8 ms·

How Surround Sound for Headphones Works

97 points by vinhnx 12y ago

fxtentacle 12y ago
i didn't submit it yet because the article wasn't 100% ready .. but in any case: Feel free to ask me about it :)
- jcr 12y ago
  Hajo, the article very reads well, so don't worry about it not being "100% ready". I may have missed something that was written, but I wanted to know if you isolate the sound that is _only_ on the given channel before applying your filters? (i.e. isolation through sound inversion to silence everything but the sound that is unique to the channel) Though it's not exactly related, Alexandre Ratchov and Jacob Meuser (and others) have built the amazingly impressive audio features of OpenBSD including sndio(7), sndiod(1), audio(4), audioctl(7), mixerctl(7) and so forth. I've got a hunch that you might really enjoy studying their work. Warning: If you dig into the OpenBSD sound system, you'll probably like it enough to never run any another OS. http://www.openbsd.org/cgi-bin/man.cgi?query=sndio&section=7 http://www.openbsd.org/cgi-bin/man.cgi?query=sndio&section=7 http://www.openbsd.org/cgi-bin/man.cgi/?query=sndiod&section=1 http://www.openbsd.org/cgi-bin/man.cgi/?query=sndiod&section... http://www.openbsd.org/cgi-bin/man.cgi?query=aucat&section=1 http://www.openbsd.org/cgi-bin/man.cgi?query=aucat&section=1 http://www.openbsd.org/cgi-bin/man.cgi?query=audio&section=4 http://www.openbsd.org/cgi-bin/man.cgi?query=audio&section=4 http://www.openbsd.org/cgi-bin/man.cgi?query=audioctl&section=7 http://www.openbsd.org/cgi-bin/man.cgi?query=audioctl&sectio... http://www.openbsd.org/cgi-bin/man.cgi?query=mixerctl&section=7 http://www.openbsd.org/cgi-bin/man.cgi?query=mixerctl&sectio... http://undeadly.org/cgi?action=article&sid=20120401171457 http://undeadly.org/cgi?action=article&sid=20120401171457 http://2010.asiabsdcon.org/papers/abc2010-P1B-paper.pdf http://2010.asiabsdcon.org/papers/abc2010-P1B-paper.pdf http://en.wikipedia.org/wiki/Sndio http://en.wikipedia.org/wiki/Sndio
  - fxtentacle 12y ago
    Thanks for the OpenBSD links :) No, currently I do not do any sound isolation. The reason is that I want the virtualization to be as unobtrusive as possible.
- andrewjkerr 12y ago
  Not a question, but I just installed it on my Mac Mini and WOW! I am blown away by the difference. My music sounds much better. I can't wait to try it out with a movie :)
  - fxtentacle 12y ago
    :)
DiabloD3 12y ago
I'm sorry, but surround sound for headphones (defined as: HRTF implementations) don't work. What does work? Actual binaural recordings made with dummy head recordings. Trying to reprocess 5.1 surround into either a) making it sound like I'm there, or b) making it sound like I'm listening to a 5.1 audio system, has never worked for me. Dolby Headphone is the least objectionable one of them, but it just mangles audio. I wish someone would try to do Ambisonics-like calculations to try to bake 5.1 into working surround sound. I'd even pay for it (for, say, a faux passthrough driver on Windows that outputs to your default sound card).
- manmal 12y ago
  I tried the tool and it really produces some kind of surround sound feeling. Weak, I admit, but it's there.
  - fxtentacle 12y ago
    Well I deliberately called my tool "Hajo's Headphone Enhancer" because it is optimized for my head / ear sizes ... that is (in my opinion) also the biggest problem with measuring actual HRTFs with dummy heads: It'll only work if the user has a head that is similar to the dummy head used for recording.
- acjohnson55 12y ago
