What S/N?
I did that "whispering test" with console strips, comparing several strips with different opamps.
About 60 dB and 10 opamps it was a metaphor, I meant the method "under microscope", when the experiment is designed to stretch, to highlight the problem in question. Don't take it so literally.
+1, jcx,
No one can be confused by a blind test between a strait line and a 60dB gain amp, because the hiss.
I found the Doug Sax's whispering test not so much of interest, unless you drive a mastering room specialised in classical recordings, for several reasons, including the followings:
- I wonder the intelligibility of the first bits of a CD.
- We do not record very low level signals in music production. More than that, we often use noise gates to get rid of parasitic ones confusing the message, before mixing the tracks.
- If there is some low level content in a tune (reverb, end of notes), you are able to listen if any change in it. if you don't listen any change, you have not to worry about.
- I am more in concern with music itself than room ambiance or reverberation quality at the last 1/2 sec of a classical public recording.
etc...
But everybody is free to find his pleasure where he want. Some prefer Rolls Royce, some get more pleasure with Ferrari. Some prefer comfortable tube amps, some nervous solid states ones.
Last edited:
Yeah... I recently tried a true two-pole composite as per his TI app note sboa015, fig.9, using 5534's. Works like a charm... and in inverting config they can come with lower signal gain and adding a zero+pole to shelve the LF noise gain is easy.
Currently I'm extending that to LM3886/TDA7294 as slave opamps....
Last edited:
My wife has been working with software that does (with a skilled operator driving it!) a stunning job of making digital photos look like film. Enough so that she showed me some B&W prints she'd been working on, and I was able to immediately identify the "film" as Tri-X. That made her day.
Sound engineers are not so much in concern with fidelity, during recording or mixing, apart of the listening channel.
They use equipment for their *personality* (often opposite of fidelity), they create sounds, torturing the original all the way the can, levels, equalization, compression/expansion, noise gates, distortions, phase and delays, fake level stereo positioning etc..
As well as a hard rock guitarist don't chose his amp for reproduce the original sound of his electric guitar ;-)
(That where my previous remark about tube preamps takes it signification)
They don't look too much at datas or technical characteristics, they prefer to listen...
They "make believe" and try to create a credible musical landscape.
Where they are in concern with transparency and fidelity, it is when it comes to the listening channel, to be sure that what they hear during those tortures is as close as possible to what is really on the final tape (or hard disk).
They use equipment for their *personality* (often opposite of fidelity), they create sounds, torturing the original all the way the can, levels, equalization, compression/expansion, noise gates, distortions, phase and delays, fake level stereo positioning etc..
As well as a hard rock guitarist don't chose his amp for reproduce the original sound of his electric guitar ;-)
(That where my previous remark about tube preamps takes it signification)
They don't look too much at datas or technical characteristics, they prefer to listen...
They "make believe" and try to create a credible musical landscape.
Where they are in concern with transparency and fidelity, it is when it comes to the listening channel, to be sure that what they hear during those tortures is as close as possible to what is really on the final tape (or hard disk).
Around these parts, most of the time you never hear anything like the last decays of the soundfield at the end of a piece anyway, because one or more people are so eager to break into loud applause --- indeed, it seems, to be the first in the hall to do so
It was not about hiss and blind test. It was about your "no difference" claim when inserting opamps with unity gain without any need in power gain. Such tests prove nothing. The more of power gain you want from opamp, the more you hear their flaws. And it is not necessary to test them with voltage gain in 60 dB (even though it is revealing), you may test them with unity gain, but loaded on impedance which they see in real active filters, for example. Or, when used in microphone preamps. Or, used in power amps. Then you will hear the difference that you can measure if to know what causes that audible differences.
This is the main point: either capture the nature, or to create your artificial reality adding digital reverberation later. Both approaches are valid. But requirements are different.
However, I don't understand how somebody would seriously consider capturing some 5+1 record from the natural event. Especially using a single microphone, even if it looks like a hedgehog of capsules.
Please quote the line where i wrote that ? (i answered exactly the contrary, telling you that i'm not enough stupid to limit my tests to such a unique and stupid configuration, while trying to explore quality and default of some part). Remember "i tried different girls..."
I tried various configuration +40, +20, -20, +1, -1. And, contrary at what you seem to imply, unity gain if often far to be the best sounding situation for some opamps.
