prk@charm.UUCP (Paul Kolodner) (03/12/85)
There was a recent posting asking questions about the Carver CD player which raised other, more general questions concerning CD sampling rate and bit resolution. There has been a great deal of discussion lately concerning these technical aspects. Without getting too involved, I'd like to add a few comments: 1. 14 bits vs 16 bits and oversampling: 14-bit digitization is 4X noisier than 16-bit, but I think that both noise levels are inaudible. However, the oversampling rate DOES affect how the analog electronics deal with the aliases in the input power spectrum. Given constant funds and no other criteria, I'd go for fancier oversampling at the expense of extra bits. 2. Amplifier power: The dynamic range of CD's is overwhelming. At my house, I found that my 100W/channel Sumo - 9 power amp could drive my Mordant-Short Festival 3 speakers to deafening levels in my moderate- sized living room without any trace of distortion. I would bet that 100W/channel is a reasonable minimum for safety. Remember that some amplifiers produce speaker-damaging high harmonics when they clip, so that adequate amplifier power can be quite important. 3. Specific players: I went to Lyric Hi-Fi in NY to find out about CD players. Lyric is an incredible store. Their salespeople are a little less neanderthal than in other places, but their strong suit is the care they put into the acoustic design of the place. The rooms are built out of brick for isolation, have irregular shapes and absorbing materials to avoid resonances, have floating floors to isolater the speakers from everything elase, and the equipment is mounted on shelves attached to brick alls for isolation. Additionally, the doors are of the same construction as those in the meat lockers in butcher shops: heavy and well sealed. Also, no one is allowed in the room when you are there. The guy I talked to assured me of two things: 1. with my pathetic stereo system (<$2500), I wouldn't be able to hear the difference between a good CD player and a cheap one like the Yamaha CD-X2; and 2. The Meridian ($650 typically) was the absolute best. As a demon- stration of his sincerity, he let me into the secret room with the $20,000 system inside to compare. The difference between the Meridian and the $1200 Revox was enormous and obvious. The Meridian produced a spatial definiton and openness that was astounding. The Revox didn't. I don't consider myself the type of person to whom these things are easily apparent or, for that matter, very important. If it's loud, noise-free, and has no distortion, I like it. But, even to me, there was a large difference. Gleeful at the salesperson's first assurance of the inferiority of both my humble self and my lowly stereo system, I ran downtown and bought a Yamaha CD-X2 and am quite happy. If you're better than I am, by the Meridian.
molnar@utflis.UUCP (Tom Molnar) (05/25/85)
Well, I took the plunge. I bought a CD player even though I own one of the best turntable tonearm systems available (Oracle Delphi/SAEC/Dynavector). I decided to step gingerly and bought one of the less expensive Yamaha CD-X2 CD players. The price was right ($490 Cdn). Before buying the unit, I read as many reviews in back issues of audio mags as I could find in the local library. The general opinion of reviewers in the "main stream" (read: non-esoteric) magazines is that CD players all sound alike in general, and differ primarily in the "features". Funny thing was, that when I listened to the Mission, Nakamichi, Philips, Yamaha, Luxman etc CD players - I could *definitly* hear a difference. Now am I imagining this? Or have others found significant differences in the sounds of the various CD players? There was a marked difference in the sound between a Meridian and a Yamaha, between a Nakamichi and a Sony... etc. This difference was primarily in the high end, and in the imaging. The older Yamaha CD-2 is downright shrill. Strings are squeaky, voices shrill, and in general slightly uncomfortable. In fact, I had to turn the treble down because I experienced fatigue. The Mission and Philips players were easier to listen to than the bright Yamaha and Sony (I forgot the Sony model, I think it was a second generation unit). Strings were more natural, voices easier to listen to etc. The Mission and the Nakamichi both exhibited very good imaging. Better than the others I had listened to. I expect this might be attributed to careful filtering techniques (? correct me if I am wrong..). I finally settled on the Yamaha CD-X2 since it is a reliable machine. On the bright side mind you, but I can tame it with my tone controls. Besides I figure I'll move on to a Mission later and give this unit to a friend. I want to see what the third generation machine will be like before I sink lots of cash into CD stuff. I suggest listening to the CD players before buying one. They sure did sound different to me, and they might to you too. Take along (or borrow) a good set of head phones (I used Stax Sigmas) too. I was (am) very impressed with my CD player. Incredible. I paid less than 20% for the CD player than for my turntable and the music quality sure does approach my Oracle. Tom Molnar
rfg@hound.UUCP (R.GRANTGES) (05/29/85)
[] You ought to try making a few of those comparisons in people's homes where you <know> what's going on in the test. You will probably discover, as many of us have, that when you know it is a fair comparison, when you know where all the wires go and what they do, when you know what is and isn't being done to each element, that then all the CD players, or most of them , sound alike. Sure it's possible to make one that sounds different. It's easy to screw up a simple design and add noise and various distortions. But there isn't any obvious advantage in doing so. Tail fins did not adversely affect the performance of cars, they just didn't improve them appreciably, but they did product differentiate. -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg
dw@rocksvax.UUCP (Don Wegeng) (05/30/85)
