Crosstalk cancellation

Bob Carver once made a crosstalk cancellation box. What happened to it and what is it?

[@gotham61]

The most sophisticated crosstalk cancellation device is the BACCH-SP processor developed by Dr Edgar Choueiri at Princeton University.

[@TheDanEdwards]

Yeah, but it's anathema to the digiphobes.

[@AmazonasBiotop]

He has a more modest setup with a std MAC at a 1/10 of the price compared to his highest end solution. But build on standardized components that bring down the HW cost and development cost of the same. (Web cam, MAC mini and a professional external sound card. I think it is called Bacch4MAC.) With first hand experience of a DIY solution in my dedicated listening space. I can without a doubt say this is the greatest thing since the invention of Stereo! (Yes, big words but as stereo, when you heard it you can't go back, it is so fundamental difference.) For 2ch audiophiles (they tend to sit in the sweet spot and listen).😂

[@user-od9iz9cv1w]

@@AmazonasBiotop Cool. How does it sound compared to good headphones? It seems conceptually like they should sound the similar.

[@AmazonasBiotop]

@@user-od9iz9cv1w There is some rather big differences between 2ch speakers and headphones. Speakers performing like if there is artist is in front of you somewhere between the speakers and maybe like a looking at a performance in front of you. Usually the soundstage with headphones is restricted in your head the singer is in middle of your head. Plus when you turn your head with headphones the singer/performance is moving with your head as the headphones is attached to your head. With speakers the still in front of you even if you turn your head. That is nothing special that is standard deviation between headphones and speakers. I am not a headphones guy. But one cool thing is that Bacch4MAC company also have developed a filter for headphone usage. The cool thing is when the headphone filter is demonstrated in audio shows there is a speaker setup and a pair of headphones. The thing is they put the headphones on their ears and after a while they saying "can't you turn off the speakers (that is in front of them)" OR they're taking off the headphones from their head and just to discover that the speakers in front of them are indeed not in use.. So I believe the headphone filter make you to believe that the soundstage is Infront of you and gives you some of the speaker qualities that those has. But my experience with 2ch speakers with the interaural crosstalk cancellation on and off. (Remember I am not a headphone guy at all..) Is that even if I have made most things right to get a soundstage (width and depth). In my dedicated 2ch listening room with dipoles far out in the room, various sound treatment, symmetry, PEQ and so on and on. I experience that ordernary 2ch listing is like to look at a performance in front of you with somewhat depth. But more like a rather flat painting in-between your speakers. You can hear the recording room acustics but it is over there between the speakers in front of you. But with interaural crosstalk cancellation (IAC) enabled. You are transported into the recording room and sitting in it and the performance is closer in front of you. It is more as you are there with them. Instead of viewing them as a separate event that have happened in front of you. Hard to describe (I don't know if it is the same with headphones when I am not into that but I imagine the headphones make the artist small like smurfs in your head and not somewhat life like natural sized humans in front of you.) But the "effect" is huge and works on most of all recordings more or less. And it is like back in the day when we had a stereo/mono switch button on our amplifiers. It were always in stereo mode and that got to be the default norm/choice and the button has been removed when nobody wants to be without using the stereo mode. The same is here when using and comparing IAC on/off. You do not want to use the system without IAC off like back in the day with the stereo button.. It is that good! Largest "effect" it has on binural recordings reproduction. But I found it to be good on all types of recordings. Except one "Madonna -Vogue" some strange mixing going on in that track that is not so obvious in normal stereo reproduction. I hoped this helped somewhat.👍

[@jakeslavin9355]

@@user-od9iz9cv1wI think the idea is it has advantages of binaural audio that headphones can provide but it sounds more natural and there’s more a realistic sound field since the source of the sound isn’t strapped to your head. Plus for the top end model you can move around the room and it will adjust to maintain levels.

[@johannesk1855]

Wow, love that room!

