digital faders distort sound

[Co]

Archived from groups: rec.audio.pro (More info?)

> > Even a 0,1db change (compared to off) gives a noticable loss of
> > ambient sound on a high resolution setup.
>
> In any resonable comparison, no way, Jose'


Your missing my point. I'm not saying 0.1db is audible but the lesser
quality digital fader kickes in at -0.1 db as compared to 0 db (as in OFF,
as in not in the loop.)
So my point is if not well executed it can be harmfull. To a lesser degree
top quality digital attenuation might do harm as well.


> > Using a transformer to do this retains te highest quality though.
>
> This very much depends on the quality of the transformer. Since your
> baseline DCX2496 is budget-priced digital, it's logical to use a
> budget-priced transformer for the comparison. BTW, the budget priced
> transoformer will still cost far more. The sound quality losses in
> budget-grade transformers can easily be so egregious that the claim that
> "Using a transformer to do this retains te highest quality though." is
> summarily demolished.

Indeed, expensive transformers.......

 

[Guest]

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"CO" <nomail@plea.se> wrote in message
news:10ncpsgh49ikpbd@corp.supernews.com

>>> Even a 0,1db change (compared to off) gives a noticable loss of
>>> ambient sound on a high resolution setup.

>> In any resonable comparison, no way, Jose'

> Your missing my point.

Really?

> I'm not saying 0.1db is audible but the lesser
> quality digital fader kickes in at -0.1 db as compared to 0 db (as in
> OFF, as in not in the loop.)

Good quality digital faders can be shown to be completely undetectable when
set for up to a 1-2 0.1's of a dB because of the audibility of the change
for larger amounts of attenuation. Good digital faders are inaudible when
compared to a good quality analog fader set for the identically same amount
of attenuation. I've done this experiment many times, but blind testing can
be very helpful to avoid listener bias, particularly among listeners who are
analog bigots or simply poorly-informed.

Digital attenuators can be readily built with incredibly large amounts of
resolution for example 100's of dBs, while analog attenuators have
real-world resolution issues in the 120-130 dB that I described in the part
of my post that you decided to ignore. The digital attenuators in my
favorite mixer have dynamic range around 1,000 dB. Of course there is no
audible difference between dynamic range of 120 dB or 1000 dB.

> So my point is if not well executed it can be harmfull. To a lesser
> degree top quality digital attenuation might do harm as well.

The sky might fall. So much for global claims including the word "might".

>>> Using a transformer to do this retains te highest quality though.
>>
>> This very much depends on the quality of the transformer. Since your
>> baseline DCX2496 is budget-priced digital, it's logical to use a
>> budget-priced transformer for the comparison. BTW, the budget priced
>> transoformer will still cost far more. The sound quality losses in
>> budget-grade transformers can easily be so egregious that the claim
>> that "Using a transformer to do this retains te highest quality
>> though." is summarily demolished.

> Indeed, expensive transformers.......

....still corrupt the signal far more than well-executed but far less
expensive active and passive approaches, given that we're talking about
circuitry inside the console.

Transformers can be justified as interfacing devices to the outside world
when that world is atypically noisy, or as a means to obtain desired kinds
audible coloration.

 

[Guest]

