Originally Posted by Lukien
Some theoretical stuff written there, but i get what you guys mean
But when i read reviews about high, mids and lows, i could simply assume that these terms refer to high pitches, meduim pitch and low pitches right? I mean, that would be what they are talking about
Yes, but not exactly. To my understanding (and I'm no expert), pitch refers to the fundamental frequency of a musical note (i.e. the lowest frequency of the note). However that is only one of many frequency that is generated when you say press a key on a piano or pick a guitar string. There are also a multitude of higher frequencies generated (harmonic frequencies).
Lets say for example that you press the lowest note on a piano. The pitch of this note is 'A'. This will generate a fundamental frequency of 27.5 Hz (almost at lowest audible threshold), and multiple harmonic frequencies up to say (for illustration purposes) up to 20 Hz. Not all of the frequencies generated will have an equal amount of energy. Generally the higher harmonics will have less energy. For instance, you may not be able to detect frequencies above 10 Hz, either because they are not loud enough, or they are 'drowned out'.
If you record and playback this note, it will not sound exactly like it did when you played it live. Recording and reproduction equipment is not perfect, but lets say that is a very good reproduction. You can alter the sound via a graphic equalizer so as to emphasise or de-emphasise selected frequencies. The frequencies on a graphic equalizer are somewhat arbitrarily grouped in to low, mid, and high frequencies.
By manipulating the lows, mids, or highs on the EQ, you are changing the energy of those frequencies, and thereby emphasising the sound characteristics, which may be characterised as bassy, middy, trebly etc. But you are not affecting the pitch, it is still an 'A' note.
As playback equipment is not perfect, it will emphasise/ de-emphasise certain frequencies. Different manufactures and models will have different characteristics. It is sort of like they have applied their own EQ to the product. The 'better' gear will typically have less (or more subtle) 'E.Q.', but they will still have a characteristic 'sound signature'. This is where people generally describe the signature in terms of lows, mids, and highs.
Treble 'roll off' just refers to the point (frequency) where treble energy starts to diminish, or cease to exist above a certain frequency. Mids don't 'roll off' as such, but are often described as neutral, recessed (de-emphasised), or forward (emphasised), pretty much like applying E.Q.
Playing around with E.Q. is good way to familiarise yourself with these sound characteristics and find your preferred sound signature without having to spend money on gear (you should always lower E.Q. bands rater than boosting them, as this can introduce distortion). But E.Q. can only compensate so much for the characteristics design and limitations of the equipment. For example, headphones with bass roll of at 100 Hz will undoubtedly distort and 'drown out' other frequencies (i.e. mids and highs) if you apply enough E.Q. to try to bring out frequencies below 100 Hz.
I hope this helps.