jj@alice.UUCP (04/16/85)
Well, I haven't been reading this part of nutnews for a while, but since I've been getting mail about the A-B test that involved my CD player (gasp, yes, JJ has one of those heathen devices), I figured that I should at least read the comments on the test. I've seen several humorous comments (why is it that some people can't recognize humor when they see it? Kudos to the Bavarian Beagle for making the humor clear.. or will someone take THAT seriously, too?) and two comments about the speakers that were used. Neither of the speaker commentators bothered to notice that headphones were also used, and both saw fit to behave as though they were the one and only guardians of the truth. Nobody in the review claimed that the test was conclusive, in fact, the conditions were carefully explained so that people could draw their own conclusions, and get some idea of the minimum sensitivity necessary to hear a difference. (Face it, the system described is't audiophile, but it's much, much better than 98% (or more) of systems "installed", so there IS useful information contained.) (No, I don't own Bose speakers.) Hedley... Your comments seem to indiciate that your speakers are good enough for the test. Care to explain why? (Or were you really being sarcastic? If so, it seems to me that the sarcasm was not obvious enough, given the attitudes in nut.audio, where superstition masquerades as fact, and physical fact as superstition, experience only counts if you don't have an education in acoustics, and being a researcher in the field of audio means that you are automatically wrong.) That's why I don't contribute to nut.audio anymore. 'nuff said? -- TEDDY BEARS NEED SECURITY BLANKETS, WRAP YOURS TODAY! "I think I'm going to regret this!" ihnp4!icarus!jj
herbie@watdcsu.UUCP (Herb Chong [DCS]) (04/17/85)
In article <3583@alice.UUCP> jj@alice.UUCP writes: >Neither of the speaker commentators >bothered to notice that headphones were also used, and both >saw fit to behave as though they were the one and only guardians of >the truth. i don't remember the type of headphones being posted in the original article. about the only pair of headphones that i am sure almost no-one will dispute as a reference set are stax pro's. having the good fortune to know someone who owns a pair, i use them when i can. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET, EARN: herbie@watdcs, herbie@watdcsu
peters@cubsvax.UUCP (Peter S. Shenkin) (04/19/85)
In article <> jj@alice.UUCP writes: > (a modicum of stuff) > Wait till I tell the folks: jj was back, if only for a visit! I hope it's for longer... life has been too dull for too long around this here newsgroup. "If ya can't stand the fire, don't walk in the flame." (or however it goes....)
caf@omen.UUCP (Chuck Forsberg WA7KGX) (04/19/85)
)i don't remember the type of headphones being posted in the original )article. about the only pair of headphones that i am sure almost no-one )will dispute as a reference set are stax pro's. having the good fortune )to know someone who owns a pair, i use them when i can. ) )Herb Chong... They were comparing CD players, not speakers or phones! Unless both the speakers and phones used block out the same portions of the audio spectrum, the DIFFERENCES should have still been audible unless all the listeners were total tin ears (seems unlikely) or the cat was meowing too loudly. I'd like to hear the results of a similar CD A-B test with the Sony CDP-200 and the Pioneer 900 videodisc/CD player. I would also like to know about any headphones with great sound, reasonable price and 50 to 60 db attenuation of ambient sound. I have a pair of Sony MDR-CD5 that sound great and give maybe 10-30 db attenuation (vs Sen's which have almost NO ambient attenuation) but would like to have more isolation, the better to enjoy CD's in my computer room. -- Chuck Forsberg WA7KGX ..!tektronix!reed!omen!caf Omen Technology Inc 17505-V NW Sauvie IS RD Portland OR 97231 Voice: 503-621-3406 Modem: 503-621-3746
ben@moncol.UUCP (Bennett Broder) (04/22/85)
