[Dave Plowman (News)]

In article m,
David Nebenzahl wrote:
On 2/4/2009 9:10 AM Brian Gaff spake thus:

The worst I've encountered is the very audible signal from the
adjacent turn so to speak. I wonder what your sample had been played
on though.

What you're describing has nothing to do with vinyl; you're talking
about "print-through", which is an artifact of the tape mastering
machine feeding the cutter, where you can hear signals from adjacent
lengths of tape.

Dunno about the record industry but I would edit in leader tape to
remove any from the start of a track.

--
*A 'jiffy' is an actual unit of time for 1/100th of a second.

Dave Plowman London SW
To e-mail, change noise into sound.

[David Looser]

"Karl Uppiano" wrote in message
...



Fortunately, long wavelengths and large excursions are mostly in the low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).


More to the point as far as subwoofers are concerned, the ability of human
hearing to determine the direction of a sound source becomes less effective
as the wavelength lengthen, becoming pretty well non-existent at frequencies
of 50Hz and below. So not only does it not matter if these frequencies are
presented in mono, but it doesn't matter much where the subwoofer is in
relation to the subs either.

David.

[Serge Auckland[_2_]]

"David Looser" wrote in message
...
"Karl Uppiano" wrote in message
...



Fortunately, long wavelengths and large excursions are mostly in the low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).


More to the point as far as subwoofers are concerned, the ability of human
hearing to determine the direction of a sound source becomes less
effective as the wavelength lengthen, becoming pretty well non-existent at
frequencies of 50Hz and below. So not only does it not matter if these
frequencies are presented in mono, but it doesn't matter much where the
subwoofer is in relation to the subs either.

David.


That has not been my experience. I ended up with two subs, each sitting
alongside each main, as I couldn't get on with one only. If the sub was
centred between the two loudspeakers, that wasn't too bad, as at least the
extreme bass was mono, but when the sub was to one side, it was most
peculiar. I find there is stereo in the extreme bass, especially in Jazz,
and classical music, although not a lot in rock, and very little on vinyl,
which tends to mono the extreme bass anyway.

S.
--
http://audiopages.googlepages.com

[[email protected]]

On Feb 5, 11:23*pm, "Karl Uppiano" wrote:
Fortunately, long wavelengths and large excursions are
mostly in the low frequencies,

Uh, I would hope long wavelengths are mostly at low
frequencies. :-)

which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).

I assume you mean "single" or "mono" subwoofers here.

I have seen grooves intersect on records that I own,
but the stylus rides a long ways below the surface,
so it is really only a problem if the *bottoms*
of the grooves overlap. Then the stylus would have
a "choice" wouldn't it?
That would be bad...

I have such a record in my collection. It's an old RCA
release of (I believe) Toscanini conducting Dukas'
Sorcerer's Apprentice. At the final orchestral crash
before the concluding section, on playing you hear
the final bars before that note leading up to it and
then, ... nothing but reverb tail. By adjusting the
anti-skating a little on the high side, it would play
just fine. I looked at it with a microscope once and,
indeed, there was a lot of confused grooves for about
2 revolutions.

[[email protected]]

On Feb 6, 9:36*am, "Serge Auckland"
wrote:
"David Looser" wrote in message

...

"Karl Uppiano" wrote in message
...

Fortunately, long wavelengths and large excursions are mostly in the low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).

More to the point as far as subwoofers are concerned, the ability of human
hearing to determine the direction of a sound source becomes less
effective as the wavelength lengthen, becoming pretty well non-existent at
frequencies of 50Hz and below. So not only does it not matter if these
frequencies are presented in mono, but it doesn't matter much where the
subwoofer is in relation to the subs either.

David.

That has not been my experience. I ended up with two subs, each sitting
alongside each main, as I couldn't get on with one only. If the sub was
centred between the two loudspeakers, that wasn't too bad, as at least the
extreme bass was mono, but when the sub was to one side, it was most
peculiar.

That's primarily because most subwoofers aren't: they tend to have
substantial output at higher frequencies anyway. The very low
frequency material could well be in mono, but stuff an octave or
two higher could have substantial difference information, and
that can easily find its way through many subwoofers.

[Don Pearce]

On Fri, 6 Feb 2009 09:30:41 -0800 (PST),
wrote:

On Feb 6, 9:36*am, "Serge Auckland"
wrote:
"David Looser" wrote in message

...

"Karl Uppiano" wrote in message
...

Fortunately, long wavelengths and large excursions are mostly in the low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).

More to the point as far as subwoofers are concerned, the ability of human
hearing to determine the direction of a sound source becomes less
effective as the wavelength lengthen, becoming pretty well non-existent at
frequencies of 50Hz and below. So not only does it not matter if these
frequencies are presented in mono, but it doesn't matter much where the
subwoofer is in relation to the subs either.

