Last week, I mentioned a buddy of mine had recently picked up a new pair of speakers that are known to help create that magic, holographic stereo field I described.
Along with them, he bought a DSP device to correct remaining issues in the sound due to their location in his living room. Audio scientists know that much of the music that reaches our ears is actually reflected off of and changed by the surfaces around us.
With the recent rise in affordable DSP (Digital Signal Processing — think high-quality equalization) solutions like the MiniDSP that my friend bought, the room can be addressed cheaply and quickly. And with some devices, correction can be automatic.
My friend set up his new speakers with great care, making sure of each connection. With the DSP in place, the resulting sound was good, but he noticed that the sweet spot (the point in space where the music enveloped him and it sounded closest to the ideal) had shrunk to a pinpoint. If he turned his head, the sound changed dramatically. He listened to the new speakers for a week with a feeling that all was not right.
And then, a week later, he was making adjustments to the DSP settings and saw it: two small labels with checkboxes — stereo and mono. Guess which box was checked?
The DSP stuff can adjust in realtime, so when he moved the checkmark to the stereo column, all hell broke loose in front of his ears.
Instead of a focused, tonally good but vaguely lacking stream of music, his whole room burst awake with a vivid, three-dimensional wall of sound.
Eureka! Problem solved. But in this case, speakers and DSP were only part of the solution. His room opened up with 3-D music because he was also listening to "natural stereo" recordings, like what the "father of stereo" Alan Blumlein was trying to create in the 1930s.
Nowadays, most classical music is recorded to produce a natural stereo sound — a sound that makes you feel like you're inside the performance hall. For an example, check out Yo-Yo Ma's 2015 album "Songs From The Arc of Life."
Nearly everything else — pop, rock, country, you name it — is a combination of stereo and mono, so only part of the music will sound like it's coming from beyond the speakers. For example, using two microphones (remember, two mics for two ears) to record drums is fairly common, but often there is just one microphone on an electric guitar.
As a listener, you can hear the hi-hat and snare drum sounds come from the right, the toms from the middle, and the ride cymbal and floor tom from the left side of the stereo image. But the guitar often sounds like a single voice coming directly from one speaker or the other.
Only with two microphones recording in stereo can you sense that you're listening from a point in space above the music.
Actual, nonclassical albums using natural stereo recording are rare but currently growing in popularity. They're called "audiophile" recordings, and if you're the curious sort, check out the website 2L — www.2l.no — which makes original recordings like this across several genres.