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One step further

Paul's Posts — 03 July 2012

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One step further

In yesterday’s post I put forth the idea that it doesn’t seem to matter sonically what you might feed into a guitar amp/speaker combo – a live guitar or a recorded version of the same – what you hear will be so close to the same one cannot tell the difference.  Reminds me of that old ad for Memorex tape “is it live or recorded”?

But this observation seems to fly directly in the face of what most of us would consider to be a basic truth – that we can easily tell differences in recordings – certainly the difference between a digital recording and an analog recording – and live vs. recorded.  Yet this simple thought problem would seem to counter that.

OK, now let’s go one more step.  Take that same setup with the guitar and amp/speaker and record the sound with a microphone – as they many times do in a recording studio when a musician wants their sound to be captured.  Now, play it back through a high-end loudspeaker.  Will it sound identical to the original?  No.

It can’t because even if the high-end loudspeaker used for playback is 100% neutral in its colorations (none are) it can never sound the same as what you hear standing in the room.

Why, you might ask?  There are at least two big hurdles: first there probably isn’t anywhere you can place that microphone that will capture what you’re hearing in the room and even if you could the playback speaker is typically in another environment as well.

Only when you have the playback speaker replace the original source of the sound in exactly the same spot in exactly the same room might you have a chance.

To make matters worse, there’s even another problem which we’ll discuss tomorrow.

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About Author

Paul McGowan

Paul McGowan is the CEO and co-founder of PS Audio Inc. a Boulder Colorado design and manufacturing company of high-end audio products and services. McGowan has been designing and building high-end products for nearly 40 years. Hobbies include skiing, music, hiking, artisan bread baking, kick boxing and cooking. He lives in Boulder Colorado with his wife Terri and his 4 sons.

(7) Readers Comments

  1. Bassman23

    July 3, 2012 at 4:42 am

    The essence of the problem; we don’t hear sounds, we hear sounds within their environments.
    Capturing the effect of the original environment on the sound is the chasm we face.

  2. Soundminded

    July 3, 2012 at 7:55 am

    “There are at least two big hurdles: first there probably isn’t anywhere you can place that microphone that will capture what you’re hearing in the room and even if you could the playback speaker is typically in another environment as well.”

    That’s how commercial recordings are made and conventional playback systems are set up. A different approach is to put the microphones where your ears would be. This is how binaural recordings were envisioned and usually made. Then the playback was through headphones which excludes the room environment but it could just as well be played through large panel speakers close to your head which would minimize room interference. This negates both of your objections. However, it’s been known for at least fifty years that this method doesn’t work. The usual explanation is that when you turn your head the sound turns with you (when using headphones.) That explanation is right insofar as it goes but clearly there’s much more to it than that. Attempts to overcome this problem including multiple mike/track binaural recordings and accelerometers in the headphones which switch them when you turn your head haven’t worked either AFAIK. I must say I was quite impressed when I first read about this idea….that is until I got to the end of the article when they explained that it doesn’t work. But then I was onlly about 14 years old and a lot of things impressed me that didn’t anymore as I grew older.

  3. Ivan

    July 3, 2012 at 9:49 am

    “Only when you have the playback speaker replace the original source of the sound in exactly the same spot in exactly the same room might you have a chance.”

    Nope, Then you get the room’s acoustics doubled. Your chances would be better if you recorded anechoically (as Ed Villchur and Jan Syrjala did for AR’s live-vs,-recorded demos).

    Incidentally, Edison ran live-vs.-recorded demos, too — everyone swore they couldn’t tell the difference! (I could with the AR demos…some of the time.)

    • Soundminded

      July 3, 2012 at 10:09 am

      I attended two of these. One featured AR3 and a guitarist. The other featured AR3, AR4x, and a Nickelodeon. What was striking about these wasn’t that they sounded identical, they weren’t quite, but that they were so similar. Prior and subsequent experience with these two models suggested that they were not nearly as accurate as they claimed. This was with commercially produced recordings. Obviously the demonstration was very carefully contrived and the recordings were made out of doors to prevent the double echo effect. I gained new respect for these products as a result although Toole/Olive dismiss the value of these kinds of demos as advertising fluff. The fact that they were possible at all was what surprised me. I lonly learned how this illusion was done successfully in the last few years.

    • July 3, 2012 at 3:25 pm

      Maybe I wasn’t clear Ivan. if you record the output in such a way (close mic) as to avoid room reflections as best you can, then playing back in the exact same place will come close.

      • Soundminded

        July 3, 2012 at 4:36 pm

        Starting at about 29 minutes into this interview with the editor of one of the hobbyist magazines he describes his experience with trying to conduct a live versus recorded demonstration.

        http://www.youtube.com/watch?v=_mEsuKqj5wA&feature=relmfu

        What I found interesting was that the difference had to be pointed out to him by other listeners, he didn’t seem to hear it himself. He seemed befuddled and confused about it. Subsequently both he and the interviewer conjectured about it but they seemed clueless.

  4. oliver T. Finch

    July 3, 2012 at 9:30 pm

    Agree with your position that environments influence the sound live or reproduced. How is this related to the jaw dropping sound of the Hypex D amplifier? This amp. too will sound different in different listening environments.Looking forward to your next post. May be I will get the point you are trying to make. Regards.

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