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Hydrogenaudio Forum => General Audio => Topic started by: shadowking on 2015-08-11 15:55:48

Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-11 15:55:48
After much experimentation I arrived at something that will expand the crossfeed concept but isn't as radical as Dolby HP. Instead, I use the BS2B with *Foo_channel mixer. The aim is to not only cut hard panned sounds but to simulate a listening room setup with superior imaging, unlike the spacious but broken presentation of headphones. Many audiophiles will argue otherwise, But I personally know this is possible from experimenting with dolby hp. It is already a reality in Samsung TV's - called SRS surround.

The idea is :

1) Cut the super-stereo effect with Bs2b , Otherwise additional DSP's will sound distorted or artificial and hard panned sounds will be harsh.

2) Simulate a listening room. Using *Foo_channel mixer the stereo-width is expanded (up to 1.65 for my personal taste). Taking the concept further: 2ch stereo is upmixed to 4ch to provide a better 3d-spatial effect.

3) Many headphones do not have a flat response. There are spikes in the mid treble around 7khz but often occur from 2~10khz. This results in an aggressive treble that will cause fatigue and ruin imaging. If this is the case one should apply EQ to the HF region to get a smoother treble. I have had to do it to the Alessandro MS-1 and to a lesser extent to the Sens PX-100 .


After all is done the foobar DSP setup is:

- **Bs2b (c-moy or JM) > channel mixer (4ch or more, stereo width = 1.65, upmix=copy or surround)

** must be the 1st plugin in chain if using > 2ch

* link: http://wiki.hydrogenaud.io/index.php?title..._channel_mixer) (http://wiki.hydrogenaud.io/index.php?title=Foobar2000:Components/Channel_Mixer_(foo_channel_mixer))



I welcome feedback.
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-11 16:46:48
Sorry for being direct, but I think that sounds horrible.

The increased stereo mix will just boost the side signal (L-R) or cut the mid signal (L+R). Why upmix to 4 channels? How are they downmixed onto your 2 headphone channel, if at all (in which case surround instead of copy would just further distort the sound)?


Have you tried a reverb plugin after the crossfeed and EQ after that?
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-11 16:52:09
Sorry for being direct, but I think that sounds horrible.

The increased stereo mix will just boost the side signal (L-R) or cut the mid signal (L+R). Why upmix to 4 channels? How are they downmixed onto your 2 headphone channel, if at all (in which case surround instead of copy would just further distort the sound)?


Have you tried a reverb plugin after the crossfeed and EQ after that?



Yes I know it sounds bad. But that is where the crossfeed comes in - to cut the bad effect.  I haven't tried reverb yet. Its almost unreal vs switched off.  the 4ch upmix sound more 'full' or '3d' to my ears. Again the effect is subtle. Switching to 2ch + bs2b sounds more hollow but still much better than default headphone sound.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-11 16:58:33
I have switched back and forth many times and am astonished at the great result. The center is there unless the stereo-width is 2.00 or close. The result effect is similar to my Samsung TV .

If you think about it its like improving subjective quality even at the expense of objective quality. Just like psychoacoustic.
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-11 17:30:23
I have used bs2b as you suggested followed by the channel mixer to boost the side channel (stereo width 1.65) and the result is a mess imo.
There stereo image is all over the place and the end result is more out of phase than even the original stereo track.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-12 04:12:33
I have used bs2b as you suggested followed by the channel mixer to boost the side channel (stereo width 1.65) and the result is a mess imo.
There stereo image is all over the place and the end result is more out of phase than even the original stereo track.



Thanks for testing. There could be several things:

- I still use foobar 1.03. Maybe the DSP behave differently like bs2b isn't working with channel mixer. This can be checked by removing bs2b from the chain. On my setup it has to be the first one in the chain. If its not enabled then the stereo field is totally off as you describe.

- Stereo-width value is too much for the given setup - Try a lower one like 1.05 ~ 1.30

- Headphone needs EQ in the mid treble. This is the worst and most complex issue I faced thus far. If treble has spikes and not smooth then the sound will have a rough bombastic character.  You have to lose a bit of detail to  gain a better stereo image.
Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-12 04:25:42
After much experimentation I arrived at something that will expand the crossfeed concept but isn't as radical as Dolby HP. Instead, I use the BS2B with *Foo_channel mixer. The aim is to not only cut hard panned sounds but to simulate a listening room setup with superior imaging, unlike the spacious but broken presentation of headphones. Many audiophiles will argue otherwise, But I personally know this is possible from experimenting with dolby hp. It is already a reality in Samsung TV's - called SRS surround.

