phil@amdcad.UUCP (Phil Ngai) (08/05/85)
Recently Phil Karn was accused of audio heresy because a test he participated
in showed no audible difference between CD players. Would the accuser or any
other golden ear care to conduct a blind listening test and report the
results? You can use any two CD players you want, I just want to know if you
can reliably identify which one is which. No need to defend the more expensive
one as sounding better for whatever reason. Just reliably pick out which one
is which. A double blind experiment is preferred. Be sure to match output
levels.
--
I like vegetables that start with "a". Artichokes, avocadoes, etc.
Some of the "b"s are ok, like broccoli, but brussels sprouts are out.
As for cabbage, forget it!
Phil Ngai (408) 749-5720
UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil
ARPA: amdcad!phil@decwrl.ARPArfg@hound.UUCP (R.GRANTGES) (08/05/85)
[] It is, of course, important that not only are the levels matched and the two test discs synchronized, but that one has reasonable certainty that the units are operating correctly. This, to people "from Missouri", suggests tests <not> made in a dealer's show room, however well appointed and/or annointed. -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg
karn@petrus.UUCP (Phil R. Karn) (08/05/85)
I'll make the test even easier for ya. You don't have to tell which player is which, only whether or not there is a difference when switching from one player to the next. Of course, the person who is doing the switching has to be able to simulate the same switching transient even when going from player A to player A, otherwise the lack of a transient would clue the listener that no change had occurred. This can be done by very briefly switching to silence and then coming back, either to the same player or to the other. Be certain that with whatever method you choose, there is no clue from the switching action that gives the listener a clue. Phil
ark@alice.UUCP (Andrew Koenig) (08/06/85)
Addendum to Phil Karn's note: If the levels are not PRECISELY matched, all bets are off. If you did not use a voltmeter to match them, I will strongly suspect your results.
steve@amdimage.UUCP (Steve eidson) (08/06/85)
I hate to disagree with a fellow AMD'er and I'm probably opening
Pandora's box, but recently I found that there is an audible
difference in low-end (under $500) players. Now, I'll be the
first one to admit that there probably shouldn't be a difference
and before last week I'd have told anyone saying there was that
they were full of it.
Anyhow, a good friend of mine has been interested in purchasing
a new player in the past few weeks, and asked me to come along to do
some test listening. So we went to several local shops (no high-end
stores, we weren't interested in how much we could spend), and found
one that had the two players my friend had taken a shine to (Technics
SL-P2 and Yamaha CD-X2). He had narrowed his choice for drawer
mechanics and programming features. He preferred the Technics at first
because of its styling and programming, but both our minds quickly
changed after an A/B test (through the same pre-amp, amp, & speakers)
using a digital recording of the Nutcracker.
The triangle which was crisp and clear using the Yamaha, almost
disappeared when played through the Technics. This was not meant
to be an ad for Yamaha, but there are two new believers in CD
differences.
My suggestion (aside from a double blind A/B test) is to thoroughly
quiz any salesman about the type and number of DACs used as well as
the analog anti-alias filters. Find out whether the DACs are
14-bit or 16-bit, and if interpolation is used or not. Interpolation
relaxes the constraints on the analog output filter since the
aliased signals that must be attenuated are at a higher frequency.
Sloppy filter design will ruin any advantage gained by
interpolation. Two DACs are theoretically better than one.
The most unfortunate thing is that most salesmen don't know
what the hell they're talking about. In one of the stores we
went to, a salesman tried to tell that the Yamaha had three lasers
(it does actually) and the player took a vote on the proper
digital code; best two out of three, majority rules. We couldn't
help laughing at him. When we asked for an owner's manual,
he left pretty quickly.
Happy shopping.
----------
"...but you've got no arms and no legs,
what are you going to do, bleed all over me ..."
Steve Eidson (408) 749-2303
UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!amdimage!steve
ARPA: amdcad!amdimage!steve@decwrl.ARPAwhizzo@mit-eddie.UUCP (David Hardy) (08/08/85)
This is in general response to the slew of messages on which CD player is
better than the next. I've been reading this with some interest for some
time now, but do have some doubts about it all.