  I thought your comment was unnecessarily downvoted, but I also don't think you provide much information. A dummy head recording has the downside that it's no longer fully suitable for playback over anything besides headphones. Also, it is dependent on the HRTF of the dummy matching that of the listener. I'm not sure Ambisonics [1] would work for 5.1 sound. In most cases, 5.1 isn't produced by mic'ing in the directions of the ideal 5.1 speaker placement (at least for movies and music, I don't know anything about 5.1 production for video games). Typically, the L and R channels are used for directional sound, the C is used for dialog and other things that might be corrupted by panning, and the surround and bass channels are used for (weakly directional) ambient sound. So trying to 3-D pan the surround channels will probably just muddle the effect. Really, the best thing would be to actually record or synthesize in the Ambisonic format, and resynthesizing based on the playback setup. But a 5.1 recording, even one created with a 5.1 rig, is poorly suited for this. [1] For those who aren't aware, Ambisonics is a a format for storage of 3-D recordings, independent of the mic and speaker placements at the time of recording and playback. If the mic positions are known, you can project the raw recorded signals from multiple mics onto a neutral format. Likewise, if the speaker positions are known at playback time, the neutral format can be projected onto the proper signals for the playback setup to best simulate the recorded soundfield. Ideally, the recording and playback setups are optimized to capture the full 3-D soundfield.
clarry 12y ago
What's obviously missing is a sample, unprocessed and processed, so that people can listen to the effect without running any os x crapps..
- vosper 12y ago
  You're absolutely right, though "os x crapps" is a bit unfair.
- fxtentacle 12y ago
  the dude abides ;) Original: http://www.hajoheadphone.com/assets/417586_hybrid_orig.mp3 http://www.hajoheadphone.com/assets/417586_hybrid_orig.mp3 Virtualized: http://www.hajoheadphone.com/assets/417586_hybrid_hahe.mp3 http://www.hajoheadphone.com/assets/417586_hybrid_hahe.mp3
  - Groxx 12y ago
    Think you could make one without the heavy equalizer changes? It's hard to compare apples to apples :\
- Robadob 12y ago
  If you search for dolby headphone on youtube, there seems to be alot of mixes of a presumably similar (commercial) technique being used to encode the audio from some music that was recorded in 5.1 (https://www.youtube.com/watch?v=547i8RSveZs https://www.youtube.com/watch?v=547i8RSveZs).
deleted 12y ago
[deleted]
joblessjunkie 12y ago
Headphone surround sound (including recordings made with a binaural "head" microphone) can be very convincing until the listener moves his head. The sounds don't change to match the head motion, and this kills the illusion.
- fxtentacle 12y ago
  Absolutely correct. I'm also working on real-time compensation with the Oculus Headtracker ;) but that won't be ready until a few months from now ...
coreyja 12y ago
Just wanted to say I was looking for something like this last week and couldn't find one for my Mac. Thanks this is awesome! I'll def buy a license here soon
balls187 12y ago
Nice write up. I installed the app to give it a whirl. Admittedly I haven't tried it with movies yet, but it gives a "warmer" sound to my Spotify tracks while using my Polk ANC headphones. I went to purchase the product, but not sure why it's asking me for my mailing address? I'd recommend streamlining the workflow (if possible). Ask for Email address Ask to select Payment Type Then, if credit card is selected: Name as it Appears on the Card Credit Card Number Credit Card Expiry Credit Card CVS Billing Address Billing Phone Number If I chose to use Paypal, why do you need the mailing and phone number?
- fxtentacle 12y ago
  That's a good question.. and I don't know the answer myself: The shop site is run by FastSpring because I didn't want to have to deal with all the VAT weirdness in the EU. Maybe that's why they asked you, so they can decide wether to charge you VAT or not.
rasz_pl 12y ago
does it sound different? yes does it sound 3d? no does it sound better? no, unless you pay, then auto suggestion produces perception of better quality meh
balls187 12y ago
Just wanted to pass on a note, I watched the new Peanuts trailer, and wow, what a massive improvement in sound and bass while using your audio plugin. Going to purchase a license.

