The Null Tester

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.

I'm sorry that I didn't think to mention in this video that my Null Tester actually proves the wires are identical to around -130 dB. In the second half of the Audibility article linked below, you'll see that people can hear content 20 dB below the noise floor. And when my Null Tester is set for the deepest null, no music at all can be heard. So that means the null is actually 130 dB down, not "merely" 110 dB.

If you like this video, my Audio Expert book is full of solid audio science with plenty of myth busting:

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:

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:

This article in audioXpress magazine explains more about the tester's design, and includes the schematic for the core section of the tester:

Items mentioned in this video:

The AES “Damn Lies” video explains how audio devices are spec’d and measured:

The AES “Audio Myths” video dispels many common myths about audio and hearing:

“Phil Cramer, The Movie” video:

Vincent Burel’s freeware signal generator (Windows PCs):

Parametric equalizer (and spectrum analyzer) article with schematics:

Mojo Maestro article with schematic:

LabNation USB Oscilloscope:

Harmonic Tech “Magic Link One” RCA wire ($700.00):

Expert electronics consultant Julia Truchsess:

[johncooper]

Applied years ago for a technical position at a prominent Toronto audio speaker company. Interview was solid. Went through large vetting and finally the last interview. Didn't realize at first but they really wanted someone to SELL (very expensive) audio signal cable. Not only did I not believe a $100 three foot cable was a better conductor but had zero desire to be a company flim flam man. My interest was grounded in engineering, design and testing. Showing my interviewer the newspaper ad asked if that position was still available and given a flat out, no. Expressing my disappointment was led to the nearest airlock. If they believed I wasted their time they surely hadn't viewed it from my side. Thanks for sharing, Ethan Winer and confirming what I had suspected all along.

[WirebenderAudio]

Well done, Ethan. I'm a firm believer in ABX results, but it is nice to have test equipment proof, too. Audiophiles, audio "professionals, " and musicians desperately want to imagine their ears are golden, but ABX tests consistently prove otherwise.

[CraftAero]

Directional cables ? Pshaaw!
I reverse my cables monthly just to purge any electrons that may be stuck, ya know, before they can clot.

[hunternico]

This cracks me up. I was starting to get into an argument with some audiophiles in a forum about their $700 cables that supposedly add lows and mids and highs but also warmth and depth and dimension, but I just decided to come here instead.

[VintiqueSound]

Great video Ethan! I'm going give the most charitable scenario to any audiophile reading this comment and assume that there is indeed a difference between these wires.


What Ethan has shown in this demonstration is that the "difference" would have to be at a level of less than -110dB. In other words, the difference would be quieter than the total added distortion and noise from the high quality audio components used in his Null Tester. My Antelope Zen Studio preamps have a THD + N level of -108dB, so if I were to record the signal of any of those cables, the "difference" would be 2dB quieter than the total harmonic distortion + noise added by the preamps of a $2500 interface. Not to mention, the A/D converters have a -105dB rating, and then the D/A converter has a -98dB rating, and my speakers have an even worse rating (preamps and converters have a much better THD rating than speakers do).


If there was a difference in audio quality between the $700 cable and the $3 cable, the difference would be so buried under the 4 stages of added THD + Noise that no human could ever hear the difference. To sum things up... you're paying for $697 worth of bullshit.

[vaiman]

Audiophiles never trust science with their pieces of wire… but have full trust in science when it’s saving their lives. Makes sense 😂

[gregzakaluk]

Hi Ethan,
im retired semiconductor engineer audio and instrument madman since the 70s. hold patents in both areas as well as brain neurotransmitter trigger thru induced wave applcation.. yes i mean audio and unheard freqs. im glad you stand your ground and paul is a hack to the profession. you cant convince all the population with science they will always use weird words to describe things that dont physically exist to fool their brain. i deal with electron doping, crystel structure, atomic makeup of things daily and the biggest laugh is the wire/interconnect think and tube tricks. my dad was in same field and worked on atom bomb, microwave dev, Apollo program etc so its inherited in me.
Anyway i degress and thank you for your stand and reason. Greg the Mad scientist

[scipanda]

I love you man. My home theater sounds amazing because of you and did not cost $10, 000 to fill with gear. Keep making videos man, you

[gregoryschramuk]

Dude, you have my subscription to your channel and more importantly my attention. You have saved me money and meaningless arguments with sales pitches form business men at hi fi stores. Thank you!

