Troubleshooting the Mysterious “Right Earphone Failure”
By Robert Pritchett
Did you replace your earbuds because the right ear failed to function?
It starts out as a crackling sound in the right unit for a while and then it goes dead, never to be resurrected. If you are deaf in the right ear, this is not a problem. For the rest of us it is noticed immediately. And it only occurs with cable-based stereo headsets that use the mini-jack standard “cell phone” 2.5 mm audio jack. So let’s explore why…
Now if you have those cheap earbuds that are mono and not stereo, this apparently is not an issue. Nor is it an issue for wireless headsets. It becomes an issue when you lay down some pretty good money for tethered stereo earphones and they fail.
From recent reports, this is not isolated to Apple’s iPods alone. It is an industry-wide, any-player, cross-platform issue. Those legal beagles and high-tech ambulance chasers planning to sue Apple on this issue can stop right here. It is not an Apple-only phenomenon;
Hundreds of right-ear failure reports according to MacFixIt - http://www.macfixit.com/index.php?date=2007-03-05
http://www.macintouch.com/readerreports/ipod/topic1974.html
There were 270 comments, last time I looked in iLounge - http://forums.ilounge.com/showthread.php?threadid=144425
From MacFixIt –http://www.macfixit.com/article.php?story=200703021112569
“We are still in the initial stages of positing theories regarding the cause(s) of this issue, but some hypotheses include:
- The construction of the female mini-jack receptacle on various iPods is such that the right channel section of the male audio jack is more prone to some type of damage. The tip of a male audio jack is generally used for left channel sound, while the thicker part of the jack beneath the tip is used for left-channel sound...It is possible that the right-channel section of the audio jack is receiving some sort of adverse contact from iPods, causing this issue.
- Undue pressure on one side of the earphone jack causes strain, and eventual right-channel failure.
- Sound delivery to the right channel differs from delivery to the left channel, resulting in blown or otherwise damaged right earphones.”
Usually issues like this are a result of a physical contact failure. From years in the field as a tech, my first knee-jerk reaction was that it has to be something in the jack/plug connection being the culprit;
http://en.wikipedia.org/wiki/Phone_plug Switch Contacts.
From Wikipedia -
“Numbers indicate:
1. Sleeve - usually ground
2. Ring - Right-hand channel for stereo signals, negative phase for balanced mono signals, power supply for power-requiring mono signal sources
3. Tip - Left-hand channel for stereo signals, positive phase for balanced mono signals, signal line for unbalanced mono signals
4. Isolating rings
These examples are meant to illustrate each possible component of such jacks, but many other configurations using these basic components are available.
A. A simple two-conductor jack. The connection to the sleeve is the rectangle towards the right, and the connection to the tip is the line with the notch. Wiring connections are illustrated as white circles.
B. A three-conductor, or TRS, jack. The upper connector is the tip, as it is farther away from the sleeve. The sleeve is shown connected directly to the chassis, a very common configuration. This is the typical configuration for a balanced connection. Some jacks have metal mounting connections (which would make this connection) and some have plastic, to isolate the sleeve from the chassis, and provide a separate sleeve connection point, as in A.
C. This three-conductor jack has two isolated SPDT switches. They are activated by a plug going into the jack, which disconnects one throw and connects the other. The white arrowheads indicate a mechanical connection, while the black arrowheads indicate an electrical connection. This would be useful for a device that turns on when a plug is inserted, and off otherwise, with the power routed through the switches.
D. This three-conductor jack has two normally closed switches connected to the contacts themselves. This would be useful for a patch point, for instance, or for allowing another signal to feed the line until a plug is inserted. The switches open when a plug is inserted. A common use for this style of connector is a stereo headphone jack that shuts off the default output (speakers) when the connector is plugged in.”
Italics were added by me.
The Long and “Short” of it
Rick Auricchio wrote the following in MacFixIt with his understanding
of jack/plug technology –
“This begins to make sense now, assuming the player runs the DC power ground through the sleeve (ground) portion of the phones plug.
1. When the plug is fully inserted, there would be a contact that touches the sleeve portion of the plug. The sleeve conducts power from that contact to the ground contact of the jack, completing the power circuit for the player.
2. When a plug is inserted a little bit, the tip (L) and ring (R) “hot” leads bridge the power contact and ground. But since L and R phones are not connected (except through their grounds), there is no current flow. (The ground/sleeve hasn’t yet been inserted far enough to be a factor.)