97 points by vinhnx 12y ago

fxtentacle 12y ago

i didn't submit it yet because the article wasn't 100% ready .. but in any case: Feel free to ask me about it :)

jcr 12y ago
Hajo, the article very reads well, so don't worry about it not being "100% ready". I may have missed something that was written, but I wanted to know if you isolate the sound that is _only_ on the given channel before applying your filters? (i.e. isolation through sound inversion to silence everything but the sound that is unique to the channel) Though it's not exactly related, Alexandre Ratchov and Jacob Meuser (and others) have built the amazingly impressive audio features of OpenBSD including sndio(7), sndiod(1), audio(4), audioctl(7), mixerctl(7) and so forth. I've got a hunch that you might really enjoy studying their work. Warning: If you dig into the OpenBSD sound system, you'll probably like it enough to never run any another OS. http://www.openbsd.org/cgi-bin/man.cgi?query=sndio&section=7 http://www.openbsd.org/cgi-bin/man.cgi?query=sndio&section=7 http://www.openbsd.org/cgi-bin/man.cgi/?query=sndiod&section=1 http://www.openbsd.org/cgi-bin/man.cgi/?query=sndiod&section... http://www.openbsd.org/cgi-bin/man.cgi?query=aucat&section=1 http://www.openbsd.org/cgi-bin/man.cgi?query=aucat&section=1 http://www.openbsd.org/cgi-bin/man.cgi?query=audio&section=4 http://www.openbsd.org/cgi-bin/man.cgi?query=audio&section=4 http://www.openbsd.org/cgi-bin/man.cgi?query=audioctl&section=7 http://www.openbsd.org/cgi-bin/man.cgi?query=audioctl&sectio... http://www.openbsd.org/cgi-bin/man.cgi?query=mixerctl&section=7 http://www.openbsd.org/cgi-bin/man.cgi?query=mixerctl&sectio... http://undeadly.org/cgi?action=article&sid=20120401171457 http://undeadly.org/cgi?action=article&sid=20120401171457 http://2010.asiabsdcon.org/papers/abc2010-P1B-paper.pdf http://2010.asiabsdcon.org/papers/abc2010-P1B-paper.pdf http://en.wikipedia.org/wiki/Sndio http://en.wikipedia.org/wiki/Sndio
- fxtentacle 12y ago
  Thanks for the OpenBSD links :) No, currently I do not do any sound isolation. The reason is that I want the virtualization to be as unobtrusive as possible.
andrewjkerr 12y ago
Not a question, but I just installed it on my Mac Mini and WOW! I am blown away by the difference. My music sounds much better. I can't wait to try it out with a movie :)
- fxtentacle 12y ago
  :)

DiabloD3 12y ago

I'm sorry, but surround sound for headphones (defined as: HRTF implementations) don't work. What does work? Actual binaural recordings made with dummy head recordings. Trying to reprocess 5.1 surround into either a) making it sound like I'm there, or b) making it sound like I'm listening to a 5.1 audio system, has never worked for me. Dolby Headphone is the least objectionable one of them, but it just mangles audio. I wish someone would try to do Ambisonics-like calculations to try to bake 5.1 into working surround sound. I'd even pay for it (for, say, a faux passthrough driver on Windows that outputs to your default sound card).

