On 02 May 2009 13:17:54 GMT, John Phillips
wrote:

On 2009-05-02, Jim Lesurf wrote:
In article , Rob
wrote:
Dave Plowman (News) wrote:
You bandy words like 'depth' etc without knowing what they mean.

Doesn't it (depth) just mean some sort of spatial representation of
sound? Like an instrument at the front, another a couple of feet behind,
a vocalist over there on the left, towards the back?

...and with a layout that was intended by those making the recording or
broadcast, and that - for relevant types of music - gives the same audible
layout as you would have experienced in the hall. Not just " blur out the
sense of location depth."

I have recently been thinking about the factors that lead to good depth
perception in stereo systems. I suspect there are depth cues which
can come from mono systems:

- amplitude (relative: quieter = further away)
- timbre (absolute: less HF = further away)

And stereo cues:

- image width (absolute: narrower = further away)

I am wondering if reflections matter, either "original" ones from the
recording venue or introduced ones from the listening room (which may
blur the originals).

Don mentioned 'speaker toe-in earlier. Since the frequency response of
'speakers off-axis tends to fall off at HF faster than at LF I suspect
toe-in matters somewhat in achieving good timbral depth perception.

The big depth cue in recordings, and which can be adjusted fairly
realistically even in close-miked multitrack, is the ratio of direct
to reverberant sound. Most reverb synthesizers (I use a convolution
reverb, which accepts impulses recorded in real spaces as the source),
and with that I can go from 100% direct to 100% reverb. You can
actually hear the player moving back and forth in front of you as you
change it.

d

On Sat, 02 May 2009 13:42:31 GMT, (Don Pearce) wrote:

On 02 May 2009 13:17:54 GMT, John Phillips
wrote:

On 2009-05-02, Jim Lesurf wrote:
In article , Rob
wrote:
Dave Plowman (News) wrote:
You bandy words like 'depth' etc without knowing what they mean.

Doesn't it (depth) just mean some sort of spatial representation of
sound? Like an instrument at the front, another a couple of feet behind,
a vocalist over there on the left, towards the back?

...and with a layout that was intended by those making the recording or
broadcast, and that - for relevant types of music - gives the same audible
layout as you would have experienced in the hall. Not just " blur out the
sense of location depth."

I have recently been thinking about the factors that lead to good depth
perception in stereo systems. I suspect there are depth cues which
can come from mono systems:

- amplitude (relative: quieter = further away)
- timbre (absolute: less HF = further away)

And stereo cues:

- image width (absolute: narrower = further away)

I am wondering if reflections matter, either "original" ones from the
recording venue or introduced ones from the listening room (which may
blur the originals).

Don mentioned 'speaker toe-in earlier. Since the frequency response of
'speakers off-axis tends to fall off at HF faster than at LF I suspect
toe-in matters somewhat in achieving good timbral depth perception.

The big depth cue in recordings, and which can be adjusted fairly
realistically even in close-miked multitrack, is the ratio of direct
to reverberant sound. Most reverb synthesizers (I use a convolution
reverb, which accepts impulses recorded in real spaces as the source),
and with that I can go from 100% direct to 100% reverb. You can
actually hear the player moving back and forth in front of you as you
change it.

d


Here's how it works. Quick speech recording, played against a constant
reverb impulse (a local church, in fact), repeated five times with the
ratio of direct and reverberant sound changed each time - final one is
reverberant only.

Obviously greatly exaggerated for illustration.

http://81.174.169.10/odds/depth.mp3

d

"Don Pearce" wrote


Here's how it works. Quick speech recording, played against a constant
reverb impulse (a local church, in fact), repeated five times with the
ratio of direct and reverberant sound changed each time - final one is
reverberant only.

Obviously greatly exaggerated for illustration.

http://81.174.169.10/odds/depth.mp3


Reminds me I've still got a 'Norwegian Wood' clip here somewhere! :-)

Anyway, nothing new there Don - Pinky was on about that years ago and also
claiming the better 'spatiality' (I'm avoiding the word 'depth' - it's
become the subject of controversy) from triode valves was due entirely to
*internal reverb/feedback* caused by 'Miller Effect' (IIRC)...??