I own (gee, do I dare say this in this group) a Technics SL-P7 CD player. So
do a couple of my friends. This machine produces the best sound that I have
ever heard, and at least one of my friends can attest to that also. The other
one I never asked about it. Not to say that EVERY disc sounds phenomenal,
but generally the ones that don't I heard don't sound good on any player.
So, from the idea I get from some of the postings here, this is not a
particularly good CD player. If there is such a difference between machines,
what would I hear if I had a "good" one?
Are my ears shot from listening to lots of loud music? What benefits would I
receive if I were to upgrade the CD player? Would it make lousy disks sound
great? Are my Walkman batteries interfering with my musical judgement? :-)
Does anyone agree with this, or are we on an isolated island in a world filled
with oversampling and digital filtering?
--
-------------------------------------------------------------------------
"An argument is a connected series of statements intended to establish a
proposition. It isn't just contradiction .................. Can be! "
Dave Hardy (whizzo@mit-eddie)
ARPA: whizzo@mit-eddie.ARPA -or- haadav%mitvma@mit-multics.ARPA
CSNET: haadav%mitvma.bitnet@wiscvm.csnet BITNET: haadav@mitvmadavid@daisy.UUCP (David Schachter) (08/09/85)
Here's another data point for the graph: A friend of mine has a Nakamichi CD player he bought a month ago for $1300. I have a Sony D-5 for which I paid $280. We did some simple comparisons, not double-blind, with levels matched by ear-- very crude. We were both hoping to hear the $1300 deck sound better than the D-5. We failed. My friend is not happy. Somehow, he thinks the programmability and the remote control on the Nakamichi is not worth an extra $1000 for him. Perhaps the Nakamichi produces better sound than the D-5 but it is not relevant: we can't hear the difference. To quote Mr. Spock: "A difference which makes no difference is no difference." I make no claims as to accuracy so send flames to the bitbucket. Thanks.
rfg@hound.UUCP (R.GRANTGES) (08/10/85)
[] If you really have been following net.audio you will have observed that the most carefully controlled A-B testing done so far has failed to detect any difference at all (sonically) between two representative first generation designs, the much maligned Sony CDP-101 and the much praised Magnavox (Phillips)...something or other. The last such comparison, fully described on the net as to equipment, test procedure and environment, and material failed to draw a single flame until 3 0r 4 months later when one of the golden ears made a few remarks (including criticism of the material which he had forgotten he had chosen himself). There is,therefore, some reason to suspect that audible differences between units are somewhat exaggerated (i.e., mostly BS). However, this is not yet proven. Far from it. In fact, it is theoretically impossible to prove such a position. There <are> obvious differences between units in such things as control flexibility, structural integrity, convenience features, etc. We hope soon to conduct another careful A-B test with different equipment and involving a comparison of first and second generation machines. In the meantime, enjoy, enjoy. -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg
ark@alice.UUCP (Andrew Koenig) (08/11/85)
Steve Edison says he heard a difference between two CD players in a dealer's showroom. I don't doubt him. I do doubt, though, that it was a fair test. In our testing (smb, jj, bem, llf, rfg, karn, ark), we found that two players sounded different until we accurately matched the levels and synchronized the programs. The apparent differences then vanished. If your dealer did not prove to you that he had used accurate test equipment to match levels, the test is suspect.