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"Logan Shaw" <lshaw-usenet@austin.rr.com> wrote in message
news:0Indd.22261$Rf4.19316@fe2.texas.rr.com...
> Arny Krueger wrote:
>> I've noticed the same thing with analog faders. Don't you think that
>> might
>> be due to the Fletcher Munson effect?
> :
> :
>> When it comes to human perception, psychoacoustics rules.
>
> Oh, speaking of that, I've been wondering about something for a while,
> and I'm curious if maybe someone here has any insight.
>
> Sometimes I find myself hearing music at a level that is quite low.
> Not quite down to the level of barely perceptible, but more at the
> kind of level where I can hear the music well enough to recognize
> parts of it but not well enough to necessarily follow along. For
> instance, this happens in my car, where the aftermarket CD unit I
> installed has a habit of resetting its volume level to something
> way too low whenever I turn off the ignition. It is low enough
> that, because of ambient noise, I often don't even notice that it's
> playing.
>
> Anyway, if I'm listening at this low level, I get a certain idea of
> the pitch, i.e. the key that the song is in. If I then turn the
> volume up so that it's normal listening level (or even below normal
> listening level but high enough that I can clearly make everything
> out), then the pitch seems to increase by something on the order
> of 1/2 of a semitone to a full semitone! If I then lower the volume
> again, it doesn't seem to go back down in pitch and instead stays
> where it was at the higher volume, as if my brain has somehow "locked
> on" to the proper pitch once it got a taste of it.
>
> Perhaps coincidentally or perhaps not, I am trying to develop perfect
> pitch, and I have a habit of coming in about 1 semitone low or maybe
> a little less than that. For instance, I'll hear a song in my head
> and start singing it, and I'll be in C#, but then I'll put the CD in
> and play it to compare, and the song is actually in D.
>
> So am I a brain-damaged freak or is this a known phenomenon?

I don't know if you could say it's a known phenomenon exactly as you
describe it, but it's similar to an effect that happens to singers who are
trying to sing while monitoring with full cans (i.e. NOT leaving one ear
open/off), or even sometimes onstage/live... if the music's too loud -
relative to their own vocal volume in the mix - they tend to go sharp, if
the music's too soft - again, relative to their vocal volume - they tend to
go flat. This is certainly not universal, but it's common enough to where
I'd bet most everyone here has seen it happen.

Neil Henderson

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

> Try setting up some routing in a DAW so the same signal is routed
> both to the master outs and through as many channels and busses as
> possible, all with their faders at different levels. Then, put a polarity
> inversion plug on the last bus, and adjust the level so it nulls with the
> original signal.
>
> In Cubase SX the faders don't seem to lose information, so even with the
> most tortuous routing, it will still null.

Digital distortion appears above 5KHz to my ears.
try doing the same thing above with a FULL RANGE WELL RECORDED SIGNAL
(a group playing or a solo performance that has some high end to it).

the fletcher munsen curve is volume--dependent, and the whole idea is
to listen to the sound always AT THE SAME LEVEL by using an external
volume control you trust to be reasonably distortion -free

AF sine waves are not music, they are absolutely the easyest waveform
to reproduce, and this is why manufacturers love sine wave tests so
much!

 

[Co]

Archived from groups: rec.audio.pro (More info?)

> I don't know if you could say it's a known phenomenon exactly as you
> describe it, but it's similar to an effect that happens to singers who are
> trying to sing while monitoring with full cans (i.e. NOT leaving one ear
> open/off), or even sometimes onstage/live... if the music's too loud -
> relative to their own vocal volume in the mix - they tend to go sharp, if
> the music's too soft - again, relative to their vocal volume - they tend
to
> go flat. This is certainly not universal, but it's common enough to where
> I'd bet most everyone here has seen it happen.


Ive read something about not being able to judge pitch precisely at higher
volumes.

I think this is the reason when you see live (loud) music on TV you think
boy that sounds false,
but if you were there at the same concert you wouldnt have noticed.

Coolin

 

[Guest]

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"Logan Shaw" <lshaw-usenet@austin.rr.com> wrote in message
news:0Indd.22261$Rf4.19316@fe2.texas.rr.com
> Arny Krueger wrote:
>> I've noticed the same thing with analog faders. Don't you think that
>> might be due to the Fletcher Munson effect?
> :
> :
>> When it comes to human perception, psychoacoustics rules.

> Anyway, if I'm listening at this low level, I get a certain idea of
> the pitch, i.e. the key that the song is in. If I then turn the
> volume up so that it's normal listening level (or even below normal
> listening level but high enough that I can clearly make everything
> out), then the pitch seems to increase by something on the order
> of 1/2 of a semitone to a full semitone! If I then lower the volume
> again, it doesn't seem to go back down in pitch and instead stays
> where it was at the higher volume, as if my brain has somehow "locked
> on" to the proper pitch once it got a taste of it.