[mshioty]

“It doesn't matter how beautiful your theory is ... If it doesn't agree with experiment, it's wrong.”
― Richard Feynman

[cbcdesign]

According to Paul McGowan at PS Audio the differences displayed between cables is because those differences are not electrical. Give me strength! I get so sick of the BS that persists in the high end audio world with regards to cables, it is intellectual dishonesty for profit.

[MarkishMr]

Awesome work! You aren't the hero we deserve but definitely the hero we need!
In your next test could you please test a rusty, dirty coat hanger vs some crazy expensive cable? I know it's silly but as an example it could drive more attention on social media to your fantastic work. It might also be interesting to find some familiar conductive material different enough that would create some incredibly negligible difference. That might address any physics deniers who claim the Null Tester never shows a difference.

[guidorhaschke]

Sent this to my son, an up-and-coming recording engineer, he's really going to enjoy this! Thanks Ethan

[neocollective]

Are you saying that I should have sent my daughter to college instead of spending that money in audiophool wires ?...LOL.
Thank you so much sir for the enormous effort of putting this together, you are the real deal and most valuable audio community member; proudly wear your exclusion from those snobbish forums like a badge of honor !

[joej]

Doing this with DACs would be exceptionally interesting.

[amplifierexperts]

Nice work debunking a persistent myth.
Under normal listening conditions with normal commercial recordings and music, all of these residuals fall way below audibility. Even the highest dynamic range Classical recordings will not approach the limits of cheap cable. For example, at a recent concert recording with the GBSO, I measured the noise floor of the empty hall at 43dB, unweighted. When the orchestra performed, the highest recorded peak was 105dB. That is a dynamic range of 62dB. Pop and rock music have far less than that, often less than 10dB of dynamic range.
The one exception to this was a fireworks recording I made in 2010. It had a dynamic range slightly in excess of 86dB between the crickets in the woods and the loudest mortar explosions. On this recording, I noticed 60Hz buzz with my "free" included cables that came with the BD player. I replaced all the small signal wires with $5 Monoprice cables, which have nearly 100% shield coverage, and that removed the 60Hz buzz. But this is a sound that would normally be masked by the ambient noise of a concert hall with a commercial 'high dynamic range' Classical CD. It is an extreme example and playing the fireworks recording required careful gain staging of all amplification equipment to maximize signal to noise ratio of the system.

[FuzzySimon]

Sometimes, I just like to come here and watch this again to cheer me up :). Ethan is such a legend and he has done a real service to the industry, and this is a great video for lecturers too. I salute you!

[zorst]

I have played with this stuff for many years and used to sell gear, The only difference I've ever heard was less noise to worry about with XLR cable, but the sound always has sounded the same to me. I go to CES most years and have heard some good gear sound great. They are always supplied the most expensive stuff from other vendors. But I would love to step in with some cheap wires as things are sounding amazing and see if the quality of sound dropped. Thanks for this demo.

[KCRAE]

I've heard stories, some from friends, that have been cast out of Facebook groups and discussion forums for debunking common audiophile myths such as you have with your Null Tester. A long time ago, one of my FTOs said, "If you're aren't making someone angry, you're not doing your job right". Considering that I make a lot of people angry, I *must* be doing something right, even if they aren't aware of it.

[Arcsecant]

This is an excellent presentation, but the null tester can't measure the most important attribute of the wire: the price.