You can’t do anything to the sound of the recordings that you purchase. The balance of the instruments, the amount of compression, the equalization and everything of aspect of the fidelity is established at the time of the recording and the subsequent postproduction stages. The potential fidelity of any album release is limited to format that is used during the original sessions…NOT the delivery format…but we already know that. So what can you do to modify the sonics of your music at home, one the road or while jogging at the beach?
Since the earliest days of HiFi playback equipment, equipment manufacturers have included tone controls. We’ve always been able to adjust the bass and treble of our music. Newer preamps and receivers include a midrange equalization control. But these tone controls are superficial timbral modifiers and not really affected the fidelity and accuracy of the original tracks.
Somewhere along the way, I can remember getting my first graphic equalizer. You know the ones. They are stereo units with an individual boast and cut controls at every octave…the fancier ones (that we use at the studio) have 3 controls for every octave and are known as 1/3 octave graphic equalizers. The word graphic comes from the fact that you can easily see the tonal modifications that are being applied by looking at the position of the sliders on the front of the channels.
The use of graphic equalizers is typically used to modify the response characteristics of a physical space and not so much for creative reasons. I have one on each of the outputs of my console before my amplifiers.
So when considering how much tonal modification (analog or digital) to do on music that has already been properly balanced in the studio and during the mastering phase, you should keep in mind that any changes you make are being added (or subtracted) to the intentions of the producer…if and only if your playback system and room have a flat playback response. And the chances for that are slim.
Having a professional come to your place and do a careful alignment is strongly encouraged. The home-automated room correction tools are not quite ready for prime time, in my opinion. There are so many things that affect the sound of your playback system: the speakers, the cables (yes, cables can “change” the sound), the arrangement of the furniture, the amount of glass or brick in the room, whether you have carpets or rugs on the floor and the geometry of the room itself.
This might be the reason why a good set of headphones can usually out perform a very good playback setup…there is no need to address the acoustics of the space you listen in.
If you’re a critical listener, the sound of your playback system will be improved when the speakers are closer to your listening position. This is referred to as “near field monitoring”. Using this method means the interaction of the speakers output with the rest of the room is minimized.