How to instantly improve the sound quality of your Mac

I am an audiophile and I love to push my audio quality to the limit.

So here's a quick way to improve your Mac's audio quality:
Open "Audio MIDI Settings"
Click on the Built-in audio tab
Select 2 Channel 32bit 96kHz

Voila! If you have good headphones (around $50 or more) you will surely begin to feel the panning and positioning of instruments spacially. It also makes instruments separation clear.

The logic behind this is that you are increasing the bit depth to 32bits and sampling frequency to 96kHz.

Sampling rate is the number of samples of digital sound (audio snapshots) that are taken per second. So just as more pixels per inch forms a clearer, sharper image, more sampling rate forms a clearer audio profile.
The default sampling rate is 44kHz, but if you have an optical TOSLINK cable, you can even push the sampling rate to 192kHz.
You would need an external DAC to run such a sampling rate though. The most popular DAC is the Audioengine D1 DAC. It acts like an external soundcard that bypasses your PCs sound circuit thus avoiding any circuit noise that gets mingled with the digital audio signal.

And that's your audiophile knowledge for the day!