(Stewart Pinkerton) wrote in message ...
On 19 Jan 2004 00:49:24 -0800, (Svante)
wrote:

Still, IMO, the SPL is derived from the SIL, not the other way around,
since the Bel is fundamentally a power ratio measure.

NO, it was *not* originally a power ratio measure. *Fundamentally*, it
is a measure of the difference in sound pressures which we perceive as
a doubling of loudness.

Ok, I cannot give the reference to the original or fundamental
definition of the dB, and unless you can, we should settle with that
we think differently.

Hi,

In message , Svante
writes
(Stewart Pinkerton) wrote in message
...
On 19 Jan 2004 00:49:24 -0800, (Svante)
wrote:

Still, IMO, the SPL is derived from the SIL, not the other way around,
since the Bel is fundamentally a power ratio measure.

NO, it was *not* originally a power ratio measure. *Fundamentally*, it
is a measure of the difference in sound pressures which we perceive as
a doubling of loudness.

Ok, I cannot give the reference to the original or fundamental
definition of the dB, and unless you can, we should settle with that
we think differently.

The nearest I can get to an 'origin' (I use the term loosely) is this,
paraphrased from www.sizes.com...

The Bel was originally called the Transmission Unit (a power ratio), and
later renamed for Alexander Graham Bell, then later reformulated as the
decibel due to its cumbersome size. In 1937 it was adopted as an
international unit (at the first International Acoustical Conference, in
Paris) for scales of energy and pressure.

With that mixture of 'power ratio', 'energy' and 'pressure' references
in the description, I'm none the wiser. Maybe the Bel described power
ratios, while the decibel, after the renaming, described pressure
ratios?
--
Regards,
Glenn Booth

Hi,

In message , Svante
writes
(Stewart Pinkerton) wrote in message
...
On 19 Jan 2004 00:49:24 -0800, (Svante)
wrote:

Still, IMO, the SPL is derived from the SIL, not the other way around,
since the Bel is fundamentally a power ratio measure.

NO, it was *not* originally a power ratio measure. *Fundamentally*, it
is a measure of the difference in sound pressures which we perceive as
a doubling of loudness.

Ok, I cannot give the reference to the original or fundamental
definition of the dB, and unless you can, we should settle with that
we think differently.

The nearest I can get to an 'origin' (I use the term loosely) is this,
paraphrased from www.sizes.com...

The Bel was originally called the Transmission Unit (a power ratio), and
later renamed for Alexander Graham Bell, then later reformulated as the
decibel due to its cumbersome size. In 1937 it was adopted as an
international unit (at the first International Acoustical Conference, in
Paris) for scales of energy and pressure.

With that mixture of 'power ratio', 'energy' and 'pressure' references
in the description, I'm none the wiser. Maybe the Bel described power
ratios, while the decibel, after the renaming, described pressure
ratios?
--
Regards,
Glenn Booth

Hi,

In message , Svante
writes
(Stewart Pinkerton) wrote in message
...
On 19 Jan 2004 00:49:24 -0800, (Svante)
wrote:

Still, IMO, the SPL is derived from the SIL, not the other way around,
since the Bel is fundamentally a power ratio measure.

NO, it was *not* originally a power ratio measure. *Fundamentally*, it
is a measure of the difference in sound pressures which we perceive as
a doubling of loudness.

Ok, I cannot give the reference to the original or fundamental
definition of the dB, and unless you can, we should settle with that
we think differently.

The nearest I can get to an 'origin' (I use the term loosely) is this,
paraphrased from www.sizes.com...

The Bel was originally called the Transmission Unit (a power ratio), and
later renamed for Alexander Graham Bell, then later reformulated as the
decibel due to its cumbersome size. In 1937 it was adopted as an
international unit (at the first International Acoustical Conference, in
Paris) for scales of energy and pressure.

With that mixture of 'power ratio', 'energy' and 'pressure' references
in the description, I'm none the wiser. Maybe the Bel described power
ratios, while the decibel, after the renaming, described pressure
ratios?
--
Regards,
Glenn Booth

Hi,

In message , Svante
writes
(Stewart Pinkerton) wrote in message
...
On 19 Jan 2004 00:49:24 -0800, (Svante)
wrote:

Still, IMO, the SPL is derived from the SIL, not the other way around,
since the Bel is fundamentally a power ratio measure.

