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bpribadi

Reducing Crosstalk on Single Ended Cable

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Sometime ago I made some test tones using Audacity. When playing the single channel tone on my Audio Technica ATH-M50 headphones, I heard some crosstalk. When playing the left channel tone, I can hear the tone softly on the right driver, and also the other way around, when playing the right channel tone, I can hear it softly on the left driver.

 

I was wondering what causes the crosstalk. I thought my DIY headphones amplifier has bad grounding (high impedance ground channel might cause crosstalk). Then I tested the same tones using the same headphones amplifier with other headphones and IEMs, surprisingly, no crosstalk heard. I notice that the other headphones and IEMs have dual ended ‘Y’ cable, while the ATH-M50 has single ended cable connected to the left driver.

 

Then I read a news in Headfonia about cable recall by Audio Technica. Audio Technica offer cable replacement for some models, to replace single wire ground cable with 2 wires ground cable. Does it mater? 1 wire ground vs. 2 wires ground? I decided to test it, to hear if 2 wires ground will give any audible different, especially when dealing with crosstalk.

 

To replace the original ATH-M50 3 wire cable (left, right, ground), I search for starquad cable which has 4 wires / conductors per cable. I found Canare L-4E5C small size starquad (diameter 4.8 mm). Well, it is not small enough to go fully into the left driver cable hole, but that’s what available for testing. For the headphone jack, I use Neutrik 3.5mm stereo jack. Canare L-4E5C is a bit to big for the Neutrik mini jack, need some lubricant to help the jack installation. As the norm in professional audio, white conductors are used for channel’s positive (hot) and the blue which is usually used for channel’s negative (cold), is used for ground channel.

 

IPB Image

 

Assignment for the conductors:

1st White : Left channel positive

2nd White : Right channel positive

1st Blue : Left channel ground

2nd Blue : Right channel ground

Shield + the two Blue conductors are combined at the headphone jack end.

 

The original wiring of ATH-M50:

IPB Image

 

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I bypassed the small PCB on the Left driver for the Right driver positive wire, but it didn’t make any audible changes, the level of crosstalk is still the same.

IPB Image

 

ATH-M50 recabled with Canare L-4E5C:

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Just by hearing alone, I can hear the crosstalk is significantly reduced. Then I borrow another ATH-M50 with original cable, to compare it with the recabled ones. But with Canare L-4E5C I can hear some microphonic especially when I plug in the jack. But I can live with it, not really annoying.

 

The test:

1. I use iPod to play the test tones, connected to a headphones amplifier with 2 paralel outputs, one output for Recabled ATH-M50, the other for ATH-M50 with original cable.

2. I open the Right drivers of both ATH-M50, and tap directly from the driver terminal (by soldering the test cable to the driver's terminal), to the input of firewire audio interface (I use Focusrite Saffire LE). Input 1 connected to Right driver of the recabled ATH-M50, input 2 to the Right driver of the ATH-M50 with original cable.

3. First, I played a mono test signal, to set the input gain of both channels, to get equal level of signal from both drivers.

4. Play test signal only on the Left driver, and measured the crosstalk on the Right driver.

 

Recorded on Cubase AI 4:

IPB Image

 

I played and stoped the Left channel test tone a few times as you can see on the picture. The result, no crosstalk detected on the ATH-M50 driver with starquad cable, while the ATH-M50 with original cable, a significant level of crosstalk was detected. 2 wires ground is proven to reduce crosstalk significantly on headphones with single ended cable.

 

Not only crosstalk is reduced, the starquad cable also improve the sound quality, subtle but distinguishable. The more I listen to it, the more I appreciate the improvement. ATH-M50 with starquad sounds more relax, open, and the high is a bit more transparent. Compared with it, the ATH-M50 with original cable sounds a bit veiled, and the highs seems decays a bit faster. The elimination of crosstalk also improve the sound stage a little bit. This is a pretty good improvement, considering the cost of the Canare L-4E5C cable (1.5m) and neutrik jack, which is not more than SGD 7.- :cans:

Edited by bpribadi

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Hi, I am shortening the cable on my ATH-M50s. I was able to remove and shorten the cable, however I am having trouble reattaching it. It seems the solder I am using will not stick to the wire or to the existing solder.

 

Any advice? The solder I am using is rosin core 96% tin and 4% silver.

 

Thanks,

Pablo

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Are you by any chance the same person who posted on Head-Fi?

 

One possibility, as has been suggested, is that there is an enamel coating on the wire, and you'll need a really hot flame (blue) to burn it off.

 

Another possibility is that your solder iron is underpowered for the wire gauge on the M50. The wire could be dissipating the heat faster than your iron can supply, so it'll never be hot enough for tinning.

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nope, I haven't posted anywhere else...

 

If anyone knows what I can do to get the cable attached, let me know... otherwise I'm just going to send them in to Audio Technica and have them do it (for $20).

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nope, I haven't posted anywhere else...

 

If anyone knows what I can do to get the cable attached, let me know... otherwise I'm just going to send them in to Audio Technica and have them do it (for $20).

 

How do you get Audio-Technica to shorten them? Isn't the warranty void if you modify the cables? I'm interested in letting them do it too, so let me know.

 

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IPB Image

 

actually the 2 in 1 wire within the sleeve seems rather iffy.

 

Should do a continuity test for signal contamination.

Edited by The Audio Hub

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actually the 2 in 1 wire within the sleeve seems rather iffy.

 

Should do a continuity test for signal contamination.

They actually appeared to be coated with clear plastic, or perhaps clear enamel, which is why some people are have trouble recabling them - the presence of the coat really doesn't seem too obvious.

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Are you by any chance the same person who posted on Head-Fi?

 

One possibility, as has been suggested, is that there is an enamel coating on the wire, and you'll need a really hot flame (blue) to burn it off.

 

 

chances are this is probably the case. The best tool for the job, IMO is a microtorch - its kind of a cigarette lighter on steroids - you just need to give it a quick passover, and have the wire glowing red hot for just a moment

 

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****obscenity deleted by mod - please note this forum do not allow obscenities****

My boredom and curiosity made me tear apart my M50 to do some major modding LOL

But seriously the cables need to be changed, I took out the tiny black dual wire cable for the right channel and going to do a 2 side mod.

 

Gonna readjust the headband which caused me so much problems and discomfort and add better padding compared to the thin piece of foam that its on.

Edited by heady

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Are you by any chance the same person who posted on Head-Fi?

 

Are you referring to me? Yes, I also posted this thread in HF. Earfonia is my nickname in other forum. :)

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