The difference is as plain as the ear on your face!

A reader just pointed me to this comparison of the recording quality of the Samson Zoom H4 Handy Digital Recorder, the Zoom H4n, and Sony's PCM-D50 portable audio recorders, on Brad Linder's blog.

These things are little high-quality digital audio recorders. They're smaller than most portable compact-cassette recorders - actually, they're approaching the size of an old microcassette dictation recorder - but they have sound quality that the old concert bootleggers could only dream of. These sorts of recorders come with built-in microphones, of far higher quality than the mics in any small portable recorder before low-power portable audio-processing hardware and low-cost Flash RAM made this sort of device possible. You could have put super-high-quality mics on an old cassette recorder if you wanted to, but it was pointless; nothing you could stick in even a large pocket could record good enough audio to justify expensive mics.

(Yes, I know there were some relatively small analogue-tape field recorders that gave very good results - usually because they recorded on something better than a cassette - if you plugged a quality mic into them. There was probably also some integrated-microphone doodad that recorded on small reel-to-reel tape or Type IV cassettes with Dolby S or something, about which I just haven't happened to hear. But modern digital field recorders are still amazing, all right?)

Anyway, Linder set up all three recorders next to each other, and talked and then played guitar into the built-in microphones. Then he posted the audio from the three recorders, for his readers to audition.

Overall, the commenters opined that the H4 was OK, the H4n was better, and the PCM-D50 was best. They were pretty much unanimous that the difference between the H4 and the Sony was as plain as day - compared with the Sony, the H4 was "muddy" or "muddled", "disjointed", "scrambled", or slightly noisier; one commenter called it "not even worth talking about". One guy even said he heard wow and flutter. There was general agreement that the Sony was clearly superior.

The only problem with all this - which another commenter soon discovered - was that Brad actually screwed up. Instead of pasting in the embed code for all three recorders, he pasted in the H4 code, then the H4n code... and then the H4 code again. He just labelled it as the Sony PCM-D50.

So the first, and the third, sound clips were precisely identical. On account of being the same sound clip twice. But the one that was labelled Samson Zoom H4 sounded lousy, and the one that was labelled Sony PCM-D50 sounded great.

Psychoacoustics: It ain't just a river in Egypt.

Wait. That didn't come out right.

This happy accident reminds me of the techniques James Randi has so often used on people with alleged supernatural abilities. I'm re-reading his classic Flim-Flam!, which contains a number of examples. When, for instance, a woman said she could use dowsing to find ancient ruins just by examining a map, without even a scale or North-pointer, Randi tested her on three maps in sequence, all of which were actually of the same well-explored part of Peru, but rotated and scaled differently.

Needless to say, her exceedingly vague results put "ruins" in different places every time, and not a one of 'em even managed to hit Machu Picchu, which was exactly the sort of thing she said she could find.

(Audiophiles usually seem to address psychoacoustic problems by adding as many more uncontrolled variables to their sound comparisons as they can. I presume this is some sort of demonstration that their perception of sound is not merely superhuman, but super-mega-ultra-hyper-human.)

13 Responses to “The difference is as plain as the ear on your face!”

  1. Gomisan Says:

    I bought one of the Zoom recorders to use at work, mainly to record student aural presentations, but also to use myself for various multimedia projects. The sound quality is fantastic so these results don't surprise me at all. I think the one we bought was the H2 and no complaints with it!

    Great choice of audio formats and compression levels too.

  2. Microfrost Says:

    Maybe when everyone was listening to the "Sony" sample, the bit stream was being routed through network equipment with better mains cables.

  3. Steven Den Beste Says:

    IIRC, one of the maps Randi gave her had longitude and latitude marks, and on THAT one she was very accurate!

  4. Nilbog Says:

    Childhood memories...

  5. Popup Says:

    Off topic:

    > ...Flash-RAM...

    I have seen you use that phrase a couple of time, and I can't help wondering why you would use that word... It's true that some flash memories (NOR) can be read in a more-or-less 'random-access' way, (At least as random as SDRAM, with its row, page and bank restrictions...) But the fact that you can only erase it in blocks (of 64 to 256kb) at a time disqualifies it, in my opinion. With NAND flash, it's even more apparent, as erasure has to be done in blocks of (at least) 256kb and read accesses have to be of entire blocks (often 4kb each). And when we talk about Flash today, we typically mean the NAND variety.