NO, it was *not* originally a power ratio measure. *Fundamentally*, it
is a measure of the difference in sound pressures which we perceive as
a doubling of loudness.

Ok, I cannot give the reference to the original or fundamental
definition of the dB, and unless you can, we should settle with that
we think differently.

The nearest I can get to an 'origin' (I use the term loosely) is this,
paraphrased from www.sizes.com...

The Bel was originally called the Transmission Unit (a power ratio), and
later renamed for Alexander Graham Bell, then later reformulated as the
decibel due to its cumbersome size. In 1937 it was adopted as an
international unit (at the first International Acoustical Conference, in
Paris) for scales of energy and pressure.

With that mixture of 'power ratio', 'energy' and 'pressure' references
in the description, I'm none the wiser. Maybe the Bel described power
ratios, while the decibel, after the renaming, described pressure
ratios?
--
Regards,
Glenn Booth

(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

Bob Stanton

(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

Bob Stanton

(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

Bob Stanton

(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

Bob Stanton

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

TonyP.

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

TonyP.

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

TonyP.

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

TonyP.

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

(Bob-Stanton) wrote in message . com...
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

Bob Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

(Bob-Stanton) wrote in message . com...
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

Bob Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

(Bob-Stanton) wrote in message . com...
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

Bob Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

(Bob-Stanton) wrote in message . com...
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

Bob Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

On Tue, 20 Jan 2004 08:01:45 +0000 (UTC), (Stewart
Pinkerton) wrote:

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.

---
What does religion have to do with it?^)

--
John Fields

On Tue, 20 Jan 2004 08:01:45 +0000 (UTC), (Stewart
Pinkerton) wrote:

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.

---
What does religion have to do with it?^)

--
John Fields

On Tue, 20 Jan 2004 08:01:45 +0000 (UTC), (Stewart
Pinkerton) wrote:

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.

---
What does religion have to do with it?^)

--
John Fields

On Tue, 20 Jan 2004 08:01:45 +0000 (UTC), (Stewart
Pinkerton) wrote:

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.

---
What does religion have to do with it?^)

--
John Fields

(Svante) wrote in message

Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

Makers of RF amplifiers, and fiber optic equipment. All makers of CATV
and fiber optic equipment specify broadband distortion in -dB (power).
Companys like: General Instrument, Scientific Atlanta, C-Cor, and
Philips(Magnavox).

As a matter of fact, they have over the years, developed much better
tests of distortion than those used by the Audio Industry.

Bob Stanton

(Svante) wrote in message

Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

Makers of RF amplifiers, and fiber optic equipment. All makers of CATV
and fiber optic equipment specify broadband distortion in -dB (power).
Companys like: General Instrument, Scientific Atlanta, C-Cor, and
Philips(Magnavox).

As a matter of fact, they have over the years, developed much better
tests of distortion than those used by the Audio Industry.

Bob Stanton

(Svante) wrote in message

Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

Makers of RF amplifiers, and fiber optic equipment. All makers of CATV
and fiber optic equipment specify broadband distortion in -dB (power).
Companys like: General Instrument, Scientific Atlanta, C-Cor, and
Philips(Magnavox).

As a matter of fact, they have over the years, developed much better
tests of distortion than those used by the Audio Industry.

Bob Stanton

(Svante) wrote in message

Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

Makers of RF amplifiers, and fiber optic equipment. All makers of CATV
and fiber optic equipment specify broadband distortion in -dB (power).
Companys like: General Instrument, Scientific Atlanta, C-Cor, and
Philips(Magnavox).

As a matter of fact, they have over the years, developed much better
tests of distortion than those used by the Audio Industry.

Bob Stanton

On 20 Jan 2004 03:50:29 -0800, (Svante)
wrote:

(Bob-Stanton) wrote in message . com...
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.

dB Power ratio Voltage

0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

What? Of course it's valid to express voltage ratios in dB!

Audio has always been the rather backwards child of electronics.

Bob Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

The telecomms industry has used dBW (and dBm) for many decades, which
*are* power ratios referenced to specific powers of 1 watt and 1
milliwatt respectively. However, since they are commonly used in
constant-impedence systems (usually 50 ohms), they are interchangeable
with voltage ratios.

