Hope i'm not boring anyone or being overly repetitive. Wordy, for sure. My apologies for the impending flood of seemingly spontaneous and self-effacingly immodest techspeak. There is a point i'll eventually be making, but i feel like there's alot of crucial information regarding Digital Playback that may've been overlooked, or simply outside the realm of individual knowledge, yet when once understood, gives a solid foundation to successfully achieving reference level sound reproduction on iOS and other devices. And i specifically mean, achieving as close to as possible, the sound signature of a studio live performance at the original time of track recording. So, maybe not what the artist intended for you to hear,...but the sounds he/she actually made. Not quite the same, but semantics really.
Anyways...i may be staking my dubiously placental reputation out on the line here...but whatevs.
The Flat Line. Reference? Logic WOULD say yes, initially, but upon deeper mental digging & profuse headaches, something doesn't click. If sound moves in waves, there's not a single logical way in which a flat, or linear approach to reproducing sound will EVER work. Just like the exponential rise and fall of the Hertz slope, a truly organic and acoustically accurate Sound signature will look like a layered sin/cos formula, with parabolic rises and falls. Just like *gasp* a soundwave or frequency.
But the flat line DOES matter. Inconcieveably so. If the audio encoding team knows their ****, they would know that when sound is recorded correctly and accurately, that AT FLAT (+/- 0db gain to ANY frequency), there is no more PHYSICAL data that can be added. This means that the maximum amount of musical tone RECORDED is within the entire bottom half of any equalizer you use. What is usually left off of Visual EQ representations is a TRUE flow chart, which shows not only gain(db) applied to each selected frequency, but the amount of bandwidth applied as well, meaning how many adjacent frequencies are affected, and at what rate(exponent), and the crossovers where adjacent reduced frequencies create double Helix formations.
Trust me,...the most correct and truely flat reference waveforms look like DNA strands on the flowcharts. Organic, Musical, DNA. Makes a calming sort of sense. the waveforms are usually parabolically symmetrical but never EXCEED the flat line.
And any time you attempt to digitally ADD or enhance detail of ANY recorded source, you distort the original and lose reference. FOR EXAMPLE...jacking the color response of any digital image. The desired effect is achieved, the color is enhanced. Keep going and the reds will start to bleed outside the edges. This reduces, tremendously, the variation between colors, and your overall contrast, and hence, the detail and resolution of your image. THE EXACT SAME THING HAPPENS TO SOUND. This includes the EQ used in the music player utilized in any Apple OS device. Both the music App, and the Itunes Equalizer employ the use of a digital preamp. But it's not a real pre-amp. It's software driven. and horribly so. Digital enhancements have NO place in a controlled reference experiment. Real problem is...you can't reduce or affect the built-in pre-amp on the music app. :(
The REASON a digital preamp sucks> at 'flat' response, you are still adding amplitude(gain) to all points across the 10 band EQ to achieve flat response, without more hardware(more real/physical & CLEAN power/current), or increasing the volume, thereby utterly destroying accurate sound signatures. For that reason alone...itunes & the music app, while having above average sound signatures for the average listener, will logically never achieve reference sound...
wheew...that felt ... like too much.