How is your portable cd player's skip protection? best model?
Christopher Ryan Sidi
Which portable cd player has the best skip protection? What about for
under $200 ? Consumer reports rated the panasonic sl-s180 bump protection
over the sony d-235ck...even though the panasonic has no ESP. But that's
consumer reports.
any other magazine reviews? What do people think of ESP or the dampen-
ing buffers?
What I'm looking for is a portable with great skip protection and possibly
digital out..anyone selling?
Thanks very much,
Chris Sidi
gt6...@prism.gatech.edu please e-mail resonse; I'll post digest/results
--
Christopher Ryan Sidi ---> I'm looking for a cool co-op job <---
36161 Georgia Tech Station ---> that involves EE & CS work! <---
Atlanta,GA 30332 (404)206-1456 home:(704)875-2292 gt6...@prism.gatech.edu
Spanky
happy with it. You really have to thump it to make it skip. I just
put it on the floor of my car (a Honda Civic) and it has never skipped
once under real driving conditions. That includes driving across railroad
tracks everyday. The sound is much better than a cassette, especially
the stereo separation. I paid $190 for it (in Boston).
One note though, it sounds great in my Civic, but in my wife's Jeep
you have to turn up the volume to over 3/4 of a turn to get a decent
volume level. At this volume level, the sound has a lot of hiss and
engine noise. There is a "crosstalk" switch on the cassette adapter that
the instructions say you may have to put in one of three different
positions depending on the cassette player. This doesn't seem to make
any difference, though. I haven't experimented with using the headphones
jack, yet, just the lineout jack.
--
"You're Batman!" getu...@cobra.aer.com
Michael C. Calanan
>From: ande...@msai.com (David Anderson)
>Subject: Re: How is your portable cd player's skip protection? best model?
>Date: 23 Mar 95 13:51:23 GMT
>I've got an Aiwa XP-55. (I've only seen it a Circuit City.) ...It's got EASS
>--
...edit...
>I use it in my car a lot. One thing I've noticed is that, because
>the disc
>spins at double-speed with EASS on, some of the error-correction
>capability
>is lost. (I think this is the case .. maybe its just harder for
>the laser
>to track the pits.) ...Anyway, if a disc is the slightest bit dusty
>or dirty,
>it may skip MORE with the EASS on than with it off. This is especially true
>when added to the constant vibration of a car. ...I've driven 6 hours before
>with the EASS on without a disc skipping at all, but when I put a slightly
>dirty disc (that otherwise wouldn't skip), it skipped numerous times in a
>matter of minutes. I don't know if that's a problem with other
>models or not.
>Just my $.02! ...BTW, does anyone else out there have the Aiwa?
>David Anderson
>ande...@msai.com
I've got the Sony D828K Car Discman with ESP (3 seconds) and have noticed the
same problem with skipping with ESP turned on. I was told the same, that the
increased speed results in decreased error correction capability.
A very nice unit, though, and since the problem seems to be with the technology
and not the machine itself, I would highy recommend the 828K. BTW, I got it
mail order for $219 US from Camera World of Oregon (no affil, just a satisfied
customer).
Camera World of Oregon.
The Camera World Building
500 SW Fifth Avenue
Portland OR 97204
Number is: 503 227 6008 locally, or 1 800 876 7057
I can't remember the name of the salesman that helped me,
but he was VERY helpful. I know that they are Internet and Usenet
friendly, so it might be adventageous to tell them you heard
of them from me on Usenet, at least it saved me shipping costs.
Can't hurt!
-mike
+-------------------------------------------------------+
| Michael C. Calanan cal...@fstrf.org |
| Programmer / Analyst |
| Frontier Science and Technology Research Foundation |
| 4033 Maple Road Amherst NY 14226 |
+-------------------------------------------------------+
David Anderson
buffer, I think. It works great on my desk at work -- I often accidentally hit
it with my elbows or knock it on the floor or something, but it never misses a
beat. You can turn the EASS on and off by the way.
Steve Higgs
ande...@msai.com (David Anderson) wrote:
.
>Just my $.02! ...BTW, does anyone else out there have the Aiwa?
>
>David Anderson
>ande...@msai.com
>
I have the AIWA XP-55 and I am exceedingly happy with it. You did not mention
all of the numerous user-friendly features in your posting. As a matter of
fact, I am listening to it through a stereo right now. It has never skipped
on me. You mentioned some of your CDs were dirty. None of mine are dirty,
except one I spilled coke on once. Your theory about why XP-55 skips
with your dirty CDs sounds plausible. Very interesting!
