SCOUG-HELP Mailing List Archives

<< Previous Message << >> Next Message >>

Date:	Tue, 1 Jun 2004 22:19:31 PDT7
From:	Peter Skye <pskye@peterskye.com >
Reply-To:	scoug-help@scoug.com
To:	scoug-help@scoug.com
Subject:	SCOUG-Help: Re: Audio recording / editing programs?

Content Type: text/plain

=====================================================
If you are responding to someone asking for help who
may not be a member of this list, be sure to use the
REPLY TO ALL feature of your email program.
=====================================================

J. R. Fox wrote:
>
> Peter Skye wrote:
>
> > for LPs that had "long" sides we turned the volume down
> > a dB or two so there were more grooves per inch and hence
> > the thing would fit onto the disc.
>
> Is it possible those sides went to 45 minutes each, *or more* ?

Here's the math.

Your LP has a certain number of inches where the sound goes -- it's the
grooved space between the lead-in (which is where the stylus sets down
and catches the groove at the beginning) and the run-out (which is the
spiral to the looping run-out groove after the music ends). There are
also "spreads" between songs but let's not worry about them.

The groove spacing is in lines per inch. If you master the disc at 275
lines per inch then you can easily multiply that by the number of inches
that the groove uses, and then divide that by 33-1/3 to get the number
of minutes.

We mastered our longer sides at 350 lines per inch, and took the level
down 2 dB so the groove wouldn't be quite as wide and we could put the
grooves closer together. Occasionally, due to low-frequency lpi
expansion, the side wouldn't fit and we'd have to remaster at 375 or
even 400.

I forget the maximum lpi on our Neumann disc mastering lathes but I'm
sure you could get 45 minutes on a side if you wanted to. This was
_not_ a good idea, however; the level had to be taken down quite a bit
so the signal-to-noise ratio was much lower, and a lower-quality stylus
would have more trouble tracking in the smaller groove and you'd be more
prone to have skips.

There were 16-2/3 rpm recordings (half-speed 33-1/3) which were popular
at one time for classical recordings. You can still buy 16-2/3 rpm
phonographs on eBay -- I checked a while back. 16-2/3 was never big
because, except for live recordings, it costs twice as much to produce
twice as much music but the consumers weren't going to pay twice as much
for the album.

- Peter

=====================================================

To unsubscribe from this list, send an email message
to "steward@scoug.com". In the body of the message,
put the command "unsubscribe scoug-help".

For problems, contact the list owner at
"rollin@scoug.com".

=====================================================

Return to [ 01 | June | 2004 ]

SCOUG, Warp Expo West, and Warpfest are trademarks of the Southern California OS/2 User Group. OS/2, Workplace Shell, and IBM are registered trademarks of International Business Machines Corporation. All other trademarks remain the property of their respective owners.