Serious vinyl quality control problem?

[Don Pearce[_2_]]

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?

d

[Jens Rodrigo]

Don Pearce <news:4992beba.108434515@localhost...> 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?


Slight kissing of the grooves are no problem. What you see is
the surface of the disk. The stylus ball is tracing approximately
in the middle of the v-shaped groove.

Cheers Jens

[Richard Crowley]

<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?

Back in the 1970's Shure sent out marketing people to local stereo
shops demonstrating how good their latest phono cartridge (V15?)
was. The show was great until I brought them my "killer album",
(IIRC Neil Diamond "Taproot Manuscript") which had an extreme
guitar transient in the intro to one of the songs. They never found a
solution to tracking that song. My Stanton at home came closer
to success than their pickup.

[Don Pearce[_2_]]

On Wed, 4 Feb 2009 17:44:16 +0100, "Jens Rodrigo"
> wrote:

>Don Pearce <news:4992beba.108434515@localhost...> 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?
>
>
>Slight kissing of the grooves are no problem. What you see is
>the surface of the disk. The stylus ball is tracing approximately
>in the middle of the v-shaped groove.
>
>Cheers Jens
>

They had to work that close to the limit? That can't be good.

d

[Brian Gaff]

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.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
<Don Pearce> wrote in message news:4992beba.108434515@localhost...
>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?
>
> d

[Brian Gaff]

A lot of the problems with transients though is resonances in the system
between the mass of the arm and the compliance of the cartridge.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Richard Crowley" > wrote in message
...
> <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?
>
> Back in the 1970's Shure sent out marketing people to local stereo
> shops demonstrating how good their latest phono cartridge (V15?)
> was. The show was great until I brought them my "killer album",
> (IIRC Neil Diamond "Taproot Manuscript") which had an extreme
> guitar transient in the intro to one of the songs. They never found a
> solution to tracking that song. My Stanton at home came closer
> to success than their pickup.
>
>

[Iain Churches[_2_]]

<Don Pearce> wrote in message news:4992beba.108434515@localhost...
>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?
>

Neither rare nor common.
It was normal practice to examine heavily modulated passages
under ther microscope after cutting both the test and the final
master. Many cutting engineers used to also test cut loud segments
with excessive lateral excursion several times as a practice run.

But it was impossible to check every single patch with the microscope.
The master was never played, but the initial test cut usually was. If
no problems were encountered with say an SME 3009 and Shure V15
then the master went to the factory.

Are there tracking problems with the Hendrix, Don?

Iain

[Don Pearce[_2_]]

On Wed, 04 Feb 2009 17:10:13 GMT, "Brian Gaff"
> wrote:

>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.
>Brian

Just my own system and I have always been careful. I have a few vinyl
LPs that start loudly, and the opening chord is distinctly audible one
revolution before the actual start.

d

[D.M. Procida]

> 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?

I had a friend with a Bee Gees record. On the first song, there was a
very audible pre-echo of the opening moments (it was something very
loud, "Tragedy" perhaps).

I never really investigated it. I presume it must have been print-though
from a badly stored tape, but I guess it could have been a very
badly-cut record.

Daniele

[Don Pearce[_2_]]

On Wed, 04 Feb 2009 17:12:22 GMT, "Brian Gaff"
> wrote:

>A lot of the problems with transients though is resonances in the system
>between the mass of the arm and the compliance of the cartridge.
>Brian

This isn't a transient, just a large excursion that happened to meet
another coming the other way on the next groove.

d

[Richard Crowley]

<Don Pearce> wrote ...
> "Jens Rodrigo" wrote:
>>Slight kissing of the grooves are no problem. What you see is
>>the surface of the disk. The stylus ball is tracing approximately
>>in the middle of the v-shaped groove.
>
> They had to work that close to the limit? That can't be good.

It was always a tradeoff between amplitude (which translates into
SNR below the physical limits) vs. playing time. What is the total
playing time on that side of the disc?

And then there was always the problem, particularly with classical
music, where at the end where one typically finds a grand finale at
higher dynamic, one is at the inside of the disc where the linear
velocity is lowest.