Jay S
protection..has never skipped on me in my life..and only 189 bux..hella sweet
BBS Login
: foo...@netcom.com (Jay S) wrote:
: >
: > you should all check out the fisher pcd-60..10 second anti skip
: While the fisher model does have superior skip protection, it is too bulky
: and aesthetically unappealing. I prefer the sony D-335 which has a 6 second
: electronic skip protection and is much slimmer in design. It also comes with
: a digital output jack for digital rechordings
I hope you are all aware that any CD player with "electronic skip
protection" utilizes a digitally compressed lossy algorithm to store X
seconds of data stream. This compressed data stream degrades the sound
quality to some degree. If you can't hear the difference, then by all
means go for it, but technically, you are NOT getting the full
information from your CD if the signal has been processed through a lossy
compression algorithm. A lossy algorithm is one in which data is thrown
away in order to achieve high compression. The techniques used attempt
to preserve sound quality as much as possible and it's a highly complex
process. The reason why the data must be compressed is so that the CD
player can store as much "sound" (data) in the buffer. Typically,
continuous tones are not degraded by the process, but transients and
other complex waveforms are the weak point.
--
Darryl R. Lum
dr...@ohana.com
CIS: 76440,45
1993 MR2 Turbo
David R. Greenberg
>I hope you are all aware that any CD player with "electronic skip
>protection" utilizes a digitally compressed lossy algorithm to store X
>seconds of data stream. This compressed data stream degrades the sound
>quality to some degree. If you can't hear the difference, then by all
>means go for it, but technically, you are NOT getting the full
>information from your CD if the signal has been processed through a lossy
>compression algorithm. A lossy algorithm is one in which data is thrown
>away in order to achieve high compression. The techniques used attempt
>to preserve sound quality as much as possible and it's a highly complex
>process. The reason why the data must be compressed is so that the CD
>player can store as much "sound" (data) in the buffer. Typically,
>continuous tones are not degraded by the process, but transients and
>other complex waveforms are the weak point.
>--
>Darryl R. Lum
>dr...@ohana.com
>CIS: 76440,45
>1993 MR2 Turbo
Where does this information come from? It seems that the electronic shock
protection buffers in portable CD players typically store less than a third
the amount of music (in seconds) compared with those of minidisk players.
Given that both types of players probably have similar amounts of physical
memory (due to cost) and the fact that minidisk players DO store compressed
music in the buffer, it doesn't seem likely that the music in a CD player
buffer is compressed. If it is, it is certainly not being nearly as
compressed compared to minidisk (in which ATRAC reduces the data fivefold).
3 seconds of uncompressed music coming off a CD requires 4Mbits of RAM
(0.5Mbyte). This amount of computer memory is worth $20. I'm sure the RAM in
a CD player is cheaper since it needn't be random access or have a fast
access time.
Does anyone know for sure?
-> David
Mark Brindle
: dr...@ohana.com (BBS Login) writes:
: >I hope you are all aware that any CD player with "electronic skip
: >protection" utilizes a digitally compressed lossy algorithm to store X
: >seconds of data stream.
: Where does this information come from? It seems that the electronic shock
[snip]
: Does anyone know for sure?
Nope, I don't know for sure what "any CD player" does; but adding
compress/decompress logic sure seems like an *enormous* amount of
trouble and expense -- just to save a few Mbits of slow/cheap RAM.
...I'll bet *nobody* does it,
Mark
fea...@mcs.com
> Keng Guan Tay (t...@cae.wisc.edu) wrote:
> : foo...@netcom.com (Jay S) wrote:
> : >
> : > you should all check out the fisher pcd-60..10 second anti skip
> : > protection..has never skipped on me in my life..and only 189 bux..hella sweet
> : >
> : While the fisher model does have superior skip protection, it is too bulky
> : and aesthetically unappealing. I prefer the sony D-335 which has a 6 second
> : electronic skip protection and is much slimmer in design. It also comes with
> : a digital output jack for digital rechordings
>
> protection" utilizes a digitally compressed lossy algorithm to store X
> quality to some degree.
