mohler@druxu.UUCP (MohlerDS) (04/24/85)
This note is a reply to Dick Grantges on his comments to my Article,
also to Andrew Koenig and whoever else demanded sources and anyone else
who is interested. It is also a list of references from which I formed
my opinion.
First, I have no axe to grind. I meant what I said
in Article 3838, that there is absolutely nothing wrong with liking
BOSE 901's for non-critical listening. Second, in Article 3838 I
offered the following invitation; "If anyone still needs evidence
of the flaws of this design, send me mail, there is tons of documentation
on this speaker". I received no mail to date, just some postings. Third,
I suggest that you Dick, go back in the postings and notice that it was
George and Ben whom you challenged, not I. Lastly, several individuals
George Labelle, Herb Chong, myself and several others have taken the
approach: to explain the issues and facts behind the BOSE design flaws
and allow you to think about it. Herb's articles were the most thorough
and accurate I think. Instead, Dick and Andy seem to desire a Quote
from some magazine where a Technical writer, with possibly limited
credentials, draws a conclusion for you. This is not intended to slam
technical writers, it merely refers to the fact that very few audio
magazine reviewers have the training of some engineers and students on the
net. Most engineers would rather know the issues and the theory behind the
issues, so they can draw their own conclusions! Several of you either didn't
read the explanations of the BOSE flaws or you didn't understand why it is
important to the test results or you just ignored them. What was given
is evidence, if you took the time to think about it.
Dick, in my case you said: "I am not a partisan of the BOSE
901. Neither do I believe in your brand of sweeping denunciation backed
only by hot air". This is the first time I have heard facts and physics
called "hot air". I take offense at statements like this that are so
obviously intended as a personal slam and are not true. I further take offense
at you printing that Ill-conceived garbage on the net when I offered my own
time to reply to any mail. In addition, Judging by your comments, I suspect
that you can't refute any of the technical arguments several people took
the time to write. I apologize to those that feel that comments like
the above don't belong on the net, but I took Dick's comments as a
slam without basis, so I chose to expose it. In a speech J.F.K. said
something that applies to you Dick; "Too often people exercise the
privilege of opinion without the discomfort of thought!".
I originally brought up a private study about CD audible differences,
for those who are interested it was Article 3800. I chose at that
time to (nicely) mention some of the BOSE design flaws. My point then
and now is that if you use any transducer to evaluate very subtle
differences in sound between two CD players you had better be very sure
that it doesn't exhibit major flaws in those areas that you are searching
for differences in. For those that are interested there have been several
professionally conducted CD tests and audible differences have been shown
for example: Article 3800.
For those that have asked for sources, in defense of my own
thoughtful opinion, I offer the following technical references:
1. Perception and Geometry, Richard C. Heyser, Audio June 1977
2. Time & Frequency in Loudspeaker Measurements, Richard C. Heyser,
Audio July 1977
3. Doppler Distortion in Loudspeakers, James Moir, Audio August 1976
4. Results on the Audibility of Midrange Phase Distortion in Audio
Systems, Stanley P. Lipshitz et al. University of Waterloo, Ontario
Canada, Audio Engineering society 67th. Convention October 31, 1980
(This university is where Herb is from they do a lot of first
rate audio research!)
5. Audibility of Phase effects in Loudspeakers, H. D. Harwood BBC
Research Department, Wireless World January 1976
6. Stereophonic Image Sharpness, H. D. Harwood, Wireless World
Volume 74 1968
7. Phase Shift in Loudspeakers, James Moir, Wireless World April 1976
8. Time Alignment in Loudspeakers, Ed Long, Audio August 1977
9. Frequency Modulation Distortion in Loudspeakers as a Frequency design
Criteria, Stephen Kurtin, Audio December 1977
10. The Speaker and the Listener, Roy Allison, Stereo Review August 1976
11. Acoustics, L. L. Baranek, This is a masterful and still relatively
accurate text book on acoustic theory.
12. Journal of the Audio Engineering Society Loudspeaker Preprint Book.
Any of the articles on dispersion, driver control and effective mass,
driver diameter vs. dispersion etc. would be good.
Please note that these are articles defending my previously mentioned
Bose design flaws, they do not specifically mention the BOSE design.
I chose articles that are relatively easy to find, so no-one can accuse
me of using un-verifiable references. Before any of you say ahah! no
articles specifically about the BOSE design please see the following:
1. The BOSE 901, Boston Audio Society speaker, you can look up the issues!
2. How to Have the right sound in the right place, Amar Bose, House and
Garden, October 1975. I suspect this was the only magazine at the
time that would publish his propaganda - what a laugh!!
3. The BOSE 901, Martin Colloms, The Loudspeaker Anthology - Hifi Choice
older issues will have reviews.
4. The BOSE 901, High Fidelity, you can look up the issues!
5. Further evidence is the complete disregard for this design in not one
but every High - End audio magazine.
Once again I chose some of the easy to find articles. I chose not to waste
any more time looking up information on a meaningless debate.
There are many other possible references including some real zingers from
Japan, however this should be a reasonable cross-section for those who
were genuinely interested. To those who feel this is inadequate I must
reply; go to the library I wasted enough time on what is simply an
open and shut case. I do not plan to reply to any additional requests
for information, unless it is a serious request. Also, anyone who got
their nose out of joint by reading this can feel free to use the mail
and reply privately. This information wouldn't be on the net except
that is where Dick decided to dump on someone else. Lastly, I don't
intend to further discuss this issue on the net. In parting, lets try to
remember that the net is intended to be a relatively factual and friendly
place to publish general interest articles.
Once again I apologize to the general net readership, maybe this will
be the end of this fruitless discussion! I certainly hope so.
David S. Mohler
AT&T - ISL @ Denver
!druxu!mohler