As Bob says, the audio industry tends to be decades behind, and
frequently grossly incompetent.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On 20 Jan 2004 03:50:29 -0800, (Svante)
wrote:

(Bob-Stanton) wrote in message . com...
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.

dB Power ratio Voltage

0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

What? Of course it's valid to express voltage ratios in dB!

Audio has always been the rather backwards child of electronics.

Bob Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

The telecomms industry has used dBW (and dBm) for many decades, which
*are* power ratios referenced to specific powers of 1 watt and 1
milliwatt respectively. However, since they are commonly used in
constant-impedence systems (usually 50 ohms), they are interchangeable
with voltage ratios.

As Bob says, the audio industry tends to be decades behind, and
frequently grossly incompetent.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On 20 Jan 2004 03:50:29 -0800, (Svante)
wrote:

(Bob-Stanton) wrote in message . com...
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.

dB Power ratio Voltage

0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

What? Of course it's valid to express voltage ratios in dB!

Audio has always been the rather backwards child of electronics.

Bob Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

The telecomms industry has used dBW (and dBm) for many decades, which
*are* power ratios referenced to specific powers of 1 watt and 1
milliwatt respectively. However, since they are commonly used in
constant-impedence systems (usually 50 ohms), they are interchangeable
with voltage ratios.

As Bob says, the audio industry tends to be decades behind, and
frequently grossly incompetent.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On 20 Jan 2004 03:50:29 -0800, (Svante)
wrote:

(Bob-Stanton) wrote in message . com...
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.

dB Power ratio Voltage

0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

What? Of course it's valid to express voltage ratios in dB!

Audio has always been the rather backwards child of electronics.

Bob Stanton

THANK YOU! Finally a bit of support for my initial thoughts. I did not
know that other diciplines used the power ratio, could you give an
example?

The telecomms industry has used dBW (and dBm) for many decades, which
*are* power ratios referenced to specific powers of 1 watt and 1
milliwatt respectively. However, since they are commonly used in
constant-impedence systems (usually 50 ohms), they are interchangeable
with voltage ratios.

As Bob says, the audio industry tends to be decades behind, and
frequently grossly incompetent.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 20 Jan 2004 08:09:51 -0600, John Fields
wrote:

On Tue, 20 Jan 2004 08:01:45 +0000 (UTC), (Stewart
Pinkerton) wrote:

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.

---
What does religion have to do with it?^)

In high-end audio, religion has *everything* to do with it!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 20 Jan 2004 08:09:51 -0600, John Fields
wrote:

On Tue, 20 Jan 2004 08:01:45 +0000 (UTC), (Stewart
Pinkerton) wrote:

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.

---
What does religion have to do with it?^)

In high-end audio, religion has *everything* to do with it!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 20 Jan 2004 08:09:51 -0600, John Fields
wrote:

On Tue, 20 Jan 2004 08:01:45 +0000 (UTC), (Stewart
Pinkerton) wrote:

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.

---
What does religion have to do with it?^)

In high-end audio, religion has *everything* to do with it!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 20 Jan 2004 08:09:51 -0600, John Fields
wrote:

On Tue, 20 Jan 2004 08:01:45 +0000 (UTC), (Stewart
Pinkerton) wrote:

On Tue, 20 Jan 2004 16:02:28 +1100, "Tony Pearce"
wrote:

"Stewart Pinkerton" wrote in message
...
I am 6 feet 3
inches tall, I know how tall is someone who is 6 feet tall, but I have
no idea how tall is someone who is 1.83 metres tall.................

Um, the SAME. Surely you can figure that out.

Intellectually, I know this, but when I look at someone I
automatically calculate their height in feet and inches - and their
weight in stones. If you give me a description of someone as weighing
63 kilos and being 1.6 metres tall, I have no idea what they look
like, I have to convert first.

---
What does religion have to do with it?^)

In high-end audio, religion has *everything* to do with it!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Bob-Stanton wrote:
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

You mean because no one uses transmssion line models to "study" speaker
cables? Only the truly backwards does that!

No, dB as a voltage ratio is just as valid as using dB as power ratio.
Given fixed impedance, a dB is a dB!

It's nothing to do with audio. It has everything to do with the fact
that for lower frequency electronics, it is often voltage gain and
current gain that is more important than power gain. For example, if you
have a circuit based on op-amps, the power gain means very little, since
there is such a huge mismatch between source and load impedances.
Voltage gain (and sometimes current gain, or transconductance and
transimpedance gain) is the standard way to express magnitude of
transfer functions, since the op amp behaves like a voltage source and
its gain does not depend on load. It has close to infinite power gain.

