The Boulder area is home to quite a few high-end audio manufacturers, like Grace Design in Lyons, Ayre Acoustics here in Boulder, Boulder Amplifiers in Louisville, YG Acoustics in Arvada, and there's more as you go up and down the Front Range.
I work for one of these, a company called PS Audio located here in Boulder off Valmont and Foothills. All of us in this crazy industry have access to specially-tuned listening rooms for testing and experimentation, and each of these rooms and the speaker and electronics systems within are specifically designed to encourage a 3-D soundstage using two speakers.
Our two ears can separate distant and close sounds well, so we get plenty of three-dimensional information coming through. Two speakers can also recreate this experience if they are of good quality, if the music was recorded well and if the room is treated correctly to minimize interfering sound waves.
The above companies aren't the only ones with purpose-built music listening rooms. Mastering studios like Airshow Mastering or Super Audio Center nearby have very impressive listening rooms in which the full sound blooms like it is supposed to. On top of that, there are plenty of audiophiles living along the Front Range who have created the same experience in their own homes, myself included. Just like fine dining and fine wine and perfumes, fine audio is totally a thing — a treat for the sense of hearing.
With these examples, I want to remind regular readers of the 3-D effect thing when it comes to sound because that is exactly where the difference lies between switch-mode amplifiers and old fashioned linear amplifiers.
Last week, I said that big, old school amplifiers that are also heavy are linear amplifiers. Anything small and light, like those in modern Bluetooth speakers, for example, are switch-mode amplifiers. Linear amps usually have output devices (mini amplifiers within the amplifier) divided in two, with each section operating half the time at wall power speed. Both sections need to be there anyway, so instead of both being on all the time, only half the power is being used to make loud music. This is efficiency in linear amp design.
Switch-modes turn their power on and off at a much higher rate. It's like singing through a fan: If the fan goes fast enough, you don't hear the blades blocking the sound. With the power turning on and off 80,000 or 500,000 times a second, you don't even notice.
Except ... Class D (or switch-mode) amplifiers can reproduce a wide soundstage, but they tend to struggle when it comes to perceived music depth of field.
When you get the speakers set up right, without any big walls next to them, a little pulled out into the room and angled in a rough equilateral triangle (depending on the speaker — some you don't angle at all), well-recorded music will show up all around. It can sound like the music is coming from outside of the speakers and from beyond the wall behind the speakers.
You just may need a linear amp to experience it.