I went to check and found nothing and hesitate to post these links:

http://www.psaudio.com/ps/wiki/Miller-Effect/

http://www.aikenamps.com/MillerCapacitance.html

....because I don't really need to know and I don't want hitting over the
head with them; I post them only for perusal by others....

On Sat, 2 May 2009 16:08:03 +0100, "Keith G"
wrote:


"Don Pearce" wrote


Here's how it works. Quick speech recording, played against a constant
reverb impulse (a local church, in fact), repeated five times with the
ratio of direct and reverberant sound changed each time - final one is
reverberant only.

Obviously greatly exaggerated for illustration.

http://81.174.169.10/odds/depth.mp3


Reminds me I've still got a 'Norwegian Wood' clip here somewhere! :-)

That was very quick and very dirty.

Anyway, nothing new there Don - Pinky was on about that years ago and also
claiming the better 'spatiality' (I'm avoiding the word 'depth' - it's
become the subject of controversy) from triode valves was due entirely to
*internal reverb/feedback* caused by 'Miller Effect' (IIRC)...??

I went to check and found nothing and hesitate to post these links:

http://www.psaudio.com/ps/wiki/Miller-Effect/

http://www.aikenamps.com/MillerCapacitance.html

...because I don't really need to know and I don't want hitting over the
head with them; I post them only for perusal by others....



That was nothing about reproduction and hi fi kit, just the way front
to back spatial positioning is represented in recorded music. Stuff
"up front" will have much less reverb than stuff coming from far away.
That's just how it's done.

d

Don Pearce wrote:
On Sat, 02 May 2009 13:42:31 GMT, (Don Pearce) wrote:

On 02 May 2009 13:17:54 GMT, John Phillips
wrote:

On 2009-05-02, Jim Lesurf wrote:
In article , Rob
wrote:
Dave Plowman (News) wrote:
You bandy words like 'depth' etc without knowing what they mean.
Doesn't it (depth) just mean some sort of spatial representation of
sound? Like an instrument at the front, another a couple of feet behind,
a vocalist over there on the left, towards the back?
...and with a layout that was intended by those making the recording or
broadcast, and that - for relevant types of music - gives the same audible
layout as you would have experienced in the hall. Not just " blur out the
sense of location depth."
I have recently been thinking about the factors that lead to good depth
perception in stereo systems. I suspect there are depth cues which
can come from mono systems:

- amplitude (relative: quieter = further away)
- timbre (absolute: less HF = further away)

And stereo cues:

- image width (absolute: narrower = further away)

I am wondering if reflections matter, either "original" ones from the
recording venue or introduced ones from the listening room (which may
blur the originals).

Don mentioned 'speaker toe-in earlier. Since the frequency response of
'speakers off-axis tends to fall off at HF faster than at LF I suspect
toe-in matters somewhat in achieving good timbral depth perception.
The big depth cue in recordings, and which can be adjusted fairly
realistically even in close-miked multitrack, is the ratio of direct
to reverberant sound. Most reverb synthesizers (I use a convolution
reverb, which accepts impulses recorded in real spaces as the source),
and with that I can go from 100% direct to 100% reverb. You can
actually hear the player moving back and forth in front of you as you
change it.

d


Here's how it works. Quick speech recording, played against a constant
reverb impulse (a local church, in fact), repeated five times with the
ratio of direct and reverberant sound changed each time - final one is
reverberant only.

Obviously greatly exaggerated for illustration.

http://81.174.169.10/odds/depth.mp3

d

Which is a similar sensation I'd experience when valves are in the
amplification chain. I know (before you start!) that that doesn't
compute. It gives me a very believable notion of instruments (etc) and
spatial perspective.

Rob

On Sat, 02 May 2009 17:10:09 GMT, Rob
wrote:

Here's how it works. Quick speech recording, played against a constant
reverb impulse (a local church, in fact), repeated five times with the
ratio of direct and reverberant sound changed each time - final one is
reverberant only.

