Many know me to be a snobbish circumaural headphones bigot, preferring to lug the excess weight and bulk of space-helmet-looking headphones, turntables and all, to satisfy my needs for portable music. I do not compromise on my standards for noise protection, comfort, and ergonomic movement. That means a warehouse of earphones that came stock with various audio devices under my ownership, that lay as part of my "underutilised" inventory. But once in awhile, I'd get into one of those "what a waste" mood swings that makes me eye over an item, dig it out of the multiple layers of earth, and give it an operational test.
So last night, since my high-tech audio equipment is still undergoing servicing, I decided to try low-tech and dust off the stock Nokia headset. The headset is comprised of regular earphones with a short jack cable, and an extension cable that carries the clip microphone. Since these are stock equipment, the jacks are not gold-plated and have tarnished during their dormant rest for the past few millennia. These layers of metallic mucus are excellent at killing the conductivity of jack, essentially making the effort to get a balanced audio signal for all frequencies on both sides much more difficult than tuning the gain of a primitive radar. I sat there twisting and rotating the jack in the stereo port like an idiot trying to decipher an encrypted satellite porn channel; I simply could not get a balanced signal.
Then it hit me: why does the left side have greater tendency than the right side in failing to receive a good signal?
This is not the first time I encounter unbalanced problems involving the left earphone. More often I am "tuning" in order to get the left channel on par. The answer, I suspect, lies in the design of the stereo jack. The tip of the jack is the left channel. It would appear the tip is prone to connectivity misses for a deteriorated jack. Frankly if that is the case, I think a flat cylindrical jack design would have been less susceptible. Unless somebody prefers the feel of a jack with an edgy end; slides in smoother or something, I don't know.
No matter, this morning I found a real convenient solution to restoring the connectivity - simply wipe the jack with those rinse-free, alcohol hand sanitiser fluids. It managed to burn off the tarnish coat with zero stutter and static when I twisted the jack in the port. I see it certainly helps to wash up after use.
A separate matter involving the same equipment was the mystery of incomplete audio experience when I plug my fully-extended headset cable into a standard stereo port, like those on my laptops. The audio signals would be unbalanced (left again) or missing or softening of some sound frequencies, like human voices; making music sound more like instrumental karaoke tracks. No, I do not think that is the reason why there is a microphone attached to this cable.
The reason became clear when I took a closer look at the direct jack to the earphones, against the jack of the extension microphone. The latter had three division rings - four segments. A typical stereo jack should have two rings - left channel (tip), right channel, and sleeve. The microphone jack included another segment for microphone input. Makes total sense, but shows what an ignorant nut I am when it comes to basic electrical conductivity. Well at least I don't use a running toaster in the bathtub.
So the lesson is, do not plug a stereo-cum-microphone jack into a regular stereo port and expect a good audio experience. Just use another regular extension cable.