>)i don't remember the type of headphones being posted in the original >)article. about the only pair of headphones that i am sure almost no-one >)will dispute as a reference set are stax pro's. having the good fortune >)to know someone who owns a pair, i use them when i can. >) >)Herb Chong... > >They were comparing CD players, not speakers or phones! Unless both the >speakers and phones used block out the same portions of the audio spectrum, >the DIFFERENCES should have still been audible unless all the listeners >were total tin ears (seems unlikely) or the cat was meowing too loudly. Wrong. The problem with using the BOSE speakers is not one of frequency response. In fact, it would be foolish to compare CD players on the basis of frequency response because they are all so good in this regard. The primary differences in the sonic performance between various models is caused by phase anomolies introduced when filtering out aliases and smoothing the signal. Less successful designs manifest themselves in a couple of ways: 1. A harshness or hardness to the trebles, particularly noticable on female vocals and violin strings. 2. A loss of precise and stable instrument positions in the stereo image. The BOSE tends to be very forgiving of suboptimal sources, and might lack the resolution to differentiate between the players. More importantly, the quality of the stereo image cannot be judged with any pair of headphones, and is all but impossible to judge with a direct reflecting loudpeaker like the BOSE 901. Of course, the original poster of the comparison did not claim to be providing a definitive review of the players, rather to report the results of an informal comparison. Readers with top quality audiophile equipment might prefer to perform the comparison themselves or to rely on a review done by a professional reviewer using reference quality components. Ben Broder ..ihnp4!princeton!moncol!ben ..vax135!petsd!moncol!ben ..pesnta!moncol!ben
ark@alice.UUCP (Andrew Koenig) (04/22/85)
> The BOSE tends to be very forgiving of suboptimal sources, and might > lack the resolution to differentiate between the players. I would like to see your evidence for this claim.
herbie@watdcsu.UUCP (Herb Chong [DCS]) (04/22/85)
In article <3612@alice.UUCP> ark@alice.UUCP (Andrew Koenig) writes: >> The BOSE tends to be very forgiving of suboptimal sources, and might >> lack the resolution to differentiate between the players. > >I would like to see your evidence for this claim. for starters, by its very design, the Bose 901's are nonlinear phase transducers. the primary sound is from the rear speakers which reflect off of the walls and back into the listening area. great cancellations occur between the back sound wave and the one from the front speaker. there are 8 drivers in the back. even if each were an ideal point source, the combined is anything but, and after reflecting off of uncontrolled wall surfaces with absorption curves that can be wildly different between setups, flat freqency response can't be guaranteed even with equalization. which brings up another point, the supplied equalizer. the drivers in the 901's are 5 inches nominal diameter. equalization must be supplied to bring up the low end and the high end to get flat response. this also means that the 5" drivers are being used well above 10K. yes, plenty of boost will even allow a 10" woofer to play a 15K tone decently, but how much power do you have to supply when the natural roll-off of the driver is 6dB/octave above 5K? so you put high power voice-coils in, as Bose did, which increases mass, which decreases the natural roll-off frequency. fortunately, he uses a sophisticated ducting system to achieve decent low frequency response without equalization, but then massive phase shifts are produced, and the air from the ducts are such high velocity that you can sometimes hear them whistling (depends upon how much other frequencies are being reproduced at the same time). the direct/reflecting principle is very interesting and has some theoretical advantages, but they are hardly ever realized in practice. the equalizer removes some of the variables, but using electrostatic elements and properly designed conventional woofer would have been better from the point of view of reduced driver mass and little or no equalization in the high frequencies. of course, electrostatic elements have a whole set of problems of their own, but they are more appropriate for another discussion. the type of drivers that Omar Bose should have used given his design requirements were horrendously expensive back when he started and notoriously unreliable. quads were about the only option. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET, EARN: herbie@watdcs, herbie@watdcsu
mohler@druxu.UUCP (MohlerDS) (04/22/85)
There is overwhelming evidence that the Bose speaker design is highly
flawed for critical monitoring! That doesn't mean that some people
that like them can't hear, sound after all is subjective (beauty in
ear of listener). The Bose 901 series (any) is virtually worth-less
for critical monitoring (see my previous comments on the net in Re:
A-B CD).
Phase and frequency response as well as speed of the transducers
are much too flawed, to not be the weak and masking link in the comparison.