Can't you imagine than somebody can take some precaution before changing 300 operational amplifiers in a mixing desk ?
Is my English so bad that you NEVER understand what i write, or just, once more, the pleasure to argue against me, with no oratorical precautions, diverting my remarks ?
I believe it will be the end of communication between us, on my side, because it is just...boring for every body, including myself.
With all my respect.
Last edited:
And I explained you already how to hear the differences in order to find them. In my tests I did not try to prove anything. I tried to find the difference. And the main difference is in audibility of phase and non-linear distortions on low level of wideband sounds. Whisper is such sound. However, if you gate everything it does not matter to you. But please don't use your arguments in talks about fidelity. It is a totally different matter.
I presume i don't have, after 40years, of real life experience both as an electronic engineer , sound engineer and technical director of several studios to learn so much of your so called experience (all i read form you comes form some books or papers, like theDoug Sax's whispering test.)...
'I explained you": don't you feel the ridiculous of it ?
Please, leave-me alone.
Last edited:
Around these parts, most of the time you never hear anything like the last decays of the soundfield at the end of a piece anyway, because one or more people are so eager to break into loud applause --- indeed, it seems, to be the first in the hall to do so
You actually hear that decays, even between applauses. Coming from different directions. Dynamic in nature. It is what is absent when audiophiles complain on absence of an air.
In 1970'th I created applauses using noise generators, VCAs, VCFs, comparators and R-C shaping networks. Quite naturally sounding.
No, you are wrong.
My experience comes from my education in TIASUR (Tomsk Institute of Automated Control Systems and Radio Electronics), works in different research laboratories including Laboratory of Electronic Sound Synthesis that I created and run in the Institute as a volunteer; as a Designer in the laboratory of Thick Film ICs's in Tomsk Institute of Semiconductor Devices, from work as an Audio Engineer in Taldy-Kurgan Phylharmony, and many years of hobby research as an enthusiast, designer and musician, to satisfy my own curiosity, un-limited by official plans and rules.
40 years? No, I have 35 only. But most productive were first 5-10 years, the rest was more like refinement, re-thinking, re-shaping. Last 10 years I would call re-turning, when I started to value what I tried to abandon before, rushing for fashions. It is that last 10 years when I re-discovered vacuum tubes and found how useful they are actually.
Who is theDoug Sax I don't know, and I swear that "whispering test" I invented for myself. And found it revealing. And humbly offered you to take it, because I thought you are as curious as I am. So, if you refuse to take the "Whispering Test", please don't blame on me, nor on that Doug Sax, it is your own fault.
Last edited:
Precisely. Whether the recording engineers intended to capture the low level information or not, it is most certainly there, and if your system can run cleanly at high volume levels then there is a huge amount of detail in the quiet whisperings, that is very natural and satisfying to the body's hearing system because it mimics how things sound in real life.
One of my favourite torture tests is very heavily produced pop recordings, even the "bad" ones, the amount of detail in them is immense. They often sound richer and more overwhelming than orchestral recordings because of the number of layers of sound that can all be unravelled, and clearly discerned in the soundscape ...
Frank
My apologies Wave. I did take you literallyI did that "whispering test" with console strips, comparing several strips with different opamps.
About 60 dB and 10 opamps it was a metaphor, I meant the method "under microscope", when the experiment is designed to stretch, to highlight the problem in question. Don't take it so literally.
I have in fact done what you suggested.
If you look at a typical 1980 BBC spec for a broadcast mixing desk, you'll think its really quite easy to meet .. until you read the fine print with "under all operating conditions." On a Calrec 72 channel desk, part of Final Test is to daisy chain all 72 channels and check for this 'easy' spec. There were inevitable arguments over which knobs you could twiddle "under all operating conditions." I expect Calrec M-series & UA8000 to have any signal fade smoothly into the noise floor and still sound clean under it.
Did you have 60dB gain and 60dB attenuators on each strip?
I daren't tell you how many evil OPAs this represents.
Agree, and i wonder if any studio sound engineer had never listened a whispered conversation between musicians drinking in the back of big studios during pauses. It was one of the traditional jokes, to record them on some tapes and playback when they were back in the control room...
I wonder if any professional don't know Doug SAX's mastering studio, known even in France. About his test, thanks to a member of this forum:
[COLOR=#0000FF ]"Capturing Music: The Impossible Task," a seminar by James Boyk[/COLOR]
- Status
- Not open for further replies.