIOS
PRIR look-angles
SVS simplifies the personalisation process by acquiring a sparse set of PRIR measurements for each active loudspeaker. Typically the system measures these responses for three different head positions, at approximately -30º, 0º and +30º azimuthal angle.
(...)
The three positions chosen allow simple rotational head- tracking to be accomplished by interpolation between the binaural data sets from each head position – for example, within the scope of the left and right speakers. This is a necessary but reasonable compromise. For critical listening the only viable monitoring position is looking straight ahead at the centre speaker, and thus is accurately virtualized using the SVS methodology. Head-tracking induced interpolation is only engaged when the user's head moves off centre.
(...)
PRIR data: are three positions enough?
The three positional PRIR data sets, typically used by the SVS system, allow restricted head movements around the central monitoring position, sufficient to maintain the authenticity of the virtualisation. Nevertheless, interpolating between PRIRs does introduce some degree of inaccuracy. However experimental evidence [7] has shown that interpolation between two individualised HRTFs with an azimuthal separation of up to 30º does not introduce perceptible errors. Where SVS is used to virtualise 5.1ch loudspeaker arrangements, the PRIR separation is typically 30º.
It should also be noted that any inaccuracy introduced is mitigated by two factors. First, the normal monitoring position is looking straight at the centre speaker, and here the interpolation distance is negligible. Therefore the PRIR data used for virtualisation during critical listening is almost identical to the measured data. Taking this a step further, the user can opt to temporarily disable the head-tracking, thereby completely removing inaccuracies introduced by PRIR interpolation.
(...)
[7] Martin, R. and McAnally, K. 2007. "Interpolation of Head-Related Transfer Functions", Australian Government, DSTO-RR-0323
http://www.smyth-research.com/articles_files/SVSAES.pdf

On the other hand, if competitors start offering, for instance “head-related transfer functions (HRTFs)” calculated “directly from head scan point clouds of a subject using a database of HRTFs”, I don’t see why Smyth would not use an AES standard if that approach has better performance than their interpolation...

A method for efficiently calculating head-related transfer functions directly from head scan point clouds
Authors: Sridhar, R., Choueiri, E. Y.
Publication: 143rd Convention of the Audio Engineering Society (AES 143)
Date: October 21, 2017

A method is developed for efficiently calculating head-related transfer functions (HRTFs) directly from head scan point clouds of a subject using a database of HRTFs, and corresponding head scans, of many subjects. Consumer applications require HRTFs be estimated accurately and efficiently, but existing methods do not simultaneously meet these requirements. The presented method uses efficient matrix multiplications to compute HRTFs from spherical harmonic representations of head scan point clouds that may be obtained from consumer-grade cameras. The method was applied to a database of only 23 subjects, and while calculated interaural time difference errors are found to be above estimated perceptual thresholds for some spatial directions, HRTF spectral distortions up to 6 kHz fall below perceptual thresholds for most directions.

Q20: Will the A16 support AES69-2015 format (an open file format for binaural impulse responses)?

A20: Not initially but we will keep the situation under review. The Realisers use a proprietary format developed by Smyth Research. Since our products all permit owners to create their own personalised binaural measurements and to exchange these measurements among themselves, compatibility with the AES format is not an urgent priority.
http://www.smyth-research.com/A16Q&A.html

But chances are the memory from the measurement itself plays a role. If that is true, then every solution relying exclusively in biometric measurement will need to deal with that untrained sound perception. And then training with VR headsets might be a good idea...

Ultimately, you have to ask a lot of users where they hear sounds to be sure that the perceived positions match the real source positions (and the restrictions are not only the interpolation performance itself, but also, for intance, the record format, playback environment etc..). Really fascinating research line for @pfzar, Smyth, Choueiri, Toole, Farina, Hans Peter Gasselseder, Teck Chee Lee and others.

 

[Fox1977]

So, while we wait, I have nothing that does surround processing for movies from my Bluray or DirectTV.. anything fairly cheap that I can buy to make due until this gets done? Something under $500
Maybe the creative sounds X7?

While waiting for the A16, i'm using Out Of Your Head to read my movies via Blu-Ray, Netflix or downloads. It works quite fine for me, even though A16 with the PRIR we made in Paris should be far superior, but for now, i can still have a clear out-of-my-head sound (at least with the preset i got with it, many did not sound right to me). I'd say i can locate sounds around 50cm-1m from my ears.

 

[MichaelJames99]

Maybe Im missing something here... But if you are using Out of Your Head, that is PC based software. I need a stand alone processor that can take an HDMI or Toslink input...
here are some examples, but these are older...

Virtual Surround Devices
Astro Mixamp Pro (2013 Edition)
Astro Mixamp Pro (2011 Edition)
Astro Mixamp 5.8
Beyerdynamic Headzone (Base only)
Creative Sound Blaster Recon3D USB
Creative X7
Tritton AX 720
Turtle Beach DSS (old version)
Victor SU-DH1

 

[kh36267]

Maybe Im missing something here... But if you are using Out of Your Head, that is PC based software. I need a stand alone processor that can take an HDMI or Toslink input...
here are some examples, but these are older...

Virtual Surround Devices
Astro Mixamp Pro (2013 Edition)
Astro Mixamp Pro (2011 Edition)
Astro Mixamp 5.8
Beyerdynamic Headzone (Base only)
Creative Sound Blaster Recon3D USB
Creative X7
Tritton AX 720
Turtle Beach DSS (old version)
Victor SU-DH1

I've been using the Beyerdynamic Headzone for many years. I've really enjoyed the way it processes the surround sound signal.......although looking forward to upgrading to the A16

 

[cachi]

Maybe Im missing something here... But if you are using Out of Your Head, that is PC based software. I need a stand alone processor that can take an HDMI or Toslink input...

Why don't you just get an external bluray player for your computer, then you can use all the computer solutions (OOYH, sennheiser GX1000 etc)

 

[MichaelJames99]

Good suggestion if I didnt have so many different sources... 3 sources.. DirectTV reciever, HDDVD player, and a BluRay player going out to a 65" Panasonic Plasma 65VT60 TV

 

[cachi]

Good suggestion if I didnt have so many different sources... 3 sources.. DirectTV reciever, HDDVD player, and a BluRay player going out to a 65" Panasonic Plasma 65VT60 TV

Thats not really a good excuse, you can get an hdmi switcher (there are cheap ones to be had).