3. When the plug is inserted further, however, the tip clears the power contact but the ring touches it. At this point, the sleeve has contacted ground. The right earbud completes the circuit between the power contact and ground, and DC flows through the earbud to ground.
This begins to make sense now, assuming the player runs the DC power ground through the sleeve (ground) portion of the phones plug.
I am in total agreement with Rick on this one, but there could also be other factors involved besides possibly a-less-than-optimum design. Call it the law of unintended consequences –
- If this earphone failure happened to you, what were you doing when the right earpiece failed? Were you working out and dripping perspiration all over the place and possibly getting the moisture into the hole where the plug is sitting? Perhaps the body-salt enhanced the electrical characteristics, such that arcing occurred from one part of the plug to another. It happens.
- Is there any corrosion?
- Did you disconnect/reconnect the earphones while the unit was running?
- Are the plugs nickel (silver) or gold-plated? Gold seems to hold up better, but we’d like to get a better statistical sampling just to be sure.
- Are the plugs clean or not (metal molecules that eventually created a path across the thin black insulator rings)?
- Did the wires separate (cable cover pull out) from the earpiece?
- How are the headphones treated? (Wire, even braided, can only be bent so much before it breaks, so don’t wrap them into a small ball or squeeze the loops tightly against each other.)
Trust Your Ears
If you hear “crackling” in one ear and not the other, more than likely, the braided wire is coming apart somewhere along that cable or the connection(s) at the need of the cable is/are going bad due to a mechanical failure of some kind.
And the issues of the plug/jack short-circuit activities between ground (earth) and the “mic” circuit is a common issue discussed at great length (okay, not so much) among electronics hobbyists. Unfortunately it happens quite often.
The rule of thumb for troubleshooting circuits is that usually 80% of failures are mechanical in nature (broken wires, bad solder jobs, opens, shorts), so we start there until they are ruled out.
This is almost funny – “Sudden Cable Death Syndrome” by Jens Moller, but he makes some excellent points about cable failure. Go read what he wrote a long, long time ago –
http://colomar.com/Shavano/audio_cables.html
Impedance Issues
This might be of interest regarding Impedance vs. Frequency - http://en.wikipedia.org/wiki/Electrical_characteristics_of_a_dynamic_loudspeaker
Some theories point to impedance levels and earbuds at 16 ohms that get “blown out” vs. 32-ohm systems that seem to have not experienced this. More inexpensive earphone sets have experienced failure than more expensive units.
Who know if the impedance really is the weak link here? We don’t know at this point, but there does seem to be a correlation of less expensive earbuds/earphones having right-ear failures more than the over-$100 earphones having an issue. Then again, it could be that folks who paid up to $1,000 (yes, that much!) for their earphones, are more careful with how they handle the units.
Personally, I’m not buying the notion that the issue is caused by overdriving the earphones where the right earphone is failing and the left is not.
Apple Shuffle - http://www.apple.com/ipodshuffle/specs.html
Etymotic - http://www.etymotic.com/ephp/epcomp.aspx
Shure - http://www.shurestore.com/earphones/eseries_comparison.html
Fixing the Issue
Remove the earphones when the machine is off and plug them in prior to turning the machine on. Apparently the power shorts out the electronics in the stereo earphones predominately for the right ear.
Perhaps the Tip-Ring-Sleeve design that works so well for larger form factors (6.35 mm) needs to be re-engineered for the smaller form factor (2.5 mm)?
Treat your earphones with kid gloves (those soft, dainty, white leather gloves ladies used to wear)! Don’t yank the cable out of the jack! Pull it out gently. I’ve found that if I’m good to my equipment it is good to me. Be respectful. And get the earphones replaced when they go bad. If they are still under warranty and enough folks turn them in, the “this never happened before” excuse will fade away and something will be done about it.
Digging Deeper
Inside iPod - http://www.elecdesign.com/Articles/Index.cfm?ArticleID=9500&pg=2
Fixit Guides - http://www.ifixit.com/Guide/iPod/
Pinouts - http://pinouts.ru/pin_index.shtml
Apple iPod Jack Pinouts - http://pinouts.ru/Devices/ipod_jack_pinout.shtml
iPod Schematics - http://members.chello.nl/~m.heijligers/ipod/Engineering/engineering.html
http://ipodlinux.sourceforge.net/techdetails.shtml
Wolfson Microelectronics headphone Driver chips –
http://ipodlinux.sourceforge.net/techdetails.shtml and http://www.wolfsonmicro.com/products/WM8721/
Apple Audio Protocols http://www.ipodlinux.org/Apple_Accessory_Protocol
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