Headphone cable crosstalk - how to avoid? - diyAudio
Go Back   Home > Forums > Amplifiers > Headphone Systems

Headphone Systems Everything to do with Headphones

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 17th November 2002, 07:19 PM   #1
diyAudio Member
 
Join Date: Apr 2002
Question Headphone cable crosstalk - how to avoid?

I'm purchasing a set of headphones that runs the headphone cable only to one side of the headphone (i.e. they don't split visibly to two different wires outside the headphone cup).

Inside the first cup there are a connection spots for the left and right cup signal wires respectively AND a shared common ground which then leads to both cups.

The standard cable that comes with the headphone is therefor a three wire cable with a shared ground along the whole of the signal path after the headphone amp.

Now, I'm concerned about crosstalk due to the shared ground and especially the low impedance (40 Ohms) of the phones.

I've seen measurements (for Sony MDR V6) that shows that the crosstalk noise components can rise up to the relative level of -30 dB compared to the signal level.

This is clearly not acceptable for my purposes.

Is there any way I can hack/modify such headphones (by building my own cables) in order to reduce this type of crosstalk?

I'm sure I could get rid of it with proper cable construction and IF I could have separate ground contacts for each transducer. However, I don't think I'm brave enough to tear apart my $300 USD headphones band in order to fit a separate ground wire for the second cup.

So, can anything be done (to crosstalk) just by exchanging the cable, if the contact at the end of the headphone has only one place for the ground to which both transducers are connected?

All help / corrections are welcome.

Best regards,
Halcyon

PS I'm an electronics novice, but you don't have to treat me with silky gloves. If I can't understand the explanation with my own books (and net searches) I'll ask for a clarification.
  Reply With Quote
Old 17th November 2002, 11:14 PM   #2
lohk is offline lohk  Europe
diyAudio Member
 
lohk's Avatar
 
Join Date: Apr 2001
Location: Northern Noricum, near the Limes
Are you kidding ?
Did you hear crosstalk of the cables ?
Common cables is "common" practice with headphones, ane there is no crosstalk (specially with low impedances).
The crosstalk you hear happens in the electronics "before" the output.
  Reply With Quote
Old 18th November 2002, 07:10 AM   #3
diyAudio Member
 
Join Date: Apr 2002
No, I'm not kidding.

I have seen actual measurement data of headphones which have a shared common ground and with which the crosstalk components exist at the relative level of -30 dB below signal.

These tests were conducted by expert psychoacousticians and audiometric personnel who specialize in the audibility tests.

Their recommendations NOT to buy any headphones with a shared ground (unless you have a way of measuring it's crosstalk components) sure looks valid to me.

Most high quality audiophile and studio headphones have a separate ground wire for each cup.

Not all, but many of them.

Honestly, what make you think that I am kidding?

Have you not heard about cable crosstalk (induced by shared ground) before?

regards,
Halcyon
  Reply With Quote
Old 18th November 2002, 08:18 AM   #4
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Some headphones have shared ground and this can result in a little bit crosstalk. When the cable is separated into two wires all the way from the connecter to speaker elements, you will get better separation. My (quite good) Sennheiser HD545 reference (in fact most Sennheiser phones) has separate cables all the way.

I think though that your concern is a little bit "overkill". In order to get good stereo you need 10-15 dB channel separation. Compare to the good old vinyl with approx. 20 dB channel separation.

Have you tried the headphone experts at www.headwize.com ? try also www.head-fi.com
__________________
/Per-Anders (my first name) or P-A as my friends call me
  Reply With Quote
Old 18th November 2002, 09:36 AM   #5
diyAudio Member
 
Join Date: Apr 2002
peranders,

I'm trying to locate a suitable closed circumaural headphone pair for psychoacoustic testing. Hence I have a higher requirements for crosstalk immunity than with normal listening (if not for anything else, but so that nitpickers can't shoot down the test setup based on that).

Thanks for the tip on head-fi and headwize. I have discussed the problem in Head-Fi forums (but not yet at headwize). I have done extensive searches on the issue on the net and read the relevant parts in 'Loudspeaker and Headphone Handbook' (2001 ed.)

The trouble is finding people who have actually constructed their own replacement cables and actually measured their crosstalk when connected to an actual pair of headphones with a shared ground connector.

Currently I don't have the needed measuring equipment (nor enough trust in my skills) to test myself, which makes life a little bit more difficult

But back to my original question:

Can something be done to alleviated the normal three cable wire and a shared common ground contact in otherwise high quality pair of headphones?
  Reply With Quote
Old 18th November 2002, 09:57 AM   #6
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Quote:
Originally posted by halcyon

But back to my original question:

Can something be done to alleviated the normal three cable wire and a shared common ground contact in otherwise high quality pair of headphones?
Yes! Use headphones with separate cables like Sennheiser or change cables at your headphones.

