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

On Sat, 2 May 2009 14:46:05 +0100, "Keith G"
wrote:


Means the two waveforms won't be 'mirro images' so won't null.


An important point.


Again, what odds to anyone prepared only to pay as little as possible
for 'budget' speakers?

None. Just that the user won't be hearing clear stereo imaging.


That's a presumption I presume?


No, not really. The quality of the null you get when you wire the
speakers out of phase is a good indicator of the quality
(locatability, if you like) of the stereo image they can produce. A
setup that produces a solid central image in the centre when playing
mono will also produce a reasonable null with out-of-phase mono. The
same goes of course for all the other image locations between the
speakers.

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

In article ,
"Keith G" wrote:

"MiNe 109" wrote in message
...
In article ,
"Keith G" wrote:

(Bit more interested in Dragonetti atm, tbh! :-)

The double bass composer?


Yes, and ground-breaking virtuoso and nutter - do a Wiki for more.

The collection of life-size doll traveling companions does seem unusual.

Stephen

"Don Pearce" wrote in message
news:49fe52c2.7943468@localhost...
On Sat, 2 May 2009 14:46:05 +0100, "Keith G"
wrote:


Means the two waveforms won't be 'mirro images' so won't null.


An important point.


Again, what odds to anyone prepared only to pay as little as possible
for 'budget' speakers?

None. Just that the user won't be hearing clear stereo imaging.


That's a presumption I presume?


No, not really. The quality of the null you get when you wire the
speakers out of phase is a good indicator of the quality
(locatability, if you like) of the stereo image they can produce. A
setup that produces a solid central image in the centre when playing
mono will also produce a reasonable null with out-of-phase mono. The
same goes of course for all the other image locations between the
speakers.


You're on the wrong tack, or making the same mistake yourself - the
'presumption' I refer to is to presume the budget speakers won't deliver a
good 'stereo image' (or out of phase 'null', if you prefer) simply beause
they are *budget*! My experience is that they can, in fact, image very well
(often, the smaller cabinet, the better) and would go further and say that
many 'budget' speakers up to the 250 quid level these days will 'out image'
a lot of the soggy old chuffer-boxes that quite a few Old Sweats still
revere and will pay silly money for today.

(Time for someone else to make the effort/expense and look into it, if they
have their doubts - I've completed my own researches into this subject!)

FWIW, like 50mm 'standard' lenses for 35mm cameras, I believe the small
'entry level' bookshelf speakers are usually *especially good* VFM (if not
quite loss-leaders) to encourage brand loyaly at an early stage and
'imaging' is always mentioned in the advertising and by the comix in their
reviews....

"MiNe 109" wrote in message
...
In article ,
"Keith G" wrote:

"MiNe 109" wrote in message
...
In article ,
"Keith G" wrote:

(Bit more interested in Dragonetti atm, tbh! :-)

The double bass composer?


Yes, and ground-breaking virtuoso and nutter - do a Wiki for more.

The collection of life-size doll traveling companions does seem unusual.


They got the best seats in the house (front row) at some of his
performances, I gather!! :-)

On Sat, 2 May 2009 16:49:33 +0100, "Keith G"
wrote:


"Don Pearce" wrote in message
news:49fe52c2.7943468@localhost...
On Sat, 2 May 2009 14:46:05 +0100, "Keith G"
wrote:


Means the two waveforms won't be 'mirro images' so won't null.


An important point.


Again, what odds to anyone prepared only to pay as little as possible
for 'budget' speakers?

None. Just that the user won't be hearing clear stereo imaging.


That's a presumption I presume?


No, not really. The quality of the null you get when you wire the
speakers out of phase is a good indicator of the quality
(locatability, if you like) of the stereo image they can produce. A
setup that produces a solid central image in the centre when playing
mono will also produce a reasonable null with out-of-phase mono. The
same goes of course for all the other image locations between the
speakers.


You're on the wrong tack, or making the same mistake yourself - the
'presumption' I refer to is to presume the budget speakers won't deliver a
good 'stereo image' (or out of phase 'null', if you prefer) simply beause
they are *budget*! My experience is that they can, in fact, image very well
(often, the smaller cabinet, the better) and would go further and say that
many 'budget' speakers up to the 250 quid level these days will 'out image'
a lot of the soggy old chuffer-boxes that quite a few Old Sweats still
revere and will pay silly money for today.

(Time for someone else to make the effort/expense and look into it, if they
have their doubts - I've completed my own researches into this subject!)