David.

That has not been my experience. I ended up with two subs, each sitting
alongside each main, as I couldn't get on with one only. If the sub was
centred between the two loudspeakers, that wasn't too bad, as at least the
extreme bass was mono, but when the sub was to one side, it was most
peculiar.

That's primarily because most subwoofers aren't: they tend to have
substantial output at higher frequencies anyway. The very low
frequency material could well be in mono, but stuff an octave or
two higher could have substantial difference information, and
that can easily find its way through many subwoofers.

That was indeed my own experience until I built my own subwoofer. It
turns over at about 50Hz, and is impossible to localize in the room by
sound.

d
--
Pearce Consulting
http://www.pearce.uk.com

[Serge Auckland[_2_]]

"Don Pearce" wrote in message
...
On Fri, 6 Feb 2009 09:30:41 -0800 (PST),
wrote:

On Feb 6, 9:36 am, "Serge Auckland"
wrote:
"David Looser" wrote in message

...

"Karl Uppiano" wrote in message
...

Fortunately, long wavelengths and large excursions are mostly in the
low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).

More to the point as far as subwoofers are concerned, the ability of
human
hearing to determine the direction of a sound source becomes less
effective as the wavelength lengthen, becoming pretty well
non-existent at
frequencies of 50Hz and below. So not only does it not matter if these
frequencies are presented in mono, but it doesn't matter much where
the
subwoofer is in relation to the subs either.

David.

That has not been my experience. I ended up with two subs, each sitting
alongside each main, as I couldn't get on with one only. If the sub was
centred between the two loudspeakers, that wasn't too bad, as at least
the
extreme bass was mono, but when the sub was to one side, it was most
peculiar.

That's primarily because most subwoofers aren't: they tend to have
substantial output at higher frequencies anyway. The very low
frequency material could well be in mono, but stuff an octave or
two higher could have substantial difference information, and
that can easily find its way through many subwoofers.

That was indeed my own experience until I built my own subwoofer. It
turns over at about 50Hz, and is impossible to localize in the room by
sound.

d
--
Pearce Consulting
http://www.pearce.uk.com

My subs (Meridian D1500) are designed to work with the D5000 mains, and have
a 2nd order Butterworth response at 36 Hz. And yet, having one to the side,
it's very obvious where the bass is coming from.

I built a single sub for my son some years ago, and it had to integrate with
a pair of small Missions, which meant a rollover around 70Hz, 2nd order.
That was very noticeable, and disturbing when not between the main
'speakers. Either my room acoustics are peculiar, or I'm particularly
sensitive to bass positioning. Perhaps to make up for my complete
insensitivity to cables, CD players, amplifiers, spikes, cable lifters etc
etc.

S.
--
http://audiopages.googlepages.com

[GregS[_3_]]

In article , "Serge Auckland" wrote:

"Don Pearce" wrote in message
...
On Fri, 6 Feb 2009 09:30:41 -0800 (PST),
wrote:

On Feb 6, 9:36 am, "Serge Auckland"
wrote:
"David Looser" wrote in message

...

"Karl Uppiano" wrote in message
...

Fortunately, long wavelengths and large excursions are mostly in the
low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).

More to the point as far as subwoofers are concerned, the ability of
human
hearing to determine the direction of a sound source becomes less
effective as the wavelength lengthen, becoming pretty well
non-existent at
frequencies of 50Hz and below. So not only does it not matter if these
frequencies are presented in mono, but it doesn't matter much where
the
subwoofer is in relation to the subs either.

David.

That has not been my experience. I ended up with two subs, each sitting
alongside each main, as I couldn't get on with one only. If the sub was
centred between the two loudspeakers, that wasn't too bad, as at least
the
extreme bass was mono, but when the sub was to one side, it was most
peculiar.

That's primarily because most subwoofers aren't: they tend to have
substantial output at higher frequencies anyway. The very low
frequency material could well be in mono, but stuff an octave or
two higher could have substantial difference information, and
that can easily find its way through many subwoofers.

That was indeed my own experience until I built my own subwoofer. It
turns over at about 50Hz, and is impossible to localize in the room by
sound.

d
--
Pearce Consulting
http://www.pearce.uk.com

My subs (Meridian D1500) are designed to work with the D5000 mains, and have
a 2nd order Butterworth response at 36 Hz. And yet, having one to the side,
it's very obvious where the bass is coming from.

I built a single sub for my son some years ago, and it had to integrate with
a pair of small Missions, which meant a rollover around 70Hz, 2nd order.
That was very noticeable, and disturbing when not between the main
'speakers. Either my room acoustics are peculiar, or I'm particularly
sensitive to bass positioning. Perhaps to make up for my complete
insensitivity to cables, CD players, amplifiers, spikes, cable lifters etc
etc.

I suspect some crossovers having cutoff at some point, but may not
be true at the second and third harmonic, depending how good
the design is. Easy on active crossovers but requiring Zoebles otherwise.
I can sometimes hear spyder noise and of course wind noise.
In general I would prefer using a bandpass box, but you still have to
watch wind noise.

greg

[Don Pearce]

On Fri, 06 Feb 2009 18:53:10 GMT, (GregS)
wrote:

In article , "Serge Auckland" wrote:

"Don Pearce" wrote in message
...
On Fri, 6 Feb 2009 09:30:41 -0800 (PST),
wrote:

On Feb 6, 9:36 am, "Serge Auckland"
wrote:
"David Looser" wrote in message

...

"Karl Uppiano" wrote in message
...

Fortunately, long wavelengths and large excursions are mostly in the
low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).

More to the point as far as subwoofers are concerned, the ability of
human
hearing to determine the direction of a sound source becomes less
effective as the wavelength lengthen, becoming pretty well
non-existent at
frequencies of 50Hz and below. So not only does it not matter if these
frequencies are presented in mono, but it doesn't matter much where
the
subwoofer is in relation to the subs either.

David.

That has not been my experience. I ended up with two subs, each sitting
alongside each main, as I couldn't get on with one only. If the sub was
centred between the two loudspeakers, that wasn't too bad, as at least
the
extreme bass was mono, but when the sub was to one side, it was most
peculiar.

That's primarily because most subwoofers aren't: they tend to have
substantial output at higher frequencies anyway. The very low
frequency material could well be in mono, but stuff an octave or
two higher could have substantial difference information, and
that can easily find its way through many subwoofers.

That was indeed my own experience until I built my own subwoofer. It
turns over at about 50Hz, and is impossible to localize in the room by
sound.

d
--
Pearce Consulting
http://www.pearce.uk.com

My subs (Meridian D1500) are designed to work with the D5000 mains, and have
a 2nd order Butterworth response at 36 Hz. And yet, having one to the side,
it's very obvious where the bass is coming from.

I built a single sub for my son some years ago, and it had to integrate with
a pair of small Missions, which meant a rollover around 70Hz, 2nd order.
That was very noticeable, and disturbing when not between the main
'speakers. Either my room acoustics are peculiar, or I'm particularly
sensitive to bass positioning. Perhaps to make up for my complete
insensitivity to cables, CD players, amplifiers, spikes, cable lifters etc
etc.

I suspect some crossovers having cutoff at some point, but may not
be true at the second and third harmonic, depending how good
the design is. Easy on active crossovers but requiring Zoebles otherwise.
I can sometimes hear spyder noise and of course wind noise.
In general I would prefer using a bandpass box, but you still have to
watch wind noise.

greg


My sub is IB and over 50 cu. ft., so no wind noise.

d
--
Pearce Consulting
http://www.pearce.uk.com

[Mr.T]

wrote in message
...
That's primarily because most subwoofers aren't: they tend to have
substantial output at higher frequencies anyway. The very low
frequency material could well be in mono, but stuff an octave or
two higher could have substantial difference information, and
that can easily find its way through many subwoofers.

So true, I find it annoying that what we once called simply a woofer, is now
called a "sub woofer" by many manufacturers. Many don't go anywhere near
20Hz, and may go well over 200Hz by design. And many more go there simply
because of inadequate filtering.

MrT.

[Mr.T]

"Serge Auckland" wrote in message
...
My subs (Meridian D1500) are designed to work with the D5000 mains, and
have
a 2nd order Butterworth response at 36 Hz. And yet, having one to the
side,
it's very obvious where the bass is coming from.

I built a single sub for my son some years ago, and it had to integrate
with
a pair of small Missions, which meant a rollover around 70Hz, 2nd order.
That was very noticeable, and disturbing when not between the main
'speakers. Either my room acoustics are peculiar, or I'm particularly
sensitive to bass positioning.

Nah you really need to use a fourth order network, or greater. Remember you
ear is more sensitive at higher bass frequencies than low bass, so a second
order network may hardly attenuate the higher bass frequencies much at all,
as far as your hearing is concerned anyway.

MrT.

[Karl Uppiano[_2_]]

"David Looser" wrote in message
...
"Karl Uppiano" wrote in message
...



Fortunately, long wavelengths and large excursions are mostly in the low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).


More to the point as far as subwoofers are concerned, the ability of human
hearing to determine the direction of a sound source becomes less
effective as the wavelength lengthen, becoming pretty well non-existent at
frequencies of 50Hz and below. So not only does it not matter if these
frequencies are presented in mono, but it doesn't matter much where the
subwoofer is in relation to the subs either.