greg@olivee.UUCP (Greg Paley) (08/12/85)
> There is,therefore, some reason to suspect that audible differences > between units are somewhat exaggerated (i.e., mostly BS). However, this > is not yet proven. Far from it. In fact, it is theoretically impossible > to prove such a position. > I think that this is the type of thing that's futile to argue in writing on the net. Anyone seriously concerned about sonic differences should attempt to hear them for himself rather than deciding that whoever has the greatest verbal clout must be right. As to the manner of making listening comparisons, it seems to me that the sort of rigorous conditions suggested in other articles should be no more necessary in evaluating CD players than in evaluating speakers or phono cartridges. That is, if it is otherwise that difficult to detect a difference, then that difference can't be that significant to you. I, personally, have been able to hear definite differences between various CD players. However, hearing a difference and making a preference can be two different things altogether since it's rarely the case that the strengths and weaknesses of two different players are so simply stacked up on opposing sides. My own sonic preferences led me to choose the Magnavox 3040 over the Sony 302 or others in the same price bracket. Similarly, I preferred the sound of the Audioquest 404 cartridge over the Shure V15/5MR. On the other hand, the reference system used by the panel who write the "Sounds in Retrospect" column for Gramophone magazine, who could well afford to use whatever they pleased, utilizes the Shure V15/5MR and the Sony CDP-101. Incidentally, my own method of choosing equipment is to use what you might call a "top down" approach. That is, rather than just comparing directly units within my price category, I make a point of trying to listening to the very best available at any price and then try to find the components in my price class which capture the same characteristics as closely as possible. In the case of CD players, I listened to the Revox, Nakamichi, and top NEC and Kyocera models before choosing within my budget. - Greg Paley
jonu@tekchips.UUCP (Jon Udell) (08/13/85)
In article <447@amdimage.UUCP> steve@amdimage.UUCP (Steve eidson) writes: > So we went to several local shops (no high-end >stores, we weren't interested in how much we could spend), and found >one that had the two players my friend had taken a shine to (Technics >SL-P2 and Yamaha CD-X2). He had narrowed his choice for drawer >mechanics and programming features. He preferred the Technics at first >because of its styling and programming, but both our minds quickly >changed after an A/B test (through the same pre-amp, amp, & speakers) >using a digital recording of the Nutcracker. This looks like a good time for me to throw in some comments on the two CD players I have owned: a Magnavox 3030SL and a Technics SL-P2. I liked my Magnavox very much, although it was a little short on features and a few of them bugged me. It appeared to have very good shock resistance - I kept it on a desk, directly above a heavy file drawer which I was able to open and close without causeing mistracking. Unfortunately, some uninvited (and unwanted) guests liked it (and the rest of my stereo) too, and that's the last I saw of it. The first time I looked at the SL-P2, I liked it's features. However, I had brought along a copy of Stravinsky's Rites of Spring (Telarc), and heard some funny noises that I had never noticed before. Besides, I really had my heart set on the new Magnavox 3040. When the 3040 finally reached the stores, I was disappointed. It sounded good, but I didn't like the lack of features (on the remote, especially) or the control panel layout. However, we still heard funny noises on the Telarc disk. After listening to them a few times, we decided that the noises were squeaking chairs in the orchestra (how's that for an example of the benefits/drawbacks of digital recording?). This led me to reconsider the Technics, and I bought one the next day. After six weeks without a CD player, I was in paradise again. However, after only a few hours of use, the SL-P2 started to mistrack. I traced the problem to disk defects - there were several places where paint on the label showed through on the music side. This upset me, both in that I had a defective disk, and in that my new player couldn't track it, while my old player could. I took the player back, and received another. (Tower Records readily exchanged the disk for me, and I'm not even sure that I bought it from them!) (Aside: >The most unfortunate thing is that most salesmen don't know >what the hell they're talking about. Most salesman are also so used to selling to people who don't know what they're buying, that they don't believe you when you tell them that your CD player doesn't work.) The new player was better (it could track the defective disk), but it still did not track as well as the Magnavox had (I had to move the heavy drawer to the other side of the desk). This has lead me to believe that companies that use 3-beam tracking do so not to EXCEED one-beam tracking of other companies, but to MATCH it. Three-beam tracking also leads to a more complex machine, with more parts to break, as I soon found out. The SL-P2 broke (started making mechanical clicking noises and skipping every 2 or 3 seconds) June 2nd (2 and 1/2 months after purchase). I returned it to the store (probably the same chain Steve was at). They promised to mail it to me at my new address as soon as it was returned by Technics (2-4 weeks). After many calls to California about the machine, they finally called Technics and found that they were waiting for parts (from Japan! #$&@). 9 (Nine) weeks after a took it in, they claimed it was ready, and would be mailed to me Monday morning (Aug 5). Well, its now Aug 12, and as of 1:00 pm, the machine has not arrived. In short (I apologize for being so long-winded), I would not recommend a Technics player. I also fail to see how a store that claims "After the sale, it's the service that counts!" can continue to sell the brand (mine isn't the first machine with which they've had this experience). Jon Udell (Maybe Steve (or anyone else down there) could show a copy of this to a salesperson at the store.) -- Jon Udell jonu@tekchips until mid-September -------------------------------------- udell@shasta t.tedium@lotsb
saltiel@cdstar.UUCP (Jack Saltiel) (08/13/85)
The only strategy that makes sense today, is to buy the least expensive unit with the minimum complement of features that you need included. Then in 18 months, when the new technilogical developments have become so overwhelming and you can't resist spending $500-$1000 for a unit that can record, and do other marvels, you won't feel bad about the $250 you spent today. Besides which, you'll be able to copy and edit your CD's with the pair of machines.