Please see page one of
http/www.acoustics.hut.fi/teaching/S-89.320/2004/KA6b.pdf .

The diagram is labelled "Pitch of a pure tone as a function of amplitude",
It's shown as being an inverse effect at low frequencies, about neutral at 2
KHz. and as a positive (increase amplitude, increase perceived pitch) above
2 KHz.

http/www.diku.dk/musinf/courses/mi/perception.pdf

Page 3 slide 2 shows a similar, but slightly different story.

 

[Co]

Archived from groups: rec.audio.pro (More info?)

>Even a 0,1db change (compared to off) gives a noticable loss of ambient
> >sound on a high resolution setup.
> >Indeed it becomes a little lifeless.
>
> This is still very bad, and I would not consider this acceptable. Have
you
> submitted a bug report to the Behringer guys?


There is an update available but i havent done that yet, i doubt this has
been resolved though....


> >I cant say all digital attenuation is bad perse..
>
> It shouldn't be, and there is really no reason for it to be bad at all
because
> CPU time is cheap. It takes so little to do it right that there is no
reason
> not to.


It might be cheap but theres a cpu status and even without using alot of
functions its already
80~90% busy depending on configuration. They had to cut corners
somewhere.....


> >Resistive fading could do even more damage though depending on the
> >brand/materials/setup.
> >There are a couple of pots that standout though........
> >
> >Using a transformer to do this retains te highest quality though.
>
> I disagree. A good resistive attenuator should be a lot cleaner than an
> autotransformer fader. If you don't like pots, stepped attenuators are
just
> fine.

Define good. There are BIG differences here. Resistors have there own sound.
It also depends on Impedance and gear of course. Resistors are very clean
and detailed sounding but they still do damage in a musical sense.

Later, Coolin

 

[Guest]

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"CO" <nomail@plea.se> wrote in message
news:10nenehjij5gbfd@corp.supernews.com
>> Even a 0,1db change (compared to off) gives a noticable loss of
>> ambient
>>> sound on a high resolution setup.
>>> Indeed it becomes a little lifeless.
>>
>> This is still very bad, and I would not consider this acceptable.
>> Have
> you
>> submitted a bug report to the Behringer guys?
>
>
> There is an update available but i havent done that yet, i doubt this
> has been resolved though....

No doubt the B. tech staff are used to dealing with people who really
believe that there is such a problem to hear.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

On or about 19 Oct 2004 13:34:55 -0400, Scott Dorsey allegedly wrote:

> In article <w9cdd.25055$rY1.7345@fe2.texas.rr.com>,
> Logan Shaw <lshaw-usenet@austin.rr.com> wrote:
> >CO wrote:
> >> Digital is an aproximation of the signal already,
> >
> >So is analog...
>
> It's right. Only live music is any good at all.

Yes, but if I'm standing next to you, I will still only hear approximately
what you are hearing. So which one of us is getting the truth?


Noel Bachelor noelbachelorAT(From:_domain)
Language Recordings Inc (Darwin Australia)

 

[gary]

Archived from groups: rec.audio.pro (More info?)

You're not getting Doppler distortion caused by ramming your car
repeatedly into your stereo are you?

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

maxdm wrote:

> AF sine waves are not music, they are absolutely the easyest waveform
> to reproduce, and this is why manufacturers love sine wave tests so
> much!

Continuous reproduction of a sine wave is demanding of power amplifiers,
so as a measure of an amp's ability to deliver power it can be a
valuable measurement parameter. Manufacturers, particularly those in the
consumer realm, did not much appreciate having to subject their amps to
continuous RMS testing because under such conditions their amps could
deliver only a fraction of their marketing department's TIP (Totally
Imaginary Power).

The relative purity of a sine wave facilitates determination of harmonic
distortion.

A very good flautist can produce a reasonably nice sine wave, and lots
of people consider flutes a musical instrument.

