Hackaday Links: January 11, 2015

Listening tests reveal significant sound quality differences between various digital music storage technologies. Finally the audiophile press is tackling the important questions. This listening test looks at the difference between two four-bay NAS boxes, with one making the piano on Scherzo and Trio from Penguin Café Orchestra’s Union Cafe sound more Steinway-like, while another NAS makes it sound more like a Bosendörfer. Yes, your choice of digital storage medium can change the timbre of a piano. Another gem: “Additionally, the two units also had different processor architectures, which might also affect perceived audible differences.” There must be a corollary to Poe’s Law when it comes to audiophiles…

[10p6] has begun a project that can play every old Atari cartridge. Right now it’s just a few bits of plastic that fits every non-Jaguar Atari cartridge, but it’s a start.

The Android IMSI-Catcher Detector. You’ve heard about Stingrays, devices used by law enforcement that are basically fake cell towers. These Stingrays downgrade or disable the encryption present in all cellphones, allowing anyone, with or without a warrant, to listen in on any cell phone conversation. Now there’s an effort to detect these Stingrays. It’s open source, and they’re looking for volunteers.

[Rob] sent in something that’s the perfect application of projection mapping. It’s called Face Hacking, and it’s pretty much just a motion capture systems, a few projectors, a whole lot of CG work, and just a tiny bit of dubstep. It look cool, but we’re wondering what the applications would be. Theatre or some sort of performance art is the best I can come up with.

A while ago, [4ndreas] saw a 3D printed industrial robot arm. He contacted the guy for the files, but nothing came of that. [4ndreas] did what anyone should do – made his own 3D printable industrial robot arm. The main motors are NEMA 17, and printing this will take a long time. Still, it looks really, really cool.

39 thoughts on “Hackaday Links: January 11, 2015

    1. I always thought it was a blue sharpie. That’s probably why it never worked for me…

      They also forgot to mention that the temperature of your NAS has to be kept stable for the best sound. I’ve had great success with a wine cooler featuring two temperature zones. Apart from a stable temperature, the cooler has another advantage: By keeping the drives storing bits for high notes exactly 3.5 °C above the temperature of the ones storing low notes, the sound gets so much better that even the recording of a toy piano sounds like it was played on a Steinway.

    1. My favorite comment on that one:
      “A lot of high end audio gear these days doesn’t use potentiometers. The knobs are connected to little optical encoders that send digital pulses to the logic to increase or decrease gain in a circuit. Changing the knob will have no more effect on the detectable sound than changing your shorts.”

      Is it immature of me to imagine an audiophile changing through all his shorts in order to get a better sound? :D

  1. Ahahahahaha that’s brilliant.. Reminds me of the sales chap in PC World trying to convince me a £60 gold plated shielded optical SPDIF cable was worth it because “around electrical equipment you get all this interference….” A £2 one from Farnell did the job instead…. Or the £1500 Ethernet cable that makes bass less muddy…. Only if it’s installed the correct way around though….

    1. When I asked to see the specs on a piece of stero equipment circa 1990, a sales rep(tile) from Circuit City asked what specs I wanted to see. I said, “frequency response, SNR, THD.” That’s when he told me I didn’t need to worry about THD, because “now they’re using integrated circuits with negative feedback.”

      1. It says plating, not solid, a few micrometerer thick layer on a product that requires a combo of a very rich and dumb customer to sell will hardly make a dent in the market…

  2. I think the best one I’ve ever heard was in a Tandy store (kinda RadioShack that was in Australia)
    A customer asked what RMS meant, the sales guy replied,

    “Real Music Sound”

    Or one of the “Experts On Everything” I used to shoot with was telling me a sales guy showed him a hideously expensive set of speakers that were so good “you could hear the drumstick hit the drum before you heard the drum!”

    But seriously in this day and age where most of us have terabyte or multi terabyte drives, why bother with compression?

    I’m going to re-rip all my CD’s and just keep them as WAV files, just coz I can!

      1. Lossless compression is reasonable if you have good headphones or speakers. My former studio Koss headphones would let me hear the difference between mid-bit-rate MP3 and FLAC, and for some brass or cymbals you can hear the difference even compared to high-rate MP3. But, they were quality cans. Even if I did pick them up from someone for about $5, and kept my speakers connected with a $2 optical cable (some going out of business sale). Maybe the encoders have changed since I ripped to FLAC a decade ago, but when I ripped stuff it was still the best choice for me.

