A thought occurred to me the other day when pulling up my zipper.
No, not that zipper.
It was early morning and I was zipping up my puffy jacket and trying not to wake the girls upstairs.
ZZZIIIIIIIPPPP … dammit! How can I make this thing shut the hell up? I had my hand over the zipper while I was pulling it up, but that didn’t seem to affect the volume much.
And it hit me. The reason I can’t make my jacket zipper much quieter is the same reason that Martin Logan’s electrostatic speakers or Magnapan’s planar magnetic speakers sound so realistic and lifelike.
Planar speakers make their sound by taking advantage of what happens when you put vibrations onto a stretched, thin film (in the case of the jacket, waterproof nylon). A surprising amount of sound can leap off of these thin materials, and audio engineers from these and many other audio companies have worked to harness that effect in order to reproduce music.
The reason these types of speakers are prized is that they do something normal speakers can’t. Because the vibrating element that makes the sound waves is lighter by a large margin than its heavy speaker-cone cousins, the “plane” can start and stop on a dime.
At the end of the music signal chain, speakers are just reacting to what they’re fed down the line. But when you’re making music, you really do start and stop on a dime. One second, you’re not making music, and the next, your brain says “go” and sound commences. It’s pretty fast.
Most electronics are fast enough to not slow down the music, although some high-end amplifiers can claim impressive “slew rates,” which is how fast the amp can switch from no voltage to a large voltage.
Instead, it’s in the speakers where speed matters the most. This is because the weight of the speakers is involved and the effect of that weight exists outside of the music. In fact, it can change the music, distorting it.
That’s why low-distortion speakers like planar designs are considered more accurate compared to more common and modern designs.
Back in the day, when tube amps were the only amps, and when they used to only kick out a few watts to each speaker, the manufacturers of speakers made their drivers much more sensitive and capable of speedy music delivery.
A good set of planars can take you on a wonderful sonic trip back in time.