In article <145@utflis.UUCP> molnar@utflis.UUCP (Tom Molnar) writes: >Funny thing was, that when I listened to the Mission, Nakamichi, Philips, >Yamaha, Luxman etc CD players - I could *definitly* hear a difference. >Now am I imagining this? Or have others found significant differences >in the sounds of the various CD players? As I've stated on the net before, when I was shopping for a cd player I had the chance to A-B several models from several price ranges. I found that the Mission sounded best. I bought the NAD for I found it to be the best sounding unit in my price range. Given that many people cannot hear any difference between, say, amps it does not surprise me that the same statement is made about cd players. I've noticed, though, that many of the consumer stereo magazines seem to be moving away from their previous stand that cd players sound pretty much the same (Audio comes to mind). /Don -- "Old age and treachery will overcome youth and skill." arpa: Wegeng.Henr@Xerox.ARPA csnet: Wegeng.Henr@Xerox.ARPA ns: Wegeng:Wbst207V:Xerox uucp: {allegra,amd,decvax!rochester,princeton}!rocksvax!dw
ron@brl-tgr.ARPA (Ron Natalie <ron>) (05/31/85)
> when you know what is and isn't being done to each element, that then > all the CD players, or most of them , sound alike. BULL! The difference between my original cheapie slp-7 and my neighbors 4x sampling player was very apparent on certain pieces. Just a few days ago we got together three CD players: NEC (4x Oversampling, one of the early models)....$1400 Technics SLP-7 (we have about eight bought when they price plummetted to $300) $ 300 Meridian (2x oversampling, MAGNAVOX with souped up analog circuit) $ 600 Each one of these DEC's sounds different. Noticeably the TECHNICS has a brighter EQ than the Meridian, which is also different than the NEC. While in therory, all the digital sound should be the same, the diffence in the output filtering and analog stages of each manufacturer makes CD's far from being identical. -Ron
ark@alice.UUCP (Andrew Koenig) (06/02/85)
> Just a few days > ago we got together three CD players: > > NEC (4x Oversampling, one of the early models)....$1400 > Technics SLP-7 (we have about eight bought when they price > plummetted to $300) $ 300 > Meridian (2x oversampling, MAGNAVOX with souped up analog > circuit) $ 600 > Each one of these DEC's sounds different. Noticeably the TECHNICS > has a brighter EQ than the Meridian, which is also different than > the NEC. Interesting. Can you tell us: (a) what precautions you took to match the levels of the three players accurately, and (b) whether or not the percieved differences remained when the listeners did not know in advance which machine they were hearing?
dca@edison.UUCP (David C. Albrecht) (06/03/85)
> Given that many people cannot hear any difference between, say, amps > it does not surprise me that the same statement is made about cd players. > I've noticed, though, that many of the consumer stereo magazines seem > to be moving away from their previous stand that cd players sound pretty > much the same (Audio comes to mind). Well, of course, silly if they can't point out differences in the components they review they are asking to go out of business (wether they can really hear them or not). Besides, AUDIO has had an influx in the past year of "Golden Ear" dialogue it's beginning to read like a guide to mid-eastern mysticism. They even have the Auricle section now. Pretty humorous reading. David Albrecht General Electric
ron@brl-tgr.ARPA (Ron Natalie <ron>) (06/04/85)
> > Each one of these DEC's sounds different. Noticeably the TECHNICS > > has a brighter EQ than the Meridian, which is also different than > > the NEC. > > Interesting. Can you tell us: (a) what precautions you took to > match the levels of the three players accurately, and (b) whether > or not the percieved differences remained when the listeners did > not know in advance which machine they were hearing? The listeners did not know in advance which machine they were listening to. We had the capability of hooking any two of the decks up at the same time. The tests done were MERIDIAN vs. NEC and MERIDIAN vs. TECHNICS, as it was the MERIDIAN we were trying to evaluate. It was easy to tell one from the other during the test (but not which was which since the person working the a/b switch didn't show the listener). We attempted to match up the NEC and the MERIDIAN by ear, admittedly the slight level difference would cause problems but, in any case, anyone who would evaluate these would admit that that was not a problem in this case. The tests were done by syncing identical CD's in both players and having a third person work the a/b switch. -Ron
wagner@uw-june (Dave Wagner) (06/06/85)
> > I've noticed, though, that many of the consumer stereo magazines seem > > to be moving away from their previous stand that cd players sound pretty > > much the same (Audio comes to mind). > > Well, of course, silly if they can't point out differences in the components > they review they are asking to go out of business (wether they can really > hear them or not). Besides, AUDIO has had an influx in the past year of > "Golden Ear" dialogue it's beginning to read like a guide to mid-eastern > mysticism. They even have the Auricle section now. Pretty humorous > reading. Now wait just a second! I'm convinced that the guys at Audio really can hear those differences. Check out the following comments by Len Feldman, June 85 Audio (note: emphasis on certain phrases was added by me): "The ADS CD3 ranks *among the best* sounding CD players I have tested thus far; it reproduces well-engineered CDs with *smoothness* and *clarity*. I was particularly impressed with its sound quality during very soft musical passages, where *earlier CD players* have *sometimes* been *less than outstanding*. Boy, that Len Feldman sure has some strong convictions about CD sound! I am especially amazed by the fact that he can perceive these differences between players that he listens to months apart. I hate to point out the obvious, but I am being sarcastic. (It seems that some of our net readers can't recognize sarcasm unless it walks up and punches them in the nose.) Dave Wagner University of Washington Comp Sci Department wagner@washington.arpa {ihnp4,decvax,ucbvax}!uw-beaver!uw-june!wagner
ark@alice.UUCP (Andrew Koenig) (06/07/85)
> We attempted > to match up the NEC and the MERIDIAN by ear, admittedly the slight > level difference would cause problems but, in any case, anyone who would > evaluate these would admit that that was not a problem in this case. You can't successfully match levels by ear. When the two sources get about 1/4 dB apart, level differences stop being perceived as level differences and start being heard as differences in quality.
