Getting Groovy -- Playing Records without a Needle

WillOutPower writes "The New York Times is carrying a story of two physicists at the Lawrence Berkeley National Laboratory developing a method of recording sound from old records (remember spinning your platters on the hi-fi?) but not by playing them, instead taking a picture of them. Or more specifically the groove in the record. The Library of Congress is funding the research, which is in the nascent stages. Now maybe I can throw out that old Victrola in the attic and make room for my clunker i386 PC." We've mentioned this before.

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Re:Another approach

[glen604]

Actually.. Vinyl tends to be mastered with the dj in mind, so they boost the bass for club/large sound systems when it is made. It has nothing to do with whether the sound is analog or digital in origin.

as far as bass goes- very few speakers/subs in existence can produce sound accurately down below 20hz anyway. Most party sound systems are lucky if they hit 35hz-ish with any accuracy, and generally any attempts to produce sounds lower than this just makes the speakers distort. The bass you can feel is pretty much anything below 100hz.

and yes, I'm a dj as well (own about 1000 records), and while vinyl does sound different than cds, it doesn't have better bass just due to it's "analog nature"

Re:Difference?

[shamino0]

Can someone with clue explain to us lay-people how what the article describes is different from what this kid did 'in a couple of late nights'? His software scans the record in using a standard flatbed scanner. Is the new version being goverment funded supposed to able to 'rip' at a better quality, or what exactly is the deal with the government funding on this?

I'm not exactly sure, but this paragraph from the NYT article implies quite a bit:

The team shoots thousands of precise sequential images of the groove and then stitches the images together, measuring the shape of each undulation and calculating the route a stylus would take along the path.

It seems to me that they are taking lots of close-up photos of the grooves. Probably from an oblique angle. This will let you make a 3-D contour map of the record. (Note the image on the NYT article).

When you have a 3-D map, you can decode the variations in the diagonal sides of the groove to extract the stereo audio content.

With a 2-D top-down image, such as what you get from a flatbed scanner, the only data you have is the floor of the groove. For stereo recordings (and probably modern mono ones as well), this contains little more than noise and aliassing.