Anyone heard of applying a sine wave to audio?

[docsavage20]

I heard someone talk about applying a sine wave to audio as some kind of mastering tweak. I've never heard of this, is this a term/technique you're familiar with? If so how does it work?

Thanks.

[Trevor]

"docsavage20" > wrote in message
...
>I heard someone talk about applying a sine wave to audio as some kind of
>mastering tweak. I've never heard of this, is this a term/technique you're
>familiar with? If so how does it work?

ALL sound consists of sine waves (look up fourier analysis)
Who knows what you possibly thought you heard, or what that "someones"
qualifications are, or indeed what drugs they were possibly on. (assuming
you weren't :-)

Trevor.

[Sean Conolly]

"Neil Gould" > wrote in message
...
> Trevor wrote:
>> "docsavage20" > wrote in message
>> ...
>>> I heard someone talk about applying a sine wave to audio as some
>>> kind of mastering tweak. I've never heard of this, is this a
>>> term/technique you're familiar with? If so how does it work?
>>
>> ALL sound consists of sine waves (look up fourier analysis)
>>
> So... square, triangle, and sawtooth waves (to name a few that can't be
> reconciled as sine waves) are what, if not sound? ;-)

A pure sine wave is nothing more than a waveform with a single frequncy
component. By combining multiple frequencies, with the correct phase and
amplitude you can create any repeating waveform - even a square wave.

Sean

[John Williamson]

On 02/06/2014 15:32, Neil Gould wrote:
> Trevor wrote:
>> "docsavage20" > wrote in message
>> ...
>>> I heard someone talk about applying a sine wave to audio as some
>>> kind of mastering tweak. I've never heard of this, is this a
>>> term/technique you're familiar with? If so how does it work?
>>
>> ALL sound consists of sine waves (look up fourier analysis)
>>
> So... square, triangle, and sawtooth waves (to name a few that can't be
> reconciled as sine waves) are what, if not sound? ;-)
>
Square, triangle and sawtooth waves can all be synthesised by adding
sine waves having the appropriate harmonic and phase relationships to
the base note. The more harmonics you add, the closer they get to
perfection. Back in the days before digital waveform synthesis by
replaying samples, you often started by using a square wave and applying
filters to remove certain harmonics.

Many of the distortions you get in the analogue world when trying to
reproduce these waves are due to the partial or complete removal and
time shifting of these harmonics.

--
Tciao for Now!

John.

[Neil Gould]

Trevor wrote:
> "docsavage20" > wrote in message
> ...
>> I heard someone talk about applying a sine wave to audio as some
>> kind of mastering tweak. I've never heard of this, is this a
>> term/technique you're familiar with? If so how does it work?
>
> ALL sound consists of sine waves (look up fourier analysis)
>
So... square, triangle, and sawtooth waves (to name a few that can't be
reconciled as sine waves) are what, if not sound? ;-)
--
best regards,

Neil

[Neil Gould]

John Williamson wrote:
> On 02/06/2014 15:32, Neil Gould wrote:
>> Trevor wrote:
>>> "docsavage20" > wrote in message
>>> ...
>>>> I heard someone talk about applying a sine wave to audio as some
>>>> kind of mastering tweak. I've never heard of this, is this a
>>>> term/technique you're familiar with? If so how does it work?
>>>
>>> ALL sound consists of sine waves (look up fourier analysis)
>>>
>> So... square, triangle, and sawtooth waves (to name a few that can't
>> be reconciled as sine waves) are what, if not sound? ;-)
>>
> Square, triangle and sawtooth waves can all be synthesised by adding
> sine waves having the appropriate harmonic and phase relationships to
> the base note. The more harmonics you add, the closer they get to
> perfection.
>
Thanks... I understand Fourier's synthesis concepts, and know that sine
waves can be used via additive synthesis to approximate other waveforms.
However, due to the inherent complexity of that process, that isn't how
those waveforms have typically been generated in electronic gear, so I
wonder whether such generated signals are identical to analog sound events.
More to the point, I've not seen a clear statement that all waveforms are
solely the result of additive synthesis using sine waves.

Hmm... food for thought, at least. ;-)
--
best regards,

Neil

[John Williamson]

On 02/06/2014 17:19, Neil Gould wrote:
> John Williamson wrote:
>> On 02/06/2014 15:32, Neil Gould wrote:
>>> Trevor wrote:
>>>> "docsavage20" > wrote in message
>>>> ...
>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>> term/technique you're familiar with? If so how does it work?
>>>>
>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>
>>> So... square, triangle, and sawtooth waves (to name a few that can't
>>> be reconciled as sine waves) are what, if not sound? ;-)
>>>
>> Square, triangle and sawtooth waves can all be synthesised by adding
>> sine waves having the appropriate harmonic and phase relationships to
>> the base note. The more harmonics you add, the closer they get to
>> perfection.
>>
> Thanks... I understand Fourier's synthesis concepts, and know that sine
> waves can be used via additive synthesis to approximate other waveforms.
> However, due to the inherent complexity of that process, that isn't how
> those waveforms have typically been generated in electronic gear, so I
> wonder whether such generated signals are identical to analog sound events.
> More to the point, I've not seen a clear statement that all waveforms are
> solely the result of additive synthesis using sine waves.
>
> Hmm... food for thought, at least. ;-)
>
Well, given half a dozen signal generators at school <mumble> years ago,
we managed to get a fair approximation to most of 'em. To be honest,
though, it was more of a demonstration of the theory than a practical
way to do the job.

It's always been easier to start with a square wave and apply some
filtering. To get back to the original post, it might make sense to add
a low subharmonic of the fundamental frequency to a signal lacking the
bottom octave or two, if the intention was to play it back using a
system with a *really* good low bass response, as used in some dance
halls or cars, which have been known to couple a mass driver to the
dancefloor or cabin floor respectively. You'd then be hoping for a high
pass filter in most gear not to pass the damaging lows to the output
devices and power amps.

--
Tciao for Now!

John.

[Scott Dorsey]

Neil Gould > wrote:
>Trevor wrote:
>> "docsavage20" > wrote in message
>> ...
>>> I heard someone talk about applying a sine wave to audio as some
>>> kind of mastering tweak. I've never heard of this, is this a
>>> term/technique you're familiar with? If so how does it work?
>>
>> ALL sound consists of sine waves (look up fourier analysis)
>>
>So... square, triangle, and sawtooth waves (to name a few that can't be
>reconciled as sine waves) are what, if not sound? ;-)

They are mathematical abstractions that don't exist in the real world.
All we have here in reality are finite-bandwidth signals.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Neil Gould > wrote:
>More to the point, I've not seen a clear statement that all waveforms are
>solely the result of additive synthesis using sine waves.

There's a proof by induction done by Fourier in 1811 but it has some
handwaving in it. There is a more modern proof that involves group theory
which I don't understand but I'm willing to accept as accurate.

Any arbitrary function, periodic or aperiodic, can be represented as the
sum of sine functions with varying frequency and phase.

When this idea was rediscovered by Oliver Heaviside around 1905 it totally
revolutionized signals theory.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Don Pearce[_3_]]

On 2 Jun 2014 13:59:25 -0400, (Scott Dorsey) wrote:

>Neil Gould > wrote:
>>More to the point, I've not seen a clear statement that all waveforms are
>>solely the result of additive synthesis using sine waves.
>
>There's a proof by induction done by Fourier in 1811 but it has some
>handwaving in it. There is a more modern proof that involves group theory
>which I don't understand but I'm willing to accept as accurate.
>
>Any arbitrary function, periodic or aperiodic, can be represented as the
>sum of sine functions with varying frequency and phase.
>
>When this idea was rediscovered by Oliver Heaviside around 1905 it totally
>revolutionized signals theory.
>--scott

Fourier synthesis of music works 100% if the whole tune repeats
forever. A single rendition is compromised by the temporal truncation,
which necessarily means that the frequency domain is also changed - it
get's sidebands like the FFT of an impulse. The shorter the piece, the
further they stretch. So a Fourier representation of a real, finite
piece of music is an approximation.


A really good one.

d

[Neil[_9_]]

On 6/2/2014 1:59 PM, Scott Dorsey wrote:
> Neil Gould > wrote:
>> More to the point, I've not seen a clear statement that all waveforms are
>> solely the result of additive synthesis using sine waves.
>
> There's a proof by induction done by Fourier in 1811 but it has some
> handwaving in it. There is a more modern proof that involves group theory
> which I don't understand but I'm willing to accept as accurate.
>
> Any arbitrary function, periodic or aperiodic, can be represented as the
> sum of sine functions with varying frequency and phase.
>
Representations of phenomena can be comprised of many things, but is
there not a definable difference between such representations and the
actual phenomena? IOW, how does any representation absolutely define the
construction of a dissimilar phenomenon?

==
best regards,
Neil

[Neil[_9_]]

On 6/2/2014 1:51 PM, Scott Dorsey wrote:
> Neil Gould > wrote:
>> Trevor wrote:
>>> "docsavage20" > wrote in message
>>> ...
>>>> I heard someone talk about applying a sine wave to audio as some
>>>> kind of mastering tweak. I've never heard of this, is this a
>>>> term/technique you're familiar with? If so how does it work?
>>>
>>> ALL sound consists of sine waves (look up fourier analysis)
>>>
>> So... square, triangle, and sawtooth waves (to name a few that can't be
>> reconciled as sine waves) are what, if not sound? ;-)
>
> They are mathematical abstractions that don't exist in the real world.
> All we have here in reality are finite-bandwidth signals.
> --scott
>
Perhaps therein lies the rub, from both constructive and representative
perspectives.

--
best regards,
Neil

[John Williamson]

On 02/06/2014 20:40, Neil wrote:
> On 6/2/2014 1:59 PM, Scott Dorsey wrote:
>> Neil Gould > wrote:
>>> More to the point, I've not seen a clear statement that all waveforms
>>> are
>>> solely the result of additive synthesis using sine waves.
>>
>> There's a proof by induction done by Fourier in 1811 but it has some
>> handwaving in it. There is a more modern proof that involves group
>> theory
>> which I don't understand but I'm willing to accept as accurate.
>>
>> Any arbitrary function, periodic or aperiodic, can be represented as the
>> sum of sine functions with varying frequency and phase.
>>
> Representations of phenomena can be comprised of many things, but is
> there not a definable difference between such representations and the
> actual phenomena? IOW, how does any representation absolutely define the
> construction of a dissimilar phenomenon?
>
It can't, but the representation can be made as good as you have time
and facilities for.