FWIW, like 50mm 'standard' lenses for 35mm cameras, I believe the small
'entry level' bookshelf speakers are usually *especially good* VFM (if not
quite loss-leaders) to encourage brand loyaly at an early stage and
'imaging' is always mentioned in the advertising and by the comix in their
reviews....


Well, you generally get pretty much what you pay for, and with the
more expensive drivers that go into more expensive speakers, what you
are paying for is consistency - quality control in other words. It is
the small differences between the two speakers that determine the
imaging quality, not the actual responses themselves. Of course all
this goes for absolutely nothing until you have the room sorted -
without that you are whistling at the moon if you want decent imaging.

And it has to be said that good imaging is easier to achieve with
smaller boxes, unfortunately at the expense of all the other good
stuff, like bass.

d

"Keith G" wrote in message
...


Watched the 'Burn-E' short for a 1080 comparison and wuz *blown away* -
vast improvement on the 720 PJ (no downscaling)* but not possible to
photograph the screen and get a decent picture yet as stills don't freeze
razor sharp on the Samsing player we're using

Stills aren't "razor sharp" regardless of which player you are using. Don't
forget that even "full" 1080p HD is only equivalent to a 2megapixel still
image (and would you blow one of them up to 6' wide?)



* These digiclowns that think signals aren't bashed about by processing
should have a look at the damage that can be done by upscaling and
downscaling *video*....

Depends what you mean by "processing", there are processes and processes.
It's not that many years ago the TV standards conversion (which is what up
and downscaling is) could only be done by bits of pro-video kit that cost
megabucks, it still amazes me that you can get a standards converter for
"free" inside a cheap domestic BD player at all, you can't expect it to be
done well at the price. Audio sample rate conversion is a doddle by
comparison.

But if you are basing your comments by comparing one projector with another
may I suggest that that might have just a little to do with the difference?

David.

"Don Pearce" wrote in message
news:4a006be5.14377828@localhost...
On Sat, 2 May 2009 16:49:33 +0100, "Keith G"
wrote:


"Don Pearce" wrote in message
news:49fe52c2.7943468@localhost...
On Sat, 2 May 2009 14:46:05 +0100, "Keith G"
wrote:


Means the two waveforms won't be 'mirro images' so won't null.


An important point.


Again, what odds to anyone prepared only to pay as little as possible
for 'budget' speakers?

None. Just that the user won't be hearing clear stereo imaging.


That's a presumption I presume?


No, not really. The quality of the null you get when you wire the
speakers out of phase is a good indicator of the quality
(locatability, if you like) of the stereo image they can produce. A
setup that produces a solid central image in the centre when playing
mono will also produce a reasonable null with out-of-phase mono. The
same goes of course for all the other image locations between the
speakers.


You're on the wrong tack, or making the same mistake yourself - the
'presumption' I refer to is to presume the budget speakers won't deliver a
good 'stereo image' (or out of phase 'null', if you prefer) simply beause
they are *budget*! My experience is that they can, in fact, image very
well
(often, the smaller cabinet, the better) and would go further and say that
many 'budget' speakers up to the 250 quid level these days will 'out
image'
a lot of the soggy old chuffer-boxes that quite a few Old Sweats still
revere and will pay silly money for today.

(Time for someone else to make the effort/expense and look into it, if
they
have their doubts - I've completed my own researches into this subject!)

FWIW, like 50mm 'standard' lenses for 35mm cameras, I believe the small
'entry level' bookshelf speakers are usually *especially good* VFM (if not
quite loss-leaders) to encourage brand loyaly at an early stage and
'imaging' is always mentioned in the advertising and by the comix in their
reviews....


Well, you generally get pretty much what you pay for,


Usually applies to just about everything on the planet....


and with the
more expensive drivers that go into more expensive speakers, what you
are paying for is consistency - quality control in other words.


I don't think the 'names' are likely to risk alienating future loyalty with
duff drivers and poor QC - modern speaker cabinets are automatically churned
out to perfection like kitchen cabinet drawers these days and the people who
fit the drivers are almost certainly quite capable of building the computers
we're on right now!

..

It is
the small differences between the two speakers that determine the
imaging quality, not the actual responses themselves. Of course all
this goes for absolutely nothing until you have the room sorted -
without that you are whistling at the moon if you want decent imaging.


An easy *say*, not such an easy *do* - most people have to blend in with the
decor these days....


And it has to be said that good imaging is easier to achieve with
smaller boxes, unfortunately at the expense of all the other good
stuff, like bass.


insert Heinlein free lunch chestnut here