Nearly stopped reading at the golden ratio bit, but kept going. Interesting idea but on first read not sure why he didn't measure after the crossover as well, as intuitively that would be the place you can really tell if there is any benefit.
Yeah, I hear what you're saying. But it seems like you are disallowing that the artists and producers hire and work with engineers that will help them get the sound they want. Engineers who add distortion and other effects are part of the production team and are usually doing exactly what the client wants. They better if they want keep getting more work. Any idea idea that the engineers are reckless mavericks going off damaging the artists already perfect sound is not how it normally works, certainly not at a professional level. For garage bands recorded by their buddies, sure, but I wouldn't consider that to be a professional level activity.
I never read the speaker cable stuff either. its interesting and i have a few of the Pearson current transformers. I think they are not sensitive or linear enough but I'll try them sometime soon. What he is saying does dovetail to some degree with what jneutron was saying about speaker cables.
I never waxed on about it. I do have the original CD. But that has a messed up vocal track etc that is out of phase since day one CD. With a good system, the cancellation is almost complete. A sloppy recording.
I hear someone finally noticed it and next reissue will be corrected. HD and all.
There ARE plenty to wax on about though that are exceptional recordings and great music also.
-RNM
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It was produced by Jimmy Page. I guess he can be blamed for signing off on the master. He also hired his old friend Glyn Johns as engineer, another error on Page's part?
From wikipedia: "Page reportedly used natural room ambience to enhance the reverb and recording texture on the record, demonstrating the innovations in sound recording he had learned during his session days. Up until the late 1960s, most music producers placed microphones directly in front of the amplifiers and drums. For Led Zeppelin, Page developed the idea of placing an additional microphone some distance from the amplifier (as far as twenty feet) and then recording the balance between the two."
It sounds like Page was very much involved in the details of recording.
A sloppy producer then, would you say?
Years later I came up with the same idea, but used it mostly for fade outs. Instead of simply reducing the level, I'd go to the distant track. I thought it was the coolest thing ever. No one else even noticed. 🙄
Who wrote that wiki? J.Page? An ambience mic has been done for ever... classical does it all the time... mic out in the audience area and back of hall.
The only thing I like is the musical drama when the bass comes in. Live it is deep and thunderous. Still, vocal is messed up in a way that isnt producer love. I have been told it will be fixed though.
-RNM
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It is at very low level, not sure that a clean sine can be better reproduced using only the 3 least significant bits, here i see 125uV peak, so in respect of say 2.5V pk max level it is 86dB below this max, i think it should still be miles beyond in quality than -86db level on a MC cartridge.
Edit : Since the debate evolve around recording quality i point this record (among others) that i use to test speakers, it s one the first DDD record, sound is clear and quite good :
https://www.youtube.com/watch?v=iwwrklmwjVg
https://www.youtube.com/watch?v=QomH6ve68YQ
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Jon Risch seems to be not aware of the work AP has done on multitone testing. The multitude of frequencies (31 of them) are spaced so that all harmonics, all im products from all fundamentals and combined im products fall all in separate FFT bins. So with one single test you can look at THD, and im over the whole band. They even leave a few bins open where you can measure the noise produced under this test.
As you can imagine, the definition of the various test frequencies and levels (they also make sure the crest factor doesn't get too high so as to clip) isn't simple and they used to have an app to calculate all this. You'd see freq defines like '5.0031 Hz'.
It even made it into an ISO standard (ISO31 is a 31 frequencies test signal).
I think I still have an Excel file used as input which I can post if there is interest.
Jan
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That is the point, but is it is an exceedingly good test of low level linearity. If you get the 3 levels and gibbs 'ringing' then you have a good DAC. Bang in some dither and you get a sine wave. 90dB down even if it is above your room (and body) noise floor you are unlikely to hear it with your system set to normal levels.
I'd be interested in seeing that Jan, thanks. I've been messing with multitones for some years now, although I haven't tried looking at distortion with them - mostly just frequency response-related stuff. I use an old software synthesizer called Analog Box, or ABox2 to generate them.
- Jim
[EDIT] For what it's worth, if there's any interest I could also upload the multitone generators I've constructed to run on the above software (which is a free download). I have one that is aligned with the 1/48 octave RTA function in the popular Room EQ Wizard software. It generates simultaneous sines, 48 per octave, from 10 Hz to 20 KHz - a total of 528 simultaneous tones. There are probably easier ways to do the types of tests I've done with this setup (I always have more to learn), but one thing is certain - it makes an amazing noise!
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Imo there two main reasons, first of all there is no exact definition what "accurate reproduction" really means. Even for pure acoustical performance there are at least two diverging points of view.
According to Wolfgang Hoeg, any transmission/reproduction should evoke a listening experience that is most similar to the listening experience one would have had if present during the original event.
The other point of view, expressed by for example by conductors, is/was that even a perfect sound reproduction need enhancement to compensate for the missing visual influence.
And remember the loudspeaker differences, german "taunus sound" vs "british smoothing" and what about the famous BBC dip?
Interesting is that the targets of modern automatic measurement systems are often quite similar to the old british downward tilt.
At present there is only the binaurl headphone concept able to reproduce nearly original soundfields at/in the ear channel, hence chances for really accurate reproduction are high.
Everything else is apparently much less accurate.
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