In video, for example, a very good representation of windblown hair can
be made entirely from mathematical constructs, and this can be shown as
a solid form (Assuming normal eye separation and a fixed viewing angle)
if enough effort is made. Just ask, among others, Pixar.


--
Tciao for Now!

John.

[Scott Dorsey]

Neil > wrote:
>On 6/2/2014 1:59 PM, Scott Dorsey wrote:
>> Neil Gould > wrote:
>>> More to the point, I've not seen a clear statement that all waveforms are
>>> solely the result of additive synthesis using sine waves.
>>
>> There's a proof by induction done by Fourier in 1811 but it has some
>> handwaving in it. There is a more modern proof that involves group theory
>> which I don't understand but I'm willing to accept as accurate.
>>
>> Any arbitrary function, periodic or aperiodic, can be represented as the
>> sum of sine functions with varying frequency and phase.
>>
>Representations of phenomena can be comprised of many things, but is
>there not a definable difference between such representations and the
>actual phenomena? IOW, how does any representation absolutely define the
>construction of a dissimilar phenomenon?

The transformation from time domain to frequency domain and back again is
not lossy. You can go in either direction without losing anything, that is
the point of the Fourier proof.

Now, going from a wave in free air to an electrical representation and
back, THAT is hard.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Neil > wrote:
>On 6/2/2014 1:51 PM, Scott Dorsey wrote:
>> Neil Gould > wrote:
>>> Trevor wrote:
>>>> "docsavage20" > wrote in message
>>>> ...
>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>> term/technique you're familiar with? If so how does it work?
>>>>
>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>
>>> So... square, triangle, and sawtooth waves (to name a few that can't be
>>> reconciled as sine waves) are what, if not sound? ;-)
>>
>> They are mathematical abstractions that don't exist in the real world.
>> All we have here in reality are finite-bandwidth signals.
>>
>Perhaps therein lies the rub, from both constructive and representative
>perspectives.

Not at all, squares and triangles are not things you'll encounter from real
sources. Imagine trying to create a real square wave from an instrument,
you'd have to move air back and forth instantaneously with no time lag
involved.

It's not a thing you can create in the real world.... it's a thing you can
represent mathematically but from the standpoint of recording sounds from
the real world, they are all going to be bandlimited in some fashion because
we can't move things at infinite speeds.

It's possible to mathematically model all possible waveforms, whether or
not those waveforms can be made real or not. Mathematicians would argue
this is why math is better than the real world. Physicists would argue
the opposite for the same reasons.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Neil Gould]

Scott Dorsey wrote:
> Neil > wrote:
>> On 6/2/2014 1:59 PM, Scott Dorsey wrote:
>>> Neil Gould > wrote:
>>>> More to the point, I've not seen a clear statement that all
>>>> waveforms are solely the result of additive synthesis using sine
>>>> waves.
>>>
>>> There's a proof by induction done by Fourier in 1811 but it has some
>>> handwaving in it. There is a more modern proof that involves group
>>> theory which I don't understand but I'm willing to accept as
>>> accurate.
>>>
>>> Any arbitrary function, periodic or aperiodic, can be represented
>>> as the sum of sine functions with varying frequency and phase.
>>>
>> Representations of phenomena can be comprised of many things, but is
>> there not a definable difference between such representations and the
>> actual phenomena? IOW, how does any representation absolutely define
>> the construction of a dissimilar phenomenon?
>
> The transformation from time domain to frequency domain and back
> again is not lossy. You can go in either direction without losing
> anything, that is the point of the Fourier proof.
>
> Now, going from a wave in free air to an electrical representation and
> back, THAT is hard.
>
Math is like that in many ways. But, is that not what we are faced with when
creating or reproducing music? ;-)
--
best regards,

Neil

[Neil[_9_]]

On 6/2/2014 3:49 PM, John Williamson wrote:
> On 02/06/2014 20:40, Neil wrote:
>> On 6/2/2014 1:59 PM, Scott Dorsey wrote:
>>> Neil Gould > wrote:
>>>> More to the point, I've not seen a clear statement that all waveforms
>>>> are
>>>> solely the result of additive synthesis using sine waves.
>>>
>>> There's a proof by induction done by Fourier in 1811 but it has some
>>> handwaving in it. There is a more modern proof that involves group
>>> theory
>>> which I don't understand but I'm willing to accept as accurate.
>>>
>>> Any arbitrary function, periodic or aperiodic, can be represented as the
>>> sum of sine functions with varying frequency and phase.
>>>
>> Representations of phenomena can be comprised of many things, but is
>> there not a definable difference between such representations and the
>> actual phenomena? IOW, how does any representation absolutely define the
>> construction of a dissimilar phenomenon?
>>
> It can't, but the representation can be made as good as you have time
> and facilities for.
>
Agreed. The salient points being "as good as" differentiated from "is"
in the real world.
--
best regards,
Neil

[Neil[_9_]]

On 6/2/2014 4:12 PM, Scott Dorsey wrote:
> Neil > wrote:
>> On 6/2/2014 1:51 PM, Scott Dorsey wrote:
>>> Neil Gould > wrote:
>>>> Trevor wrote:
>>>>> "docsavage20" > wrote in message
>>>>> ...
>>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>>> term/technique you're familiar with? If so how does it work?
>>>>>
>>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>>
>>>> So... square, triangle, and sawtooth waves (to name a few that can't be
>>>> reconciled as sine waves) are what, if not sound? ;-)
>>>
>>> They are mathematical abstractions that don't exist in the real world.
>>> All we have here in reality are finite-bandwidth signals.
>>>
>> Perhaps therein lies the rub, from both constructive and representative
>> perspectives.
>
> Not at all, squares and triangles are not things you'll encounter from real
> sources. Imagine trying to create a real square wave from an instrument,
> you'd have to move air back and forth instantaneously with no time lag
> involved.
>
> It's not a thing you can create in the real world.... it's a thing you can
> represent mathematically but from the standpoint of recording sounds from
> the real world, they are all going to be bandlimited in some fashion because
> we can't move things at infinite speeds.
>
Again, therein lies the rub, making it impossible to create an accurate
recording process (and is greatly complicated by reproduction processes)
unless the inherent imperfections are taken for granted.

But, if we can accept such imperfections, then one can accept that some
electronic instruments can easily create square and sawtooth waves,
though I know of none that do so by additive synthesis using sine waves.

> It's possible to mathematically model all possible waveforms, whether or
> not those waveforms can be made real or not. Mathematicians would argue
> this is why math is better than the real world. Physicists would argue
> the opposite for the same reasons.
>
Math is like that, and the beauty of it is that it doesn't bother either
mathematicians or physicists that the circumference of a circle can't be
specified, since that requires the expressed intersection of zero and
infinity at the same location. By comparison, square waves are simple. ;-)

--
best regards,
Neil

[[email protected]]

Niel,

there is reality and there are representations of reality.

You can view reality from the time domain and view triangle and square waves signals on an o scope.

You can view reality from the frequency domain and view a series of frequencies on a spectrum analyzer.

BOTH views are equally valid!

Depending on what you want to accomplish, there may be advantages to using one view or the other, but both are equally valid representations of reality.

You are probably more accustomed to thinking in the time domain, the frequency domain is equally valid and sometimes has advantages.

Mark

[Scott Dorsey]

Neil > wrote:
>On 6/2/2014 4:12 PM, Scott Dorsey wrote:
>> It's not a thing you can create in the real world.... it's a thing you can
>> represent mathematically but from the standpoint of recording sounds from
>> the real world, they are all going to be bandlimited in some fashion because
>> we can't move things at infinite speeds.
>>
>Again, therein lies the rub, making it impossible to create an accurate
>recording process (and is greatly complicated by reproduction processes)
>unless the inherent imperfections are taken for granted.

No, not at all. There is no need to be able to reproduce signals that can't
exist as sounds.

The problems all have to do with being able to reproduce signals that can.

>But, if we can accept such imperfections, then one can accept that some
>electronic instruments can easily create square and sawtooth waves,
>though I know of none that do so by additive synthesis using sine waves.

No, they can't create square or sawtooth waves. The "square wave" coming out
of a synthesizer looks like a square wave on a scope if you don't look at it
too hard, but the closer you look the more you'll find that it isn't a real
square wave; the edges are not completely parallel because it's not possible
to instantaneously change the voltage.

What you get out of the synthesizer is only a rough approximation of the
archetypical square wave. Real, perfect square waves require infinite
bandwidth and therefore cannot exist in the real world.

For similar reasons we don't have real op-amps in the real world. We have
very high gain chips that say "op-amp" on the datasheet, but when you actually
put them in a circuit you can run into situations where they don't behave like
op-amps at all. That's just how the real world is.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[William Sommerwerck]

I had no intention of entering this discussion. But I have to ask the question
I thought someone else would have gotten around to by now...

What, exactly, does the OP's question //mean//? How can you answer a question
you don't understand?

[Neil[_9_]]

On 6/3/2014 11:07 AM, Scott Dorsey wrote:
> Neil > wrote:
>> On 6/2/2014 4:12 PM, Scott Dorsey wrote:
>>> It's not a thing you can create in the real world.... it's a thing you can
>>> represent mathematically but from the standpoint of recording sounds from
>>> the real world, they are all going to be bandlimited in some fashion because
>>> we can't move things at infinite speeds.
>>>
>> Again, therein lies the rub, making it impossible to create an accurate
>> recording process (and is greatly complicated by reproduction processes)
>> unless the inherent imperfections are taken for granted.
>
> No, not at all. There is no need to be able to reproduce signals that can't
> exist as sounds.
>
> The problems all have to do with being able to reproduce signals that can.
>
I was referring to the physical limitations of mechanical and electronic
processes that prevent the precise reproduction of signals that *are*
sounds. So, it seems that we may be speaking of the same thing, here.