[Don Pearce]

On Wed, 4 Feb 2009 19:17:45 +0200, "Iain Churches"
> wrote:

>
><Don Pearce> wrote in message news:4992beba.108434515@localhost...
>>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?
>>
>
>Neither rare nor common.
>It was normal practice to examine heavily modulated passages
>under ther microscope after cutting both the test and the final
>master. Many cutting engineers used to also test cut loud segments
>with excessive lateral excursion several times as a practice run.
>
>But it was impossible to check every single patch with the microscope.
>The master was never played, but the initial test cut usually was. If
>no problems were encountered with say an SME 3009 and Shure V15
>then the master went to the factory.
>
>Are there tracking problems with the Hendrix, Don?
>
>Iain
>
>

No, not at all. I was just feeling a bit bored and curious. I thought
that even in '68 there was some automation that predicted amplitude
and widened the pitch a little.

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

[Jens Rodrigo]

<Don Pearce> schrieb im Newsbeitrag news:4993c85e.110902812@localhost...
> On Wed, 4 Feb 2009 17:44:16 +0100, "Jens Rodrigo"
> > wrote:
>
>>Don Pearce <news:4992beba.108434515@localhost...> 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?
>>
>>Slight kissing of the grooves are no problem. What you see is
>>the surface of the disk. The stylus ball is tracing approximately
>>in the middle of the v-shaped groove.
>
> They had to work that close to the limit? That can't be good.


You are right, but the customers want high level and long
playing time. The spiral has a fixed length, so the necessary
playing time and high level forces the kisses of the grooves.
Use 6 dB less level and there are no kissing problems.

Cheers Jens

[Don Pearce]

On Wed, 4 Feb 2009 09:26:54 -0800, "Richard Crowley"
> wrote:

><Don Pearce> wrote ...
>> "Jens Rodrigo" wrote:
>>>Slight kissing of the grooves are no problem. What you see is
>>>the surface of the disk. The stylus ball is tracing approximately
>>>in the middle of the v-shaped groove.
>>
>> They had to work that close to the limit? That can't be good.
>
>It was always a tradeoff between amplitude (which translates into
>SNR below the physical limits) vs. playing time. What is the total
>playing time on that side of the disc?

Not sure, but this is just a single, and the dead area at the end of
the track is pretty broad, so they weren't running into space
problems.

>
>And then there was always the problem, particularly with classical
>music, where at the end where one typically finds a grand finale at
>higher dynamic, one is at the inside of the disc where the linear
>velocity is lowest.
>

Not such a big problem for a 45, I guess.

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

[Richard Crowley]

"Don Pearce" wrote ...
> "Richard Crowley" wrote:
>><Don Pearce> wrote ...
>>> "Jens Rodrigo" wrote:
>>>>Slight kissing of the grooves are no problem. What you see is
>>>>the surface of the disk. The stylus ball is tracing approximately
>>>>in the middle of the v-shaped groove.
>>>
>>> They had to work that close to the limit? That can't be good.
>>
>>It was always a tradeoff between amplitude (which translates into
>>SNR below the physical limits) vs. playing time. What is the total
>>playing time on that side of the disc?
>
> Not sure, but this is just a single, and the dead area at the end of
> the track is pretty broad, so they weren't running into space
> problems.

Then maybe it was just sloppy cutting since they could have used
a slightly bigger pitch.

[David Nebenzahl]

On 2/4/2009 9:32 AM Don Pearce spake thus:

> On Wed, 4 Feb 2009 09:26:54 -0800, "Richard Crowley"
> > wrote:
>
>><Don Pearce> wrote ...
>>> "Jens Rodrigo" wrote:
>>>>Slight kissing of the grooves are no problem. What you see is
>>>>the surface of the disk. The stylus ball is tracing approximately
>>>>in the middle of the v-shaped groove.
>>>
>>> They had to work that close to the limit? That can't be good.
>>
>>It was always a tradeoff between amplitude (which translates into
>>SNR below the physical limits) vs. playing time. What is the total
>>playing time on that side of the disc?
>
> Not sure, but this is just a single, and the dead area at the end of
> the track is pretty broad, so they weren't running into space
> problems.