The idea is :

1) Cut the super-stereo effect with Bs2b , Otherwise additional DSP's will sound distorted or artificial and hard panned sounds will be harsh.

2) Simulate a listening room. Using *Foo_channel mixer the stereo-width is expanded (up to 1.65 for my personal taste). Taking the concept further: 2ch stereo is upmixed to 4ch to provide a better 3d-spatial effect.

3) Many headphones do not have a flat response. There are spikes in the mid treble around 7khz but often occur from 2~10khz. This results in an aggressive treble that will cause fatigue and ruin imaging. If this is the case one should apply EQ to the HF region to get a smoother treble. I have had to do it to the Alessandro MS-1 and to a lesser extent to the Sens PX-100 .


After all is done the foobar DSP setup is:

- **Bs2b (c-moy or JM) > channel mixer (4ch or more, stereo width = 1.65, upmix=copy or surround)

** must be the 1st plugin in chain if using > 2ch

* link: http://wiki.hydrogenaud.io/index.php?title..._channel_mixer) (http://wiki.hydrogenaud.io/index.php?title=Foobar2000:Components/Channel_Mixer_(foo_channel_mixer))



I welcome feedback.


You're reducing the stereo separation in step 1. and then expanding it again in step 2, then up-mixing to 4-channels before down-mixing to your stereo headphones?  Did I read that right?
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-12 04:39:33
After much experimentation I arrived at something that will expand the crossfeed concept but isn't as radical as Dolby HP. Instead, I use the BS2B with *Foo_channel mixer. The aim is to not only cut hard panned sounds but to simulate a listening room setup with superior imaging, unlike the spacious but broken presentation of headphones. Many audiophiles will argue otherwise, But I personally know this is possible from experimenting with dolby hp. It is already a reality in Samsung TV's - called SRS surround.

The idea is :

1) Cut the super-stereo effect with Bs2b , Otherwise additional DSP's will sound distorted or artificial and hard panned sounds will be harsh.

2) Simulate a listening room. Using *Foo_channel mixer the stereo-width is expanded (up to 1.65 for my personal taste). Taking the concept further: 2ch stereo is upmixed to 4ch to provide a better 3d-spatial effect.

3) Many headphones do not have a flat response. There are spikes in the mid treble around 7khz but often occur from 2~10khz. This results in an aggressive treble that will cause fatigue and ruin imaging. If this is the case one should apply EQ to the HF region to get a smoother treble. I have had to do it to the Alessandro MS-1 and to a lesser extent to the Sens PX-100 .


After all is done the foobar DSP setup is:

- **Bs2b (c-moy or JM) > channel mixer (4ch or more, stereo width = 1.65, upmix=copy or surround)

** must be the 1st plugin in chain if using > 2ch

* link: http://wiki.hydrogenaud.io/index.php?title..._channel_mixer) (http://wiki.hydrogenaud.io/index.php?title=Foobar2000:Components/Channel_Mixer_(foo_channel_mixer))



I welcome feedback.


You're reducing the stereo separation in step 1. and then expanding it again in step 2, then up-mixing to 4-channels before down-mixing to your stereo headphones?  Did I read that right?


Yes. The upmix is optional. Using 2 channel gives nearly the same result. The width value can be adjusted to suit ones personal taste. The result should be subtle : the advantages of crossfeed with a spacious sound.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-12 10:41:23
I have tested the setup with the current Foobar 1.3.8 and everything works identical to 1.03

I also suggest to let the ear / brain acclimate for several minutes with each setting as jumping from one to another often causes fatigue.
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-12 12:44:44
Well, what's happening is this:

bs2b basically mixes a low-pass filtered signal into the other channel. With the additional delay it adds this means that you'll get the biggest reduction of stereo separation at lows and mids - approximately like we hear in nature.
(http://xserv.compress.to/xnor/audio/images/bs2b-cmoy.png)
Test signals is just an impulse in the left (red) channel. Without crossfeed we'd just see the left channel signal as a straight line. So far that's not so bad.