>> But, if we can accept such imperfections, then one can accept that some
>> electronic instruments can easily create square and sawtooth waves,
>> though I know of none that do so by additive synthesis using sine waves.
>
> No, they can't create square or sawtooth waves. The "square wave" coming out
> of a synthesizer looks like a square wave on a scope if you don't look at it
> too hard, but the closer you look the more you'll find that it isn't a real
> square wave; the edges are not completely parallel because it's not possible
> to instantaneously change the voltage.
>
> What you get out of the synthesizer is only a rough approximation of the
> archetypical square wave. Real, perfect square waves require infinite
> bandwidth and therefore cannot exist in the real world.
>
Yes, we are in agreement that synthesizers produce distorted
representations of the archetypical waveforms. Neither can real, perfect
reproductions of acoustic events. The caveat was the acceptance of those
imperfections, which IMO do not amount to more than the distortions
involved in any other part of the sound creation, recording or
reproduction processes. Synths are better at creating these waveforms
than trying to achieve the same through additive synthesis using sine
waves in the real world. So those waveforms which are not comprised of
sine waves should be considered "sounds", IMO.
--
best regards,
Neil

[Scott Dorsey]

Neil > wrote:
>On 6/3/2014 11:07 AM, Scott Dorsey wrote:
>> Neil > wrote:
>>> On 6/2/2014 4:12 PM, Scott Dorsey wrote:
>>>> It's not a thing you can create in the real world.... it's a thing you can
>>>> represent mathematically but from the standpoint of recording sounds from
>>>> the real world, they are all going to be bandlimited in some fashion because
>>>> we can't move things at infinite speeds.
>>>>
>>> Again, therein lies the rub, making it impossible to create an accurate
>>> recording process (and is greatly complicated by reproduction processes)
>>> unless the inherent imperfections are taken for granted.
>>
>> No, not at all. There is no need to be able to reproduce signals that can't
>> exist as sounds.
>>
>> The problems all have to do with being able to reproduce signals that can.
>>
>I was referring to the physical limitations of mechanical and electronic
>processes that prevent the precise reproduction of signals that *are*
>sounds. So, it seems that we may be speaking of the same thing, here.

I know you were, and I am NOT talking about that at all. That is a
different issue altogether. Go back and read what I wrote.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[None]

"Scott Dorsey" > wrote in message
...
> For similar reasons we don't have real op-amps in the real world.

Of course we do. Your very narrow theoretical definition is not the
only definition of "op-amp". Other, more practical, definitions exist,
are valid definitions, and are much more practical in real-world
situations.

[None]

"Scott Dorsey" > wrote in message
...
> Go back and read what I wrote.

Now who does that remind me of?

[William Sommerwerck]

"None" wrote in message
m...
"Scott Dorsey" > wrote in message
...

>> Go back and read what I wrote.

> Now who does that remind me of?

Someone a lot brighter than you.

[William Sommerwerck]

"None" wrote in message
m...
"Scott Dorsey" > wrote in message
...

>> For similar reasons we don't have real op-amps in the real world.

> Of course we do. Your very narrow theoretical definition is not the only
> definition of "op-amp". Other, more practical, definitions exist, are valid
> definitions, and are much more practical in real-world situations.

If you design without paying attention to an op-amp's practical limitations
(especially gain-BW), you can wind up with circuits that don't work the way
you expect.

[None]

"William Sommerwerck" > wrote in message
...
> "None" wrote in message
> m...
> "Scott Dorsey" > wrote in message
> ...
>
>>> For similar reasons we don't have real op-amps in the real world.
>
>> Of course we do. Your very narrow theoretical definition is not the
>> only definition of "op-amp". Other, more practical, definitions
>> exist, are valid definitions, and are much more practical in
>> real-world situations.
>
> If you design without paying attention to an op-amp's practical
> limitations (especially gain-BW), you can wind up with circuits that
> don't work the way you expect.

Of course. You need to know both its capabilities and limitations.
That doesn't mean it's not a real op-amp, if you use the most
widespread, almost universal, dictionary definition.

[Trevor]

"Neil Gould" > wrote in message
...
> Trevor wrote:
>> "docsavage20" > wrote in message
>> ...
>>> I heard someone talk about applying a sine wave to audio as some
>>> kind of mastering tweak. I've never heard of this, is this a
>>> term/technique you're familiar with? If so how does it work?
>>
>> ALL sound consists of sine waves (look up fourier analysis)
>>
> So... square, triangle, and sawtooth waves (to name a few that can't be
> reconciled as sine waves) are what, if not sound? ;-)

Oh yes they can. As I said, they are simply sine waves and harmonics. Do
what I suggested and look up fourier analysis.

Trevor.

[Trevor]

"Neil Gould" > wrote in message
...
> John Williamson wrote:
>> On 02/06/2014 15:32, Neil Gould wrote:
>>> Trevor wrote:
>>>> "docsavage20" > wrote in message
>>>> ...
>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>> term/technique you're familiar with? If so how does it work?
>>>>
>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>
>>> So... square, triangle, and sawtooth waves (to name a few that can't
>>> be reconciled as sine waves) are what, if not sound? ;-)
>>>
>> Square, triangle and sawtooth waves can all be synthesised by adding
>> sine waves having the appropriate harmonic and phase relationships to
>> the base note. The more harmonics you add, the closer they get to
>> perfection.
>>
> Thanks... I understand Fourier's synthesis concepts, and know that sine
> waves can be used via additive synthesis to approximate other waveforms.
> However, due to the inherent complexity of that process, that isn't how
> those waveforms have typically been generated in electronic gear, so I
> wonder whether such generated signals are identical to analog sound
> events.
> More to the point, I've not seen a clear statement that all waveforms are
> solely the result of additive synthesis using sine waves.

Nobody said any such thing . How they are physically generated is
irrelevant.


> Hmm... food for thought, at least. ;-)

Nope, physical reality has little interst in ones thoughts.

Trevor.

[Trevor]

"Scott Dorsey" > wrote in message
...
> It's possible to mathematically model all possible waveforms, whether or
> not those waveforms can be made real or not. Mathematicians would argue
> this is why math is better than the real world. Physicists would argue
> the opposite for the same reasons.

So true :-)

Trevor.

[John Williamson]

On 04/06/2014 11:56, Neil Gould wrote:
> Trevor wrote:
>> "Neil Gould" > wrote in message

>>> Thanks... I understand Fourier's synthesis concepts, and know that
>>> sine waves can be used via additive synthesis to approximate other
>>> waveforms. However, due to the inherent complexity of that process,
>>> that isn't how those waveforms have typically been generated in
>>> electronic gear, so I wonder whether such generated signals are
>>> identical to analog sound events.
>>> More to the point, I've not seen a clear statement that all
>>> waveforms are solely the result of additive synthesis using sine
>>> waves.
>>
>> Nobody said any such thing . How they are physically generated is
>> irrelevant.
>>
> That may not be what you meant, but your statement that " ALL sound consists
> of sine waves" was pretty unambiguous.
>
And accurate. All repeating sound waves *can* be made by adding
sinusoidal harmonics to a sinusoidal fundamental.

This does not mean that it is the *only* way such waveforms can be
generated. FM synths use a totally different method, for instance, and a
lot of synths are subtractive, starting with all the harmonics in the
signal, and removing or reducing the ones that aren't wanted.

--
Tciao for Now!

John.

[Trevor]

"Neil Gould" > wrote in message
...
>>>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>>>> term/technique you're familiar with? If so how does it work?
>>>>>>
>>>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>>>
>>>>> So... square, triangle, and sawtooth waves (to name a few that
>>>>> can't be reconciled as sine waves) are what, if not sound? ;-)
>>>>>
>>>> Square, triangle and sawtooth waves can all be synthesised by adding
>>>> sine waves having the appropriate harmonic and phase relationships
>>>> to the base note. The more harmonics you add, the closer they get to
>>>> perfection.
>>>>
>>> Thanks... I understand Fourier's synthesis concepts, and know that
>>> sine waves can be used via additive synthesis to approximate other
>>> waveforms. However, due to the inherent complexity of that process,
>>> that isn't how those waveforms have typically been generated in
>>> electronic gear, so I wonder whether such generated signals are
>>> identical to analog sound events.
>>> More to the point, I've not seen a clear statement that all
>>> waveforms are solely the result of additive synthesis using sine
>>> waves.
>>
>> Nobody said any such thing . How they are physically generated is
>> irrelevant.
>>
> That may not be what you meant, but your statement that " ALL sound
> consists
> of sine waves" was pretty unambiguous.

Yes, and it is, regardless of how it's generated. I'm not sure what part you
don't get?
So what does "applying a sine wave to audio as some sort of mastering tweak"
actually mean to you?

Trevor.

[Sean Conolly]

"Scott Dorsey" > wrote in message
...
> Neil > wrote:
>>On 6/2/2014 4:12 PM, Scott Dorsey wrote:
>>> It's not a thing you can create in the real world.... it's a thing you
>>> can
>>> represent mathematically but from the standpoint of recording sounds
>>> from
>>> the real world, they are all going to be bandlimited in some fashion
>>> because
>>> we can't move things at infinite speeds.
>>>
>>Again, therein lies the rub, making it impossible to create an accurate
>>recording process (and is greatly complicated by reproduction processes)
>>unless the inherent imperfections are taken for granted.
>
> No, not at all. There is no need to be able to reproduce signals that
> can't
> exist as sounds.
>
> The problems all have to do with being able to reproduce signals that can.
>
>>But, if we can accept such imperfections, then one can accept that some
>>electronic instruments can easily create square and sawtooth waves,
>>though I know of none that do so by additive synthesis using sine waves.
>
> No, they can't create square or sawtooth waves. The "square wave" coming
> out
> of a synthesizer looks like a square wave on a scope if you don't look at
> it
> too hard, but the closer you look the more you'll find that it isn't a
> real
> square wave; the edges are not completely parallel because it's not
> possible
> to instantaneously change the voltage.
>
> What you get out of the synthesizer is only a rough approximation of the
> archetypical square wave. Real, perfect square waves require infinite
> bandwidth and therefore cannot exist in the real world.


