Hopefully I don’t get flamed for this, but I’ll share this anyways. I’m one of the guys who spent $1K on a Synergistic Research Atmosphere Mini X4, mostly because I have a full SR Atmosphere loom and a ton of their HFTs around my room and on my speakers. I find the Atmosphere Mini X4 to be worth the investment.
It’s pretty much a pimped out Schumann Resonator. A typical resonator emits a low frequency below human hearing at approximately 7hz, which helps to cancel out radio frequencies and standing waves that may interfere with the nominal way sound waves should travel. The thought is due to the sun’s rays being more intense during the day, radio frequencies become more intense, and at night, they drop a lot, which is why many people think their systems sound better at night. A Schumann Resonator is a good way of extinguishing or normalizing those unwanted frequencies. For some, it phases out, and for others, it supports correct phasing.
The Atmosphere Mini X4 (and its bigger siblings) basically add a much stronger antenna (and more of them) to improve the broadcasting of the frequency. What differentiates it the most is that it has many different “scenes”, which I think are really just different pulsing patterns, or perhaps slightly different frequencies or broadcasting patterns, but the scenes can shape the way the sound hits you, whether you want to improve soundstage width or depth, make it feel like you’re in a small room, a large stadium, or improve attack - and like a Schumann Resonator, it’s not hooked up to the system / chain in any way.
I’m not trying to sell anyone on the Atmosphere Mini X4, but just wanted to bring awareness of it. I can attest that it works, but whether people think it’s worth the investment is entirely up to them. It’s definitely diminishing returns compared to a $10 resonator, but after having it in my system, I can’t not go on without it.