--
ha

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

"Noel Bachelor" <see.my.sig@bigpond.com> wrote in message
news:4177616d.527891427@news.bigpond.com...
> Yes, but if I'm standing next to you, I will still only hear approximately
> what you are hearing. So which one of us is getting the truth?

What is "truth" grasshopper

TonyP.

 

[Guest]

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Gary wrote:

> You're not getting Doppler distortion caused by ramming your car
> repeatedly into your stereo are you?

Probably not. It's rumored he has a trunk full of WD40.

--
ha

 

[Guest]

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"maxdm" <maxdimario@aliceposta.it> wrote in message
> Not exactly.
> Try this:
>
> Place the cursor at - 20 db and RAISE THE CONTROL ROOM VOLUME 20 dB so
> that the listening volume is the SAME.
>
> You will notice loss of detail etc. and on some of the DAW you will
> notice a different spectral balance (brighter darker etc.)
> this won't happen with a proper analog 600/600 attenuator (fader) but
> a similar effect *might* come through on an improperly biased VCA I
> guess.

Of course yo will if you crank the gain ! You are then listening to the
equivalent of a 13 bit signal. If you crank the analogue gain as you
suggest, it is not a meaningful observation.

geoff

 

[Guest]

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"Geoff Wood" <geoff@paf.co.nz-nospam> wrote in message news:<SiJdd.13285$mZ2.780795@news02.tsnz.net>...
> "maxdm" <maxdimario@aliceposta.it> wrote in message

> Of course yo will if you crank the gain ! You are then listening to the
> equivalent of a 13 bit signal. If you crank the analogue gain as you
> suggest, it is not a meaningful observation.
>
> geoff

If you feel that having 13 bit signals in your mix is ok, that's fine.
analog faders have absolute resolution all the way down to infinity.

when you have 20 tracks going at the same time you've got to back off
on those faders a bit. or turn the master down.

by the way I noticed that the master at -10 sounds different than at 0
even for the same rms output.

digital is not a perfect mixing medium, but very convenient and cheap.

 

[Guest]

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"Geoff Wood" <geoff@paf.co.nz-nospam> wrote in message
news:SiJdd.13285$mZ2.780795@news02.tsnz.net

> "maxdm" <maxdimario@aliceposta.it> wrote in message

>> Place the cursor at - 20 db and RAISE THE CONTROL ROOM VOLUME 20 dB
>> so that the listening volume is the SAME.

>> You will notice loss of detail etc. and on some of the DAW you will
>> notice a different spectral balance (brighter darker etc.)
>> this won't happen with a proper analog 600/600 attenuator (fader) but
>> a similar effect *might* come through on an improperly biased VCA I
>> guess.

> Of course yo will if you crank the gain ! You are then listening to
> the equivalent of a 13 bit signal. If you crank the analogue gain as
> you suggest, it is not a meaningful observation.

Since this is a properly-dithered system, the 13 bits is far less
signficiant than the correspointing 78 dB dynamic range, just like an analog
system with ultimate dynamic range of about 96 dB.

However, with real world recordings, 78 dB is unlikely to actually cause an
audible difference. Bias-controlled listening tests would probably bear this
out.

Either the Behringer or the listener is not performing up to general
expectations, but the listener may be hearing his expectations.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

On Thu, 21 Oct 2004 05:39:39 -0700, maxdm wrote:

>> Try setting up some routing in a DAW so the same signal is routed
>> both to the master outs and through as many channels and busses as
>> possible, all with their faders at different levels. Then, put a polarity
>> inversion plug on the last bus, and adjust the level so it nulls with the
>> original signal.
>>
>> In Cubase SX the faders don't seem to lose information, so even with the
>> most tortuous routing, it will still null.
>
> Digital distortion appears above 5KHz to my ears.
> try doing the same thing above with a FULL RANGE WELL RECORDED SIGNAL
> (a group playing or a solo performance that has some high end to it).

I tried this with whatever was in the multitrack at the time... vox,drums
and bass I think. Anyway, if it nulls, it nulls. The signal is identical.