***Info deleted***
That is true for some of the CD players. If my memory is correct, the Fisher model
degrades the quality of sound due to its 10 second buffer. But I haven't heard
anything about the Sony versions, well atleast not the ones with 3 second buffers,
degrading the sound. Additionally, I would hesitate in buying *any* Fisher products
anyway :-)
Soren Ragsdale
: I hope you are all aware that any CD player with "electronic skip
: protection" utilizes a digitally compressed lossy algorithm to store X
: seconds of data stream. This compressed data stream degrades the sound
: quality to some degree.
[...]
: The techniques used attempt
: to preserve sound quality as much as possible and it's a highly complex
: process. The reason why the data must be compressed is so that the CD
: player can store as much "sound" (data) in the buffer. Typically,
: continuous tones are not degraded by the process, but transients and
: other complex waveforms are the weak point.
So you'd have us believe that the CD player (usually an ultracompact
portable) is employing this "highly complex process" IN REAL TIME? Even
if it were, do you think that the added cost of a DSP and the engineering
of this lossy compression would offset the cost of, say 250K of extra RAM
in the buffer? I don't buy it. There is _no_ loss or transformation of
data in the buffer.
Marko H. Fong
It definitely sounds better with the skip protection turned off, for
whatever reason.
HUTZLER, BRYAN A
>dr...@ohana.com (BBS Login) writes:
>>I hope you are all aware that any CD player with "electronic skip
>>protection" utilizes a digitally compressed lossy algorithm to store X
>>seconds of data stream.
>
>
> --- Jamie Hanrahan, Kernel Mode Systems, San Diego CA
>Internet: j...@cmkrnl.com (JH645) CompuServe: 74140,2055
I would have though it simply but it into a FIFO buffer with no
compression. If you notice, the Sony CD equipment does not store as much as
their Minidisc equipment. Maybe because the Minidisc is compressed and the
CD is not?!
Bryan Hutzler
bah...@venus.tamu
Wei Soo
: I hope you are all aware that any CD player with "electronic skip
Portable CD players do not do any sort of compression when storing the
data stream coming off the disk.
To ensure that the buffer is always full, the disk is spun faster than normal,
up to 2x in the case of the Fisher unit. This is why there's a pause in the
music when you turn on or off the ESP when a disk is playing. It has to get
the disk up to or down to speed. If you chek out the spec sheet, the battery
life with ESP on is shorter since the unit is drawing more power to spin the
disk faster.
Meng
--
\ -------------------------------------------------------------------
\(*)|\ W. Meng Soo | s...@bnr.ca
\ --_\o Bell Northern Research Ltd. | '91 GTI 16V
\(*)! Ottawa, Canada | "Hakuna Matata"
\ -------------------------------------------------------------------
David Anderson
If you're talking about the Aiwa XP-55 with EASS, then I have the same model.
And there is no compression involved. It simply uses enough RAM to store
about 4 seconds of uncompressed data in a FIFO buffer. There is NO DIFFERENCE
in the way it sounds, unless perhaps you are using dirty or scratched CD's.
I believe in this case, the error detection/correction circuitry cannot
operate as robustly because the data rate is twice as high. Thus, errors
in the bit stream caused by dirt/scratches on the disc are not concealed as
well, and you often get a "chirp" when you hit the errors. Try using a
CLEAN or brand new disc, and there will be no difference between using the
EASS and not using it.
David Anderson
ande...@msai.com
Steve Higgs
so...@GAS.UUG.Arizona.EDU (Soren Ragsdale) wrote:
>BBS Login (dr...@ohana.com) wrote:
>
>: I hope you are all aware that any CD player with "electronic skip
>: protection" utilizes a digitally compressed lossy algorithm to store X
>: seconds of data stream. This compressed data stream degrades the sound
>
>There is _no_ loss or transformation of
>data in the buffer.
Intuitively, I would tend to agree that there is no transformation of
sound in the buffer. However, AUDIO magazine very recenctly reviewed an AIWA,
a FISHER and a SANYO portable CD player. For whatever reason, the AIWA
maintained its perfect frequency response in its memory-storing "EASS" mode,
while the FISHER and the SANYO, both with already less-than-perfect (but still
excellent) frequency response, were found to have a slightly degraded
frequency response in their electronic anti-shock modes. I don't know if this
is due to some sort of compression in the SANYO and the FISHER in anti-skip
mode or not. I believe Audio magazine's frequency response measurements,
although I found the writing and analysis to be absolutely pathetic.