[arnaud]

May I ask what headphone setup you're using? This is one of the areas(more wet/reverberant rooms) where I observed significant increases in fidelity from specific equipment. I use an isolated, crystek clocked hub chip and usb to i2s board powered by an isolated ultracapacitor supply, non feedback current signal amplifiers with discrete double stage regulation, balanced drive, and planar headphones. And depending on your personal beliefs, using an r2r dac or doing real time 512dsd conversion can improve that naturalness further, though I have little experience with the latter and none with the former, so your standard es9018 does rather well ;]

I am not using ooyh these days (the clock just gets out of whack within a few minutes with pop/click sounds that get worse. It’s unusable as I need to keep switching away and back to the output card (su-1 per sig). But when I did, I was using a rather resolving rig (totaldac d1-dual/six > bhse > sr009). I plan to use the rig in my sig with the a16.

In regards to how realistic the reverb sounds, the resolution of the rig probably plays a role but we also need to keep in mind how low fidelity these PRIRs are (cheap electret mics with probably not very good snr etc). I have admittedly very little experience with this as I just used ooyh (never owned an a8) but never could get to enjoy listening to music through ooyh. The only prirs I can stand are those from aix and even there, the coloration outweights benefit from binaural rendering. The plan for me is to use the a16 for movies and, as such, I actually am not too worried about the quality of dac etc...

It is possible to use a PRIR made with only a tweeter to have a high quality BRIR personalised for you on the exchange website. That probably would have been what you recall them suggesting. I don't think such a tweeter-only PRIR could be used as-is to listen to (well, of course it is possible, but it would not give a full range sound). The reason why such a tweeter only PRIR is sufficient to personalise a BRIR with is that the individual differences in HRTFs are mainly in the higher part of the frequency spectrum.

Yes, exactly, I always like to refer to Tyll’s articles as he had this ability to make technically involved topics accessible to anyone motivated to learn about the subject: https://www.innerfidelity.com/content/headphone-measurements-explained-frequency-response-part-one

Now, looking at the various gains chart, the head and torso already play a role from 200Hz so I guess this is why PRIRs actually cover all frequency range (except below 100Hz where user can just use raw signal right?). I was hoping I could use a small broadband single driver equed to measure flat on axis from 200Hz or so but that might not be enough then?

When you think about it, it’s such a waste of effort to try acquire PRIRs below 200Hz and ironic that we then get into requirement to make the PRIR measurement through a room equalized speaker system when we should just not record LF content in the first place...

 

[sahmen]

So is there a limit to the number of possible PRIRs a person can possibly have for use with one A16?

Also can one have more than one PRIR configuration loaded on the A16 at the same time, for on the fly swapping (or "rolling") between PRIRs (i.e. rather than using more than one of them at the same, which is not my intention)?

 

[arnaud]

To be more precise, I am not sure if relying solely on the recording reverberation (without the reverb from a PRIR) would render a coherent perception of distance.

It’s an interesting topic. As I recall, one issue with listening to speakers in too dry a space is that their tonality will be off since they’ve been designed to measure flat in standard environment. Besides, I can imagine that we may experience poor imaging with just left/right/center blobs because the sources are very directional. The one interesting experience I had though was listening to a roger waters recording in full anechoic chamber where the speakers cross-talk to L/R ears been filtered out. I forgot the recording name but not the dog barking and sounds coming from all around despite using 2 speakers! Here actually, the perception of depth was vivid so I can surely say that (just like when listening to headphones), the reverb in the recording can be enough to make one perceive depth.

One issue I can imagine with playback of standard multi-channel recordings isthat surround tracks may not sound realistic when sound from each speaker is very directional (e.g. isn’t the HT standard guideline that all speakers should not be too easy to localize and combine a bit of direct and reverb field to the listener to make the surround experience realistic?)

I hope I will find time to experiment with this if/when the a16 ships (make a direct field dominant PRIR set and another with more reverb contribution but truncated decay).

 

[Dixter]

The on board non volatile memory should hold 200 PRIR files ... and the sd card can hold more PRIR files still..... and of course you get to mate the PRIR files with the different headphone HPEQ files for each of your different headphones... so Rolling won't be an issue... you get to choose a PRIR and a HPEQ and it gets saved to a preset... then you can switch between presets..

 

[arnaud]

isn't 50cm a little close? I think even the big circular stuff used in labs to measure HRIR stuff will settle on 1m or more around the subject. or is it that you really don't want to risk having any remaining reverb once you shorten the duration of the impulse?

about reverb, I think there is a fairly large agreement on people preferring fake room reverb to be less than how the room would "behave" in reality. but IDK if everybody is fine without any reverb. I'm guessing that once again it will depend on the person and what he/she/spaghetti monster prioritizes when interpreting sensory cues.
I usually prefer the reverb in the room I'm in even if it sucks, instead of big space reverb, but nothing at all can be a little too clean for music IMO. while with movies the reverb that seems to go with the scene is usually enough for me. so it seems that I don't even fully agree with myself ^_^.

Thanks for the feedback, I have to admit I have too little experience to assess which will be the way to go for me. I have a gut feeling that main limitation of dry room prirs may be because it makes the individual channels easy to localize (which can ruin the surround effect I guess) and I guess I could be happy with prirs recorded with a bit of reverb but not too much ...

As for the 50cm distance, yes indeed it would be probably too short if the PRIR starts from 200Hz. An HRTF is defined by a planar incident wavefront so head should be a few acoustic wavelengths away from the point source...