Oh, it's a 45? You didn't tell us that at first.

My reaction to that is, "So what? Who cares?" Keep in mind the vastly
different environments for 45s versus LPs; for the most part, lo-fi
jukeboxes. So long as the damn thing didn't actually skip, nobody was
going to notice little problems like that.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[David Nebenzahl]

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.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[John Williamson]

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.
>
I've heard it a number of times over the years on first play of a vinyl
record, on both 33 and 45 rpm discs, and the pre-echo has always been
*exactly* one revolution ahead of the peak, both on the lead-in and
between tracks or in quiet passages. I'd put it down as an artifact of
either the material of the master deforming slightly while being cut, or
distortion of the plastic while the hot record was cooling after coming
out of the mould. Unless, of course, the feed reel on the tape deck
being used just happened to rotate at the same speed as the turntable.

--
Tciao for Now!

John.

[David Nebenzahl]

On 2/4/2009 10:49 AM John Williamson spake thus:

> 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.
>>
> I've heard it a number of times over the years on first play of a vinyl
> record, on both 33 and 45 rpm discs, and the pre-echo has always been
> *exactly* one revolution ahead of the peak, both on the lead-in and
> between tracks or in quiet passages. I'd put it down as an artifact of
> either the material of the master deforming slightly while being cut, or
> distortion of the plastic while the hot record was cooling after coming
> out of the mould. Unless, of course, the feed reel on the tape deck
> being used just happened to rotate at the same speed as the turntable.

The latter is much more likely. Can't see how the vinyl could deform
that much and still retain an accurate image from the mold.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[Dave Platt]

>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?

Poor quality control from U.S. record suppliers was a large part of
what led me to pretty much stop buying vinyl back in the 1980s.

I became disgusted with the frequent need to return brand-new albums
to the store (often more than once!) in order to get a copy which did
not have objectionable pressing defects.

My impression was that the causes of problems were several-fold:

- Cutting the master with too much modulation (such as the case
you've noticed). This didn't seem to happen too often, but it
did happen sometimes, and was not limited to U.S. pressings (I got
one from Island U.K. which was cut so hot that it was almost
impossible for even a good cartidge to track).

- Poor-quality vinyl stock. This became a really serious issue
during the OPEC oil embargo in the 1970s, as the price of "virgin"
vinyl soared, and most record-makers started using an increasingly
large amount of "regrind" from recycled-and-shredded LPs in their
vinyl mix. I once got a copy of Mike Oldfield's "Hergest Ridge" LP
which had a chunk of paper sticking up out of the groove... they'd
clearly re-ground at least one record into the vat without removing
the entire label area properly :-)

I don't think that the vinyl quality of U.S. mainstream LPs ever
fully recovered after the embargo ended.

- High levels of noise in the groove, which I suspect was due to a
combination of worn stampers and too-fast pressing cycle times
(inadequate time for the hot vinyl to fill the grooves and solidify
properly).

- Scuffs, dirt, and dust from poor handling during manufacture.

I have a feeling that the high cutting levels of some U.S. pressings
may have been in part an attempt to reduce the impact of the noisy
vinyl.

For quite some time, I bought almost all of the music I liked on
imported pressings. European pressing plants, and (especially!)
Japanese ones, were turning out pressings that were quieter and
sounded much better than the U.S. equivalents. It was worth it to me
to pay an extra dollar or three for an import copy of an album I
really wanted, and I dealt with an importer (Greenworld / Paradox in
Torrance, CA) which carried 'em.

Unfortunately, the RIAA and the U.S. labels made a stink about these
"parallel" imports, claiming that the importing of same was an
infringement of the labels' exclusive U.S. license to distribute many
titles. The U.S. government cracked down (I understand that Customs
started seizing shipments), and it became essentially impossible to to
buy an out-of-country pressing of any title which was licensed to a
U.S. label.

I was quite unhappy with the situation and stopped buying music
almost entirely... didn't start again until several years into the CD
era.