[@nancy4don]

I have one of those "Carver boxes" that I use all the time. (It's officially the "Carver C9 Sonic Hologram Generator.") Yep, the stereo image can get just plain ridiculously big. There are a couple of things it does, though. that don't get mentioned often. First, it absolute locks in the center of the music. It almost sounds like I've added a center speaker to my system. Second, there is a great separating of instruments in music. It makes it possible to easily concentrate on, say, the rhythm guitar, in the midst of the whole mix. I would also add this: if you want "less big" images but more freedom to move around (not stay locked in the dead center between your speakers), you switch the "window" adjustment to Wide and the Injection Rate to Theoretical. Using these settings, I've had the startling experience, with TV audio, of hearing people who sound like they're speaking or whatever out on my front porch! It's great technology that requires some playing around with speaker (and listener!) placement. Oh, and I recorded some live concerts at my churches, so no multi-tracking and mixing down. The reproduction of those live recordings is incredible.

[@carlosanvito]

Let's not forget the system developed by Polk (I think) in the 1980s that incorporated two midrange speaker elements in each cabinet. One element was wired normally, while the other was driven by an attenuated and phase-inverted signal from the other channel. That caused cancellation of the crosstalk and was quite effective in improving the stereo image. Very simple and purely analog.

[@tjmbv8680]

I'm curious what the model of that is.

[@jeffwalther]

@@tjmbv8680 Polk SDA "Stereo Dimensional Array"

[@FatFolksProductions]

Not sure of the 80's model from Polk, but the newer versions are the L800 towers.

[@MichaelLHill-fd3kw]

I’m not sure but I think DCM had a sound stage design that was similar to the Polk version.

[@adc4392]

The listening experience with a Bacch Filter is a dream come true for all audiophiles, in my opinion (referring to Edgar’s Bacch Purifier Technology from Princeton University)! You can place the speakers quite close together and the soundstage will reach from 9:00 to 15:00 with 3D depth of instruments distance reaching from just 1m away from you to 30m away from you completely ignoring the dimensional limits of your listening room! It is a break through sonic improvement of realism, for me of a magnitude of switching from mono to stereo! I think Paul should better take Bacch technology on board, as others start to do (Dutch & Dutch), rather than to ignore research and development achievements of great acoustic engineers!

[@lbudt29]

I have a BBE 882I SONIC INHANCEMENT, that does that and it does get the sound image out from the speaker, and seems clean it up .

[@sidesup8286]

Crosstalk cancellation opens up the sound, but the amazing focus it provides by doing its little thing, isn't going to be equalled by sheer spatiality. If anything spatiality usually makes the sound more diffuse. Hearing that kind of openness opennesscombined with that kind of focus would really be something. Audiophile with budget gear. "Life is unjust." Audiophile with mid tier equip, "Life is partly just." Audiophile with the best most expensive gear available, "Life is just."

[@CoolJay77]

The single speaker box is a wonderful idea. One can also get two speakers close together and apply cross talk cancellation.

[@jovenlara5868]

Great video Paul thank you...I think this concept is what Peter from @PSsound uses on his amazing car audio instalations as Differential Rearfill..he does all the "out of phase" stuff through a DSP of course

[@mikesmith5389]

Paul I had a cheap but good stereo system that had a pseudo surround sound feature and it did just that, threw the midrange and tweeter out of phase and it was phenomenal. I would watch movies and the sound would be coming from everywhere, even all around me. It's the only one I've ever heard that worked and I miss it so I know exactly what you mean.

[@patrick-ll5qd]

I never could understand the notion that people want music but do not want "those big ugly evil speakers" in their living space. Of all the ugly things people have in their homes I don't think speakers are the worst.

[@georgemasonsghost4062]

That's because we love music. Some people just want to hear music.

[@flargosa]

In the headphone world, some say isolating the left and right channels causes ear fatigue. So companies like Chord Electronics add cross feed which makes the headphone sound like a speaker, both channels are mixed but phase remains the same before outputting to the headphone.