Dispersion and delta directionality with respect to frequency are also
very poor (yes even with the direct-reflecting idea). If the Bose were
perfect in the previously mentioned areas (which it is far from) it
would still be poor for critical monitoring because of the multiple
driver effect on phase and dispersion as well as the direct-reflecting
design pulling the other weak link (the room) into the comparison much
more than most speakers.
If anyone still needs evidence of the flaws of this design send me mail,
there is tons of documentation on this speaker.
Most headphones have similar problems.
David S. Mohler
AT&T-ISL @ Denver
DRUXU!MOHLERrfg@hound.UUCP (R.GRANTGES) (04/23/85)
[] Considering the alleged "tons of documentation" available, it seems strange you are unable to cite even one when challenged twice. I am not a partisan of the Bose 901. Neither do I believe in your brand of sweeping denunciation backed only by hot air. At least you didn't start talking about Consumers Research. Thanks for that. -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg
ark@alice.UUCP (Andrew Koenig) (04/23/85)
> There is overwhelming evidence that the Bose speaker design is highly > flawed for critical monitoring! Let's see it.
ben@moncol.UUCP (Bennett Broder) (04/23/85)
>> The BOSE tends to be very forgiving of suboptimal sources, and might >> lack the resolution to differentiate between the players. > >I would like to see your evidence for this claim. The BOSE 901 is used in many commercial applications in our area: bars, nightclubs, etc. As such, I have had many opportunities to compare its sound to friends B&Ws, Theils, Celestions as well as to my own ProAcs. First, I think the fact that professionals have chosen the speaker for sound reinforcement is a clear indicator of the speaker's strengths: It has great power handling capability, and puts out reasonably good sound, despite mishandled records played on turntables designed for durability rather than sonic excellence. Second, to my ears, they fall far short of any of the above speakers in terms of imaging, depth, dimensionality, and transient response. Third, the critics have had little good to say about this speaker the last five years. The Absolute Sound has joked about the speaker, and even the mainstream pulications like High Fidelity seemed more impressed that BOSE has been able to update the speaker and keep it a major force in the marketplace than they were about its reproduction. Don't get me wrong, I don't dislike the BOSE 901. What is does, it does well. It is still a reasonable alternative for someone who likes to listen to rock music at high volumes, or for whom the ability to achieve a reasonable stereo image from almost any place in the room is important, or who just like the sound of the speaker. BOSE has sold an awful lot of these speakers, people do like the sound of them. But I don't think you would find any professional who would claim that the speaker is state of the art in upper mid-range and treble detail, or in imaging properties. And these properties, as I pointed out in my previous article, are where the major differences in CD players lie. Ben Broder {petsd,pesnta,princeton}!moncol!ben
karn@petrus.UUCP (04/24/85)
I submit that the discussion has gotten off track. The original purpose of Andy Koenig's posting was to report some results of A/B CD player testing, which of necessity involved a finite number of tests with a finite amount of hardware. Instead of nitpicking his results, how about going out there and re-running his experiments with different speakers and subjects? The more tests that have been done, the larger the body of experience on which to base conclusions. It's easier to piss on a study than it is to do one. Give the guy a break. Phil
rfg@hound.UUCP (R.GRANTGES) (04/24/85)
[] But, Phil, if more tests were run they might show the same results shown in the infamous Bose Experiment. Now, while that wouldn't really <PROVE> anything (because you can never prove that no one can hear a difference under any conditions) it would sure put a crimp in the style of those who want to believe there are differences. It's much better to pursue a red herring,especially if it allows one to defame another good product. That's two good products one can defame (Bose and Sony). And it's a lot more fun. Now what I would like to hear is a no holds barred, flat out AB of a Sony CDP-101 vs a Sony CDP-102. This would pit a mfr against himself. It would be 16 bit 41khz sampling vs 16 bit double sampling with low phase shift filters. I'd like to hear this on a good system (but not a Bose to spare us the same old flames). I will volunteer the CDP-101 and a pretty fair system (*) if someone has a CDP-102 in the area around Holmdel, N.J. and wants to AB. (*) Pioneer 9800, AR-9's - a fair system but one which one golden ear told me could "never give vinyl a chance." I would be delighted with either a positive or negative result. -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg