[78-L] Reversing audio (was: 78-L Digest, Vol 22, Issue 17, was Why I Hate LPs)

[Michael Biel]

Rob Spencer wrote:
> On 7/11/2010 12:00 PM, Steve Barr wrote:
>   
>> A microgroove LP can often develop skips/sticks that arise from
>> (presumably) groove damage...which is (1) invisible to the naked
>> human eye...and (2) impossible to correct?!
>>     
> I had a skip of this type to deal with recently when dubbing a record. 
> Happily, my phonograph has a reverse gear, and in reverse the record 
> didn't skip. I then reversed the resultant file in my sound editor.
>
>
> Rob Spencer

We had a session at ARSC in New Orleans which demonstrated that 
reversing recordings digitally must NOT be done.  They demonstrated how 
a square wave turns into curicules and regular sound waves become almost 
unrecognizable in comparison to the original.  They might sound ok but 
they aren't.   Sound can be reversed in analogue with minimal problems, 
but even there you can run into an absolute-phase issue if you are not 
careful. But NEVER EVER reverse audio in the digital domain. 

Mike Biel   mbiel at mbiel.com