I would say that not all DAWs compensate for latency properly when doing
this, so you may have to line up the tracks again afterwards.

Digital nasties above 5k is probably a clocking problem, jitter or
something not dithered properly. Are you dithering the output when
listening?

>
> the fletcher munsen curve is volume--dependent, and the whole idea is
> to listen to the sound always AT THE SAME LEVEL by using an external
> volume control you trust to be reasonably distortion -free

Naturaly.

>
> AF sine waves are not music, they are absolutely the easyest waveform to
> reproduce, and this is why manufacturers love sine wave tests so much!

More likely because the results are most useful from sine waves. Not all
tests are done with a single pure sine. IMD for instance.

I wonder if they are the easiest to reproduce? Personally, I can hear very
small amounts of distortion with a single sine wave, but it's harder to
hear with a complex signal.

 

[Guest]

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"maxdm" <maxdimario@aliceposta.it> wrote in message
news:25150933.0410211020.27ed9a46@posting.google.com
> "Geoff Wood" <geoff@paf.co.nz-nospam> wrote in message
> news:<SiJdd.13285$mZ2.780795@news02.tsnz.net>...
>> "maxdm" <maxdimario@aliceposta.it> wrote in message
>
>> Of course yo will if you crank the gain ! You are then listening to
>> the equivalent of a 13 bit signal. If you crank the analogue gain
>> as you suggest, it is not a meaningful observation.
>>
>> geoff
>
> If you feel that having 13 bit signals in your mix is ok, that's fine.
> analog faders have absolute resolution all the way down to infinity.

That's your big mistake. Well-done digital faders have just as good
resolution down to infinity.

13 bit digital signals have the same resolution as an analog signal with
approximately 80 dB dyanmic range. Since 16 bit digital signals are common
place, but there is essentially no generally-used analog media that is
capable of 96 dB dynamic range, digital generally has the advantage when it
comes to resolution at low signal levels.

> when you have 20 tracks going at the same time you've got to back off
> on those faders a bit. or turn the master down.

It's not a problem. The world is full of 24 bit digital equipment with
dynamic range > 140 dB. I suggest you start trying to find an analog console
with > 140 dB dynamic range and not post until you can find one.

> by the way I noticed that the master at -10 sounds different than at 0
> even for the same rms output.

I think you're *hearing* your misapprehensions about digital, pure and
simple.

> digital is not a perfect mixing medium, but very convenient and cheap.

 

[Guest]

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philicorda <philicordaNOOSPAM@azriel.tydrwg.com> wrote in message news:<pan.2004.10.23.02.55.55.42508@azriel.tydrwg.com>...
> On Thu, 21 Oct 2004 05:39:39 -0700, maxdm wrote:

> I tried this with whatever was in the multitrack at the time... vox,drums
> and bass I think. Anyway, if it nulls, it nulls. The signal is identical.
>
Could you describe what you did? I didn't get the technical details.
keep in mind that two signals that distort in the same way when summed
out of phase will null anyway.
Sine waves in digital come out fairly well. up until near sampling
frequency.
the more complex the wave the more difficult it is to reproduce.
THD is not the kind of distortion I am talking about, I am talking
about loss of imaging, depth and transient distortion.
Someone posted that a flute is like a sine wave, but the flute only
resembles a sine wave, I think most musicians and listeners will agree
that there is a lot more to the flute sound than a sine wave!

the ear is very sensitive to transients and phase/time distortion.

 

[Guest]

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On 21 Oct 2004 11:00:06 -0700, Gary <midicad2001@yahoo.com> wrote:
> You're not getting Doppler distortion caused by ramming your car
> repeatedly into your stereo are you?

Oh THAT brings back memories! The final exam for Engineering Physics II
oh . um . .*COUGHS* years ago:

"You are driving towards a perfectly reflective brick wall at 100m/s.
The temperature is 35C and there is no wind.
Your blow your horn, which sounds a pure tone at 200Hz.

What pitches do you hear?

Note all the "Only in physics class" contrivences.