manmal 12y ago
I tried the tool and it really produces some kind of surround sound feeling. Weak, I admit, but it's there.
- fxtentacle 12y ago
  Well I deliberately called my tool "Hajo's Headphone Enhancer" because it is optimized for my head / ear sizes ... that is (in my opinion) also the biggest problem with measuring actual HRTFs with dummy heads: It'll only work if the user has a head that is similar to the dummy head used for recording.
acjohnson55 12y ago
I thought your comment was unnecessarily downvoted, but I also don't think you provide much information. A dummy head recording has the downside that it's no longer fully suitable for playback over anything besides headphones. Also, it is dependent on the HRTF of the dummy matching that of the listener. I'm not sure Ambisonics [1] would work for 5.1 sound. In most cases, 5.1 isn't produced by mic'ing in the directions of the ideal 5.1 speaker placement (at least for movies and music, I don't know anything about 5.1 production for video games). Typically, the L and R channels are used for directional sound, the C is used for dialog and other things that might be corrupted by panning, and the surround and bass channels are used for (weakly directional) ambient sound. So trying to 3-D pan the surround channels will probably just muddle the effect. Really, the best thing would be to actually record or synthesize in the Ambisonic format, and resynthesizing based on the playback setup. But a 5.1 recording, even one created with a 5.1 rig, is poorly suited for this. [1] For those who aren't aware, Ambisonics is a a format for storage of 3-D recordings, independent of the mic and speaker placements at the time of recording and playback. If the mic positions are known, you can project the raw recorded signals from multiple mics onto a neutral format. Likewise, if the speaker positions are known at playback time, the neutral format can be projected onto the proper signals for the playback setup to best simulate the recorded soundfield. Ideally, the recording and playback setups are optimized to capture the full 3-D soundfield.

clarry 12y ago

What's obviously missing is a sample, unprocessed and processed, so that people can listen to the effect without running any os x crapps..

vosper 12y ago
You're absolutely right, though "os x crapps" is a bit unfair.
fxtentacle 12y ago
the dude abides ;) Original: http://www.hajoheadphone.com/assets/417586_hybrid_orig.mp3 http://www.hajoheadphone.com/assets/417586_hybrid_orig.mp3 Virtualized: http://www.hajoheadphone.com/assets/417586_hybrid_hahe.mp3 http://www.hajoheadphone.com/assets/417586_hybrid_hahe.mp3
- Groxx 12y ago
  Think you could make one without the heavy equalizer changes? It's hard to compare apples to apples :\
Robadob 12y ago
If you search for dolby headphone on youtube, there seems to be alot of mixes of a presumably similar (commercial) technique being used to encode the audio from some music that was recorded in 5.1 (https://www.youtube.com/watch?v=547i8RSveZs https://www.youtube.com/watch?v=547i8RSveZs).

deleted 12y ago

[deleted]

joblessjunkie 12y ago

Headphone surround sound (including recordings made with a binaural "head" microphone) can be very convincing until the listener moves his head. The sounds don't change to match the head motion, and this kills the illusion.

fxtentacle 12y ago
Absolutely correct. I'm also working on real-time compensation with the Oculus Headtracker ;) but that won't be ready until a few months from now ...

coreyja 12y ago

Just wanted to say I was looking for something like this last week and couldn't find one for my Mac. Thanks this is awesome! I'll def buy a license here soon

balls187 12y ago

Nice write up. I installed the app to give it a whirl. Admittedly I haven't tried it with movies yet, but it gives a "warmer" sound to my Spotify tracks while using my Polk ANC headphones. I went to purchase the product, but not sure why it's asking me for my mailing address? I'd recommend streamlining the workflow (if possible). Ask for Email address Ask to select Payment Type Then, if credit card is selected: Name as it Appears on the Card Credit Card Number Credit Card Expiry Credit Card CVS Billing Address Billing Phone Number If I chose to use Paypal, why do you need the mailing and phone number?

fxtentacle 12y ago
That's a good question.. and I don't know the answer myself: The shop site is run by FastSpring because I didn't want to have to deal with all the VAT weirdness in the EU. Maybe that's why they asked you, so they can decide wether to charge you VAT or not.

rasz_pl 12y ago

does it sound different? yes does it sound 3d? no does it sound better? no, unless you pay, then auto suggestion produces perception of better quality meh

balls187 12y ago

Just wanted to pass on a note, I watched the new Peanuts trailer, and wow, what a massive improvement in sound and bass while using your audio plugin. Going to purchase a license.