Headphone test for the faults you can only hear on your head

No — a perfect inverted score is a reversed pair, and the pair is much more likely to be reversed than your hearing. Check the obvious first: many headphones mark L and R faintly on the inside of the headband, and a detachable cable can be plugged into the wrong cup on models where both cups take a jack. After that comes the cable itself, where a repair or a cheap extension has crossed the two channels. A pair that is genuinely miswired inside the cup is rare and shows up as one wrong side on every source you try.

Test the seal before you conclude anything, because a broken seal costs more bass than a tired driver does. Press the suspect cup gently against your head during a low tone: if the level jumps, you are hearing the pad rather than the driver, and a flattened, hardened or split earpad on one side is the most common cause of a lopsided pair. Glasses arms breaking the seal do the same thing, and so does long hair on one side only.

Sometimes, and the noise tells you which case you are in. A buzz that is constant at one frequency and gone at the next is usually the voice coil rubbing in the magnet gap after the diaphragm has been driven past its travel — that is permanent, and the driver has to be replaced. A rattle that moves around or comes and goes when you tilt the cup is more often a loose particle or an unglued piece of trim inside the housing, which a service center can clear. Either way it is mechanical damage, so no equalizer setting will remove it.

Because something in the chain is switching channels rather than mixing them. The usual culprit is an adapter: a mono-to-stereo splitter, or a four-conductor plug in a three-conductor socket, gives you two paths that are either on or off with nothing in between. The second cause is a Bluetooth link that has dropped into the narrow-band profile used for calls, which is mono by definition. A pair that sweeps smoothly on a cable and jumps wirelessly has answered the question for you.

A small lean is common and is not always the headphones. Manufacturers match drivers to a tolerance — often quoted as within 1 to 3 dB between channels — and a 1 dB difference is already enough to shift a phantom image visibly off center. Before blaming the pair, swap the cups round on your head and listen again: if the image follows the headphones, it is the drivers or the pads; if it stays on the same side of your head, it is your own hearing, and asymmetric wax is the usual reason.

The identification and image passes do; the low tones are less trustworthy. Wireless headphones apply their own equalization and limiting inside the cup, and a limiter that clamps down at 30 Hz will make a perfectly healthy driver sound like it has given up. Run the low steps over a cable if the pair has a socket. What Bluetooth adds instead is a fault a wired pair cannot have: a link that has negotiated the call profile is carrying one channel, and a pair that fails the blind run wirelessly and passes it wired was never sent two.

Nothing here needs it, and the measured case for burn-in is much weaker than the folklore. Where researchers have measured new drivers before and after many hours of play, the changes in frequency response have generally been fractions of a decibel — well below the roughly 1 dB it takes for a person to notice a difference at all, and far below the several decibels of variation that pad wear and headphone position produce on the same pair in the same session. Every fault this page looks for is binary or mechanical, and none of them improve with use.