[@zibikonti8901]

Yes, this is true. I am a headphones listener. I listen to old jazz recordings that were mixed just for speakers and the lack of crossfeed makes them very unnatural and unpleasant, like for example John Coltrane blowing his sax directly into my right ear and piano playing almost behind my left ear. This is true for many genres and many recordings, but not all. For example, Electronic/Techno, EDM, DUBs sound great without crossfeed anyway. This is why I bought REM ADI-2 FS DAC that has sound stage Width and Crossfeed functions, so I can adjust the soundstage according to the music that I listen to. Another DAC that I know and offers this functionality is Weiss DAC501.

[@ignaciocruzatcorrea3595]

Great pronunciation of the name Javier. Congrats!

[@franciscogaston8367]

Yes it surprised me as well

[@SimonSezSo]

I own Water's "Amused to Death" on CD. The placement of sounds in the 360 degree field from just two speakers is AWESOME! I always wondered how he did that and why other recording didn't sound nearly as good.

[@BB..........]

QSound was also used on Madonna's The Immaculate Collection CD, Sting's Soul Cages, Paula Abduls Spellbound and Fates Warning's Parallels. The Immaculate Collection has been an imaging reference CD of mine for many years.

[@SimonSezSo]

@@BB.......... Interesting. I might pick some of those up. Thanks.

[@BB..........]

@@SimonSezSo You're welcome. Amused is a good demo CD, but Madonna's Immaculate Collection, to my ears, is even better. There's spots on some of those songs where it sounds like there's music coming from the side walls; it's almost spooky. My speakers (Dunlavy SC-V) are imaging champs anyway, but that CD blows anything else I've listened to out of the water for imaging.

[@Geerladenlad]

I think he's referring to the Sonic holography from Carver.

[@curtspoerer4424]

Sting-Soul Cages is another great Q sound album

[@ingenfestbrems]

These speakers are about the same price as Bowers and Wilkins 801D4 Paul, what are the most differences and the most similarities between?

[@Alexandra-Rex]

Were you thinking of the _Amused to Death_ album by Roger Waters? It has some interesting imaging, if you're in the middle.

[@joepostle3561]

Pink Floyd’s live album from the mid 1990’s also had Q Sound processing.

[@BB..........]

Madonna's The Immaculate collection is the best known CD using QSound, but there were around 60 CDs released using the process. en.wikipedia.org/wiki/QSound#Selected_albums_%22mixed_in_QSound%22

[@jabbejokker]

What happened to those corner Helmholtz resonators? Looks like theyve been discreetly camouflaged.

[@ChiefExecutiveOrbiter]

Polk has SDA, but their technology and prices are grounded in reality, so, shunned by the elite.

[@carlubambi5541]

So many gadgets to add frim dbx to noise cancelling and phase control processors and more .Its not a recoding studio .Just listen to the music and enjoy .Ok quadraphonic systems were fantastic but you cant find any vinyl with it nor regular Cds with that encoding system .And dolby 7.1 now .Dont know any of the 60s 70s or 80s music that be converted without re mastering eveything .2 speakser 4 speakers 6 speakers 8 speakers 9 speakers .How far do you need to go

[@Roosville1]

If you could model the entire room including occupants for distance, object acoustic reflectance and absorption over the full frequency range, and then run some 3D “field solver” in real time for each point relative up to half the of the highest wavelength that you could hear, then a technique of destructive phase interference in theory would work, so long as you didn’t move a jot. This sort of processing power doesn’t yet exist. In reality, it’s a compromise of applying blanket compensation over a complicated issue. Software has for years existed which will process audio in terms of perceived width. You can also to convolve an particular environment (say a church hall) over a dry recording using an impulse response from the environment. Is it as the producer at the recording desk intended, well no, but then does that matter?

[@duanewalker1011]

It can be done.