Similarly, if one designs integrated circuits, one seldom uses power
gains internally, since there is no transmission line effects to worry
about, and the impedance levels are not constant.

At high frequencies where transmission line effects are considered, dB's
are used both as voltage and power ratios, often interchangeably. There
is really no preference of one over the other. In fact, if you look at
your beloved s-parameters, they are standing wave ratios, of voltages!
S21, uusually expressed in dB and phase, is a voltage ratio.

I would however agree that high-end audio is the backwards child of
electronics.

Bob-Stanton wrote:
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

You mean because no one uses transmssion line models to "study" speaker
cables? Only the truly backwards does that!

No, dB as a voltage ratio is just as valid as using dB as power ratio.
Given fixed impedance, a dB is a dB!

It's nothing to do with audio. It has everything to do with the fact
that for lower frequency electronics, it is often voltage gain and
current gain that is more important than power gain. For example, if you
have a circuit based on op-amps, the power gain means very little, since
there is such a huge mismatch between source and load impedances.
Voltage gain (and sometimes current gain, or transconductance and
transimpedance gain) is the standard way to express magnitude of
transfer functions, since the op amp behaves like a voltage source and
its gain does not depend on load. It has close to infinite power gain.

Similarly, if one designs integrated circuits, one seldom uses power
gains internally, since there is no transmission line effects to worry
about, and the impedance levels are not constant.

At high frequencies where transmission line effects are considered, dB's
are used both as voltage and power ratios, often interchangeably. There
is really no preference of one over the other. In fact, if you look at
your beloved s-parameters, they are standing wave ratios, of voltages!
S21, uusually expressed in dB and phase, is a voltage ratio.

I would however agree that high-end audio is the backwards child of
electronics.

Bob-Stanton wrote:
(Svante) wrote in message om...
Harmonic distorsion is expressed as the ratio between the distorsion
components and the fundamental. What surprises me is that it is the
VOLTAGES that are compared (in the electrical case) not the POWERS. So
if we have a second harmonic 40 dB down, the second harmonic
distorsion is 1 %, not 0.01 %.
(In this case the voltage of the harmonic is 1% of the fundamental,
and its power is 0.01% of the fundamental)

What is the reason for this convention? I'd think that power would be
more logical.

Using power is more valid. Power is used to express distortion,
outside of the audio industry. Distortion in other areas of
electronics is expressed in "dB's". For example, "the distortion is 20
dB down", means the distortion power is 0.01% of the signal power.



dB Power ratio Voltage


0 dB = 1 to 1 (of refrence power) 1.00 V (or ref. Voltage)
-10 dB = 1 to 0.1 0.316 V
-20 dB = 1 to 0.01 0.100 V
-30 dB = 1 to 0.001 0.031 V
-40 dB = 1 to 0.0001 0.010 V

In the audio community, voltage ratios are often expressed in dB, even
though it is not strictly valid to do so.

Audio has always been the rather backwards child of electronics.

You mean because no one uses transmssion line models to "study" speaker
cables? Only the truly backwards does that!

No, dB as a voltage ratio is just as valid as using dB as power ratio.
Given fixed impedance, a dB is a dB!

It's nothing to do with audio. It has everything to do with the fact
that for lower frequency electronics, it is often voltage gain and
current gain that is more important than power gain. For example, if you
have a circuit based on op-amps, the power gain means very little, since
there is such a huge mismatch between source and load impedances.
Voltage gain (and sometimes current gain, or transconductance and
transimpedance gain) is the standard way to express magnitude of
transfer functions, since the op amp behaves like a voltage source and
its gain does not depend on load. It has close to infinite power gain.

Similarly, if one designs integrated circuits, one seldom uses power
gains internally, since there is no transmission line effects to worry
about, and the impedance levels are not constant.

At high frequencies where transmission line effects are considered, dB's
are used both as voltage and power ratios, often interchangeably. There
is really no preference of one over the other. In fact, if you look at
your beloved s-parameters, they are standing wave ratios, of voltages!
S21, uusually expressed in dB and phase, is a voltage ratio.

I would however agree that high-end audio is the backwards child of
electronics.