    Still,calling them flash ROM would be even more wrong (even though it's more common).

    I have also seen them being called Flash PROM, Flash EPROM and Flash EEPROM (sometimes written as "flash e2prom"), but the most common seems to be simply 'Flash Memory'.

    I decided to ask gogole, and the following are the number of hits for each combination:

    -"flash memory" 193,000,000
    -"flash ram" 321,000
    -"flash rom" 2,400,000
    -"flash prom" 31,000
    -"flash eprom" 161,000
    -"flash eeprom" 242,000
    -"flash e2prom" 10,300

    Clearly in common web-use the term "Flash memory" is the winner. I also decided to look at the worlds no.1 flash manufacturer (Samsung), and it appears that they occasionally used "flash rom" - but not since 2003. It's all "flash memory" now.

    And now back to the audiophile discussion...

  6. Daniel Rutter Says:

    I've never really thought about this in detail, but have instantly ginned up the following justification:

    Is flash memory a sequential-access device? Clearly not, except in a very restricted sense of the term. Is it therefore a random-access device, if we define that as storage which takes the same amount of time to access data anywhere on the device? Yes, it is.

    I don't think the block-erase limitation and resultant background controller trickery disqualifies it as a random-access device. So it's random-access, and it's memory, and thus it's RAM.

    (Of course, if someone made a reel-to-reel tape drive that worked at a billion miles an hour and could whip data under the heads as fast as a hard disk can, with no noticeable extra delay for accessing data on any part of the tape, then that might also qualify as RAM under this loose definition.)

  7. Popup Says:

    While I ought to know better than to pick a fight with someone who buys pixels by the barrel...

    Would you also call a hard disk RAM?

  8. Popup Says:

    As a matter of fact, I wouldn't call a NAND flash memory 'random access', as the latency of a read is strongly dependent on previous reads. (For two reasons:
    - as the hardware will have to read an entire 4kb block at a time (to do error-checking/correction) odds are that sequential reads will already be available.
    - If the system is clever enough it will automatically pre-fetch the next block, and have it available in some kind of cache.

    In fact, you'll be hard-pressed to find true 'random access' anywhere, certainly not SDRAM, and in most application not even SRAM qualifies - even in those cases sequential accesses often lead to shorter latency, thanks to pre-fetching by the hardware, or caching at a higher level.

    In fact, the only 'random access' memory I can think of is 'ROM' i.e. good old-fashioned EPROM or the equivalent...

  9. Alex Whiteside Says:

    Well, by definition, it's either got to be "random" or "sequential", and it sure as hell isn't "sequential" access, as we had back in the old tape days, when the latency was linear with the distance between the memory locations. It's not completely address-independent random access, but nothing is. Even a perfectly crafted ROM will give you different (miniscule) latencies depending on where the address is physically stored on the silicon.

  10. Alex Whiteside Says:

    Linear and additive, at that.

  11. Popup Says:

    > Well, by definition, it's either got to be "random" or "sequential",
    Does it?

    I have heard (and used) the term 'block access' to mean the kind of devices where the latency is more-or-less independent of the size of the read request (up to the 'block size').

    A prime example would be a hard disk, where the average latency is (as defined by the spin speed) on the order of 10ms, but the extra time required to read a single byte (as defined by transfer speed) is on the other of 30ns!

  12. Alex Whiteside Says:

    I'd still consider that "block access" a subset of random access. You can access addresses arbitrarily, with additional latencies appearing for traversing the heirarchy in certain ways. Maybe it's a side effect of coming in from the "sequential access" side and putting up with tape decks. It's probably not a taxonomically relevant distinction these days when every form of storage does random access in some fashion. My concern is that if you're going to say that "block access" isn't random access, then it's a slippery slope into saying that nothing is really random access.

    (I recall a CU Amiga article where the author found CD-ROM to be a huge misnomer, preferring CD-RAD (Random Access Disk). I'm not that bad, thankfully.)

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