Re: [ARSCLIST] Archiving at double speed

["Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>]

At 11:24 PM 6/22/2006, you wrote:
> "Good quality" is somewhat relative.  For comparisons on various sample-rate
> converters, see here:
>
> http://src.infinitewave.ca/
>
>
> I believe the Sequoia engine is the same as Samplitude's...  Correct me
> Richard, if I'm wrong...

We've had a bit of a discussion of that site on the Ampex list or 
here--I forget which--and I got better results than those shown for 
Sequoia for Samp 8 in some quick testing that I did.

The artifacts are so far below the noise in the application Kevin is 
discussing, that I doubt they would be audible.

I would also downsample and truncate/dither in the same pass and I 
suspect that while measurable differences exist, I'm not sure any of 
them would be audible. As I understand what Kevin is doing, he has 
field recordings made on battery-operated portable recorders. He 
wants to capture all that is there, but he's got a lot of 
them--there's a lot to capture.

While I tend not to do multiple-speed digitization I have done it and 
do it with micro-cassettes as it seems that a microcassette tape at 
2x on a Dragon sounds better than a microcassette on a Sony pocket 
recorder. I am looking at the transcribers, but the ones I saw of 
those several years ago were no better than the pocket machines.

In this case it's hard to beat the noise floor of a Dragon in 
cassette-land. I'd rather have the noise recording limited than 
playback deck limited.

Also, I do SRC for CDs when I transfer at 88.2/24 and then make 
44.1/16 files for the CD. In that way, I've archived my client's 
tapes in a higher quality format.

There are always better and better products. The challenge most of us 
have in the transfer world is there are worse and worse 
tapes--they're not getting better with age (I love the line from 
"Money Pit" where the "Executive Plumber" uses that phrase about plumbing).

The other challenge we have is playback equipment. When the anomalies 
we're discussing are an order of magnitude below the analog playback 
chain anomalies, we need to look there first. I've had a run of bad 
SSS tapes with huge amounts of modulation noise due in part to 
pinning of the tapes.

I think SRC is the least of the worries. One of the last times we 
discussed this I stuck my foot in my mouth and Goran reminded me that 
gap lengths that work at 1x also work at multiple times. It doesn't change.



> Anyway, I don't want to distract from the original thread - sample-rate
> conversion aside, there are plenty of other reasons *not* to use
> double-speed digitization.

And there are plenty of reasons TO use it.

I have an alternate preferred method that drives me crazy, but 
increases throughput. This is for ORAL HISTORY tapes only...not 
quality music or drama tapes.

I run 3-4 tapes simultaneously. I currently have three APR-5000s in 
my studio so I can run 3x 1.88 in/s reels and I have four Dragons so 
I can run 4 cassettes. I have 16 channels of A-D so I'm only using 
half of them.

I run the monitor matrix so that I can listen to one program out of 
each corner in summed mono. I don't do anything else but listen for 
glitches. If I hear something, I write down the machine and the time 
and go back and fix it.

In fact, unedited, unplayed oral histories usually go quite smoothly 
once you figure out what you have to do to get them started.

I will also do the full width of a 1/4" tape in one pass and flip the 
necessary channels -- again this is for a certain group of projects 
that I have repeatedly in house. On the oral history reels, if 
there's going to be a perturbation on playback, it will go across 
both forward and backward, so I only have to listen to forward and 
mark the problem.

One estimate is there's 400,000,000 hours of recorded sound tapes out 
there. We're never going to get to them all. That is probably good in 
some places, but I'd rather we do 2x at 95% quality than 1x at 96% 
quality <smile>. I think our grandkids will probably say the same 
thing...especially being the second generation growing up listening 
to MP3 or worse.

Cheers,

Richard

Richard L. Hess                   email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.