--
Dave Platt > AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[David Looser]

"David Nebenzahl" > wrote in message
s.com...
> On 2/4/2009 10:49 AM John Williamson spake thus:
>
>>>
>> I've heard it a number of times over the years on first play of a vinyl
>> record, on both 33 and 45 rpm discs, and the pre-echo has always been
>> *exactly* one revolution ahead of the peak, both on the lead-in and
>> between tracks or in quiet passages. I'd put it down as an artifact of
>> either the material of the master deforming slightly while being cut, or
>> distortion of the plastic while the hot record was cooling after coming
>> out of the mould. Unless, of course, the feed reel on the tape deck being
>> used just happened to rotate at the same speed as the turntable.
>
> The latter is much more likely. Can't see how the vinyl could deform that
> much and still retain an accurate image from the mold.
>
>
I've met that as well, pre-echo exactly one revolution of the disc ahead. It
would seem to be a remarkable co-incidence if all tape spools revolve at
exactly 33 1/3rd rpm! I'm not sure that the fact that you don't understand
the process is important.

David.

[Arny Krueger]

"David Nebenzahl" > wrote in message
s.com

>> I've heard it a number of times over the years on first
>> play of a vinyl record, on both 33 and 45 rpm discs, and
>> the pre-echo has always been *exactly* one revolution
>> ahead of the peak, both on the lead-in and between
>> tracks or in quiet passages. I'd put it down as an
>> artifact of either the material of the master deforming
>> slightly while being cut, or distortion of the plastic
>> while the hot record was cooling after coming out of the
>> mould.

The former being the most likely. Remember that when hot plastic is being
deformed to create grooves, it is being supported by the die. When the
lacquer is being cut, the previous groove is not being supported by anything
but air.

>> Unless, of course, the feed reel on the tape deck
>> being used just happened to rotate at the same speed as
>> the turntable.

Unlikely.

> The latter is much more likely. Can't see how the vinyl
> could deform that much and still retain an accurate image
> from the mold.

Heat and pressure backed up by solid metal can really work! ;-)

[1D10T]

<Don Pearce> wrote in message news:4992beba.108434515@localhost...
>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

If you have a scanner, use it to get a good image of the record:
http://www.photosig.com/go/photos/view?id=29473&forward=viewportfolio

[Iain Churches[_2_]]

"David Nebenzahl" > wrote in message
s.com...
> On 2/4/2009 10:49 AM John Williamson spake thus:
>
>> 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.
>>>
>> I've heard it a number of times over the years on first play of a vinyl
>> record, on both 33 and 45 rpm discs, and the pre-echo has always been
>> *exactly* one revolution ahead of the peak, both on the lead-in and
>> between tracks or in quiet passages. I'd put it down as an artifact of
>> either the material of the master deforming slightly while being cut, or
>> distortion of the plastic while the hot record was cooling after coming
>> out of the mould. Unless, of course, the feed reel on the tape deck being
>> used just happened to rotate at the same speed as the turntable.
>
> The latter is much more likely. Can't see how the vinyl could deform that
> much and still retain an accurate image from the mold.
>

Well actually, its the master acetate that deforms. This is carried
through to matrix, and stanpers to the vinyl pressing.

Tape pre-echo can be easily eliminated by leadering up tight to the start
of the music.

Iain

[Don Pearce[_2_]]

On Wed, 4 Feb 2009 13:36:07 -0600, "1D10T" > wrote:

>
><Don Pearce> wrote in message news:4992beba.108434515@localhost...
>>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
>
>If you have a scanner, use it to get a good image of the record:
>http://www.photosig.com/go/photos/view?id=29473&forward=viewportfolio
>

My old scanner only manages 1200dpi, so it is nothing like as good as
my picture.

Couldn't open your link without registering, BTW, and I don't do that.

d

[1D10T]

<Don Pearce> wrote in message news:4989f986.809312@localhost...


> My old scanner only manages 1200dpi, so it is nothing like as good as
> my picture.
>
> Couldn't open your link without registering, BTW, and I don't do that.

Here's one you don't need to sign in to see:

http://flickr.com/photos/joearnold/3253546109/

[David Looser]

"Dave Platt" > wrote in message
...
>
> Poor quality control from U.S. record suppliers was a large part of
> what led me to pretty much stop buying vinyl back in the 1980s.
>
<snip>

> I was quite unhappy with the situation and stopped buying music
> almost entirely... didn't start again until several years into the CD
> era.
>
> --
Pretty much my experience, except that I was in the UK.

