What is crosstalk?
Sep 3, 2006 at 9:53 AM Thread Starter Post #1 of 20

sidewinder

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Hence title.

Is crossfeed related to this subject?
 
Sep 3, 2006 at 10:01 AM Post #2 of 20
It's an unwanted interference from one channel of a signal into another.

Those shadows you get to the right of people when you have poor TV reception is crosstalk. You get the same effect in analogue audio too, although it can be harder to spot. In audio measurements crosstalk is counted in decibels.
 
Sep 3, 2006 at 10:02 AM Post #3 of 20
Crosstalk is a natural occurence with speakers - it's all part of the speaker experience though.
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Crossfeed is a feature on amps that tries to implement crosstalk on headphones.
 
Sep 4, 2006 at 10:16 PM Post #4 of 20
Quote:

Originally Posted by sidewinder
Hence title.

Is crossfeed related to this subject?



In a standard stereo system, with speakers (not headphones), the listener's left ear hears both speakers and the right ear hears both speakers. If the left ear heard only the left speaker and the right ear heard only the right speaker, there would be no crosstalk. Put differently, crosstalk occurs when the left ear hears the right speaker and the right ear hears the left speaker. Some people, including me, believe that crosstalk reduces sound quality. With headphones, there is no crosstalk because the left ear hears only the left phone and the right ear hears only the right phone. HeadRoom, in their headphone amps, provide a crossfeed circuit that introduces crosstalk. I have two such HeadRoom amps. Both sound better to me with the crosstalk circuit switched off. --Best, Les
 
Sep 4, 2006 at 10:26 PM Post #5 of 20
Whoa~ I think some of you are confusing crosstalk and crossfeed. Unless I'm not updated with the current definitions, Carl has it right. Crosstalk is UNWATED and crossfeed is a deliberate effect. I've never heard the term crosstalk referring a sound wave, only electric signals. The two terms don't really have much to do with each other.
 
Sep 4, 2006 at 10:28 PM Post #6 of 20
Quote:

Originally Posted by Headphoner
Some people, including me, believe that crosstalk reduces sound quality. . . . HeadRoom, in their headphone amps, provide a crossfeed circuit that introduces crosstalk. I have two such HeadRoom amps. Both sound better to me with the crosstalk circuit switched off. --Best, Les


On the other hand, some people like crossfeed because it often makes the music sound more coherent and live. When you go to see live musicians, it's impossible for them to beam one channel into one ear and another channel into the other as headphones can. However, certain types of music don't need crossfeed, which can make the music sound more distant and less impactful and detailed IMO.
 
Sep 4, 2006 at 10:29 PM Post #7 of 20
Quote:

Originally Posted by powermung
Whoa~ I think some of you are confusing crosstalk and crossfeed. Unless I'm not updated with the current definitions, Carl has it right. Crosstalk is UNWATED and crossfeed is a deliberate effect. I've never heard the term crosstalk referring a sound wave, but electric circuit signals. The two terms don't really have much to do with each other.


This was my understanding, as well.
 
Sep 4, 2006 at 11:49 PM Post #9 of 20
Quote:

Originally Posted by powermung
Whoa~ I think some of you are confusing crosstalk and crossfeed. Unless I'm not updated with the current definitions, Carl has it right. Crosstalk is UNWATED and crossfeed is a deliberate effect. I've never heard the term crosstalk referring a sound wave, only electric signals. The two terms don't really have much to do with each other.


I believe I am using the terms correctly. In a standard stereo system (speakers, not headphones), when your left ear hears the right speaker and your right ear hears the left speaker, this is called acoustic crosstalk. You can check at Ralph Glasgal's Ambiophonics web site. It is this acoustic crosstalk that circuits like Carver's Hologram, Glasgal's crosstalk reducer's, and Lexicon's Panorama are designed to reduce. These circuits were designed to reduce acoustic crosstalk because the engineers that designed the Hologram, Ambiophonic crosstalk reducers, and Panorama believe acoustic crosstalk sounds bad and is unwanted. Crossfeed, like that used by HeadRoom, to imitate acoustic crosstalk in headphones, is a deliberate effect which is wanted by the HeadRoom company. I think the crossfeed sounds bad. I also think that Bob Carver (who designed the Hologram), Ralph Glasgal, and the engineers at Lexicon (who designed Panorama) would think that the crossfeed circuit in HeadRoom amps is conceptually a mistake. Without getting into theoretical arguments about whether it is a conceptual mistake, I have two HeadRoom amps with crossfeed circuits and I think both amps sound better with the crossfeed circuit turned off. --Best, Les
 
Sep 5, 2006 at 12:04 AM Post #10 of 20
PS There are two kinds of crosstalk, electrical and acoustical. You guys are thinking of electrical crosstalk. I believe the original poster had in mind acoustic crosstalk in his question.