Forget how it looks on the wire, how do you get air to move like that? Play
a square wave through any device you choose, and I believe the resulting
*sound* would be a lot simpler to replicate with additive synthesis from
sine waves.

Sean

[Neil Gould]

Trevor wrote:
> "Neil Gould" > wrote in message
> ...
>> John Williamson wrote:
>>> On 02/06/2014 15:32, Neil Gould wrote:
>>>> Trevor wrote:
>>>>> "docsavage20" > wrote in message
>>>>> ...
>>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>>> term/technique you're familiar with? If so how does it work?
>>>>>
>>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>>
>>>> So... square, triangle, and sawtooth waves (to name a few that
>>>> can't be reconciled as sine waves) are what, if not sound? ;-)
>>>>
>>> Square, triangle and sawtooth waves can all be synthesised by adding
>>> sine waves having the appropriate harmonic and phase relationships
>>> to the base note. The more harmonics you add, the closer they get to
>>> perfection.
>>>
>> Thanks... I understand Fourier's synthesis concepts, and know that
>> sine waves can be used via additive synthesis to approximate other
>> waveforms. However, due to the inherent complexity of that process,
>> that isn't how those waveforms have typically been generated in
>> electronic gear, so I wonder whether such generated signals are
>> identical to analog sound events.
>> More to the point, I've not seen a clear statement that all
>> waveforms are solely the result of additive synthesis using sine
>> waves.
>
> Nobody said any such thing . How they are physically generated is
> irrelevant.
>
That may not be what you meant, but your statement that " ALL sound consists
of sine waves" was pretty unambiguous.
--
best regards,

Neil

[Neil Gould]

Scott Dorsey wrote:
> Neil > wrote:
>> On 6/3/2014 11:07 AM, Scott Dorsey wrote:
>>> Neil > wrote:
>>>> On 6/2/2014 4:12 PM, Scott Dorsey wrote:
>>>>> It's not a thing you can create in the real world.... it's a
>>>>> thing you can represent mathematically but from the standpoint of
>>>>> recording sounds from the real world, they are all going to be
>>>>> bandlimited in some fashion because we can't move things at
>>>>> infinite speeds.
>>>>>
>>>> Again, therein lies the rub, making it impossible to create an
>>>> accurate recording process (and is greatly complicated by
>>>> reproduction processes) unless the inherent imperfections are
>>>> taken for granted.
>>>
>>> No, not at all. There is no need to be able to reproduce signals
>>> that can't exist as sounds.
>>>
>>> The problems all have to do with being able to reproduce signals
>>> that can.
>>>
>> I was referring to the physical limitations of mechanical and
>> electronic processes that prevent the precise reproduction of
>> signals that *are* sounds. So, it seems that we may be speaking of
>> the same thing, here.
>
> I know you were, and I am NOT talking about that at all. That is a
> different issue altogether. Go back and read what I wrote.
>
What you wrote was:
"The problems all have to do with being able to reproduce signals that can
(exist as sounds)".

How does my statement disagree with that?
--
best regards,

Neil

[Luxey]

I've heard about it along time ago. Can't say I really understood it, even if I did back then, I forgot about it, completely, until your post. It was supposed to work as some kind of bias, but was it aimed at equipment, or hearing apparatus in humans, I don't know.

Chances are,
- in order to have effect it should be strong enough
- in order not to be distract it should be above, below, or at the very edge of
hearing range
- If below, it could generate harmonics within the range. Might serve good, but probably not.
- If above, it would not have any influence, since equipment would not be able to reproduce it, and we would not be able to hear it.

in all cases, various electronic stages would filter it all out before getting to reproduction stage.

Maybe it was some early form of dither?

[William Sommerwerck]

This has to rank as one of the most useless discussions I have seen in any
UseNet group.

The OP asked an incomprehensible question about -- who knows what? -- that has
provoked a trivial and unnecessary discussion about waveform analysis and
synthesis -- to no end (in both senses of no end).

Maybe we can try to figure out how many angels can dance on the head of a pin.

[Scott Dorsey]

In article >, Trevor > wrote:
>"Neil Gould" > wrote in message
...
>> Trevor wrote:
>>> "docsavage20" > wrote in message
>>> ...
>>>> I heard someone talk about applying a sine wave to audio as some
>>>> kind of mastering tweak. I've never heard of this, is this a
>>>> term/technique you're familiar with? If so how does it work?
>>>
>>> ALL sound consists of sine waves (look up fourier analysis)
>>>
>> So... square, triangle, and sawtooth waves (to name a few that can't be
>> reconciled as sine waves) are what, if not sound? ;-)
>
>Oh yes they can. As I said, they are simply sine waves and harmonics. Do
>what I suggested and look up fourier analysis.

In the case of squares and triangles, though, they require an infinite number
of sine waves in the series.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Sean Conolly > wrote:
>>
>> What you get out of the synthesizer is only a rough approximation of the
>> archetypical square wave. Real, perfect square waves require infinite
>> bandwidth and therefore cannot exist in the real world.
>
>
>Forget how it looks on the wire, how do you get air to move like that? Play
>a square wave through any device you choose, and I believe the resulting
>*sound* would be a lot simpler to replicate with additive synthesis from
>sine waves.

Right! Actual sounds are bandlimited signals, and can be represented as a
finite series of summed sine waves.

Square waves aren't actual sounds.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[hank alrich]

Scott Dorsey > wrote:

> In article >, Trevor > wrote:
> >"Neil Gould" > wrote in message
> ...
> >> Trevor wrote:
> >>> "docsavage20" > wrote in message
> >>> ...
> >>>> I heard someone talk about applying a sine wave to audio as some
> >>>> kind of mastering tweak. I've never heard of this, is this a
> >>>> term/technique you're familiar with? If so how does it work?
> >>>
> >>> ALL sound consists of sine waves (look up fourier analysis)
> >>>
> >> So... square, triangle, and sawtooth waves (to name a few that can't be
> >> reconciled as sine waves) are what, if not sound? ;-)
> >
> >Oh yes they can. As I said, they are simply sine waves and harmonics. Do
> >what I suggested and look up fourier analysis.
>
> In the case of squares and triangles, though, they require an infinite number
> of sine waves in the series.
> --scott

This is impractical.

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

[Neil[_9_]]

On 6/4/2014 6:05 AM, John Williamson wrote:
> On 04/06/2014 11:56, Neil Gould wrote:
>> Trevor wrote:
>>> "Neil Gould" > wrote in message
>
>>>> Thanks... I understand Fourier's synthesis concepts, and know that
>>>> sine waves can be used via additive synthesis to approximate other
>>>> waveforms. However, due to the inherent complexity of that process,
>>>> that isn't how those waveforms have typically been generated in
>>>> electronic gear, so I wonder whether such generated signals are
>>>> identical to analog sound events.
>>>> More to the point, I've not seen a clear statement that all
>>>> waveforms are solely the result of additive synthesis using sine
>>>> waves.
>>>
>>> Nobody said any such thing . How they are physically generated is
>>> irrelevant.
>>>
>> That may not be what you meant, but your statement that " ALL sound
>> consists
>> of sine waves" was pretty unambiguous.
>>
> And accurate. All repeating sound waves *can* be made by adding
> sinusoidal harmonics to a sinusoidal fundamental.
>
There is more than a subtle difference between "can" and "consists of",
where the latter defines the composition of such waves, not ways to
emulate them.

> This does not mean that it is the *only* way such waveforms can be
> generated. FM synths use a totally different method, for instance, and a
> lot of synths are subtractive, starting with all the harmonics in the
> signal, and removing or reducing the ones that aren't wanted.
>
No synths that I've owned, used or even know of use sine waves to
generate the other standard waveforms that they produce.
--
best regards,
Neil

[Neil[_9_]]

On 6/4/2014 6:30 AM, Trevor wrote:
> "Neil Gould" > wrote in message
> ...
>>>>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>>>>> term/technique you're familiar with? If so how does it work?
>>>>>>>
>>>>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>>>>
>>>>>> So... square, triangle, and sawtooth waves (to name a few that
>>>>>> can't be reconciled as sine waves) are what, if not sound? ;-)
>>>>>>
>>>>> Square, triangle and sawtooth waves can all be synthesised by adding
>>>>> sine waves having the appropriate harmonic and phase relationships
>>>>> to the base note. The more harmonics you add, the closer they get to
>>>>> perfection.
>>>>>
>>>> Thanks... I understand Fourier's synthesis concepts, and know that
>>>> sine waves can be used via additive synthesis to approximate other
>>>> waveforms. However, due to the inherent complexity of that process,
>>>> that isn't how those waveforms have typically been generated in
>>>> electronic gear, so I wonder whether such generated signals are
>>>> identical to analog sound events.
>>>> More to the point, I've not seen a clear statement that all
>>>> waveforms are solely the result of additive synthesis using sine
>>>> waves.
>>>
>>> Nobody said any such thing . How they are physically generated is
>>> irrelevant.
>>>
>> That may not be what you meant, but your statement that " ALL sound
>> consists
>> of sine waves" was pretty unambiguous.
>
> Yes, and it is, regardless of how it's generated. I'm not sure what part you
> don't get?
>
The part that conflates emulation with structure.

> So what does "applying a sine wave to audio as some sort of mastering tweak"
> actually mean to you?
>
To me, it means a misconception about the process of audio mastering.
What does it mean to you?
--
best regards,
Neil

[Neil[_9_]]

On 6/4/2014 8:02 AM, Scott Dorsey wrote:
>
> Square waves aren't actual sounds.
>
The term is jargon, representing real-world waves of a certain
configuration. As such it communicates effectively and more efficiently
than saying "trapezoidal waves with angles closely approaching 90°" or
"triangle waves with radically different slopes" instead of "sawtooth",
and so forth. The inherent acceptance of the limitations of such
waveforms in the real-world does not alter the fact that they are not
generated from or comprised of sine waves. Of course, the mathematical
emulation of these waveforms using sine waves is convenient because sine
waves contain all of the angular values that other waveforms possess.
But, that construction is what is not in the real-world.

