Re: [ARSCLIST] square waves....Re: [ARSCLIST] Libraries disposing of records

[Scott Phillips <scottp@xxxxxxxxxxxxxxxxxxx>]

I remember the early days of doing 24 track or video lockup with time
code, and all the reader problems that went with it. A analog tape
recorder mangles a digital signal 'square wave' to the extreme unless
the EQ is cranked off. Even then, it looks like crap (sorry for the
expletive). As is pointed out here, a square wave is just about
impossible to reproduce from a speaker... So why would anyone ever think
that the typical CD full of them would sound good..?

I recently listened to and imported from the CD as a file a famous rock
track from the 80's that as it turned out I had worked on during
recording with Andy Johns. I still had a cassette of the original final
mix, and the cassette was far superior to the CD. What a dreadful
comment that is. Looking at the directly imported file from the CD, it
was so compressed and hard limited that it was gross.... And sounded
like it. The LP version had no such problems. For that the mastering
engineer applied about 2-3 db of compression on some songs to help bring
the songs in line with one another, but that was all. The 12 hours we
spent on big drum sounds were lost on the CD, and they were the basis
for the track(s)..... But were also the source of all the peaks as well.

Sooooo sad...

Scott



-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of phillip holmes
Sent: Sunday, January 07, 2007 1:08 AM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: [ARSCLIST] square waves....Re: [ARSCLIST] Libraries disposing
of records

A square wave on a record doesn't look like a square because of the
velocity involved--or something--that I can't explain.  A square wave is
built up of stacked "odd integer harmonics" and contains multiple
harmonics.  Somewhere around 12 harmonics, it really looks like a square
wave.  The more harmonics present, the more perfectly formed the square
wave becomes.  A perfect square wave would require infinite bandwidth
and infinitely fast electronics (forget the stylus, we can't even
generate a perfect square wave, only a mathematical representation of
one).  What it looks like on record is fundamentally different from what
a scope shows.  There's no co correlation.  Somewhere I have an email
from Stan Ricker about it.  If I can find it, I'll send it along.
Phillip

Mike Richter wrote:
> Steven C. Barr(x) wrote:
>> ----- Original Message ----- From: "Scott Phillips" 
>> <scottp@xxxxxxxxxxxxxxxxxxx>
>>> Use sound forge or similar and look at a remastered LP at the least,

>>> or a current recording... The results are a LOT of square 
>>> waves<snip>
>>>
>> Would it be possible/practical to record a signal containing "square 
>> waves" (or approximately such)? Can an analog stylus make such an 
>> abrupt right/left turn?
>
> Yes on both counts - but with caveats.
>
> 1. The signal will not be captured perfectly. One needs to define how 
> accurate a capture qualifies as success.
>
> 2. The higher the frequency, the lower the accuracy of capture. The 
> higher the amplitude, the more likely that artifacts will be detected.
>
> 3. The detector (stylus, cartridge and preamp) are sources of 
> imprecision in matching input to output.
>
> NOTE: Ringing can be eliminated by rolling off the highs - another 
> source of inaccuracy.
>
> Mike