After the crap that was sold as LPs, CDs were a revelation. Not only no
clicks, pops, crackle, whooshes and thumps (all pressed into the vinyl, not
due to poor handling) but significantly less distortion and a clearer, more
listenable sound. The added bonuses were the end of spending time with a
cleaning brush and having to be so careful with the pick-up, plus the
smaller size and the longer uninterrupted playing time.

Why *anyone* still wants to mess with vinyl is totally beyond me.

David.

[Dave Platt]

In article >,
David Looser > wrote:

>>> I've heard it a number of times over the years on first play of a vinyl
>>> record, on both 33 and 45 rpm discs, and the pre-echo has always been
>>> *exactly* one revolution ahead of the peak, both on the lead-in and
>>> between tracks or in quiet passages. I'd put it down as an artifact of
>>> either the material of the master deforming slightly while being cut, or
>>> distortion of the plastic while the hot record was cooling after coming
>>> out of the mould. Unless, of course, the feed reel on the tape deck being
>>> used just happened to rotate at the same speed as the turntable.
>>
>> The latter is much more likely. Can't see how the vinyl could deform that
>> much and still retain an accurate image from the mold.
>>
>>
>I've met that as well, pre-echo exactly one revolution of the disc ahead. It
>would seem to be a remarkable co-incidence if all tape spools revolve at
>exactly 33 1/3rd rpm! I'm not sure that the fact that you don't understand
>the process is important.

I've read that this sort of LP pre-echo can occur as a result of the
original lacquer-cutting process during the making of the master. The
cutting stylus cannot do a perfect, side-effect-free job of cutting
the groove - that is, it cannot magically remove the unwanted portion
of the lacquer while having no effect at all on other portions of the
lacquer. There's some amount of "pushing aside" action, which
deforms the un-cut part of the lacquer - pushing some of it "inwards"
(towards the as-yet-uncut part of the master disc) and pushing some of
it back "outwards" (towards the groove that was cut one revolution ago).

If the pitch between the grooves is too narrow, this pushing of the
lacquer will have the effect of deforming the inner wall of the
previous groove... in effect, "imprinting" the modulation from this
groove upon the previous groove.

This unwanted adjacent-groove modulation effect becomes a permanent
part of the lacquer, is carried over into the metallization process
and the the creation of the mold/stampers, and is molded into every
piece of vinyl created from those stampers.

--
Dave Platt > AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[Mr.T]

"Dave Platt" > wrote in message
...
> I've read that this sort of LP pre-echo can occur as a result of the
> original lacquer-cutting process during the making of the master. The
> cutting stylus cannot do a perfect, side-effect-free job of cutting
> the groove - that is, it cannot magically remove the unwanted portion
> of the lacquer while having no effect at all on other portions of the
> lacquer. There's some amount of "pushing aside" action, which
> deforms the un-cut part of the lacquer - pushing some of it "inwards"
> (towards the as-yet-uncut part of the master disc) and pushing some of
> it back "outwards" (towards the groove that was cut one revolution ago).
>
> If the pitch between the grooves is too narrow, this pushing of the
> lacquer will have the effect of deforming the inner wall of the
> previous groove... in effect, "imprinting" the modulation from this
> groove upon the previous groove.
>
> This unwanted adjacent-groove modulation effect becomes a permanent
> part of the lacquer, is carried over into the metallization process
> and the the creation of the mold/stampers, and is molded into every
> piece of vinyl created from those stampers.

Yep, just one more reason to prefer CD's :-)

MrT.

[Karl Uppiano[_2_]]

"Don Pearce" wrote in message news:4993c85e.110902812@localhost...
> On Wed, 4 Feb 2009 17:44:16 +0100, "Jens Rodrigo"
> > wrote:
>
>>Don Pearce <news:4992beba.108434515@localhost...> 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?
>>
>>
>>Slight kissing of the grooves are no problem. What you see is
>>the surface of the disk. The stylus ball is tracing approximately
>>in the middle of the v-shaped groove.
>>
>>Cheers Jens
>>
>
> They had to work that close to the limit? That can't be good.