--
best regards,
Neil

[John Williamson]

On 04/06/2014 16:23, Neil wrote:
> On 6/4/2014 6:05 AM, John Williamson wrote:
>> On 04/06/2014 11:56, Neil Gould wrote:
>>> Trevor wrote:
>>>> "Neil Gould" > wrote in message
>>
>>>>> Thanks... I understand Fourier's synthesis concepts, and know that
>>>>> sine waves can be used via additive synthesis to approximate other
>>>>> waveforms. However, due to the inherent complexity of that process,
>>>>> that isn't how those waveforms have typically been generated in
>>>>> electronic gear, so I wonder whether such generated signals are
>>>>> identical to analog sound events.
>>>>> More to the point, I've not seen a clear statement that all
>>>>> waveforms are solely the result of additive synthesis using sine
>>>>> waves.
>>>>
>>>> Nobody said any such thing . How they are physically generated is
>>>> irrelevant.
>>>>
>>> That may not be what you meant, but your statement that " ALL sound
>>> consists
>>> of sine waves" was pretty unambiguous.
>>>
>> And accurate. All repeating sound waves *can* be made by adding
>> sinusoidal harmonics to a sinusoidal fundamental.
>>
> There is more than a subtle difference between "can" and "consists of",
> where the latter defines the composition of such waves, not ways to
> emulate them.
>
As you claim to understand Fourier analysis, then you know that
statement to be false at a theoretical level. If you understand Fourier
analysis, you will know that it is the process of breaking down complex
waveforms into their component frequencies.

>> This does not mean that it is the *only* way such waveforms can be
>> generated. FM synths use a totally different method, for instance, and a
>> lot of synths are subtractive, starting with all the harmonics in the
>> signal, and removing or reducing the ones that aren't wanted.
>>
> No synths that I've owned, used or even know of use sine waves to
> generate the other standard waveforms that they produce.

How about a pipe organ? They're not always perfect sine waves, but still....

http://music.columbia.edu/cmc/musicandcomputers/chapter4/04_02.php

--
Tciao for Now!

John.

[John Williamson]

On 04/06/2014 17:16, John Williamson wrote:
> On 04/06/2014 16:23, Neil wrote:
>> On 6/4/2014 6:05 AM, John Williamson wrote:
>>> On 04/06/2014 11:56, Neil Gould wrote:
>>>> Trevor wrote:
>>>>> "Neil Gould" > wrote in message
>>>
>>>>>> Thanks... I understand Fourier's synthesis concepts, and know that
>>>>>> sine waves can be used via additive synthesis to approximate other
>>>>>> waveforms. However, due to the inherent complexity of that process,
>>>>>> that isn't how those waveforms have typically been generated in
>>>>>> electronic gear, so I wonder whether such generated signals are
>>>>>> identical to analog sound events.
>>>>>> More to the point, I've not seen a clear statement that all
>>>>>> waveforms are solely the result of additive synthesis using sine
>>>>>> waves.
>>>>>
>>>>> Nobody said any such thing . How they are physically generated is
>>>>> irrelevant.
>>>>>
>>>> That may not be what you meant, but your statement that " ALL sound
>>>> consists
>>>> of sine waves" was pretty unambiguous.
>>>>
>>> And accurate. All repeating sound waves *can* be made by adding
>>> sinusoidal harmonics to a sinusoidal fundamental.
>>>
>> There is more than a subtle difference between "can" and "consists of",
>> where the latter defines the composition of such waves, not ways to
>> emulate them.
>>
> As you claim to understand Fourier analysis, then you know that
> statement to be false at a theoretical level. If you understand Fourier
> analysis, you will know that it is the process of breaking down complex
> waveforms into their component frequencies.
>
>>> This does not mean that it is the *only* way such waveforms can be
>>> generated. FM synths use a totally different method, for instance, and a
>>> lot of synths are subtractive, starting with all the harmonics in the
>>> signal, and removing or reducing the ones that aren't wanted.
>>>
>> No synths that I've owned, used or even know of use sine waves to
>> generate the other standard waveforms that they produce.
>
> How about a pipe organ? They're not always perfect sine waves, but
> still....
>
> http://music.columbia.edu/cmc/musicandcomputers/chapter4/04_02.php
>
I forgot about the Hammond tonewheel organs, too, though the sine wave
from the tonewheel isn't a pure sine wave, they uses the same principle
of mixing harmonics and sub harmonics to make different qualities of
sound. Even the Leslie speakers add a sine wave based frequency and
amplitude modulation to the sound.

--
Tciao for Now!

John.

[John Williamson]

On 04/06/2014 16:27, Neil wrote:
> On 6/4/2014 6:30 AM, Trevor wrote:
>> So what does "applying a sine wave to audio as some sort of mastering
>> tweak"
>> actually mean to you?
>>
> To me, it means a misconception about the process of audio mastering.
> What does it mean to you?

To me, without further explanation of *how* it is applied, it means
nothing, which is why we've all gone off into Fourier theory.

Is it used to modify the frequency, modulate the amplitude, or just
mixed in either at a single frequency or as a (sub) harmonic of the note
being played?

Or could you be using a very high frequency signal to perform a similar
function to tape bias, where the HF bias remains at a constant
amplitude, with the signal modifying the average deviation from 0 volts?
This *may* reduce some non-linearities in some transformers, although
most decent transformers in good circuits are pretty close to perfect.

--
Tciao for Now!

John.

[John Williamson]

On 04/06/2014 16:46, Neil wrote:
> On 6/4/2014 8:02 AM, Scott Dorsey wrote:
>>
>> Square waves aren't actual sounds.
> >
> The term is jargon, representing real-world waves of a certain
> configuration. As such it communicates effectively and more efficiently
> than saying "trapezoidal waves with angles closely approaching 90°" or
> "triangle waves with radically different slopes" instead of "sawtooth",
> and so forth. The inherent acceptance of the limitations of such
> waveforms in the real-world does not alter the fact that they are not
> generated from or comprised of sine waves. Of course, the mathematical
> emulation of these waveforms using sine waves is convenient because sine
> waves contain all of the angular values that other waveforms possess.
> But, that construction is what is not in the real-world.
>
The difference between theory and practice, then?

The theoretical version is needed to fully understand the practical system.

--
Tciao for Now!

John.

[John Williamson]

On 04/06/2014 15:42, hank alrich wrote:
> Scott Dorsey > wrote:
>
>> In article >, Trevor > wrote:
>>> "Neil Gould" > wrote in message
>>> ...
>>>> Trevor wrote:
>>>>> "docsavage20" > wrote in message
>>>>> ...
>>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>>> term/technique you're familiar with? If so how does it work?
>>>>>
>>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>>
>>>> So... square, triangle, and sawtooth waves (to name a few that can't be
>>>> reconciled as sine waves) are what, if not sound? ;-)
>>>
>>> Oh yes they can. As I said, they are simply sine waves and harmonics. Do
>>> what I suggested and look up fourier analysis.
>>
>> In the case of squares and triangles, though, they require an infinite number
>> of sine waves in the series.
>> --scott
>
> This is impractical.
>
Yes, but the more waves you combine, the closer you get. Stop when you
run out of space, oscillators or money, whichever happens first.

--
Tciao for Now!

John.

[Scott Dorsey]

Neil > wrote:
>> generated. FM synths use a totally different method, for instance, and a
>> lot of synths are subtractive, starting with all the harmonics in the
>> signal, and removing or reducing the ones that aren't wanted.
>>
>No synths that I've owned, used or even know of use sine waves to
>generate the other standard waveforms that they produce.

A pipe organ would be a good example.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[PStamler]

On Wednesday, June 4, 2014 4:30:50 AM UTC-6, Trevor wrote:

> So what does "applying a sine wave to audio as some sort of mastering tweak"
> actually mean to you?

I repeat: it sounds like the original poster has heard something incomplete about dither.

Peace,
Paul

[Neil[_9_]]

On 6/4/2014 12:42 PM, Scott Dorsey wrote:
> Neil > wrote:
>>> generated. FM synths use a totally different method, for instance, and a
>>> lot of synths are subtractive, starting with all the harmonics in the
>>> signal, and removing or reducing the ones that aren't wanted.
>>>
>> No synths that I've owned, used or even know of use sine waves to
>> generate the other standard waveforms that they produce.
>
> A pipe organ would be a good example.
> --scott
>
Well, it's a good example of an instrument that uses sine waves. But
pipe organs (and the Hammond Tonewheel that was mentioned in another
part of the thread) are not what the term "synthesizer" has referred to
in the last 50 years or so, either in concept or execution.
--
best regards,
Neil

[[email protected]]

Niel,
As an illustrative example, look up the spectral composition of a square wave that is exactly 50% duty cycle and compare it to one that is say 55%.

Mark

[[email protected]]

Niel,
As an illustrative example, look up the spectral composition of a square wave that is exactly 50% duty cycle and compare it to one that is say 55%.

Mark

[Trevor]

"Scott Dorsey" > wrote in message
...
> In article >, Trevor >
> wrote:
>>"Neil Gould" > wrote in message
...
>>> Trevor wrote:
>>>> "docsavage20" > wrote in message
>>>> ...
>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>> term/technique you're familiar with? If so how does it work?
>>>>
>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>
>>> So... square, triangle, and sawtooth waves (to name a few that can't be
>>> reconciled as sine waves) are what, if not sound? ;-)
>>
>>Oh yes they can. As I said, they are simply sine waves and harmonics. Do
>>what I suggested and look up fourier analysis.
>
> In the case of squares and triangles, though, they require an infinite
> number
> of sine waves in the series.

For a theoretically *perfect* waveform, sure. However what people are happy
to call square, triangle, sawtooth etc. are NEVER perfect, but often good
enough for their purpose. This is easily the case in audio since you can
generate harmonics into the GHz region *if* you really wanted to! :-)

Trevor.

