On Mar 27, 12:26 pm, "Arny Krueger" wrote:
"duty-honor-country" wrote
in ooglegroups.com
On Mar 26, 9:30 am, "Arny Krueger"
wrote:
"DeserTBoB" wrote in message
25-20 KHz at what level and with how many dBs
tolerance? If you can't provide those two key
addiational parameters, you're talking marketing crap,
not technology.
OK Arnie K- please evaluate this BIC T-4M deck- here is a
complete spec and review writeup- please tell me how the
dB's tolerance and levels shown in these tests, affect
this unit. It seems to have quite wide FR to me.
http://i9.tinypic.com/352re5f.jpg
http://i11.tinypic.com/4dgxj7p.jpg
http://i9.tinypic.com/2qcngyd.jpg
I do value educated, experienced opinions, backed by
fact. There are graphs for various levels and FR. Have
at it. Tell me how this vintage BIC 3.75 IPS cassette
deck, is "junk".
While I'd prefer to actually test the machine up front and personal, the
supplied test report is damning enough.
Please focus your attention on figure 3, the lower two plots, taken at your
preferred operational speed of 3.75 ips.
The upper of the two lower plots is taken at 3.75 ips and 0 dB. It does not
shed any light on response at 20 KHz becasue data stops at 15 KHz, where
response is already a whopping 7 dB down. Response is reasonably flat from
400 Hz to 5 KHz. There is an approximate 1 octave rise that averages about 1
dB, centered at about 100 Hz. This might cause a slight thickening of the
sound of a variety of instruments with strong response in the 100 Hz range,
such as pipe organs, bass guitars, etc.
Treble response is about 3 dB down at 10 KHz, and rolling off at 12 dB or
more per octave. This should be clearly audible as a noticable dulling of
the upper treble range. This will take the live edge off of brushed cymbals,
etc.
The same data taken from a CD burned on a PC and played on a $39 DVD player
is flat within a few tenths of a dB from 20 to 16 KHz, which along with
normal extensions of response outside this range, is sufficient to eliminate
any perceptible change in the sound quality of musical recordings. The same
is true of iPods and portable digital recorders such as the Microtrack
operating on 16/44 .wav files.
A modern digital recorder that was 3 dB down at 10 KHz would be called
"junk" by just about any knowlegeable person. One of the lowest quality
kinds of digital players around is the analog audio section of a computer's
optical (CD or DVD) drive. For years they have all been within 1 dB or
better of flat at 10 KHz. Of course, in digital mode, these same players
are perfectly flat and add no distortion.
I believe this test you asked me to review was published in Audio Magazine,
February 1980. This was prior to the introduction of the CD player by about
3 years.
IME, what really deep-sixed the cassette format in the ears of discerning
audiophiles such as myself was the fact that it was impossible to use a
cassette machine operating at either 1 7/8 or 3 3/4 ips to make sonically
identical transcriptions of a wide variety of CDs. Of course, the same was
true of open reel tape up to at least half track and 15 ips.
Based on my own personal measurements of cassette recorders, this BIC deck
must have been a high point of the development of the cassette recorder and
George W. Tillet (GWT) was a wizard on the test bench.
For example, most cassette tapes shift their characteristics enough from end
to end that GWT had to be very careful how he made his measurements. The
machine was probably carefully adjusted for this exact sample of cassette
tape. Using a different cassette from the same batch, or even removing and
replacing the cassette in the well, might lead to far less impressive
measurements. Compare this with digital recorders that produce the
identically same response with any of very many different pieces of media
from various batches and sources.- Hide quoted text -
- Show quoted text -
yes, I can see the response rolled off at the "0 dB" level
and it looks pretty darn good at the "- 20" level
now, explain why ?
why is it better at -20 dB ?
# 2- believe it or not, in actual listening tests, the cassette deck
is much better sounding than a CD player- I think it has a better
sound. I credit that to, there is more information within the
bandwidth it is operating at. While a CD may be flatter from 20-20k,
the analog tape captures more at 20-15k, than the CD does
and how much is really at 15k-20k to hear ? connecting a signal
generator to headphones and pushing it past 15k, a human being can't
hear anything
or, am I playing it at -20 dB ?
can anyone play it at -20 dB ? is it physically possible ?
someone explain that- my ears are open