I think they had automated lathe pitch control that would preview the
upcoming audio and space the grooves optimally to maximize dynamic range and
recording time.

[Karl Uppiano[_2_]]

"Richard Crowley" > wrote in message
...
> <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?
>
> Back in the 1970's Shure sent out marketing people to local stereo
> shops demonstrating how good their latest phono cartridge (V15?)
> was. The show was great until I brought them my "killer album",
> (IIRC Neil Diamond "Taproot Manuscript") which had an extreme
> guitar transient in the intro to one of the songs. They never found a
> solution to tracking that song. My Stanton at home came closer
> to success than their pickup.

I'll have to fetch my copy and see about that. I don't remember any
trackability problems with that album. I had Shure V15 type IIIs and IVs in
those days.

[Karl Uppiano[_2_]]

"1D10T" > wrote in message
...
>
> <Don Pearce> wrote in message news:4989f986.809312@localhost...
>
>
>> My old scanner only manages 1200dpi, so it is nothing like as good as
>> my picture.
>>
>> Couldn't open your link without registering, BTW, and I don't do that.
>
> Here's one you don't need to sign in to see:
>
> http://flickr.com/photos/joearnold/3253546109/

If you want to see some really gnarly grooves, go find a copy of
Tchaikovsky's 1812 Overture on Telarc. One of the cannon blasts looks nearly
at right angles to the direction of travel. I have to increase my tracking
force to two grams to play it without skipping. The sound is spectacular,
though.

Oh, and they leave plenty of space between *those* grooves, I must say...

[D.M. Procida]

David Looser > wrote:

> Why *anyone* still wants to mess with vinyl is totally beyond me.

* some things are only available on vinyl (or shellac)
* playing records can be more fun
* record players can be beautiful to look at
* records smell nice and have bigger sleeves

Daniele

[UnsteadyKen[_3_]]

Richard Crowley wrote...

> The show was great until I brought them my "killer album",
> (IIRC Neil Diamond "Taproot Manuscript") which had an extreme
> guitar transient in the intro to one of the songs. They never found a
> solution to tracking that song. My Stanton at home came closer
> to success than their pickup.

Just had a listen and the most likely canditate is "I am the lion":
African drum intro, deep bass voice, "Hey hey, Bobbaladinga" Keraaang!

'Tap Root' really is an excellent album, the African Trilogy is one of
those perfect album sides which demands to be listened to as whole.
Super recording too and "African Suite" is one of the best orchestral
compositions in popular music.
Young kids absolutely love it, they sit enthralled from the opening
roll of thunder to the closing frog.

--
Ken

http://www.geocities.com/unsteadyken/

[Arny Krueger]

"Richard Crowley" > wrote in message

> <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?
>
> Back in the 1970's Shure sent out marketing people to
> local stereo shops demonstrating how good their latest
> phono cartridge (V15?) was.

AFAIK, there were at least 5 different V15s, 3 or 4 came out during the 60s
and 70s.

> The show was great until I
> brought them my "killer album", (IIRC Neil Diamond
> "Taproot Manuscript") which had an extreme guitar transient in the intro
> to one of the songs. They
> never found a solution to tracking that song. My Stanton
> at home came closer to success than their pickup.

That's pretty strange (but I'll take your words at face value) because IME
Stantons weren't that great at tracking.

Furthermore, Shure kept at it, and continued to make significant
improvements in the tracking of their cartrdiges.

A friend gave me a Stanton 681EEE with a stylus assembly that worked but not
well, and another stylus assembly NOS, NIB that was quite amazingly totally
dead. I'm under the impression that Stanton stylus assemblies are passive,
so finding one that seemed to be normal, but had zero output is really
weird.