mike@peregrine.UUCP (Mike Wexler) (08/02/85)
I've been told by a salesperson that the Sony portable Cd player does not produce as good a sound as some of the inexpensive <$300 non-portable units. The reason given was that the Sony only has one laser and the non-portable units have two. Is there any truth to this? Could this have something to to with error-correction? I was under the impression that the Sony portable had this feature. Mike Wexler 15530 Rockfield, Building C Irvine, Ca 92718 (714)855-3923 (trwrb|pesnta|scgvaxd)!pertec!peregrine!mike -- Mike(always a dreamer) Wexler 15530 Rockfield, Building C Irvine, Ca 92718 (714)855-3923 (trwrb|pesnta|scgvaxd)!pertec!peregrine!mike
shauns@vice.UUCP (Shaun Simpkins) (08/08/85)
> I've been told by a salesperson that the Sony portable Cd player does not > produce as good a sound as some of the inexpensive <$300 non-portable units. > The reason given was that the Sony only has one laser and the non-portable > units have two. Is there any truth to this? Could this have something to > to with error-correction? I was under the impression that the Sony portable > had this feature. > Mike Wexler Oh, brother. If it doesn't sound as good, it's not because it has only one laser. They all have only one laser. The closest equivalent to the D-5 is the CDP-70, which like the D-5 is a brick wall filter design, and sells for about the same price. I was told by a Kyocera dealer that Kyocera CD players have better resolution than other players since other players split the laser beam into three components to track the disc, which uses up the least significant bit of the words decoded to figure out where to steer the readout beam. Kyocera, on the other hand, doesn't need a 3 beam tracking system since it mounts its electronics on ceramics which damp out the mechanical system vibrations and lets it recover ALL of the digital word with a single beam system. I awarded this fellow the Golden Shovel prize with a special commendation for reading absolutely nothing in the Kyocera sales brochure. Ignore your dealer's comments. Listen to the blasted thing instead. The wandering squash, -- Shaun Simpkins uucp: {ucbvax,decvax,chico,pur-ee,cbosg,ihnss}!teklabs!tekcad!vice!shauns CSnet: shauns@tek ARPAnet:shauns.tek@rand-relay
tdn@cmu-cs-spice.ARPA (Thomas Newton) (08/12/85)
> I've been told by a salesperson that the Sony portable Cd player does not > produce as good a sound as some of the inexpensive <$300 non-portable units. > The reason given was that the Sony only has one laser and the non-portable > units have two. Is there any truth to this? Could this have something to > do with error-correction? I was under the impression that the Sony portable > had this feature. The Sony D-5's frequency response is 20-20,000 Hz at +1, -3 dB, as opposed to the +0.5, -0.5 dB response found on the Radio Shack and larger Sony players. The "reason" that the salesperson gave you for the difference sounds like a lot of BS. I'd recommend double-checking any advice you get in the future. According to the June 1985 Consumer Reports: The D-5 wasn't as outstanding as the other players in a few respects, but the only audible consequence was a very subtle dulling in the extreme high-frequency range. The sound quality was still top-notch. The D-5 was somewhat less tolerant of dirty or damaged discs than most of the players we tested, and its scan function was slower. But it was fast at locating tracks, and it had an unparalleled immunity to bumps. We could turn it upside down and shake it while it was playing, with no audible effect. We think it would perform well while being carried in its battery pack. (But jogging with it might be too much for the laser mechanism to handle.) Specifications from the advertising brochure for the D-5: Error Correction: Sony Super Strategy Cross Interleave Reed Solomon Code D-A Conversion : 16-bit linear Freq. Response : 20-20,000 Hz, +1,-3 dB Harmonic Dist. : Less than 0.008% Dynamic Range : More than 90 dB Signal-to-Noise : More than 85 dB Channel Sep. : More than 85 dB Wow and Flutter : Below measurable limit I have no connection with Sony, other than as an occasional consumer of their products. -- Thomas.Newton Thomas.Newton@cmu-cs-spice.ARPA