steve@amdimage.UUCP (Steve eidson) (08/13/85)
I really don't want to turn this into a heated debate, but
under the conditions of that demo, it was possible to hear a
difference. I'll admit that I didn't watch the salesman the
entire time to make sure the volume level was constant. And
as you stated, without a voltmeter, it's rather futile anyway.
In any case, what both my friend and I heard was a loss of clarity
in the high frequency response of the Technics with respect to
the Yamaha using the same program material.
Granted also that it wasn't a double blind test, as I previously
said we both liked the Technics better before LISTENING to the
CD players. The only other factor that might have made a difference
is the Yamaha amp that was used (maybe Yamaha CD players sound
better connected to Yamaha amps :-)).
Given all of these caveats, I suggest that before you buy any
CD player, you go to a reputable dealer, and listen to them.
----------
"...but you've got no arms and no legs,
what are you going to do, bleed all over me ..."
Steve Eidson [not Edison] (408) 749-2303
UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!amdimage!steve
ARPA: amdcad!amdimage!steve@decwrl.ARPAmohler@drune.UUCP (MohlerDS) (08/13/85)
One must remember there are some very significant differences between CD players other than features, and the debate on sound (which I'm staying the XXIV away from). If you beat-up or torture a disc (In the name of science, of course!) you will find some very large differences in the ability to correct for non-ideal (read real world) disc problems. Also, actual laser tracking can be an issue as well as error-correcting capability. These are items where there is very little room for debate! If a disc plays flawlessly on one unit, and refuses to play at all on another I submit that these differences are indeed audible. As far as a perfect disc on two properly functioning machines in comparison, I submit that the mobile fidelity sound labs comparison (where some differences were heard) was the best conducted and best documented comparison I have heard of. David S. Mohler AT&T - ISL @ Denver drune!mohler or druxu!mohler
smb@ulysses.UUCP (Steven Bellovin) (08/14/85)
> One must remember there are some very significant differences between > CD players other than features, and the debate on sound (which I'm > staying the XXIV away from). If you beat-up or torture a disc (In the > name of science, of course!) you will find some very large differences > in the ability to correct for non-ideal (read real world) disc problems. > Also, actual laser tracking can be an issue as well as error-correcting > capability. These are items where there is very little room for debate! > If a disc plays flawlessly on one unit, and refuses to play at all on another > I submit that these differences are indeed audible. CLearly, this is a valid point, though that's not what's normally meant by "audible differences". It's also worth pointing out that there's no intrinisic reason to believe that CD players should sound identical -- there are, after all, a fair number of electronic widgets in the analog circuitry, including the DACs and the filters. There's plenty of room for substandard design, mismatches between the two channels, etc. (That, of course, raises an interesting point about why one might *want* a single- DAC machine....) I confess, my own guess is that such differences are for the most part not audible, but it can't be ruled out a priori.