The less loss firewall purifier appears to work via skin effect, filtering generally 200 kilohertz and above. Referencing Nelson pass' article "speaker cables science or snake oil" using his spectrum analyzer we can see the standing waves on the speaker line. This is a summation of reflected waves due to mismatch impedance. The additions or subtractions of the multiple reflections will impact the leading edge of the waveform and this is what you hear. The more poorly matched the speaker cable the more of a difference this item could make in a high resolution system. Believe me I fully understand the assumptions of snake oil with these applications. However while cable theory will prove their functionality it will also demonstrate the need for adequately engineered cables.
Bybee Technologies Crystal Series Plug-in Speaker Bullets.
I was first introduced to the Bybee Speaker Plug-in Bullets about about 12 years ago (the original versions) by one of my local High End Audio dealers. After hearing the simply astonishing effect they had on speakers at the dealer's, I purchased a set, plugged them into my speakers, and they have never ceased to amaze since (I recently purchased the current Crystal Series Version). Stunning improvement in: detail retrieval, ambiance and spatial presentation, vocal and instrumental color, transient and dynamic impact, and harmonic completeness. The Speaker Bullets will effectively filter out most all of the hash and jitter at the speaker terminals in order to create an extremely blacker background in the music reproduction resulting in all the improvement described above.. No snake-oil here. These bad boys work, and are definitely for real. They act in the same manner, and are just as effective on all speakers, no matter the brand or the price tag. The Bullets aren't cheap, but they are miracle workers, indeed, and (IMHO) worth every penny. I'm so glad that I was one of the fortunate few that was in the right place, at the right time, to be exposed to the Bybee Speaker Bullets. I will never, ever, be without them in my system.