[@timlink7817]

Crosstalk sounds bad. Yes, you can get a wide stereo image with just 2 speakers without addressing crosstalk but that's only half the problem. The phantom center cannot sound optimal, and the further the speakers are placed apart to create a wide soundstage the worse it gets. I've never, ever heard a straight 2 channel, 2 speaker system overcome this. It's just baked in to the setup, which was originally chosen as a way to get stereophony happening with maximum affordability and practicality, not sound quality. I'm glad to hear Paul is working on the single box. I don't see it as a compromise at all. It's actually the best way to do it, and it's not hard at all to do it without any digital processing. You just need to upmix 2 channels to 3 channels with simple channel summing and differencing. In this way you can totally end the comb filtering of center panned sounds, which I will argue are the most important to sound quality overall, while simultaneously creating a very natural width sound stage, and increasing the distance from side walls and thus increase time delay of first reflections to the listening position. Yes, it goes off if you're not sitting in the middle, but so does the 2 speaker setup. The way it fails is more graceful I think, with the center panned sound staying in the middle of the room and the panned sound positions collapsing and becoming ambiguous, but still maintaining a nice spacial effect. There's no way around that unless you go with the BACCH setup or something like that with a lot of high powered processing that tracks your position. I haven't heard that system yet so I'll reserve comment. Lesser DSP recursive crosstalk implementations have not been satisfactory for me so far in terms of overall sound quality. They do make for a wide soundstage though even with the speakers very close together in front of you.

[@leebee6382]

QSound is neat, but only works if you're sitting in the sweet-spot. Still, it's super cool. Sting used it, and I believe Madonna's greatest hits CD has it.

[@BB..........]

en.wikipedia.org/wiki/QSound#Selected_albums_%22mixed_in_QSound%22

[@shipsahoy1793]

Fact: If the speakers aren’t “big” enough, you can never “get what you want” unless the listening environment is small, and just then, maybe, you can live with the compromise that brings, which is surely doable when you have no other choice. 😉

[@naelgorgees1726]

Woo I did it before you Master! Thanks

[@doylewayne3940]

I heard back in the 80's Carver had what they called a "holographic imagizer" in a box, Is this what the questioner is referring to?

[@franciscogaston8367]

Yes the Carver boxes produce what he named holographyc sound

[@BB..........]

Carver C-9 Sonic Hologram was an external box, and the circuit was also built into a preamp.

[@stimpy1226]

You pronounce his name correctly

[@pablon9269]

Just not having the J as muted

[@stimpy1226]

@@pablon9269 I'm surprised he did not know that.

[@pablon9269]

Well, the pronunciation here in Madrid doesnt reach colorado, I guess

[@duanewalker1011]

Gimmicky ....I like that. Bob Carver .....David Blackmer (dbx). Gimmicky ...lol. As if using BOXES to project sound at your head, intending to represent voices and instruments that emit sound 3 dimensionally isn't gimmicky. Lol.

[@duanewalker1011]

@@bbbearing3380 VERY well said. Thanks!

[@larryhoffman7471]

Isn’t it unnatural though? If what we’re trying to do is have the most realistic portrait of what the musician was doing reach our ears, why would we want to cancel something that is a natural occurrence? When you’re in a club, or a hall, etc., the music gets to your ears without crosstalk cancellation. So why add something that just adds more manipulation to the musical signal?

[@homeaudiofidelity9599]

I made a video some years ago to explain and demonstrate the negative impacts of acoustic crosstalk: kzbin.info/www/bejne/ope0gaGjrpejrqs When properly done (advanced algorithms) crosstalk reduction is not a gimmick if I trust my customers feedback 😉

[@AmazonasBiotop]

