Talk:Multisided record

The article states "the oldest example of a multiple-groove record [was] issued in 1973." This is obviously in error, because multiple-groove 78s were produced long before 1973.

Arrangement of multiple grooves
I can see that the two (or more) grooves on the same side could either be intermeshed with each other or occupy separate annuli on the disc surface. Further, intermeshed grooves could start/finish anywhere relative to each other. And if they aren't intermeshed, the second groove could start just beyond the end of the first and continue inwards, or it could start at the inside and play outwards so that the ends of the two grooves almost meet.

Which of these techniques has actually been used? -- Smjg 13:46, 17 October 2007 (UTC)

Like most phonograph records, multisided records are intended to rotate clockwise and play from near the edge toward the center. Two (or more) grooves on the same side are intermeshed, starting at the lead-in. They are necessarily the same length, and usually end at the lead-out. Sometimes they end before the lead-out, where they join into a shared single groove that spirals the rest of the way in to the lead-out. The user places the stylus on the lead-in, and it plays whichever groove the stylus happens to be placed in. — Anomalocaris (talk) 02:27, 4 February 2011 (UTC)
 * Necessarily the same length? Why wouldn't it work to have the first groove starting near the edge, and the second groove starting halfway in, both ending at the same place? -- Smjg (talk) 22:40, 20 February 2011 (UTC)
 * If the grooves are interleaved, they necessarily got the same length – in a similar way as the B-side of a Compact Cassette necessarily has the same running time as the A-side. -- Pemu (talk) 17:20, 2 May 2012 (UTC)
 * Repeating the statement doesn't in any way constitute answering the question. Nor does any comparison to cassettes.  A roll of tape is a physical object with a definite length - obviously the two sides of the tape can't be different lengths.  But you can draw a line along the full length of one side of a piece of tape, and draw a line along only some of the other side.  Or likewise, two parallel lines along the same side of the tape, one full length and one partial length.  In the same way, it's physically possible to cut a groove in a record that spirals in from the outside edge like an ordinary vinyl record, and then cut another groove, starting halfway in, interleaved with it. — Smjg (talk) 13:06, 6 October 2012 (UTC)

To me, the articles name "multisided" gives me an impression of a record with grooves that occupy separate annuli. I was linked to here by an article via a link "double-grooved" – the latter name gave me the impression of two grooves interleaved/intertwined, vague thinking of grooves cut by a sewing machine's twin needle. At least the separate annuli type I've seen in reality – on a test record with a big ungrooved annulus in the middle of the record for the purpose of calibrating anti-skating facilities. Hence I propose to enrich the examples by adding the type of grooving (intertwined/separate annuli and, if applicable, abnormal winding (from inner toward outer diameter)) -- Pemu (talk) 17:20, 2 May 2012 (UTC)

Merge
This should really be merged to Unusual_types_of_gramophone_records. --OpenFuture (talk) 09:30, 6 November 2012 (UTC)