[Trevor]

"Neil" > wrote in message
...
> On 6/4/2014 12:42 PM, Scott Dorsey wrote:
>> Neil > wrote:
>>>> generated. FM synths use a totally different method, for instance, and
>>>> a
>>>> lot of synths are subtractive, starting with all the harmonics in the
>>>> signal, and removing or reducing the ones that aren't wanted.
>>>>
>>> No synths that I've owned, used or even know of use sine waves to
>>> generate the other standard waveforms that they produce.
>>
>> A pipe organ would be a good example.
>>
> Well, it's a good example of an instrument that uses sine waves. But pipe
> organs (and the Hammond Tonewheel that was mentioned in another part of
> the thread) are not what the term "synthesizer" has referred to in the
> last 50 years or so, either in concept or execution.

And the original question had *nothing* to do with synths, so no need to
restrict the discussion to them.

Trevor.

[Trevor]

"Neil" > wrote in message
...
> On 6/4/2014 6:30 AM, Trevor wrote:
>> "Neil Gould" > wrote in message
>> ...
>>>>>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>>>>>> term/technique you're familiar with? If so how does it work?
>>>>>>>>
>>>>>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>>>>>
>>>>>>> So... square, triangle, and sawtooth waves (to name a few that
>>>>>>> can't be reconciled as sine waves) are what, if not sound? ;-)
>>>>>>>
>>>>>> Square, triangle and sawtooth waves can all be synthesised by adding
>>>>>> sine waves having the appropriate harmonic and phase relationships
>>>>>> to the base note. The more harmonics you add, the closer they get to
>>>>>> perfection.
>>>>>>
>>>>> Thanks... I understand Fourier's synthesis concepts, and know that
>>>>> sine waves can be used via additive synthesis to approximate other
>>>>> waveforms. However, due to the inherent complexity of that process,
>>>>> that isn't how those waveforms have typically been generated in
>>>>> electronic gear, so I wonder whether such generated signals are
>>>>> identical to analog sound events.
>>>>> More to the point, I've not seen a clear statement that all
>>>>> waveforms are solely the result of additive synthesis using sine
>>>>> waves.
>>>>
>>>> Nobody said any such thing . How they are physically generated is
>>>> irrelevant.
>>>>
>>> That may not be what you meant, but your statement that " ALL sound
>>> consists
>>> of sine waves" was pretty unambiguous.
>>
>> Yes, and it is, regardless of how it's generated. I'm not sure what part
>> you
>> don't get?
> >
> The part that conflates emulation with structure.

What has either got to do with the original question to which my reply is
still correct?


>> So what does "applying a sine wave to audio as some sort of mastering
>> tweak"
>> actually mean to you?
>>
> To me, it means a misconception about the process of audio mastering. What
> does it mean to you?

Same, as I correctly pointed out already. So why the argument?

Trevor.

[geoff]

On 4/06/2014 11:57 p.m., Scott Dorsey wrote:
> In article >, Trevor > wrote:

>
> In the case of squares and triangles, though, they require an infinite number
> of sine waves in the series.
> --scott
>

Only for 'perfect' ones.


geoff

[geoff]

On 5/06/2014 3:23 a.m., Neil wrote:

> No synths that I've owned, used or even know of use sine waves to
> generate the other standard waveforms that they produce.

And ?

geoff

[Neil Gould]

John Williamson wrote:
> On 04/06/2014 16:46, Neil wrote:
>> On 6/4/2014 8:02 AM, Scott Dorsey wrote:
>>>
>>> Square waves aren't actual sounds.
>> >
>> The term is jargon, representing real-world waves of a certain
>> configuration. As such it communicates effectively and more
>> efficiently than saying "trapezoidal waves with angles closely
>> approaching 90°" or "triangle waves with radically different slopes"
>> instead of "sawtooth", and so forth. The inherent acceptance of the
>> limitations of such waveforms in the real-world does not alter the
>> fact that they are not generated from or comprised of sine waves. Of
>> course, the mathematical emulation of these waveforms using sine
>> waves is convenient because sine waves contain all of the angular
>> values that other waveforms possess. But, that construction is what
>> is not in the real-world.
>>
> The difference between theory and practice, then?
>
> The theoretical version is needed to fully understand the practical
> system.
>
Agreed.
--
best regards,

Neil

[Neil Gould]

Trevor wrote:
> "Neil" > wrote in message
> ...
>> On 6/4/2014 6:30 AM, Trevor wrote:
>>> "Neil Gould" > wrote in message
>>> ...
>>>>>>>>>> I heard someone talk about applying a sine wave to audio as
>>>>>>>>>> some kind of mastering tweak. I've never heard of this, is
>>>>>>>>>> this a term/technique you're familiar with? If so how does
>>>>>>>>>> it work?
>>>>>>>>>
>>>>>>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>>>>>>
>>>>>>>> So... square, triangle, and sawtooth waves (to name a few that
>>>>>>>> can't be reconciled as sine waves) are what, if not sound?
>>>>>>>> ;-)
>>>>>>>>
>>>>>>> Square, triangle and sawtooth waves can all be synthesised by
>>>>>>> adding sine waves having the appropriate harmonic and phase
>>>>>>> relationships to the base note. The more harmonics you add, the
>>>>>>> closer they get to perfection.
>>>>>>>
>>>>>> Thanks... I understand Fourier's synthesis concepts, and know
>>>>>> that sine waves can be used via additive synthesis to
>>>>>> approximate other waveforms. However, due to the inherent
>>>>>> complexity of that process, that isn't how those waveforms have
>>>>>> typically been generated in electronic gear, so I wonder whether
>>>>>> such generated signals are identical to analog sound events.
>>>>>> More to the point, I've not seen a clear statement that all
>>>>>> waveforms are solely the result of additive synthesis using sine
>>>>>> waves.
>>>>>
>>>>> Nobody said any such thing . How they are physically generated is
>>>>> irrelevant.
>>>>>
>>>> That may not be what you meant, but your statement that " ALL sound
>>>> consists
>>>> of sine waves" was pretty unambiguous.
>>>
>>> Yes, and it is, regardless of how it's generated. I'm not sure what
>>> part you
>>> don't get?
>>>
>> The part that conflates emulation with structure.
>
> What has either got to do with the original question to which my
> reply is still correct?
>
It has nothing to do with the OP's question. It has only to do with the
construction of sound waves.

>>> So what does "applying a sine wave to audio as some sort of
>>> mastering tweak"
>>> actually mean to you?
>>>
>> To me, it means a misconception about the process of audio
>> mastering. What does it mean to you?
>
> Same, as I correctly pointed out already. So why the argument?
>
I wasn't arguing your comment about the OP's question. Sorry if that is the
impression you got from my raising questions about the construction of
waveforms.
--
best regards,

Neil

[Neil Gould]

Mrak,

wrote:
> Niel,
> As an illustrative example, look up the spectral composition of a
> square wave that is exactly 50% duty cycle and compare it to one that
> is say 55%.
>
> Mark
>
I've owned, built and used synthesizers since the mid 1960s, and studied
electronic music in college. I really don't require an elementary
introduction to waveform composition at this point. ;-)
--
best regards,

Neil

[Neil Gould]

geoff wrote:
> On 5/06/2014 3:23 a.m., Neil wrote:
>
>> No synths that I've owned, used or even know of use sine waves to
>> generate the other standard waveforms that they produce.
>
> And ?
>
Eh?
--
best regards,

Neil

[Scott Dorsey]

> wrote:
>Niel,
>As an illustrative example, look up the spectral composition of a square wave that is exactly 50% duty cycle and compare it to one that is say 55%.

If the duty cycle isn't 50%, it's not a square wave, it's a pulse train.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

On Thursday, June 5, 2014 6:55:48 AM UTC-4, Neil Gould wrote:
> Mrak,
>
>
>
> wrote:
>
> > Niel,
>
> > As an illustrative example, look up the spectral composition of a
>
> > square wave that is exactly 50% duty cycle and compare it to one that
>
> > is say 55%.
>
> >
>
> > Mark
>
> >
>
> I've owned, built and used synthesizers since the mid 1960s, and studied
>
> electronic music in college. I really don't require an elementary
>
> introduction to waveform composition at this point. ;-)
>
> --
>
> best regards,
>
>
>
> Neil

You seem to think that just because a waveform was not COMPOSED by using sine wave methods that it can't be DECOMPOSED that way.

A waveform is a waveform and it doesn't matter what method was used to create it.

Any waveform can ALWAYS be decomposed into sine waves.

have a nice day

Mark

[Neil Gould]

wrote:
> On Thursday, June 5, 2014 6:55:48 AM UTC-4, Neil Gould wrote:
>> Mrak,
>>
>> wrote:
>>
>>> Niel,
>>
>>> As an illustrative example, look up the spectral composition of a
>>
>>> square wave that is exactly 50% duty cycle and compare it to one
>>> that
>>
>>> is say 55%.
>>
>>>
>>
>>> Mark
>>
>>>
>>
>> I've owned, built and used synthesizers since the mid 1960s, and
>> studied electronic music in college. I really don't require an elementary
>> introduction to waveform composition at this point. ;-)
>
> You seem to think that just because a waveform was not COMPOSED by
> using sine wave methods that it can't be DECOMPOSED that way.
>
From a theoretical POV, I don't think that at all.

> A waveform is a waveform and it doesn't matter what method was used
> to create it.
>
If we're talking about the real world, the practical options are rather
limited. So, we can just disagree.
--
best regards,

Neil

[Les Cargill[_4_]]

Scott Dorsey wrote:
> In article >, Trevor > wrote:
>> "Neil Gould" > wrote in message
>> ...
>>> Trevor wrote:
>>>> "docsavage20" > wrote in message
>>>> ...
>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>> kind of mastering tweak. I've never heard of this, is this a
>>>>> term/technique you're familiar with? If so how does it work?
>>>>
>>>> ALL sound consists of sine waves (look up fourier analysis)
>>>>
>>> So... square, triangle, and sawtooth waves (to name a few that can't be
>>> reconciled as sine waves) are what, if not sound? ;-)
>>
>> Oh yes they can. As I said, they are simply sine waves and harmonics. Do
>> what I suggested and look up fourier analysis.
>
> In the case of squares and triangles, though, they require an infinite number
> of sine waves in the series.
> --scott
>

That's okay. Our ears are bandwidth-constrained.

--
Les Cargill

[Scott Dorsey]

Les Cargill > wrote:
>Scott Dorsey wrote:
>>
>> In the case of squares and triangles, though, they require an infinite number
>> of sine waves in the series.
>>
>
>That's okay. Our ears are bandwidth-constrained.

Thank God! If we had response down to 0 Hz, there could be quarter notes
that would take an infinite amount of time to listen to.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Hank]

In article >,
William Sommerwerck > wrote:
>This has to rank as one of the most useless discussions I have seen in any
>UseNet group.
>
>The OP asked an incomprehensible question about -- who knows what? -- that has
>provoked a trivial and unnecessary discussion about waveform analysis and
>synthesis -- to no end (in both senses of no end).
>
>Maybe we can try to figure out how many angels can dance on the head of a pin.
>
Stick around, sonny, and you might actually learn something, whether
you consider it useful to you or not.

[Hank]

In article >,
Scott Dorsey > wrote:
>Neil > wrote:
>>> generated. FM synths use a totally different method, for instance, and a
>>> lot of synths are subtractive, starting with all the harmonics in the
>>> signal, and removing or reducing the ones that aren't wanted.
>>>
>>No synths that I've owned, used or even know of use sine waves to
>>generate the other standard waveforms that they produce.
>
>A pipe organ would be a good example.
>--scott
>
Yes. I'm surprised at some of this discussion, all things considered.
Any of the traditional musical instruments produces sounds that have
fundamentals and overtones. The difference in sound coming out of a
trumpet, an oboe, and a violin isn't in the fundamental frequency of
the oscillator (lip-reed, wood-reed, string) but in the higher-than
fundamental frequency content. Harry Olson discussed this in "Musical
Engineering," and that can be viewed as an extrapolation of things in
Helmholtz's "On the Sensations of Tone."

Rodgers Jenkins spent a good deal of time trying to generate organ
pipe sound from analog oscillators ca. 1960, and was fairly
successful. But there were at least two problems: one, that pipes
were cheaper, and two, the radiating area of loudspeakers pales
compared to that of a 16' organ pipe. Olson's discussion, and
Jenkins' work can be summed up as "finding the terms in a Fourier
series that lie on a musical scale" in terms of frequency and
amplitude, and generating them electronically. And, additionally,
keep in mind that pipe organs have mutant ranks and mixtures to
enhance sound at frequencies other than the fundamental.

In terms of audio, we're talking about a fairly narrow range of
frequencies. Use 20Hz to 20Khz as boundaries. That's quite narrow
compared to RF, where we may want to have an amplifier that passes
from near-DC to 100Mhz with near-flat frequency response as well as
constant delay for all frequencies. That's an oscilloscope vertical
amplifier from ca. 1960. Using a square wave as input to the
amplifier is a way to feed it most of the signal information needed to
characterize its performance. A mercury-wetted reed relay used as a
switch does the job adequately for this range. Inclusion of all the
terms in a Fourier series isn't needed; just "enough" to cover the
frequencies involved.

I still remember the relation: bandwith * risetime = .35. Risetime is
measured as 10-90% of the step.

And then there's the principle of operation behind the class C
oscillator and amplifier, where one uses a pulse signal to drive a
tank circuit. Purpose of the tank circuit is to filter out unwanted
terms in the Fourier series contained in the pulse. Just an
electronic version of a schoolgirl's skip rope, where a pulse input
can maintain the energy needed to rotate the rope.

Back to audio: the tonewheel Hammond Organ and its drawbars used the
drawbars to generate a fundamental and overtones that were
(theoretically, at least), terms in a Fourier series and on a musical
scale. We won't get into things like equal temperament tuning vs.
just tuning of intervals.

Hank

[hank alrich]

Scott Dorsey > wrote:

> Les Cargill > wrote:
> >Scott Dorsey wrote:
> >>
> >> In the case of squares and triangles, though, they require an infinite
> >> number of sine waves in the series.
> >>
> >
> >That's okay. Our ears are bandwidth-constrained.
>
> Thank God! If we had response down to 0 Hz, there could be quarter notes
> that would take an infinite amount of time to listen to. --scott

Well, are you into the music, or not??

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

[Sean Conolly]

"Scott Dorsey" > wrote in message
...
> Les Cargill > wrote:
>>Scott Dorsey wrote:
>>>
>>> In the case of squares and triangles, though, they require an infinite
>>> number
>>> of sine waves in the series.
>>>
>>
>>That's okay. Our ears are bandwidth-constrained.
>
> Thank God! If we had response down to 0 Hz, there could be quarter notes
> that would take an infinite amount of time to listen to.

Hmm, I've heard a few notes that seemed to border on infinity. Like the
singer hanging on to that note they can't quite hit...

Sean

[Les Cargill[_4_]]

Scott Dorsey wrote:
> Les Cargill > wrote:
>> Scott Dorsey wrote:
>>>
>>> In the case of squares and triangles, though, they require an infinite number
>>> of sine waves in the series.
>>>
>>
>> That's okay. Our ears are bandwidth-constrained.
>
> Thank God! If we had response down to 0 Hz, there could be quarter notes
> that would take an infinite amount of time to listen to.
> --scott
>

But there'd probably be a lot less bebop.

It's a trade.

--
Les Cargill

[hank alrich]

Les Cargill > wrote:

> Scott Dorsey wrote:
> > Les Cargill > wrote:
> >> Scott Dorsey wrote:
> >>>
> >>> In the case of squares and triangles, though, they require an infinite
> >>> number of sine waves in the series.
> >>>
> >>
> >> That's okay. Our ears are bandwidth-constrained.
> >
> > Thank God! If we had response down to 0 Hz, there could be quarter
> > notes that would take an infinite amount of time to listen to. --scott
> >
>
> But there'd probably be a lot less bebop.
>
> It's a trade.

Funny! Thank, Les.

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

[Trevor]

"Neil Gould" > wrote in message
...
> geoff wrote:
>> On 5/06/2014 3:23 a.m., Neil wrote:
>>> No synths that I've owned, used or even know of use sine waves to
>>> generate the other standard waveforms that they produce.
>>
>> And ?
>>
> Eh?

He means, SO WHAT?

Trevor.

[Don Pearce[_3_]]

On Sun, 8 Jun 2014 08:50:56 -0500, "Neil Gould"
> wrote:

>docsavage20 wrote:
>> I heard someone talk about applying a sine wave to audio as some kind
>> of mastering tweak. I've never heard of this, is this a
>> term/technique you're familiar with? If so how does it work?
>>
>The closest thing that I can come up with is the use of a sine wave sweep to
>sample the acoustics of an environment to create an impuse response (IR)
>reverb image of that environment. That result is applied as a convolution
>"map" in an IR utility, rather than as a sine wave applied directly to the
>audio. Such utilities are included with some DAWs, and/or are available as
>stand-alone plug-ins, and the logical time to use it would be during final
>mixing or mastering.

Huh? You create an impulse response with an impulse - something like
an old fashioned kids' cap gun. Or if you want better accuracy, a loud
electric spark discharge.

d

[Neil Gould]

docsavage20 wrote:
> I heard someone talk about applying a sine wave to audio as some kind
> of mastering tweak. I've never heard of this, is this a
> term/technique you're familiar with? If so how does it work?
>
The closest thing that I can come up with is the use of a sine wave sweep to
sample the acoustics of an environment to create an impuse response (IR)
reverb image of that environment. That result is applied as a convolution
"map" in an IR utility, rather than as a sine wave applied directly to the
audio. Such utilities are included with some DAWs, and/or are available as
stand-alone plug-ins, and the logical time to use it would be during final
mixing or mastering.
--
best regards,

Neil

[Richard Dobson]

On 08/06/2014 14:16, Don Pearce wrote:
> On Sun, 8 Jun 2014 08:50:56 -0500, "Neil Gould"
...
>> The closest thing that I can come up with is the use of a sine wave sweep to
>> sample the acoustics of an environment to create an impuse response (IR)
>> reverb image of that environment. That result is applied as a convolution
>> "map" in an IR utility, rather than as a sine wave applied directly to the
>> audio. Such utilities are included with some DAWs, and/or are available as
>> stand-alone plug-ins, and the logical time to use it would be during final
>> mixing or mastering.
>
> Huh? You create an impulse response with an impulse - something like
> an old fashioned kids' cap gun. Or if you want better accuracy, a loud
> electric spark discharge.
>

Not if you want best quality and low noise. Swept sine (with
deconvolution) is indeed the recommended technique these days "if you
know how". See here:

http://aurora-plugins.forumfree.it/?t=53443032

or here:

http://cnx.org/content/m15945/latest/


Richard Dobson

[david gourley[_2_]]

docsavage20 > said...news:6c44c547-7df0-41da-b029-
:

> I heard someone talk about applying a sine wave to audio as some kind of
mastering tweak. I've never heard of this, is this a term/technique you're
familiar with? If so how does it work?
>
> Thanks.


Not sure about the mastering, but I've known people that would gate a low-
frequency sine wave to augment the kick drum.

david

[None]

"Don Pearce" > wrote in message
...
> On Sun, 8 Jun 2014 08:50:56 -0500, "Neil Gould"
> > wrote:
>
>>docsavage20 wrote:
>>> I heard someone talk about applying a sine wave to audio as some
>>> kind
>>> of mastering tweak. I've never heard of this, is this a
>>> term/technique you're familiar with? If so how does it work?
>>>
>>The closest thing that I can come up with is the use of a sine wave
>>sweep to
>>sample the acoustics of an environment to create an impuse response
>>(IR)
>>reverb image of that environment. That result is applied as a
>>convolution
>>"map" in an IR utility, rather than as a sine wave applied directly
>>to the
>>audio. Such utilities are included with some DAWs, and/or are
>>available as
>>stand-alone plug-ins, and the logical time to use it would be during
>>final
>>mixing or mastering.
>
> Huh? You create an impulse response with an impulse - something like
> an old fashioned kids' cap gun. Or if you want better accuracy, a
> loud
> electric spark discharge.