Now to the stereo width slider, that mostly boosts the side signal a lot. If we do that, we get part of the inverted left signal in the right channel, creating some kind of out of phase effect...
(http://xserv.compress.to/xnor/audio/images/bs2b-cmoy-sideboost.png)

In the time domain:
(http://xserv.compress.to/xnor/audio/images/bs2b-cmoy-sideboost-time.png)


This is known to smear the stereo image, but at least it's not as bad as an inverted channel here.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-12 13:42:35
The question is which is more real to the human brain / hearing system. Isn't the out of phase thing normal for listening room once the speakers become too apart ? Sure it all seems good on paper but there is still something missing for the brain to comprehend when using just crossfeed. It seems you have to break things to fix what is already broken by default then go with the best subjective result .
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-12 15:20:02
More reading:

http://www.dts.com/consumers/sound-technol...-headphone.aspx (http://www.dts.com/consumers/sound-technology/mobile-tablet-audio/cs-headphone.aspx)
http://www.dolby.com/us/en/technologies/dolby-headphone.html (http://www.dolby.com/us/en/technologies/dolby-headphone.html)
http://www.head-fi.org/t/361251/the-holy-g...next-generation (http://www.head-fi.org/t/361251/the-holy-grail-of-true-sound-stage-cross-feed-the-next-generation)
http://www.hydrogenaud.io/forums/index.php?showtopic=39404 (http://www.hydrogenaud.io/forums/index.php?showtopic=39404)


Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-12 15:37:18
The question is which is more real to the human brain / hearing system. Isn't the out of phase thing normal for listening room once the speakers become too apart ? Sure it all seems good on paper but there is still something missing for the brain to comprehend when using just crossfeed. It seems you have to break things to fix what is already broken by default then go with the best subjective result .


What kind of listening room are you trying to simulate?  If it's an "average" one, I don't see the point.  Are you talking about comb filtering from phase cancellation?
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-12 15:47:33
The question is which is more real to the human brain / hearing system. Isn't the out of phase thing normal for listening room once the speakers become too apart ? Sure it all seems good on paper but there is still something missing for the brain to comprehend when using just crossfeed. It seems you have to break things to fix what is already broken by default then go with the best subjective result .


What kind of listening room are you trying to simulate?  If it's an "average" one, I don't see the point.  Are you talking about comb filtering from phase cancellation?



A stock living room where you sit in front of speakers / home theater system. Why you don't see the point ?

The superstereo effect is wrong from a psycho acoustic pov. I may have created a 'superstereo' like effect but more correct for the human hearing system at least to my ears.

Samsung and other manufacturers seem to know this well and can get this into TV's , software dvd etc, works for movies but can also work for 2ch audio. The main hurdle is lack of interest / objection from audiophiles or HIFI enthusiasts  - lots will not accept any processing / EQ  or even a crossfeed.
Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-12 15:53:40
The question is which is more real to the human brain / hearing system. Isn't the out of phase thing normal for listening room once the speakers become too apart ? Sure it all seems good on paper but there is still something missing for the brain to comprehend when using just crossfeed. It seems you have to break things to fix what is already broken by default then go with the best subjective result .


What kind of listening room are you trying to simulate?  If it's an "average" one, I don't see the point.  Are you talking about comb filtering from phase cancellation?



A stock living room where you sit in front of speakers / home theater system. Why you don't see the point ?

The superstereo effect is wrong from a psycho acoustic pov. I may have created a 'superstereo' like effect but more correct for the human hearing system at least to my ears.


Unless you have properly-placed acoustic treatments or perhaps Linkwitz DIY speakers, an average domestic room is just not a good listening environment.
Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-12 15:59:15
Sorry for being direct, but I think that sounds horrible.

The increased stereo mix will just boost the side signal (L-R) or cut the mid signal (L+R). Why upmix to 4 channels? How are they downmixed onto your 2 headphone channel, if at all (in which case surround instead of copy would just further distort the sound)?


Have you tried a reverb plugin after the crossfeed and EQ after that?


If he's trying to simulate a domestic-sized room, there won't actually be reverb.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-12 16:08:15
It doesn't matter treatment or not. The point is to expand the existing bs2b soundstage to improve realism. My cheap Mazda car speakers will do over long term headphone sessions. It doesn't have broken super stereo sound [it does have other issues]. I can connect emotionally to the music much easier even listening to POS car speakers.

An average living is a not too bad enviroment IMO. I had one since 2001. I was just a matter of placing the speakers correctly and I could get fairly detailed sound without headphone quirks.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-12 16:36:44
Comb filtering or reflections maybe. I am not an expert by a long shot but some reflections can be very pleasurable or even essential to the hearing system. Of course too much of it blunts the image - this setup [or dolby HP / DTS CS] doesn't sound like that to me and plenty of speaker ones are more 'off'
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-12 16:53:16
I know these algorithms, but they don't create atmosphere like that.