But... the physics behind it are related. We don't perceive low frequency
directionality because given the spacing between our ears (as opposed to the
space between our ears) doesn't allow for much phase difference at low
frequencies. Recording setups with widely spaced microphones can produce
artificial phasing artifacts, but it isn't what we normally hear. Blending
to mono at low frequencies for cutting records or driving subwoofers is
relatively benign for all the same reasons.

[Tony[_3_]]

Karl Uppiano wrote:
We don't perceive low
frequency directionality because given the spacing between our ears (as
opposed to the space between our ears) doesn't allow for much phase
difference at low frequencies.

Low frequencies can be well localised in anechoic conditions but not in a
normally reverberant room of reasonable size. I have taken part in blind
tests that indicated that you could cross over a woofer at 120 Hz without
being able to tell where it was, provided it was not very near the listener.
In fact you could push it up to 160 Hz although I think that was the limit.
The tests were with speech and music, using a normal stereo pair of speakers
for the higher frequencies.

The test system did have a very steep cut-off filter, but this was over 10
years ago and I have forgotten what the slope was. The effect of distortion
in the speaker is also very important (and inevitable) so it is a good idea
to have acoustic attenuation of frequencies above the nominal cut-off by
pointing the woofer at soft materials.

--
Tony W
My e-mail address has no hyphen
- but please don't use it, reply to the group.

[Karl Uppiano[_2_]]

"Tony" wrote in message
om...
Karl Uppiano wrote:
We don't perceive low
frequency directionality because given the spacing between our ears (as
opposed to the space between our ears) doesn't allow for much phase
difference at low frequencies.

Low frequencies can be well localised in anechoic conditions but not in a
normally reverberant room of reasonable size. I have taken part in blind
tests that indicated that you could cross over a woofer at 120 Hz without
being able to tell where it was, provided it was not very near the
listener.
In fact you could push it up to 160 Hz although I think that was the
limit.
The tests were with speech and music, using a normal stereo pair of
speakers
for the higher frequencies.

The test system did have a very steep cut-off filter, but this was over 10
years ago and I have forgotten what the slope was. The effect of
distortion in the speaker is also very important (and inevitable) so it is
a good idea to have acoustic attenuation of frequencies above the nominal
cut-off by pointing the woofer at soft materials.

I did not mean to imply that there were any absolutes in LF localization
ability by humans. It seems to drop off gradually, and of course relative
phase *and* loudness play a part in what we hear in each ear. Confounding
factors, such as harmonics and other noises coming from the LF driver can
provide clues as well (perhaps more easily discernable in an anechoic
space?).

As for whether blending LF to mono for vinyl is audible or not, might have
been less important than practical considerations related to making playable
records. Digital audio certainly does not have that constraint. I don't know
what current practice is for routing LF when mixing for CDs.

[Peter Larsen[_3_]]

Karl Uppiano wrote:

As for whether blending LF to mono for vinyl is audible or not, might
have been less important than practical considerations related to
making playable records. Digital audio certainly does not have that
constraint. I don't know what current practice is for routing LF when
mixing for CDs.

There is a plug-in called mono around, and reducing the channel separation
in the low frequency range can be useful with recordings made with some
distance between microphones. It will however also change the perspective
experience for those that play the recording on full range stereophonic
systems. The trick is also quite useful to reduce rumble from records, be it
from playback or from the cutting ... it is one of my posted enhancement
requests for Audition that the functionality should be integrated and it has
so been since way before I heard of the - admittedly useful - third party
USD 99 plug in (or stand alone, can't remember), a bit costly compared with
the upgrade price for the entire Audition package ...

Kind regards

Peter Larsen

[Eeyore]

Don Pearce wrote:

I was interested in how heavily modulated vinyl could be, so I popped
an old record (Long Hot Summer Night, Jimi Hendrix, Track Records
1968) under the microscope for a look. And what did I find? Two
adjacent grooves clearly broken into each other:

http://81.174.169.10/odds/grooves.jpg

Was this a really common back then, or is this kind of thing a rarity?

Hardly surprises me !

It's probably part of that allegedly sought-after 'vinyl sound'.

Graham

[Iain Churches[_2_]]

"Dave Plowman (News)" wrote in message
...
In article m,
David Nebenzahl wrote:
On 2/4/2009 9:10 AM Brian Gaff spake thus:

The worst I've encountered is the very audible signal from the
adjacent turn so to speak. I wonder what your sample had been played
on though.

What you're describing has nothing to do with vinyl; you're talking
about "print-through", which is an artifact of the tape mastering
machine feeding the cutter, where you can hear signals from adjacent
lengths of tape.

Dunno about the record industry but I would edit in leader tape to
remove any from the start of a track.

I think that was normal practice everywhere, except for places
that used the same tapes over and over again, but their material
was unlikely to go for cutting anyway.

Iain