No it is somewhat a wrong explanation. Our brain ear dont disregard what is coming from left ch to the right ear, maybe if you fall asleep.😂 It is the opposite but this were maybe a sale pich from Paul again.. when he is selling his speakers that he says "they disappear". Maybe that was intentional... ..it is just another pair of passive speakers and no new technology breakthroughs.. When "sound is coming from left ch to the right ear" and vice versa. When the sound reaches the other ear that is further away then it is timed delayed.. that tells the brain actively that the sound come from the left(or right) not "disregard anything". ANOTHER thing that happens is: When the sound reaches the other ear it is in the "shadow" of your head. And some frequencies especially the higher onece is attenuated and that will tell us by the brain ALSO that the sound come from the left(or right) not again "disregard anything". What do we learn from this? That our ear, Brain hearing very much locates where the sound is coming from without a doubt. That IS us as listener will without an effort hear where the speakers are placed and they're not as a illusion disappearing anywhere regardless what Paul is telling us.😅 And it is also telling us that if there were a sound cancelation mechanism for the "wrong" ear then and only then we would cancelled the sound that told the brain where the sound were coming from.. and THAT is a major REAL thing that would make the speakers to actually get the illusion of them to disappear! (But that is FAR from the sonically subjective benefits of interaural crosstalk cancellation. It has a HUGE benefit for 2ch audiophiles. Maybe for another day.. I have first hand experience of Interaural Crosstalk Cancelation in my dedicated listening space.) That Paul intentional or unintentional by omitting old well known reserch from ~40-ties that he very well knows about I am sure of by hearing him lived true Carver and polk Audio and other projects and products.. he is a sale person and be aware of the same. If you want to learn more or experience the cutting edge of where development is for 2ch audio. And not waste money on just on yet another pair of essential the same type of passive speakers.. that will give you the same results..😢 The look into BACCH4Mac and you can thank me later!🎉

[@digggerrjones7345]

It's *always* a sales pitch with this guy!

[@stLtBilko]

Yep i agree, it is how we survived as a species, cavemen didn't need inaural crosstalk cancellation to determine what direction that sabre toothed tiger was coming from & neither do we nowadays, I listen to 2ch audio 99% of the time I don't even bother using the phantom rear dsp on my AV receiver the stereo separation & imagery is already satisfactory to my ears, & I will "Thank you", I'm going to check out the Carver & the BACCH thing as well to learn more

[@duanewalker1011]

@@stLtBilko dbx also.

[@stLtBilko]

@@duanewalker1011 Thanks for the shout out on dbx, I do remember those systems from back in the day's

[@STChelvam]

Crosstalk cancellation is not cool trick.

[@stevec.6119]

And thanks to you and almost all stereo manufacturers.......If people want an "add on" unit to their integrated amps (such as cross talk cancelers such as the Carver sonic holography unit)...they have NO EXT loops or "tape in/out monitor loops" to insert them into !!!!!! I can't find ONE integrated amp or amp made in the last 15 years that has such a loop (save maybe NAD). Such a minuscule cost for such a handy feature. Heaven help anyone who wants to put a "evil" equalizer into their music (after all....everyone has the perfect speakers and listening room to listen to their ABBA cds)

[@AmazonasBiotop]

I did not understand anything of what you said.. But if you want to get the state of the art Interaural Crosstalk Cancelation solution of today that uses computational power that Carver or Polk Audio didn't have at the time back then. We have done so much advancements since Carver did his solution that is based on research of Schroeder. We have a web camera that track your face (to keep track of your ears). And the system is calibrated by earbuds that are tiny microphones and frequency sweeps. The whole system is calibrated your electronics, speakers, room, head and ear shape (those are individual like fingerprints) among others. So with the web camera you don't need to sit with your head in a vice like with Carver/Polk audio solutions. When it track you and adjust it accordingly as you move your head. Anyway when this system cancel out better than the old equipment does and therefore give even a better performance. (I think it is -50 dB cancelation.) Cool verification trick can be done. When you have the microphones in the ears. You can turn the system to make you a recording. Make a friend that goes around you and clap his hands, whisper in your ear. Play back your recording with the Interaural Crosstalk Cancelation disabled. And notice the stereo image is just performed between the two speakers. Now activate the Interaural Crosstalk Cancelation "filter" and get the full experience of your friends going 360° around you and whisper in one of your ears. Now what did sound like the original event? Yes you guessed it. But the cool thing that NOBODY can tell you "How can you know how the recording should sound, were you at the recording session?!" In fact you were there during the live recording and you can compare the live and the reproduction after a minute. 😜 This is the the next best thing that has happened to 2ch audiophiles since introduction of Stereo.🤩 Oh the Google after Bacch4MAC if you want more information on NEW technology and of course you can use this with whatever source.

