Depends. Some hifi headphones and speakrs are actually matched. Rare now, but used to be very common when driver designs and production tolerances were looser.

Depends. Some hifi headphones and speakrs are actually matched. Rare now, but used to be very common when driver designs and production tolerances were looser. I have some 1930's brandes headphines that were matched, but are basically a magneto driver and sound awful (but clear) by any modern standard.