Of if you want even better accuracy, use a swept sine wave to measure
the frequency response, and then use an FFT to derive the impulse
response. That's the way we usually do it around here. I don't know
anyone who uses a spark to measure rooms any more. It's even falling
out of favor for measuring microphones.

[Don Pearce[_3_]]

On Sun, 8 Jun 2014 12:54:48 -0400, "None" > wrote:

>"Don Pearce" > wrote in message
...
>> On Sun, 8 Jun 2014 08:50:56 -0500, "Neil Gould"
>> > wrote:
>>
>>>docsavage20 wrote:
>>>> I heard someone talk about applying a sine wave to audio as some
>>>> kind
>>>> of mastering tweak. I've never heard of this, is this a
>>>> term/technique you're familiar with? If so how does it work?
>>>>
>>>The closest thing that I can come up with is the use of a sine wave
>>>sweep to
>>>sample the acoustics of an environment to create an impuse response
>>>(IR)
>>>reverb image of that environment. That result is applied as a
>>>convolution
>>>"map" in an IR utility, rather than as a sine wave applied directly
>>>to the
>>>audio. Such utilities are included with some DAWs, and/or are
>>>available as
>>>stand-alone plug-ins, and the logical time to use it would be during
>>>final
>>>mixing or mastering.
>>
>> Huh? You create an impulse response with an impulse - something like
>> an old fashioned kids' cap gun. Or if you want better accuracy, a
>> loud
>> electric spark discharge.
>
>Of if you want even better accuracy, use a swept sine wave to measure
>the frequency response, and then use an FFT to derive the impulse
>response. That's the way we usually do it around here. I don't know
>anyone who uses a spark to measure rooms any more. It's even falling
>out of favor for measuring microphones.
>
>
The problem with the swept sine method is that you need a transducer
to generate it, and that transducer has its own response. I know it is
a convenient method and doesn't make startling bangs, but it does have
these limitations not possessed by the normal impulse method. A spark
discharge has a guaranteed spectrum in the audio band.

d

[None]

"Don Pearce" > wrote in message
...
> On Sun, 8 Jun 2014 12:54:48 -0400, "None" > wrote:
>
>>"Don Pearce" > wrote in message
...
>>> On Sun, 8 Jun 2014 08:50:56 -0500, "Neil Gould"
>>> > wrote:
>>>
>>>>docsavage20 wrote:
>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>> kind
>>>>> of mastering tweak. I've never heard of this, is this a
>>>>> term/technique you're familiar with? If so how does it work?
>>>>>
>>>>The closest thing that I can come up with is the use of a sine
>>>>wave
>>>>sweep to
>>>>sample the acoustics of an environment to create an impuse
>>>>response
>>>>(IR)
>>>>reverb image of that environment. That result is applied as a
>>>>convolution
>>>>"map" in an IR utility, rather than as a sine wave applied
>>>>directly
>>>>to the
>>>>audio. Such utilities are included with some DAWs, and/or are
>>>>available as
>>>>stand-alone plug-ins, and the logical time to use it would be
>>>>during
>>>>final
>>>>mixing or mastering.
>>>
>>> Huh? You create an impulse response with an impulse - something
>>> like
>>> an old fashioned kids' cap gun. Or if you want better accuracy, a
>>> loud
>>> electric spark discharge.
>>
>>Of if you want even better accuracy, use a swept sine wave to
>>measure
>>the frequency response, and then use an FFT to derive the impulse
>>response. That's the way we usually do it around here. I don't know
>>anyone who uses a spark to measure rooms any more. It's even falling
>>out of favor for measuring microphones.
>>
>>
> The problem with the swept sine method is that you need a transducer
> to generate it, and that transducer has its own response. I know it
> is
> a convenient method and doesn't make startling bangs, but it does
> have
> these limitations not possessed by the normal impulse method. A
> spark
> discharge has a guaranteed spectrum in the audio band.

A spark is nowhere near as perfect as all that. There is no such
guarantee.

Some of the problems with the speaker method can be mitigated. For
instance, we take a nearfield measurement of the speaker
simultaneously, which can be used to calculate a transfer function
rather than a spectrum, or to be used as a correction to the spectrum.
The very short duration of a spark means there is very little radiated
acoustic energy, especially when long acquisition times are used for
large rooms. You get much better S/N with a swept sine. No practicable
method is perfect.

[Scott Dorsey]

None > wrote:
>>
>> Huh? You create an impulse response with an impulse - something like
>> an old fashioned kids' cap gun. Or if you want better accuracy, a
>> loud
>> electric spark discharge.
>
>Of if you want even better accuracy, use a swept sine wave to measure
>the frequency response, and then use an FFT to derive the impulse
>response. That's the way we usually do it around here. I don't know
>anyone who uses a spark to measure rooms any more. It's even falling
>out of favor for measuring microphones.

The problem with swept sine method is that you now need a perfectly
omnidirectional and perfectly flat response sine wave source.

The problem with the impulse excitation method is that you need a
perfectly omnidirectional and perfectly shaped impulse.

I tend to be a fan of the impulse source method myself, although these
days a lot of people are using MLS stuff as a third method.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Neil[_9_]]

On 6/8/2014 1:44 PM, Don Pearce wrote:
> On Sun, 8 Jun 2014 12:54:48 -0400, "None" > wrote:
>
>> "Don Pearce" > wrote in message
>> ...
>>> On Sun, 8 Jun 2014 08:50:56 -0500, "Neil Gould"
>>> > wrote:
>>>
>>>> docsavage20 wrote:
>>>>> I heard someone talk about applying a sine wave to audio as some
>>>>> kind
>>>>> of mastering tweak. I've never heard of this, is this a
>>>>> term/technique you're familiar with? If so how does it work?
>>>>>
>>>> The closest thing that I can come up with is the use of a sine wave
>>>> sweep to
>>>> sample the acoustics of an environment to create an impuse response
>>>> (IR)
>>>> reverb image of that environment. That result is applied as a
>>>> convolution
>>>> "map" in an IR utility, rather than as a sine wave applied directly
>>>> to the
>>>> audio. Such utilities are included with some DAWs, and/or are
>>>> available as
>>>> stand-alone plug-ins, and the logical time to use it would be during
>>>> final
>>>> mixing or mastering.
>>>
>>> Huh? You create an impulse response with an impulse - something like
>>> an old fashioned kids' cap gun. Or if you want better accuracy, a
>>> loud
>>> electric spark discharge.
>>
>> Of if you want even better accuracy, use a swept sine wave to measure
>> the frequency response, and then use an FFT to derive the impulse
>> response. That's the way we usually do it around here. I don't know
>> anyone who uses a spark to measure rooms any more. It's even falling
>> out of favor for measuring microphones.
>>
>>
> The problem with the swept sine method is that you need a transducer
> to generate it, and that transducer has its own response. I know it is
> a convenient method and doesn't make startling bangs, but it does have
> these limitations not possessed by the normal impulse method. A spark
> discharge has a guaranteed spectrum in the audio band.
>
There benefits and limitations correlated with any method. As I see it,
the issue is not so much the fact that such imperfections exist, but how
to best work with the results. In the bigger picture, they typically
won't be the weakest spot in a production.
--
best regards,
Neil

[William Sommerwerck]

"Scott Dorsey" wrote in message ...

> The problem with swept sine method is that you now need a perfectly
> omnidirectional and perfectly flat response sine wave source.
> The problem with the impulse excitation method is that you need
> a perfectly omnidirectional and perfectly shaped impulse.

Actually, the real problem is that the impulse response is necessarily
different from each instrument or performer. What arrives at the mic is a
summation of these different responses. This means that the deconvolution will
necessary be an approximation.

[Scott Dorsey]

William Sommerwerck > wrote:
>"Scott Dorsey" wrote in message ...
>
>> The problem with swept sine method is that you now need a perfectly
>> omnidirectional and perfectly flat response sine wave source.
>> The problem with the impulse excitation method is that you need
>> a perfectly omnidirectional and perfectly shaped impulse.
>
>Actually, the real problem is that the impulse response is necessarily
>different from each instrument or performer. What arrives at the mic is a
>summation of these different responses. This means that the deconvolution will
>necessary be an approximation.

That's a different problem and it's the same no matter WHAT method you use
to record it.

In addition, of course, there are plenty of things you will want to use the
impulse response for directly that have nothing to do with deconvolution.
You might, for instance, want to use it looking for flutter echoes or
spurious room reflections or other acoustical analysis.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[William Sommerwerck]

"Scott Dorsey" wrote in message ...
William Sommerwerck > wrote:
>"Scott Dorsey" wrote in message ...

>>> The problem with the swept-sine method is that you now need
>>> a perfectly omnidirectional and perfectly flat response sine wave
>>> source. The problem with the impulse excitation method is that
>>> you need a perfectly omnidirectional and perfectly shaped impulse.

>> Actually, the real problem is that the impulse response is necessarily
>> different from each instrument or performer. What arrives at the mic
>> is a summation of these different responses. This means that the
>> deconvolution will necessarily be an approximation.

> That's a different problem and it's the same no matter WHAT
> method you use to record it.

My point is that it's more-significant than the technique you use to
measure/compute the impulse response.

[Scott Dorsey]

William Sommerwerck > wrote:
>"Scott Dorsey" wrote in message ...
>William Sommerwerck > wrote:
>>"Scott Dorsey" wrote in message ...
>
>>>> The problem with the swept-sine method is that you now need
>>>> a perfectly omnidirectional and perfectly flat response sine wave
>>>> source. The problem with the impulse excitation method is that
>>>> you need a perfectly omnidirectional and perfectly shaped impulse.
>
>>> Actually, the real problem is that the impulse response is necessarily
>>> different from each instrument or performer. What arrives at the mic
>>> is a summation of these different responses. This means that the
>>> deconvolution will necessarily be an approximation.
>
>> That's a different problem and it's the same no matter WHAT
>> method you use to record it.
>
>My point is that it's more-significant than the technique you use to
>measure/compute the impulse response.

If in fact you're using it to generate artificial room reverb, then this is
the case. But if you're using the impulse for distance measurement purposes,
for instance, it might not be.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."