[@stevec.6119]

The only reason i can think of why you don't understand what I said, is that you never grew up with analog stereo in the 60's thru the 80's. EVERY amplifier made had at least one tape monitor loop in order to add in an equalizer/compressor/sound shaper of some sort, as well as for just recording on analog tape machines. Your high tech solutions you mention in your reply are for the very small 5% of the hi-fi community. They all seem very cool and trending....but the VAST majority of people who just want to hear their music in the best light (considering their equipment/room acoustics) look on that stuff as lipstick on a pig. People these days barely listen to anything more accurate than 128khz mp3 files.

[@AmazonasBiotop]

@@stevec.6119 Thanks for your reply! Well I needed to read twice for understanding. (English is not my mother tongue.) Anyway the makeup on a pig that is technological advancements and development that probably just swishing over some audiophiles head while sitting and wish for as you said a rather simple tape loop RCA inputs on the preamps. (Simple as it has no technology advancement.) Maybe the focus should be elsewhere if we are looking for sound quality like I am doing for example? The science and research Schroeder and Dr Floyd Toole have done during decades of research on how our hearing and brain works are now implemented and harvest now. With help of new technologies advancements (computers, internet, image analysis and so on.). But then there is on the other spectra of audiophiles that want that the whole chain from the recording to reproduction is analog all the way. And call them self: "purist" in the sense that they do not manipulate or digitize at any point the signal. They miss out any technology advancements that the humanity has made since approx 1980. It is like saying that audio quality has gone downhill since then and all technology advancements is on the cost of sound quality.. So what do they have then. As they are sitting there with their pig and just trying to imagine how it may look if just they had some makeup at hand.. 😜 I think they just hide behind the word "purist" as they think that it is something cool and something to be striving for. When the reality is that they don't want or are to lazy to to go and learn, with the times and fix all that frightening technology that that has gone past them during the decades. And at best they can manage to connect their TT RCA and grounding wires to the external RIAA. Just as they did in the 60-ties. 👍 For example even if you take a fully analog recorded and created LP and played it in a fully analog system. They will and are missing out in sound quality (I have first hand experience when I am a vinyl guy with some technical know how). If we insert ONE component in the signal chain. That is a DSP. And it need to make a ADC and some sound processing and than back again to analog with its inbuilt DAC. Yes that introduction of a added piece of equipment plus a ADC and then a DAC is a smaller sound quality penalty than what the sound improvement it can improve in your biggest component in your system. That is your room with PEQ. (The room is at least contributing with some say AT LEAST 50% of the sound you hear. Of course you should try to fix as much as possible in the physical domain by different sound treatment technology but after that you fix the rest with appropriate PEQ + other "makeup techniques" as you call it. That we may go into later on if you like.) So the net sum is improved sound quality and is just one example what the purist is is denying themselves to experience the sound quality that they could have and get. Only if.. HAPPY listening! 👂👍

[@JJ-no2ob]

Bob Carver did this with his sonic holography circuit in the early to mid 90s. I had mixed results with it but I enjoyed the effect on most things. And yes you pronounce the name Javier spot on for a gringo from So California -good job Paul👍

[@stevec.6119]

@@AmazonasBiotop Not sure I follow all your points....but....I only know that audio (music) is one of the most subjective "sciences." Everyone has different ears, and different tastes....and the more choices you are given...the better. I just wish manufacturers would give more choices to people other than $10,000 systems...or $10.00 mp3 players. Happy listening to you as well !!!