Here's a simple test file: pink-lr2.flac (http://xserv.compress.to/xnor/audio/testfiles/pink-lr2.flac) (1.92 MB)

The noise source should wander slowly and evenly from left to right from about 2.5 to 12.5s.
Try this without DSP, with crossfeed alone, and with increased "stereo width".

Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-12 17:35:21
Have you tried Razer Surround?  Maybe try up-mixing to 7.1 and run it through that.  Unfortunately, you will never simulate the bone conduction or chest cavity vibration with headphones.
Title: Crossfeed - The next generation
Post by: Moni on 2015-08-12 19:30:28
Also worth checking out:  https://fongaudio.com/out-of-your-head-software/ (https://fongaudio.com/out-of-your-head-software/)
Note the free trial and pre-rendered files.
Title: Crossfeed - The next generation
Post by: includemeout on 2015-08-13 10:34:26
Speaking off crossfeed, does anyone know of any software for crossfeeding all audio output under Linux or at least a crossfeed VLC-plugin for watching films?
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-13 12:21:54
I know these algorithms, but they don't create atmosphere like that.

Here's a simple test file: pink-lr2.flac (http://xserv.compress.to/xnor/audio/testfiles/pink-lr2.flac) (1.92 MB)

The noise source should wander slowly and evenly from left to right from about 2.5 to 12.5s.
Try this without DSP, with crossfeed alone, and with increased "stereo width".



I did. I am even more impressed than before. I don't see a major problem with my setup even if its a kludge.

a) Without crossfeed or any dsp the noise trails from L to C to R but the superstereo effect adds extra noise, panning or like a rumbling effect . So its NOT transparent and painful.

b) With crossfeed much more transparent and reduced pain.

c) With crossfeed + stereo width: Nearly transparent up to 1.20 with slightly added noise. At 1.65 its more noisy but this noise to me is more preferable than a).    At 2.00 it is very noisy and distorted.

d) Stereo Width without crossfeed: The problems of a) together with extra white noise. This is the most noisy and probably the worst.

I may add that the stereo-width adds white noise like character with I like more than an ugly rumbling effect of example a).

In fact example (a) shows the biggest bug with headphones: superstereo yet a MONO rumbling character that can be painful.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-13 13:01:38
I may add that speakers when properly placed are stereo without an added ugly mono character. Even when listening to near-mono stuff it sounds respectable. Headphones are more stereo in the sides (it can also hurt) yet exhibit an unpleasant mono center-channel illusion (vocals , bass).

Adding stereo width + crossfeed reduces hard panning (L R) AND improves the mono center effect to my ears. That = better spatial imaging.
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-13 13:38:20
I'm not sure what you mean with unpleasant mono. Headphones are capable of real center-speaker like mono instead of the stereo phantom center.

a) There is no extra noise or rumbling. It's just that since there is no natural delayed crosstalk to the other ear, but instead silence, it sounds completely unnatural or "painful".

b) I wouldn't say it is more transparent, it's just more natural.

c) At 1.2 you can already notice a slight change in the panning. Instead slowly and consistently moving left-right it stays a bit longer at the sides and speeds up when moving from left-right.
At 1.65 you got a tonality change at both sides. The sound source stays way too long on each side (about 5 seconds) and in the the transition from left-right, which is too fast, it is a blurry mess.
Also, the first 4 seconds are basically like the first 2 seconds in a), except that there is a little sound in the other channel that gets rid of the painfulness.

So I don't see how c) is a positive change.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-13 13:53:10
Right so its just a matter of how much width to apply. I agree that at 1.65 tonality changes but it usually doesn't detract from my music (not test signals). From 1.05 ~ 1.20 the spatial effect can be boosted transparently more less.  Also the tonality WILL change to some extent because you cannot have it both ways. Same with EQ tonality will change but that doesn't have to be bad in real world listening.

The mono-center is when vocals / bass  sound too mono or muddy . Sometimes crossfeed makes it worse at least when using the higher settings. Sometimes the recording itself is to blame. Speakers make it more natural. Isn't the phantom center like we listen in real life ?
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-13 14:17:16
May I ask why you don't just increase the delay and crossfeed level in bs2b?

