Who here has knowlege in MINIDISC HEADUNITS?
03-01-2002, 12:16 AM
#41
Originally posted by jmax
Sorry, I haven't answered any questions of the specifics of MD because I don't keep current on items that are useless to me. So if you asked a question I didn't answer, that's why. It's also why I asked the exact compression ratio, and storage capacity of the MD. If you asked if I have ever had a CD degrade with age, the answer is no. I've also never had a problem with a tape melting in the car, but haven't stored tapes in the car for at least a half dozen years. I have had a 4 wheel drive truck, with truck suspension. No skips from the CD. The CD was installed when it was5-6 years old and continued to do so until I last disconnected it after another two plus years.
And like I said before, FM broadcast is limited to 50-15000 Hertz, so a tape deck can definitely exceed FM modulation. So there is a flaw somewhere if you think an MD sounds the same with the FM modulator, as the CD from the headunit.
Sorry, I haven't answered any questions of the specifics of MD because I don't keep current on items that are useless to me. So if you asked a question I didn't answer, that's why. It's also why I asked the exact compression ratio, and storage capacity of the MD. If you asked if I have ever had a CD degrade with age, the answer is no. I've also never had a problem with a tape melting in the car, but haven't stored tapes in the car for at least a half dozen years. I have had a 4 wheel drive truck, with truck suspension. No skips from the CD. The CD was installed when it was5-6 years old and continued to do so until I last disconnected it after another two plus years.
And like I said before, FM broadcast is limited to 50-15000 Hertz, so a tape deck can definitely exceed FM modulation. So there is a flaw somewhere if you think an MD sounds the same with the FM modulator, as the CD from the headunit.
03-01-2002, 12:23 PM
#42
Ok, first, this is not targeted at jmax, as I found it quite interesting (and hopefully the other people reading this thread will). It was something I had never done but was always curious about. Jmax just finally got me to do it. I decided I'd try to compare the waveforms of a CD, MD, and MP3 of the same song. I don't have any classical music on CD at school, so I settled for some rock. I used track 5 from the Stone Temple Pilot's album titled No. 4. I used my shelf system to make a copy of the track from the CD onto a MD. Then I recorded the CD and MD onto my computer by using the headphone out of my stereo and the sound in jack on my computer. I used iTunes to create a 192 kbps mp3 directly from the CD. I then fired up an audio app and went to the same section of the song to compare the waveforms, and I was pretty surprised at what I found.
You can all look for yourselves at http://www.z3d.com/stuff/wave_comparison.jpg
All the waves are the right channel of audio. The wave on the top is from the MD. The wave in the middle is from the CD. The wave on the bottom is from the mp3 I made.
Enjoy
You can all look for yourselves at http://www.z3d.com/stuff/wave_comparison.jpg
All the waves are the right channel of audio. The wave on the top is from the MD. The wave in the middle is from the CD. The wave on the bottom is from the mp3 I made.
Enjoy
03-01-2002, 01:16 PM
#43
Guest
Posts: n/a
Originally posted by zboy
I said it is unnoticeable because of the quality (or lack?) of the Bose system, especially once the car gets moving. That would probably be the flaw you were referring to. If you have never spent the time to listen to a MD, then I don't think you should go around saying bad things about them. They really can't be compared to mp3's. Just because they are compressed does not mean they sound worse. A MD recording sounds nothign like an mp3. That's why even though I can download songs of the internet and just dump them onto a MD I don't usually do it, because it sounds alot worse than if I make a copy from the original CD. The algorithm (ATRAC) is completely different than other formats like mp3. Would you argue that an mpeg movie file is lower (or similar) in quality then an avi or mov that has half as much data?
Like I mentioned in an earlier post, MD's are near 300 kbps (292162.5 bits/sec) which is approx. twice data of the average compressed mp3. Plus the fact that ATRAC is a much better algorithm. A MD stores about one fifth the data on a CD. However, like I already mentioned, ATRAC only compresses the audio you'll actually hear to begin with, so the compression ratio isn't really that high. In fact, you could say ATRAC doesn't even necessarily compress the audio, it simply removes enough of the junk data present (sounds the ear won't hear and sounds masked by other sounds) so that the resulting data is 1/5 the size. ATRAC also encodes the left and righ channels separately unlike other compression formats. Even after being recorded onto a MD, a standard Dolby Surround source will retain it's surround characteristics and separate properly. I doubt an mp3 retains enough data to achieve that. And if FM is 50-15000 Hz, a tape only has a 20 Hz advantage at the low end (30 instead of 50)..not a huge difference.
