Some audio enthusiasts believe there may be more to audio fidelity than is currently known, and they insist that signal wires and other audio devices can measure the same yet sound different. This video explains what a null test is and how it works, then uses a custom made Null Tester device to compare RCA wires ranging in price from a few dollars to $700. Rather than measure wires directly, the Null Tester isolates all differences between signals passing through the wires, then lets you assess and hear only that difference. Comments that are insulting, off-topic, ignorant, combative, or add no value to the conversation, will be deleted. If you like this video, my Audio Expert book is full of solid audio science with plenty of myth busting: http://ethanwiner.com/book.htm To avoid making this video even longer I didn't talk about why people believe they hear a difference with wires, even when no difference exists. These articles address that: http://ethanwiner.com/perception.htm http://ethanwiner.com/believe.html If you already know what a null test is and does, you can skip the explanation and go directly to the live portion of this video where the wires are compared at 18 minutes 23 seconds. It's difficult to have a technical discussion in YouTube comments, so for questions or extended comments, please post in the Audio Central section of my Audio Expert forum: http://the-audio-expert.freeforums.net/ If a wire vendor (or anyone else ) would like me to test their wires using this device, I'll be glad to do that and make a private video of the process for a very reasonable fee. Contact me through my web site: http://ethanwiner.com/ This article in audioXpress magazine explains more about the tester's design, and includes the schematic for the core section of the tester: https://www.audioxpress.com/article/you-can-diy-building-a-null-tester-device Items mentioned in this video: The AES “Damn Lies” video explains how audio devices are spec’d and measured: https://www.youtube.com/watch?v=Zvireu2SGZM The AES “Audio Myths” video dispels many common myths about audio and hearing: https://www.youtube.com/watch?v=BYTlN6wjcvQ “Phil Cramer, The Movie” video: https://www.youtube.com/watch?v=4_OhW9C75rk Vincent Burel’s freeware signal generator (Windows PCs): http://vincent.burel.free.fr/download/index.htm Parametric equalizer (and spectrum analyzer) article with schematics: http://ethanwiner.com/spectrum.html Mojo Maestro article with schematic: https://www.audioxpress.com/article/you-can-diy-build-the-mojo-maestro LabNation USB Oscilloscope: https://www.lab-nation.com/ https://www.audioxpress.com/article/usb-oscilloscopes-a-look-at-the-labnation-smartscope Harmonic Tech “Magic Link One” RCA wire ($700.00): https://hometheaterhifi.com/volume_11_1/harmonic-tech-magic-digital-one-link-one-cables-2-2004.html Expert electronics consultant Julia Truchsess: http://www.pragmaticdesigns.com/