Vocals are supposed to be located in the center or slightly off center. Large stereo width just smears things all over the place.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-13 14:32:23
May I ask why you don't just increase the delay and crossfeed level in bs2b?

Vocals are supposed to be located in the center or slightly off center. Large stereo width just smears things all over the place.


Yes around the center but not over-dominant or mono sounding. With some added width they are still in the center but more like speakers 6ft apart - more 3D like.  Is Width=1.00 really correct ?

Now to add more crossfeed makes things deeper and more 3D - but makes the sides too narrow and some recordings too mono.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-13 14:59:55
I find some tracks are unlistenable. Danzig- Brand new god. Its recorded mono like but in the car and on speakers sounds okay. On headphones no DSP (width=1.00) its really tough . Going up to just 1.04 makes a difference.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-13 15:14:35
For a  'transparent' setting I arrived at bs2b -  J M + width = 1.15 **

Unfortunately it seems I need a big stereo width to get the sound out of my head.  My original setting of bs2b - CM + width = 1.65 does it.  It needs to be at least 1.20


** updated from 1.15 to 1.20 and I think it sounds really good and not in the head as much.
Title: Crossfeed - The next generation
Post by: ChrisMini on 2015-08-13 16:25:33
I have used bs2b as you suggested followed by the channel mixer to boost the side channel (stereo width 1.65) and the result is a mess imo.
There stereo image is all over the place and the end result is more out of phase than even the original stereo track.



Thanks for testing. There could be several things:

- I still use foobar 1.03. Maybe the DSP behave differently like bs2b isn't working with channel mixer. This can be checked by removing bs2b from the chain. On my setup it has to be the first one in the chain. If its not enabled then the stereo field is totally off as you describe.

- Stereo-width value is too much for the given setup - Try a lower one like 1.05 ~ 1.30

- Headphone needs EQ in the mid treble. This is the worst and most complex issue I faced thus far. If treble has spikes and not smooth then the sound will have a rough bombastic character.  You have to lose a bit of detail to  gain a better stereo image.


The only real reason to be concerned with crossfeed issues would be for headphone listening.
Title: Crossfeed - The next generation
Post by: halb27 on 2015-08-13 20:05:29
Thank you for pointing to bs2b. It was new to me, and it is quite good at compressing the often too wide stereo panorama for headphones. Can be used on a regular basis though sometimes the sound changes a bit to the less favorable side IMO. Depends on the music, and not always is bs2b needed for reasons of unnatural stereo panorama.

TUsing bs2b the sound feeling is still coming from inside the head (also when advancing/lowering the cans a bit). So I understand your usage of the channel_mixer. When upmixing to 4 channels a 3d effect drops in. However in order to keep a more or less natural sound I had to stay with stereo image width around 1.10, and use upmix mode 'copy'. Stereo image gets narrower by the way by this procedure. (It gets wider when not upmixing, but I can't see an advantage in using the channel_mixer this way).
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-14 13:45:27
Thanks for the feedback Halb27. I wonder if you could test the delay option @ 2M for front and rear channels. In my experience it enhances the 3D effect even more at the slight cost of detail.

I have tested a smaller widths like 1.10 but the sound is in my head. Adding delay + 2M rectifies this to a good degree. I still  needed width @ 1.20 to get the desired effect.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-14 14:22:45
I found that the C Moy preset works very well with the mixer. Its already pretty good by itself but its slightly veiled character adds to the 3D effect IMO.

I tested an 'intermediate' setting: bs2b CM + Width= 1.20 ~ 1.25 + delay = 2m + CH=4 + Upmix=copy

The center is still pretty tight IMO. Using only bs2b CM and the sound is smaller and is back inside my head.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-14 16:42:01
I also found that setting differing delay values for front / back adds a layer mystique and veiling that makes it more realistic.

Front L/R = 2.00
Rear L/R = 0.75
Title: Crossfeed - The next generation
Post by: halb27 on 2015-08-14 18:24:43
I tried your delay settings, but this is not for me. While I can see the effect I even heard artifacts and the sound is very muffled (when having bs2b as the first in the DSP chain). Lower values improved for me while still having the effect to a certain degree. But anyway: not my taste.
So I stick with width=1.10 upmix 4 copy no delay though you're right: sound is still 'in the head'.
Out of interest I put away with bs2b, and things are still good for me.
I reloaded bs2b, this time using it as the second tool. I was surprised that to me this sounds better. I use bs2b's default setting because otherwise stereo width is too narrow for my taste.
With this DSP order when using a delay sound isn't so muffled any more, but it's still not my taste - not mentioning the artifacts.