I said it is unnoticeable because of the quality (or lack?) of the Bose system, especially once the car gets moving. That would probably be the flaw you were referring to. If you have never spent the time to listen to a MD, then I don't think you should go around saying bad things about them. They really can't be compared to mp3's. Just because they are compressed does not mean they sound worse. A MD recording sounds nothign like an mp3. That's why even though I can download songs of the internet and just dump them onto a MD I don't usually do it, because it sounds alot worse than if I make a copy from the original CD. The algorithm (ATRAC) is completely different than other formats like mp3. Would you argue that an mpeg movie file is lower (or similar) in quality then an avi or mov that has half as much data?
Like I mentioned in an earlier post, MD's are near 300 kbps (292162.5 bits/sec) which is approx. twice data of the average compressed mp3. Plus the fact that ATRAC is a much better algorithm. A MD stores about one fifth the data on a CD. However, like I already mentioned, ATRAC only compresses the audio you'll actually hear to begin with, so the compression ratio isn't really that high. In fact, you could say ATRAC doesn't even necessarily compress the audio, it simply removes enough of the junk data present (sounds the ear won't hear and sounds masked by other sounds) so that the resulting data is 1/5 the size. ATRAC also encodes the left and righ channels separately unlike other compression formats. Even after being recorded onto a MD, a standard Dolby Surround source will retain it's surround characteristics and separate properly. I doubt an mp3 retains enough data to achieve that. And if FM is 50-15000 Hz, a tape only has a 20 Hz advantage at the low end (30 instead of 50)..not a huge difference.
03-01-2002, 06:59 PM
#44
Originally posted by jmax
Thanks, that's what I've been looking for. As I said before, there was no FAQ's link on the MD site. I still wouldn't use it myself because the convenience issue for me is irrelevant. I'll try to take a look at the wave forms if my Win 98 doesn't crash a third or fourth time today. But, since the compression basically averages between the points that it records, I think we would have to magnifiy the wave significantly to see the differences. The differences in sound quality are technically unmeasureable. But experienced listeners can tell that they are different. Kinda like how we can't really hear at all below 20 Hz and even 30 hz is almost inaudible. But if we take away or add those frequencies or even lower, the difference is obvious to even average listeners.
Thanks, that's what I've been looking for. As I said before, there was no FAQ's link on the MD site. I still wouldn't use it myself because the convenience issue for me is irrelevant. I'll try to take a look at the wave forms if my Win 98 doesn't crash a third or fourth time today. But, since the compression basically averages between the points that it records, I think we would have to magnifiy the wave significantly to see the differences. The differences in sound quality are technically unmeasureable. But experienced listeners can tell that they are different. Kinda like how we can't really hear at all below 20 Hz and even 30 hz is almost inaudible. But if we take away or add those frequencies or even lower, the difference is obvious to even average listeners.
http://www.z3d.com/stuff/wave_comparison2.jpg
03-01-2002, 08:28 PM
#45
Supporting Maxima.org Member
Join Date: Feb 2002
Location: Gainesville, FL
Posts: 562
Originally posted by zboy
On your suggestion, I zoomed in on the waves a little bit. The original image was a 1:16 scale. I just made another with a 1:4 scale, and it's the begging of the waves in the 1:16 scale image. In the newer pic, the mp3 matches up better, but still not nearly as well as the MD. I also used a high quality mp3..didn't try a 160 kbps yet.
http://www.z3d.com/stuff/wave_comparison2.jpg
On your suggestion, I zoomed in on the waves a little bit. The original image was a 1:16 scale. I just made another with a 1:4 scale, and it's the begging of the waves in the 1:16 scale image. In the newer pic, the mp3 matches up better, but still not nearly as well as the MD. I also used a high quality mp3..didn't try a 160 kbps yet.
http://www.z3d.com/stuff/wave_comparison2.jpg
Thread
Thread Starter
Forum
Replies
Last Post
Max139617
5th Generation Classifieds (2000-2003)
2
08-29-2015 02:55 PM