I had long time ago a 3 x 0.4 mm sqr to my speakers. The cable was 10 meters. The resistance of the common ground cable was not small, 1.4 ohms in each wire and 4 ohm speakers.....not audiophilic connection..

Don't forget that you have crosstalk in your head also!
__________________
/Per-Anders (my first name) or P-A as my friends call me
  Reply With Quote
Old 18th November 2002, 11:57 AM   #7
halojoy is offline halojoy  Sweden
On Hiatus
 
Join Date: Nov 2002
Default Also 3.5 mm stereo-plug uses Common GND

Also the very much used 3.5mm stereo plugs use common GROUND.
And the headphones use that or 6.3mm stereo "teleplug".
I do not like it.

I want to be able to put the common ground at the place where I think it is best.
The RCA phono plugs use separate,
which makes it easy to use separate cables.
These cables could be joined by some sort of clips, or those things
used to hold together cables inside electronics.
Or some tape.
  Reply With Quote
Old 18th November 2002, 01:17 PM   #8
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Quote:
Originally posted by peranders

I had long time ago a 3 x 0.4 mm sqr to my speakers. The cable was 10 meters. The resistance of the common ground cable was not small, 1.4 ohms in each wire and 4 ohm speakers.....not audiophilic connection..
.... I ment 0.4 square millimeters = 0.437 ohms! Still it was noticable.
__________________
/Per-Anders (my first name) or P-A as my friends call me
  Reply With Quote
Old 12th March 2003, 04:02 AM   #9
diyAudio Member
 
Join Date: Mar 2003
Location: florida
Default headphone crosstalk

The phones shouldn't crosstalk. Make the measurement through the amplifier. The low source impedence should keep the crosstalk down. If you are making the measurement with one side disconnected, put a 4.7 ohm resistor across the side under test to simulate a real world condition
  Reply With Quote
Old 12th March 2003, 10:40 AM   #10
UrSv is offline UrSv  Sweden
diyAudio Member
 
UrSv's Avatar
 
Join Date: Jan 2002
Location: Sweden
Default Re: Headphone cable crosstalk - how to avoid?

Quote:
Originally posted by halcyon
I'm purchasing a set of headphones that runs the headphone cable only to one side of the headphone (i.e. they don't split visibly to two different wires outside the headphone cup).

Inside the first cup there are a connection spots for the left and right cup signal wires respectively AND a shared common ground which then leads to both cups.

The standard cable that comes with the headphone is therefor a three wire cable with a shared ground along the whole of the signal path after the headphone amp.

Now, I'm concerned about crosstalk due to the shared ground and especially the low impedance (40 Ohms) of the phones.

I've seen measurements (for Sony MDR V6) that shows that the crosstalk noise components can rise up to the relative level of -30 dB compared to the signal level.

This is clearly not acceptable for my purposes.

Is there any way I can hack/modify such headphones (by building my own cables) in order to reduce this type of crosstalk?

I'm sure I could get rid of it with proper cable construction and IF I could have separate ground contacts for each transducer. However, I don't think I'm brave enough to tear apart my $300 USD headphones band in order to fit a separate ground wire for the second cup.

So, can anything be done (to crosstalk) just by exchanging the cable, if the contact at the end of the headphone has only one place for the ground to which both transducers are connected?

All help / corrections are welcome.

Best regards,
Halcyon

PS I'm an electronics novice, but you don't have to treat me with silky gloves. If I can't understand the explanation with my own books (and net searches) I'll ask for a clarification.
That is pretty much the standard problem AFAIK. Most people concerned about this just rip their headphones apart and fit a new connector on the side without one. Depending on the model this might look good or not. I say that is the approach.
__________________
UrSv
Those who say it can't be done should not stop those who are doing it.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Interaural crosstalk eStatic Everything Else 3 28th February 2008 05:53 PM
soldering headphone cable meaghers Headphone Systems 4 21st November 2006 12:48 AM
Crosstalk in twintriodes? Ryssen Tubes / Valves 7 22nd June 2006 06:55 AM
PSRR and Crosstalk dgardner Solid State 4 20th June 2005 02:09 PM
Re-wiring a tonearm with headphone cable. mattjk Headphone Systems 1 2nd March 2005 01:40 PM


New To Site? Need Help?

All times are GMT. The time now is 06:54 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2