I try to be conservative because I want to have one universal setting with which the headphone experience is improved while keeping general sound quality as close as possible to 100%. I don't like to bother whether things get significantly worse on occasion when using such a procedure.
Title: Crossfeed - The next generation
Post by: halb27 on 2015-08-15 21:25:37
After listening a lot I made up my mind not to use the channel-mixer. I prefer a sound closer to the original. I also tried several crossfeeders and found that the Meyer crossfeed plugin, crossfeed level 2, works best for me.
Keeps the spectrum closer to the original than bs2b, and sufficiently keeps from suffering headphone-inadequate stereo panorama. Changes the soundstage slightly, usually to the more favorable side for me and the kind of music I usally listen to.

After all it's a matter of taste what to use.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-16 11:02:36
Thanks for testing . I tried a lot of setting and the hardest is to choose a universal-one-fits-all setting but that should be the goal. Interestingly everything I tried inc crossfeed only, no crossfeed + W 1.04 ~ 1.10 + 2ch / 4ch, no crossfeed + 4ch only , yielded better result than using NOTHING at all !. 

ATM i am using bs2b CM + 4ch + W=1.20..1.25

Updated the 'high' setting to W=1.60
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-16 19:41:15
Does anyone know an easier way to do "binaural" convolution than with the matrix mixer and gapless convolver plugins? If not, I can explain how it's done. That way you can use HRTFs.
Title: Crossfeed - The next generation
Post by: lvqcl on 2015-08-16 20:18:09
There is (was?) foo_dsp_stereoconv (http://www.hydrogenaud.io/forums/index.php?showtopic=54966 (http://www.hydrogenaud.io/forums/index.php?showtopic=54966))
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-16 21:22:28
There was it seems.
Title: Crossfeed - The next generation
Post by: lvqcl on 2015-08-16 21:36:48
Robertina uploaded the binary here (http://www.hydrogenaud.io/forums/index.php?showtopic=90662) and I can upload its sources if anybody wants
Title: Crossfeed - The next generation
Post by: halb27 on 2015-08-16 22:52:57
Yeah: that's the best way to get the sound out of the head IMO. I haven't tested all of the files from the IRCAM page yet, but so far individual 1020's wav file does the job fairly well for me.
The subjective frequency response however also is pretty different from the original, so I will try some equalizing to bring back brilliance.
Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-17 13:25:38
Also, which headphones are you using?  I find that crossfeed produces a more noticeable effect with closed headphones, but is very subtle with my HD800's.  If ambient noise and disturbing others isn't s concern, you might try some open-backed cans.
Title: Crossfeed - The next generation
Post by: halb27 on 2015-08-17 21:46:00
I've finished testing all the files from the IRCAM page and found individual 1031's data to fit my hearing best.
I've been doing quite intensive listening tests with my B&W P5 (the only closed one), Grado SR80e, Philips Fidelio X1 and STAX SR 202 cans.
From scratch the 3d experience is wonderful while being realistic. After listening for a while this way and then switching the convolver off flattens the soundstage making you immediately wish to reuse the convolver.
To me the closed P5 didn't have an advantage in this respect.
The bad new is as mentioned that the frequency balance changes. The drawback isn't huge with the Philips and the STAX, but for the B&W and the Grado things are getting bad here. So as shadowking mentioned already for his approach equalizing is necessary for at least some cans.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-18 14:54:38
I think the bauer may work better with lower cut off HZ for some ears or heads. I used 360hz / 8db and its sounds more natural and still works on hard panned material. I combined it with width=1.25 upmix=4ch copy for a better spatial 3D effect. The tonality is much more natural than W=1.60 .I checked if the panning effect of bauer was still working and it seems that its fine when combined with more modest width values. So double win in a way. I am pleased with this setting -  it either enhances the sound or does almost nothing when the others were at times too wide or narrow.

New setting: bs2b 360hz / 8db , ch mixer W=1.25, upmix=4ch copy
Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-18 17:40:58
Does anyone know an easier way to do "binaural" convolution than with the matrix mixer and gapless convolver plugins? If not, I can explain how it's done. That way you can use HRTFs.

