33 vs 45 speed quality


I just got into analog recently. My TT is a rega P9 which blows away my cd player for music quality. But...in truth I cannot tell any difference between 33 and 45 speed recordings. Is it just my ears or is my setup to Lowfi? I am using a Mac 6300 integrated amp and audiophysic spark speakers.
csmithbarc
Eldee: Since I don't buy 45 rpm audiophile remasterings, I can only go by what I hear with regular 7" singles vs. the same cuts as album tracks. But the theory isn't unlike that with magnetic tape, where there can be greater dyanamic and frequency range and a better S/N ratio at a higher record/play speed. (I haven't heard a 16 rpm record in years, and never on a good machine, but I'd imagine they would be decidedly low-fi at best.) Due to the more "physical" nature of tracing a groove with a stylus and the tracking errors inherent in most phono playback arrangements, I'm sure the point of diminishing returns (i.e., practical problems) with increasing speed probably sets in earlier with vinyl than with tape (I doubt the kind of speed displayed by computer data-storage tape transports of yesteryear could be approached by any needle and groove arrangement). But the "stretched-out", "big" groove on a 45 demonstrates that at least to a point, the higher rpm system also makes for a hardier medium, sailing through damage that would render an LP unplayable, though not all of this is because of speed per se. BTW, what leads you to think that if a niche audiophile standard for vinyl disks were adopted, it could sound better for encoding *greater* bass amplitude on the record, rather than less? (Well, you don't actually say that, only seem to imply it.) I have no experience with the DBX system, but I assume it also used compression/expansion? Audiophiles would never go for that, and I'd think probably with good reason...
Zaikesman...The DBX compression/expansion process was not a problem because DBX designed both ends. Master tapes for most LPs are made using DBX processing which is considered to be better than Dolby, the other method. So if there is any problem you already have it.

The most obvious advantage of the DBX processing is the elimination of audible surface noise. But there is more. The groove modulation is always near optimum for cartridge performance, which greatly reduces distortion, and mistracking. More playing time can be put on a 12" disc. There are some other advantages which I can't remember off the top of my head.
Well, most master 'tapes' these days are digital, and the ones from the 'golden era' that audiophiles like to buy remasters of largely predate Dolby and DBX. I can well understand how a compression/expansion scheme could aid LP playback in theory, but since modern carts/arms are capable of tracking pre-EQ'ed but uncompressed records without mistracking, and since no analog compression/expansion system can be totally transparent and without losses, I still doubt this would fly in the audiophile marketplace. Personally, I think if you were going to go to the trouble of developing a whole new encode/storage/decode protocol just for audiophiles (this will never, ever happen), you might want to consider an optical analog system.
Zaikesman...My view about DBX records is biased, in that I actually have some. (But the decoder died about ten years ago and I have never fixed it). It is too bad that I can't suggest how you might have this experience. The audio quality is superb, but the catalog was tiny, with few well known artists. Although modern high end cartridges are "capable of tracking..." distortion (short of outright mistracking)is very much a function of modulation amplitude, and limiting dynamic range (of the groove) is very desirable. The electronic reexpansion process may not be perfect, but has much less distortion that that which would occur if the cartridge had to track the uncompressed groove.

Master tapes made before the days of Dolby and DBX were still compressed...manually by the recording engineer (called "Gain Riding"). This avoids peak overload while allowing higher recording level for quiet passages so as to minimize tape hiss. But with this manual compression the results varied according to the engineer doing the recording, and so could not be effectively reversed on playback so as to restore the original dynamic range (although there were expander electronics that tried). By precise control of both the compression and expansion algorithms DBX and Dolby can do the job without audible problems (eg: "pumping").
Eldee, I think we might be blurring a few different topics: Compression (or gain-riding) applied during the recording, mixing, or mastering processes for artistic purposes (to enhance the desired sonic effect); compression (or gain-riding) applied during the recording process for technical purposes (to prevent overload during recording); and compression applied during the mastering process for technical purposes (to prevent overload during playback). And then there's compression applied during radio broadcast for both technical and 'artistic' purposes. I view all of these as being different from complementary compression/expansion, which are mainly used during recording as part of noise-reduction schemes (Dolby A, DBX) and aren't supposed to limit the dynamic range of the resulting master tape (though it may still undergo compression when mastering the record, or CD for that matter). There's also the rather arcane distinction between peak-limiting and compression, which as far as I can tell seems more of a definitional, quantitative one than subjectively qualitative. Anyway, I agree that most recordings we listen to, audiophile pressing or not, probably make use of compression for at least one of the first two reasons I listed at the top -- compression and EQ are the best friends of the recording engineer, producer, and mastering engineer.