[Ardour-Users] Experience? Rework an external 44.1 KHz 16 bit recording

Ralf Mardorf ralf.mardorf at alice-dsl.net
Sat Aug 21 12:57:55 PDT 2010


On Sat, 2010-08-21 at 14:53 -0400, Lamar Owen wrote:
> Ralf, you misunderstood my statement.  I'm simply cautioning that audio engineers are not immune to the placebo effect.

Pardon, full ACK, resp. half ACK, because I guess we are aware when we
reach the point, we are unable to gauge what we hear, at least when we
changed every slider by JAMin's EQ it's time to go to sleep ;).

>   Now, when gross errors are caused by cabling issues that's different; but if two delivery techniques produce equal measured specifications and yet one method 'sounds' better, then it's time to start looking at why.  But do see my comments inline.
> 
> Ralf wrote:
> > So you would use a 40-conductor IDE instead of a 80-conductor IDE, even
> > if there would be issues with a PATA drive? 
> 
> If throughput of UDMA33 or less is acceptable, why not?  An 80 pin cable is not going to change anything if the speed is UDMA33 or less, and the length is within the ATA spec.

Of cause, just my BIOS grumbles when using 40 instead of 80, resp. it
does, currently I'm using SATA only. BUT, in theory, if there should be
issues, I would test a cable with 80 conductors.

> > You would use an audio cable for the antenna, but a 75 ohm antenna cable?
> 
> In a pinch, sure;

;D I did the same at home, but it's not a safe situation, it's ok when
wasting time by watching TV, but when doing professional work, I would
be scared even if the jack wouldn't be a BNC jack ;).

>  the efficiency will be less, but it can work (I was a radio broadcast engineer full time for over ten years, specializing in AM directional phased arrays that present mutual impedance issues, and have been a consulting engineer now for twenty years; this is one topic that falls inside my area of professional expertise).  For short lengths a paperclip and a piece of chewing gum wrapper can work for S/PDIF;

;D. What's about a line of graphite on a paper? You're right. I just
wanted to point out that I'm not audiophile and that there could be
issues, even regarding to the jack, e.g. small stereo jacks, as my AIWA
portable consumer DAT has got for S/PDIF.

>  I actually did that one time with two Panasonic SV3200's back to back, and got a perfect DAT copy through S/PDIF. It was one of those situations where the tape was going south, it was very late at night, and I didn't even have an extra audio patch cable available.

:D Ok, I do understand, that you know situations were an engineer does
something less perfect. While you did something less ideal using
professional equipment, I did the same around 15 years ago, using 2
consumer DATs. I just wanted to point out, that there are situations
that could cause failure.

> > S/PDIF coaxial 75 ohm and optical might cause issues to, this has
> > nothing to do with audiophile placebo effects, resp. I don't know what
> > would cause "failure" (to avoid the word "loss", even if such failure
> > does cause loss), but there could be issues for S/PDIF. I don't know if
> > they belong to the cable, it's just a guess.
> 
> Digital cabling tends to either just work or not; however, digital signals are still analog voltages, and capacitance in the coax and optical issues in the case of fiber can occur.  My experience is that there is a very narrow margin of error between working perfectly and not working at all; however, there is an area of hysteresis that exists right on the threshold, and there you can get bit errors and such that are distinctly audible (they tend to not be subtle; something like a dirty head or tape dropout noise on a DAT deck; very distinct pulse noise is the result, at least in my nearly twenty years of experience with DAT decks).

A friend lend me a 6 m optical waveguide and he said that he never had
an issue using it for S/PDIF, even not when he used an extension cable
with this cable, but he had issues for S/PDIF when using a passive
alterable switch for the optical waveguide cable, when in use for
S/PDIF.

> > You don't need a double-blind test, if something is "really" audible.
> 
> Certainly; I'm talking about subtle things. From the medical side of things, where the term placebo originates, the placebo effect has always been in subtle cases; no placebo ever (to my knowledge) cured terminal cancer, for instance.

Indeed, I know an esoteric deceased, because of faith.

> > Audiophile subtleties aren't important for audio engineers and
> > musicians, they are just important for idiots. And I wasn't talking
> > about this.
> 
> No, I've seen enough talk on gearslutz to say that you're not correct on this point; plenty of gearheads, engineers, and musicians out there are fully impacted by the placebo effect when differences are subtle.  Things like which year of the Martin D35 is the best and gives the fuller sound, for instance.  Or certain subtleties in different manufacturer's tubes (which measure identically, but 'sound' different).

Ohhhhhh! I worked for Brauner Microphones and we really checked stereo
pairs, this isn't a joke. Two capsules from the same production could
cause a complete different sound, that isn't just subtle. Some two sided
capsules for a VM 1 became a single sided capsule for another
microphone.
I don't know this guitar, but I'm, sure there are audible differences,
regarding to the wood used by different years.
I've got a cheap Yamaha G-230, it did sound disgusting around 30 years
ago, but it does sound ok today. Of cause there are better guitars, but
often wood becomes better, when it's old.

> > Anyway, theory has less to do with the area of practice.
> 
> In practice engineer's ears are just as easily fooled as audiophile's ears are, as both are human ears.

No, engineers (me too) are unable to here the direction the cable is
connected etc. ... and we notice the point, when we aren't able to
listen anymore, e.g. as mentioned before, when we start to change any
fader for the EQ, we get aware that we are terrible wrong.

> 
> Hmm, I wonder how difficult it would be to code an A/B double-blind plugin switcher?

Knowing about a double-blind switcher includes an issue. Aaaargh, I
always switch for comparison in a way, I hope not to be aware of the
sound I'm listening too ... Ok, it even isn't a single-blind test, but
anyway, a trained ear tend to fix to some recognisable points. I passed
all blind tests, by picking out irrelevant sound properties. If we reach
this level, it's not important if there really is an issue or if it's a
placebo. I never made a double-blind test.

This thread started with a request for experiences, because I recorded a
grand piano using 2 AKG C 1000 S ;).

So, for this case there is a much harder issue ;).

I did jobs using the most expensive equipment available, but for
homerecording I always used cheap equipment and I like to read about
experiences. So, here I guess S/PDIF isn't a serious issue, but some
people seems to have knowledge about acceptable alternatives to
expensive microphones. I do believe that Rode is a good choice and I'll
focus to the used microphone, but to digital audio issues.

I just wish to read about experiences, when being in less good audio
engineer situations. I do have knowledge myself, but at least about
surround sound I was mistaken. I guess it couldn't harm to ask stupid
questions, but indeed, people might misunderstand such simple
questions ... I fear that there is such a misunderstanding regarding to
cables and S/PDIF.

Thank you for the reply :)

Ralf




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