Please explain.  Does it work as well as the test file near the end of this page?  I've heard a few binaural recordings, but none created the cognitive dissonance I get from this sample:

http://www.audiocheck.net/soundtests_headphones.php (http://www.audiocheck.net/soundtests_headphones.php)

Maybe it's just the extreme stereo separation and simplicity of the sound effect that makes it so convincing.
Title: Crossfeed - The next generation
Post by: xnor on 2015-08-18 18:07:17
No, that's something different. The simple convolution I was talking about is using e.g. +/- 30° HRTFs, where speakers would be located. That's what the stereo convolver does.
To move the sound source around you'd have to change HRTFs.

Also, naturally there is quite some crosstalk. The head acts as a shadow only at high frequencies and even there the attenuation is not great (~20 dB) and it's as low as <1 dB at low frequencies. You only get high separation if e.g. someone is whispering into one of your ears.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-19 14:04:04
I would like some feedback on :  bs2b - 360hz / 8db + channel mixer -  stereo-Width=1.25, upmix=4ch copy

So far I cannot find any regressions on my music , switching it off always resulted in more fatigue / worst quality. The aim is near transparency in relation to the original "set it and forget its there" [effect is milder than most default crossfeed settings IMO] yet improved listening quality.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-19 15:59:41
I've also observed an interesting phenomenon that staring at speakers or a TV across the room while using headphone + keeping head still reinforces a positive 'illusion' and thus results in better impression of stereo image. Staring at the PC screen isn't as good.
Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-19 17:26:33
I've also observed an interesting phenomenon that staring at speakers or a TV across the room while using headphone + keeping head still reinforces a positive 'illusion' and thus results in better impression of stereo image. Staring at the PC screen isn't as good.


Agreed...  Have you tried closing your eyes?  I think it's well-known on this forum that visual perception can have a strong influence on auditory perception.

Also, have you tried the crossfeed plugin in Jriver Media Center?  I think they offer a free trial.
Title: Crossfeed - The next generation
Post by: halb27 on 2015-08-19 21:41:45
I would like some feedback on :  bs2b - 360hz / 8db + channel mixer -  stereo-Width=1.25, upmix=4ch copy...


I've tried it, and yes: 360 Hz (more exactly: 370 Hz - I didn't manage to use 360 Hz) is enough for the effect. Your combination has a nice sound though I personally prefer stereo-width=1.10 and having the channel-mixer the first plugin the list.
But as I wrote I prefer the Meier crossfeed plugin, crossfeed level 2, over bs2b, though the difference is rather small.
After having enjoyed the stereo convolver's good 3d effect with my Fidelio X1 for quite a while I missed the vividness of the sound I am used to when listening to my Grado SR80e or Fidelio X1 without any additional procedure. So I came back to the channel-mixer + lightweight equalizing + Meier crossfeed plugin. Very good for me also with the Grados which I appreciate a lot.

It's all a matter of personal taste and what kind of compromise to accept.
Title: Crossfeed - The next generation
Post by: theriverlethe on 2015-08-19 23:08:36
Here's another one to try:

http://www.toneboosters.com/tb-isone/ (http://www.toneboosters.com/tb-isone/)

It appears to be under active development.
Title: Crossfeed - The next generation
Post by: musicreo on 2015-08-22 22:23:34
I use for binaural listening experience the VST Convolver (http://convolver.sourceforge.net/) and  this binaural impulse response files (http://spatialaudio.net/183/).  I use it for  music (foobar) and movies (MPC-HC) with 7.1 and also stereo. I really like it.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-08-23 12:23:16
I would like some feedback on :  bs2b - 360hz / 8db + channel mixer -  stereo-Width=1.25, upmix=4ch copy...


I've tried it, and yes: 360 Hz (more exactly: 370 Hz - I didn't manage to use 360 Hz) is enough for the effect. Your combination has a nice sound though I personally prefer stereo-width=1.10 and having the channel-mixer the first plugin the list.
But as I wrote I prefer the Meier crossfeed plugin, crossfeed level 2, over bs2b, though the difference is rather small.
After having enjoyed the stereo convolver's good 3d effect with my Fidelio X1 for quite a while I missed the vividness of the sound I am used to when listening to my Grado SR80e or Fidelio X1 without any additional procedure. So I came back to the channel-mixer + lightweight equalizing + Meier crossfeed plugin. Very good for me also with the Grados which I appreciate a lot.

It's all a matter of personal taste and what kind of compromise to accept.


