Thanks so much to everyone that has participated in the High-Resolution Challenge. And thanks for being patient while attempting to download the files…there was a bit of a bottleneck when hundreds of people wanted to download the files on the same day. I hope we all recognize that the High-Resolution Challenge is not a rigorous study. However, it does remove one of the critical flaws in most other studies but remains imperfect nonetheless. There is no way to tell if people are cheating or not — although I have confidence that my readers won’t see any advantage in peeking at the files. I won’t be impressed if you get all of them right! So let’s try to keep this honest.
One participant analyzed the dynamic range of the files in Foobar and pointed out that there was an amplitude difference of 1.7 dB between Tune_3_A and Tune_3_B. I failed to apply the normalization to the quieter one. It’s been corrected and uploaded again. If you want to access the FTP site again, please feel free. Otherwise, any responses submitted prior to yesterday will have only 5 accepted answers. Sorry. I won’t be revealing the correct answers for several weeks. I’m hoping we can get several hundred responses before doing some analysis. The page has been viewed over 1000 times and there has been plenty of activity around the challenge.
Anyone interested in doing a true ABX test might want to look into using the ABX comparator in Foobar. If you go that route, you can simply send me that results.
At the recent T.H.E. Show in Irvine, I met a young audio enthusiast who was carrying a couple of MC-0.5 Power Conditioners made by High Fidelity Cables. He had purchased these audiophile accessories a the show special price of $200 each. When I commented that he had fallen prey to an unscrupulous high-end cable/accessories vendor, he pushed back. “The sound definitely improved when the presented plugged in the conditioner,” he replied. I have no doubt that there was a perceptible difference in the demo room at the Marriot Hotel in Irvine. Having experienced — and exposed — some of the clever tricks that demonstrators use to hype their products, I urged him to take the MC-0.5 power conditioners home and test them using his system. He did. I received the following email from him:
“Hey Mark it was nice meeting you a few weeks back at THE Show. I don’t know if you remember me but i had purchased a pair of these magnetic power conditioners and i bought your book too! You asked me to email you an update on the items. Well it’s been a few weeks now and this is my update:
High Fidelity Cables MC-0.5 power conditioners are what i tested and i can confirm beyond a shadow of a doubt they did absolutely nothing! I have emailed them and will be using there return policy ASAP! I even did a blind test with a friend who has a good ear, i didn’t tell him what i was doing i just had him sit there with his eyes closed and i unplugged them and plugged them back in about 5 times. He repeated the same test for me. We both heard no difference. I’m sure they’ll say my humble system isn’t high end enough to take advantage of their product but that’s absolute bullshit, my system is amazing!”
I wasn’t surprised but I have to wonder how many customers don’t return a snake oil product?
The following weekend, I set up my sales table at AudioCon — the one held at Sunny Components in Covina. I was fortunate to be able to listen to the presentations by representatives from Bryston, MQA, and others. One guy was from a power cable company and spent 30 minutes talking about the importance of power cords on sound systems. He did the usual things including hooking up an audio circuit to a power outlet and showing us all the incredible amount of noise on the line — noise that never gets converted into the DC power sources used in your components. This is a red herring argument.
He then demonstrated 4 different power cords ranging in price from a few dollars (a typical IEC cable like the ones included in the box) to about $17,000 for the Nordost Odin 2 Power Cable. The two cables from his company were $750 and $4000 — a mere fraction of the price of the Nordost. I brought along a reference quality microphone and portable recording device which I kept out of view as I recorded the music selections powered through the different cables. Actually, I wasn’t the only one using this method to evaluate the presenter’s claims. As I looked to the right, another attendee was using the SPL meter app on his smartphone to do a less rigorous version of the same test! Apparently, I’m not the only skeptic in the audiophile world. Despite the presenter’s insistence that the sound was “much smoother, less harsh, and had a much lower noise floor” with the expensive power cords, my measurements showed otherwise.
I loaded the audio into Adobe Audition and carefully edited each music section to identical lengths. Then I measured the amplitude and plotted the spectra of each. As if by magic, the IEC power cord measured 2.5 dB SPL lower than the others. The most expensive cable — the Nordost Odin 2 — was louder by a substantial amount than the Dragon and Thunder cables the competitors provided. When I asked the other person measuring the SPL in the room, he concurred with me. “I saw about 2 dB difference,” he whispered. I found it curious that the presenter had to kneel down in front of the rig each time after the cables had been switched. Maybe he was adjusting the level of the preamplifier, I can’t say for sure. But I can say with certainly that power cords do not cause a 2-3 dB increase in amplitude and we don’t want them to! The role of power cords is to deliver a raw 120 volts/60 Hz current to a power supply, which cleans, converts, and supplies the needed low DC voltages to the various parts of the component.
I recorded the entire event and will have some comments on the MQA presentation in my next post. Very interesting. I didn’t pester the presenter or even ask any questions — I was very polite and let him do his thing. It was the others that asked the tough questions.