Obviously greatly exaggerated for illustration.

http://81.174.169.10/odds/depth.mp3

d

Which is a similar sensation I'd experience when valves are in the
amplification chain. I know (before you start!) that that doesn't
compute. It gives me a very believable notion of instruments (etc) and
spatial perspective.

Rob

Not sure what you mean. It's only voltage signals going through the
valves, so what they do to one, they must do to all. So do you mean
that everything sounds a bit further away with valves?

d

"Don Pearce" wrote in message
news:4a017ee2.19235296@localhost...
On Sat, 02 May 2009 17:10:09 GMT, Rob
wrote:

d

Which is a similar sensation I'd experience when valves are in the
amplification chain. I know (before you start!) that that doesn't
compute. It gives me a very believable notion of instruments (etc) and
spatial perspective.

Rob

Not sure what you mean. It's only voltage signals going through the
valves, so what they do to one, they must do to all. So do you mean
that everything sounds a bit further away with valves?


I'm going to make myself unpopular for saying it, but what I suspect Rob
really means is that he gets a similar sensation when he knows (or believes)
there are valves in the amplification chain.

David.

On Sun, 3 May 2009 10:39:31 +0100, "David Looser"
wrote:

"Don Pearce" wrote in message
news:4a017ee2.19235296@localhost...
On Sat, 02 May 2009 17:10:09 GMT, Rob
wrote:

d

Which is a similar sensation I'd experience when valves are in the
amplification chain. I know (before you start!) that that doesn't
compute. It gives me a very believable notion of instruments (etc) and
spatial perspective.

Rob

Not sure what you mean. It's only voltage signals going through the
valves, so what they do to one, they must do to all. So do you mean
that everything sounds a bit further away with valves?


I'm going to make myself unpopular for saying it, but what I suspect Rob
really means is that he gets a similar sensation when he knows (or believes)
there are valves in the amplification chain.


But a similar sensation to what? My clip has five versions, all with
different proportions of reverb. Do you think he is saying the effect
is similar to the first, the last, or one in between. It can't just be
"similar".

d

Don Pearce wrote:
On Sun, 3 May 2009 10:39:31 +0100, "David Looser"
wrote:

"Don Pearce" wrote in message
news:4a017ee2.19235296@localhost...
On Sat, 02 May 2009 17:10:09 GMT, Rob
wrote:
d
Which is a similar sensation I'd experience when valves are in the
amplification chain. I know (before you start!) that that doesn't
compute. It gives me a very believable notion of instruments (etc) and
spatial perspective.

Rob
Not sure what you mean. It's only voltage signals going through the
valves, so what they do to one, they must do to all. So do you mean
that everything sounds a bit further away with valves?

I'm going to make myself unpopular for saying it, but what I suspect Rob
really means is that he gets a similar sensation when he knows (or believes)
there are valves in the amplification chain.


But a similar sensation to what? My clip has five versions, all with
different proportions of reverb. Do you think he is saying the effect
is similar to the first, the last, or one in between. It can't just be
"similar".


I could have been clearer. The sensation is similar to reverb, albeit
very light, and much more pleasant.

Rob

David Looser wrote:
"Don Pearce" wrote in message
news:4a017ee2.19235296@localhost...
On Sat, 02 May 2009 17:10:09 GMT, Rob
wrote:

d
Which is a similar sensation I'd experience when valves are in the
amplification chain. I know (before you start!) that that doesn't
compute. It gives me a very believable notion of instruments (etc) and
spatial perspective.

Rob
Not sure what you mean. It's only voltage signals going through the
valves, so what they do to one, they must do to all. So do you mean
that everything sounds a bit further away with valves?


I'm going to make myself unpopular for saying it, but what I suspect Rob
really means is that he gets a similar sensation when he knows (or believes)
there are valves in the amplification chain.


I doff my cap :-)

Could well be. If you get the opportunity, though, I recommend you give
it a try.

Rob