        Now, if you are talking about FLAC on earbuds, I’m with ya. Even in a good car stereo is in too noisy an environment to hear the difference.

  3. I always thought the 1s from EEPROMs sounded dingy compared to mask ROMs. I always thought it was because I didn’t terminate my coaxial PCB traces with laser trimmed resistors into a silver ground plane.

    1. In some ways I agree with the theory of “test everything, because you just never know…” (after all, HiFi it is a hobby for them!) but I can’t resolve it with people’s ability to delude themselves based on preconceived ideas. However, if they do find one that they delude themselves into liking more than the others, then good for them!

      Maybe they should try placing a logic analyser on the inputs to the DACs, and then seeing if there actually is a difference in the resulting bitstreams, and in doing so remove the majority of the human factors.

      1. It would need to be an audophile-quality logic analyser though…and to establish that there would have to be more tests…and then…damn…why won’t my domain registration for provenaudiophilelogicanalyser.com go through.

  4. I firmly hope the mentioned test is a hoax / joke. They ran an audiophile test without a quantum-field-bit-stabilizer? How can they left this out? When reading data fron a magnetic storage, the bits carry a magnetic charge which some time let the bits toggle until they get actually used. When they get used these bits are worn out and may introduce quantum jitter that falts down on oxygen molecules into ordinary jitter.

    The quantum – field – bit – stabilizer stops the toggling, removes the magnetic charge and improves the overall sound quality. Just to note, these devices are hell expensive. DIY wont work because of the delicate but required neutrino diffuser and superposition divider.

  5. I posted the storage array affecting musing link in another forum. Someone noted that it’s like copying a text file to a different computer and comparing the differences in a text editor. Being someone irritated by the person’s suggestion there would be no difference, I explained:

    “That’s because you haven’t spent enough time examining how the striping of bits across platters can cause subtle changes in punctuation, Periods stretch into commas. commas get compressed into periods and don’t get me started on how warped exclamation points get?”

  6. The snake-oil speak you all used on these comments actually got me to laugh out loud. :D Unfortunately salesman are all the same, and given human stupidity is infinite, it doesn’t actually surprise me to find most audiophiles being stupid enough to believe them. Yeah, I undestand there can actually be a difference in quality depending on the audio dac used, and there might also be a difference if it’s software decoded because of some poor implementation of the decoding algorithm in a different processor architecture, but this is not related to the actual architecture, it’s just a poor software implementation. So yes, there might actually be a difference in audio quality… if these audiophiles are not using the digital audio output to their expensive audiophile amplifier, which any audiophile with a single neuron should do. Duh.
    I certainly wouldn’t call myself an audiophile, but using decent beyerdynamics cans on a ordinary laptop-embedded DAC I could barely see the difference between some samples of flac and mp3 320kbps, so you don’t really need that much of an expensive setup to enjoy quality sound, and I don’t understand how people can spend so much money on “quality”. Still, the difference was so minimal I consider 128-192kbps mp3 enough to listen on cheap amplifiers with cheap speakers, and 192-240kbps mp3 enough to listen on quality audio cans. For anything more than this, I must actually stop paying attention to music and start looking for artifacts on high frequencies to be able to discern between lossless and a “low” quality sample. If you buy an expensive sound setup to stop enjoying music and start looking attentively to artifacts just to be able to claim you’re able to discern them, then you’re living life wrong. Do these guys also buy water made from glaciers which have been frozen for at least 500 years?

    1. Some of that overpriced audiophile-grade gear actually looks quite nice, you have to admit that those $2000+ turntables are very fine pieces or art/machining porn to look at :D

  7. Audiophiles..they are highly suggestible. Years ago, audiophiles had found that old Tektronix scopes and their plugins were a cheap source of vacuum tubes for their “golden ears” tube preamp projects. To try and stop them from plundering scope parts that Tek collectors needed for their restorations. I started spreading the rumor that, once a tube has been used to amplify those square waves so often found in o-scopes, they would be way too harsh and buzzy to use in hifi audio gear. I convinced more than a few…

  8. I’m glad they also tested the same 2-bay NAS that I am using, too.
    I have to agree with them, that there really is a difference between the audio files played back from this device and audio from, for example, my mobile. The music from the NAS is so good, that it sends my neighbours knocking on my door, while the music from my mobile doesn’t ;-)

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