[Brian Gaff]

I often used to wonder about the out of phase effects on some records,
because in theory, these make the groove deeper and shallower, I'd imagine.
As for grooves actually intersecting, this would surely have shown up on the
master, I'd think. I had some issues in the 70s with that Pye plant pressing
records with bits of paper clearly poking out in some places. So much for
quality control of recycled Vinyl.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
<Don Pearce> wrote in message news:4994cd6c.112197171@localhost...
> On Wed, 04 Feb 2009 17:10:13 GMT, "Brian Gaff"
> > wrote:
>
>>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.
>>Brian
>
> Just my own system and I have always been careful. I have a few vinyl
> LPs that start loudly, and the opening chord is distinctly audible one
> revolution before the actual start.
>
> d

[Brian Gaff]

Its not always the tape though. You can on one particular LP my mother had
by Frank Sinatra, hear the tape hiss come in just before the start of the
sound, but one turn prior to that, you can hear the sound as well. Its far
too much of a coincidence it would be one turn as well.
I cannot play these games any more unfortunately.
I have to use a Technics sl5 with an Ortofon Cart these days. Its showing
signs of the dreaded sticky lubricant as well. Needs its arm serviced.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"David Nebenzahl" > wrote in message
s.com...
> 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.
>
>
> --
> Personally, I like Vista, but I probably won't use it. I like it
> because it generates considerable business for me in consulting and
> upgrades. As long as there is hardware and software out there that
> doesn't work, I stay in business. Incidentally, my company motto is
> "If this stuff worked, you wouldn't need me".
>
> - lifted from sci.electronics.repair

[David Nebenzahl]

On 2/5/2009 11:57 AM Brian Gaff spake thus:

> Its not always the tape though. You can on one particular LP my mother had
> by Frank Sinatra, hear the tape hiss come in just before the start of the
> sound, but one turn prior to that, you can hear the sound as well. Its far
> too much of a coincidence it would be one turn as well.
> I cannot play these games any more unfortunately.
> I have to use a Technics sl5 with an Ortofon Cart these days. Its showing
> signs of the dreaded sticky lubricant as well. Needs its arm serviced.

Can't fix it with a couple spritzes of contact cleaner judiciously applied?


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[Mr.T]

"Arny Krueger" > wrote in message
...
> > Back in the 1970's Shure sent out marketing people to
> > local stereo shops demonstrating how good their latest
> > phono cartridge (V15?) was.
>
> AFAIK, there were at least 5 different V15s, 3 or 4 came out during the
60s
> and 70s.
>
> > The show was great until I
> > brought them my "killer album", (IIRC Neil Diamond
> > "Taproot Manuscript") which had an extreme guitar transient in the intro
> > to one of the songs. They
> > never found a solution to tracking that song. My Stanton
> > at home came closer to success than their pickup.
>
> That's pretty strange (but I'll take your words at face value) because IME
> Stantons weren't that great at tracking.
>
> Furthermore, Shure kept at it, and continued to make significant
> improvements in the tracking of their cartrdiges.

Yep, Stanton never made a cartridge that came close to a V15VMR!
And IME a 681EEE was not as good as a V15III in the seventies.
Also My V15III at the time had no trouble with Tap Root Manuscript.
Shure's own "Audio Obstacle Course" was a more difficult test.

Maybe the Stanton had already damaged the record, and was tracking at twice
the weight!

MrT.

[Karl Uppiano[_2_]]

"Brian Gaff" > wrote in message
m...
> I often used to wonder about the out of phase effects on some records,
> because in theory, these make the groove deeper and shallower, I'd
> imagine. As for grooves actually intersecting, this would surely have
> shown up on the master, I'd think. I had some issues in the 70s with that
> Pye plant pressing records with bits of paper clearly poking out in some
> places. So much for quality control of recycled Vinyl.

Left and right channels out of phase will cause vertical groove modulation,
making the groove deeper and shallower. If you ever looked at stereo on an
oscilloscope in x-y mode, which pretty much displays the motion of the
stylus (if you're using a stylus ;-) you will see that the stylus moves in
all directions with normal stereo. The audio looks like a cotton ball on the
screen. In x-y mode, L=R (in phase) is normally a diagonal line going up to
the right; L=-R (out of phase) is normally a diagonal line going up to the
left.

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). But just in case, I do believe that record
cutters did blend left and right channels in the low frequencies, to reduce
the risk of the cutter leaving the surface entirely.

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...

[Dave Plowman (News)]

In article >,
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 >,
> 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