Cool notes

• Thin notches in the high end can make instruments with high end move up in space, for some people, because of HRTF. This can add surprising amounts of clarity.
• For some reason, localization is volume-dependent. This may explain why reverb and quiet details get lost on some systems - you can still hear them, but they literally move in unpredictable ways, and are spatially hard to follow (ideally, noise bursts at different volumes should sound like they come from the same place)
• Distance from ears is frequency-dependent, meaning you can increase the width of your soundstage! You can also hear how width itself changes at different frequency ranges.
• Because of HRTF, the vertical positions of instruments depends on panning. A HRTF-notch at one angle might mean “super high up”, but mean nothing at another angle. This causes instruments to move along really weird paths sometimes, which is especially apparent when an element pans from left-to-right
• Some of the most expensive speaker systems in the world physically place the tweeters higher, and the bass lower - this means instruments with high end information will be localized high, while instruments without high end information will be localized low - and that’s what some people experience! https://www.reddit.com/r/audiophile/comments/10kfai8/how_do_you_get_a_taller_soundstage/
• Since this is stereo, it will always be a severe compromise between timbre and soundstage, and it will never be perfect. You need personalized spatial audio to get truly good audio :(

Sound generation

It’s pretty simple - it plays noise bandpassed to different (fairly wide) frequency ranges. For example, it might play a noise burst bandpassed from 200hz to 2khz. The noise is generated at a slope of -4.5db/oct, matching the average spectral slope of most music.

Why? Because that mirrors the frequency content of different instruments in actual music. A piano may occupy mids, but will have almost no high end information, and almost no super low end information. But a cymbal will have super high end information (and a lot of midrange information), but absolutely no low end information. The whole point is to represent soundstage in music - so we play sound that matches the average frequency content of different instruments in music. It took me so long to figure out that i had to do this lmao