Quote:

Originally Posted by Headphoner
I believe I am using the terms correctly. In a standard stereo system (speakers, not headphones), when your left ear hears the right speaker and your right ear hears the left speaker, this is called acoustic crosstalk. You can check at Ralph Glasgal's Ambiophonics web site. It is this acoustic crosstalk that circuits like Carver's Hologram, Glasgal's crosstalk reducer's, and Lexicon's Panorama are designed to reduce. These circuits were designed to reduce acoustic crosstalk because the engineers that designed the Hologram, Ambiophonic crosstalk reducers, and Panorama believe acoustic crosstalk sounds bad and is unwanted. Crossfeed, like that used by HeadRoom, to imitate acoustic crosstalk in headphones, is a deliberate effect which is wanted by the HeadRoom company. I think the crossfeed sounds bad. I also think that Bob Carver (who designed the Hologram), Ralph Glasgal, and the engineers at Lexicon (who designed Panorama) would think that the crossfeed circuit in HeadRoom amps is conceptually a mistake. Without getting into theoretical arguments about whether it is a conceptual mistake, I have two HeadRoom amps with crossfeed circuits and I think both amps sound better with the crossfeed circuit turned off. --Best, Les


 
Sep 5, 2006 at 12:23 AM Post #11 of 20
No. The crosstalk to which you refer is crossfeed. The same crossfeed that is replicated in a headphone circuit. You are I regret, simply confused about your terminology.
 
Sep 5, 2006 at 5:44 AM Post #12 of 20
I agree with Headphoner. I had a pre-amp with a blend circuit, which mixed the left and right signals and found it was of no help whatsoever. Subsequently I bought a set of Polk SDA speakers, which attempt to suppress the crossfeed and realized this was where speaker reproduction should be heading. Within their sweet spot you get a very vivid sense of localization. The sound sources kind of jump out at you. In addtion localization can extend to the side beyond the location of the speakers. When you move away from the sweet spot, the image is just like regular speakers.

This convinced me that crossfeed is bad for speaker reproduction and attempting to put it in headphones is just bizarre.

The Headroom crowd do a major disservice trying to peddle this form of auditory distortion as an improvement in fidelity beause it is more "speaker-like." All they are doing is imitating the fundamental weakness of stereo speakers, the creation of an artificial blending of signals which have no correspondance in the real world.

The crossfeed signals are also referred to as "phantom channels." Essentially 2 speakers create 4 signals, the left speaker feeding the right ear and the right speaker feeding the left ear are the two"phantoms"
 
Sep 5, 2006 at 7:24 AM Post #13 of 20
Quote:

Originally Posted by Duggeh
No. The crosstalk to which you refer is crossfeed. The same crossfeed that is replicated in a headphone circuit. You are I regret, simply confused about your terminology.


Hi Duggeh,

My terminology is correct. At the University of Southampton, in England, there is an Institute of Sound and Vibration Research (ISVR). Please click on the following link and go there.

http://www.isvr.soton.ac.uk/FDAG/VAP/index.htm

Look to the bottom of the page and click on "cross-talk cancellation." You will see that I am using the term "acoustic crosstalk" correctly. Also, please Google "acoustic crosstalk" and read the first ten sites that are listed. You will see that I am using the correct terminology. Please go to the Ambiophonics web site -- click on http://www.ambiophonics.org/ --and read some of the stuff there. You will see that I am using the correct terminology. The correct term is "acoustic crosstalk," not "crossfeed."
--Best, Les
 
Sep 5, 2006 at 8:11 AM Post #15 of 20
Well, there is a lot of corruption in the use of the term (this is the English language, after all
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), but in it's pure form, the term means one or more channels of a parallel or multiplexed serial signal interfering in one or more other channels.

It's quite true that crossfeed is a form of intentionally induced (and tightly controlled) crosstalk, but the vast majority of instances involving crosstalk are undesireable.

I believe "acoustic crosstalk" is an arbitrarily applied term for noise cancellation.
 

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