 

[jgazal]

(...) The one interesting experience I had though was listening to a roger waters recording in full anechoic chamber where the speakers cross-talk to L/R ears been filtered out. I forgot the recording name but not the dog barking and sounds coming from all around despite using 2 speakers! Here actually, the perception of depth was vivid so I can surely say that (just like when listening to headphones), the reverb in the recording can be enough to make one perceive depth.(...)

Dr. Choueiri most basic Bacch filter, based on tape measurements of listening geometry, is said to be better.
To cancel crosstalk you need to be careful with speaker directivity indeed.

 

[blubliss]

Arnaud, you own an A8 and this is what you are listening through, right? Surely, you're not talking about the out of your head software?

 

[arnaud]

Arnaud, you own an A8 and this is what you are listening through, right? Surely, you're not talking about the out of your head software?

No, to be clear, I do not own an A8 and have been exclusively using OOYH with PRIRs recorded at AIX or various socal places with Darin. So, my feedback on unrealistic reverb etc is all without head tracking etc and I could not try various settings like truncating off some the IR tail etc.
It's about time for the A16 to arrive indeed

 

[blubliss]

That software is a toy compared to the A8, which i have owned for 10 years. Was really confusing to read your thoughts, hope others don't get confused.

 

[Dixter]

maybe someone can answer this question please... I am under the impression that Darin actually used/uses the A8 to capture the rooms he sells on OOYH and then just imports them into the software version of the A8 that does not support head tracking or HPEQ files.... ???

 

[blubliss]

There's no such thing as a software version of the A8. And at least one, if not all of those PRIRs he's selling came from the private, personal exchange the A8 owners set up.

 

[arnaud]

maybe someone can answer this question please... I am under the impression that Darin actually used/uses the A8 to capture the rooms he sells on OOYH and then just imports them into the software version of the A8 that does not support head tracking or HPEQ files.... ???

AFAIK, Darin uses an A8 to capture PRIRs and HPEQs then gets resulting impulse responses out of the realizer through the digital out (it's for instance "straightforward" to feed the A8 with a dirac function and recover the digital output at native 24/48 rate which is no less than the PRIR/HPEQ impulse response used by the realizer for real time convolution when tracking is off).

That software is a toy compared to the A8, which i have owned for 10 years. Was really confusing to read your thoughts, hope others don't get confused.

I don't have direct A/B experience and, if what you say is true, I can only get more excited about the A16. Having said that, I recall reading from several people in the OOYH thread that they actually did not feel a loss of fidelity when listening to the same PRIR/HPEQ pair through OOYH rather than A8 with tracking off. Actually, convolution is convolution so, unless Darin was not recovering the filters in a lossless manner, one would not expect any difference between a software vs. hardware based real time convolution.

My main issue with OOYH is that I just can't get it to work with my D2D converter under current mac OS so just left it aside and waiting for the A16.

 

[Sanctuary]

So is there a limit to the number of possible PRIRs a person can possibly have for use with one A16?

Also can one have more than one PRIR configuration loaded on the A16 at the same time, for on the fly swapping (or "rolling") between PRIRs (i.e. rather than using more than one of them at the same, which is not my intention)?

Unless they drastically cut features from the A8, you can have more PRIRs internally than you'll realistically use, and that also goes for the HPEQ. You can also store them on an SD card. On the A8 at least, you can have up to four selectable presets to switch between on the fly. Although on the A8, when you want to use dual user mode, the fourth preset is always dedicated to the second user.

 

[Indisch]

No, to be clear, I do not own an A8 and have been exclusively using OOYH with PRIRs recorded at AIX or various socal places with Darin. So, my feedback on unrealistic reverb etc is all without head tracking etc and I could not try various settings like truncating off some the IR tail etc.
It's about time for the A16 to arrive indeed

Hi arnaud,
as I will be in San Diego and LA in August I wanted to ask you if you could tell me which location in your opinion is the best to get the PRIR done. I wrote Darin Fong an email and thought, while I was waiting for a reply, to get a second opinion from someone who has done the measurements in different locations. I will be using the A16 only for gaming and movies if that is somewhat relevant for choosing a location. Of course if anyone else here has experience with getting their measurements done in SoCal I would be happy to hear their opinion too.

 

[arnaud]

Hi arnaud,
as I will be in San Diego and LA in August I wanted to ask you if you could tell me which location in your opinion is the best to get the PRIR done. I wrote Darin Fong an email and thought, while I was waiting for a reply, to get a second opinion from someone who has done the measurements in different locations. I will be using the A16 only for gaming and movies if that is somewhat relevant for choosing a location. Of course if anyone else here has experience with getting their measurements done in SoCal I would be happy to hear their opinion too.

Hi there, if we go by Blubliss comment, my opinion on the PRIRs I recorded with Darin may be flawed because I've been using them with OOYH rather than A8 so take the following with caution. In short, I ended up not liking any of the PRIRs I made except for those at AIX studio. All the others just have a weird tonality and way too much reverb and they all came from mid to high end speakers setup in standard living rooms without too much acoustic treatment. The speaker systems and the auralization sounded fine on the spot (through the A8) but a let down when I was back home behind the computer (through OOYH).

As I don't think AIX is available any longer, I would prioritize as follows:
1. Check which event Smyth Research will attend next and try to book a spot there
2. Contact Darin and see if he has alternative / better places to pick from these days (I got mine done several years ago), he's super nice dude / easy to talk to
3. Just wait for the A16 and get a single speaker ready for doing your PRIRs + some friends help to seat the mics etc.

cheers,
arnaud