Thanks for the feedback. In my setup putting mixer first disables bs2b for some reason (if using 4ch).
I arrived at an alternative preset for those that are opposed to the stereo width alteration. It involves a very mild crossfeed effect and upmixing to 4 channels. NO alteration to width :

bs2b - 360hz / 13.5db + channel mixer -  stereo-Width=1.00, upmix=4ch copy, rear volume=1.00


I did some brief listening yesterday and it retains most of the positive attributes and no regressions that I could find . Still I find that a mild width of 1.05 is better . If you can give this a check I'd appreciate it.
Title: Crossfeed - The next generation
Post by: halb27 on 2015-08-23 20:48:55
I've tried it and I really like it. It sounds very natural to my ears. You've found a good solution which also meets my taste.
Title: Crossfeed - The next generation
Post by: shadowking on 2015-10-21 15:22:08
Hello Halb27. I've worked on a new preset involving 6 channels upmix. The center channel gives a more upfront presentation including the feeling of bass which normally doesn't happen with headphones.

The parameters are:

bs2b - 360hz / 13.5db + channel mixer - stereo-Width=1.00, upmix=6ch copy, rear volume=1.00, center = 0.18


If you have time give it a test run and let me know .
Title: Crossfeed - The next generation
Post by: halb27 on 2015-10-22 21:27:38
I've tried it, and yes, it sounds good to my ears with the intended purpose in mind.

But meanwhile I wouldn't say I'd prefer it over the original sound. May be it's because I've just returned from holidays where I listened to my music collection with a smartphone the original way, so I'm much used to that right now. When switching from the crossfeed listening to the original way of listening I feel that the crossfeeds makes the music loose 'vividness' (though the sound space is more natural). ATM I prefer the vividness of the original way of listening.
Title: Crossfeed - The next generation
Post by: dhromed on 2015-10-23 09:24:30
> 'vividness'

crossfeed has a tendency to reduce high frequencies, so I guess you're describing that.
Title: Crossfeed - The next generation
Post by: halb27 on 2015-10-24 08:55:13
Probably you're right. When I started experimenting with shadowking's way of crossfeeding I also used an equalizer in order to compensate for the reduced HF. But I never got a convincing result with that.
Title: Crossfeed - The next generation
Post by: mikagenic on 2015-10-25 07:38:17
I second http://www.toneboosters.com/tb-isone/ (http://www.toneboosters.com/tb-isone/) - fantastic
Title: Crossfeed - The next generation
Post by: shadowking on 2015-12-09 04:39:58
New preset based on J Meier. DSP setup:

BS2B (JM) >> Convert stereo to 4 channels


The goal is to "set it and forget its there" . IMO there is a vast improvement over the standard JM crossfeed on most material. The sound in no longer in the head.

Title: Re: Crossfeed - The next generation
Post by: Juha on 2018-05-21 09:43:38
Anyone implemented this Linkwitz Crossfeed (http://www.linkwitzlab.com/headphone-xfeed.htm) for Headphone use?

I tried to prepare it as a EqualizerAPO preset (https://sourceforge.net/p/equalizerapo/discussion/general/thread/2c57ff29/) - but, with this implementation it's not easy to make direct comparisons against those common plug-in type implementations so, I can't be sure or say if it sounds OK or is implemented correctly. Any thoughts?
Title: Re: Crossfeed - The next generation
Post by: 40th.com on 2018-05-21 21:05:29
...Linkwitz Crossfeed

https://40th.com/jb/gfx/08_settings_dialogs_pt2.png

Top left box.  Adds delay, because it can.  Works fine.

Title: Re: Crossfeed - The next generation
Post by: xnor on 2018-06-18 20:32:27
Anyone implemented this Linkwitz Crossfeed (http://www.linkwitzlab.com/headphone-xfeed.htm) for Headphone use?
That's what bs2b implements.


I tried to prepare it as a EqualizerAPO preset (https://sourceforge.net/p/equalizerapo/discussion/general/thread/2c57ff29/) - but, with this implementation it's not easy to make direct comparisons against those common plug-in type implementations so, I can't be sure or say if it sounds OK or is implemented correctly. Any thoughts?Anyone implemented this Linkwitz Crossfeed (http://www.linkwitzlab.com/headphone-xfeed.htm) for Headphone use?
Why not? Equalizer APO monitors the file for changes, there's even a UI where you can switch included files on or off.
Comparison shouldn't be hard at all.
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