gfxgfx
 
Welcome, Guest. Please login or register.

Login with username, password and session length
logo
 
gfx gfx
gfx
622476 Posts in 25035 Topics by 3555 Members - Latest Member: Spoonito December 10, 2017, 07:42:03 PM
*
gfx*HomeHelpSearchCalendarLoginRegistergfx
Pages: 1 2 3 4 5 [6] 7 8 9 10
 51 
 on: Yesterday at 01:44:50 PM 
Started by Stephen W. Desper - Last post by SloopJohnB
You may also find it of interest that the CD or DVD actually has three dedicated (so-called) tracks or pathways of information. That is, one song is actually represented by three independent pathways on the disc. Each is read and the processor, called a comparitor, looks to see if the information from each of the three readings is the same. If not (due to dust or a scratch) the comparitor will take any two sets of information and discard the third. Since these pathways are in different parts of the surface of the CD, a scratch at one point on the surface will not effect the reading of the same information from one of the other pathways since they are at different areas of the disc. So the comparitor takes any two matching sets of information (bits). If the comparitor cannot read two signals that are equal, it will makeup the missing bits by a process call extrapolation. For extrapolation, the processor looks at the bits right before and right after the missing information and assumes or creates bits that are kind of an average between the two. Thus, the missing data is added back by assumption. All this is call "error correction." There are programs which tell you the error correction rate as you play a CD. On a dirty CD, or one that has be mis-handled by its user, the error correction rate can be quite high, but you never hear it.

Error correction takes time. We humans never hear it, but it does take microseconds to be processed. Error correction requires that the tracing information first be stored so it can be compared. Back when files were being traded for free a case was brought against the file traders with the ruling of the court that no CD could be copied as it violated the copyright law. Technicians and engineers laughed at that ruling since it would mean that you could not play a CD. The court had to change the law to accommodate error correction, because for error correction to work, the CD data must be stored in the player (or recorded). 

I never knew this. Fascinating and clever. Thank you!

 52 
 on: Yesterday at 01:43:21 PM 
Started by Spoonito - Last post by SMiLE Brian
Great, reminds me of the H&V mixer! Cool

 53 
 on: Yesterday at 01:14:10 PM 
Started by WyattFunderburk - Last post by WyattFunderburk
I've enjoyed the episodes thus far and look forward to more.  It's great to finally have a Beach Boys podcast out there!   Thumbs Up

Not to nitpick, but there are several fan podcasts and podcast-ish productions out there, but most of them are really subpar or not widely accessible.  There's a gawd-awful video podcast that some lady shoots in her living room. Pray for Surf(?) is pretty good, but I couldn't find it on iTunes the last time I checked. Ghosty's show is great, but YouTube isn't exactly the best delivery method for that type of content.  Not sure about this podbean thing for Sail On (I think it's a crappy app), but I can get it on Apple's Podcast app, so I'm good.  Sail On is the first good BB fan podcast that's also accessible. And I love it.

Yeah we know there are some other programs out there and we enjoy them for what they are but we wanted to do something new.  Glad you're enjoying it!

 54 
 on: Yesterday at 12:56:13 PM 
Started by Spoonito - Last post by Mike Garneau
Sounds incredible! Love it!

 55 
 on: Yesterday at 12:39:09 PM 
Started by Jim Murphy - Last post by c-man
Hey guys - picked up my copy from the PO Box the other day, and WOWWWW is the word! Fantastic, 400-plus pages in this tome, WELL WORTH it to everyone on here, I am sure!
Please support the author by ordering a copy! The more of these types of projects that generate significant interest, the more likely there will be for more to come, from various authors!
FYI, Ken tells me that he has re-ordered a small stock of the hardbacks, in case anyone prefers that edition!

 56 
 on: Yesterday at 12:17:59 PM 
Started by Rocker - Last post by Rocker


Mike Love

Have Yourself a Merry Little Xmas
Do You Hear What I Hear




Oh, did he record them? I vaguely remember him singing those on some TV special. Is that correct?


EDIT:

And I just remembered that the single version of "Little Saint Nick" differs from the album version. So that one could be added as well.

https://www.youtube.com/watch?v=0_3HLtW8mCw

 57 
 on: Yesterday at 12:15:10 PM 
Started by Spoonito - Last post by JK
I wanted to hear what Heroes and Villains might have sounded re-assembled with all the casualties from Smile, guided by Brian's demo and interviews and plenty of posts on this forum. Welcome back Barnyard, You are my Sunshine, I'm in Great Shape, Do a Lot, Vega-table Fade, All Day, and Bicycle Rider. The result is obviously not historically accurate in any sense, but I thought you all might dig it.

https://www.youtube.com/watch?v=Arpt53KsHO4

Bookmarked!

 58 
 on: Yesterday at 10:08:18 AM 
Started by Watamushi(Polly Poller) - Last post by NOLA BB Fan
4
I do love the vocals only track on the Hawthorne VS album.

 59 
 on: Yesterday at 09:51:06 AM 
Started by Spoonito - Last post by Spoonito
Oh, I'd love to hear it-- I'm a big fan of your stuff from youtube!

 60 
 on: Yesterday at 09:07:57 AM 
Started by Stephen W. Desper - Last post by Stephen W. Desper
Wow, that's pretty cool! I had always thought that on a stereo LP, one side of the groove stored the left side of the sound, and the other side of the groove stored the other side of the sound, but I guess not.

COMMENT to SMiLE-addict:  You are CORRECT.  The inside side of the groove stores the right channel information and the outside side the left channel. You can see it on the electron-microscope video cited in my first post.

Did you know that the LP cutting head actually cuts a Sum/Difference (S/D) signal, not a Left-Right signal.
 
Further that the LP is intentionally cut out-of-phase by 180 degrees.

Here's why.

When the Stereo LP was first introduced in 1959, it was important that all the previously cut mono LP's not become obsolete but remain playable with the new stereo equipment. So here's what the engineers did.

In order to make the Stereo LP compatible with the Mono LP or in other words, so that you can play a Mono LP on a Stereo player, the signal is first converted to the Sum/Difference format, i.e., Sum = (L+R) and Difference = (L-R). This would normally put the sum signal (both channels added) moving the stylus vertically. But that would cause mis-tracking or in loud cases, throw the styles up and out of the groove. To avoid this the polarity on one channel is inverted when cut so that a sum signal is now lateral motion, just like the groove of the mono LP. The stereo playback cartridge is wired out-of-phase also, reverting the signal to normal. Thus, playing a mono disc on a stereo player places the image in the center without removing bass. Bass is usually centered (and never out-of-phase) so it is cut laterally. The stereo information is cut vertically. Sending a Sum/Dif signal to the cutting head causes the cutting stylus to engrave the left channel on one side and the right on the other side of the groove by the natural vectorial outcome of physical movement when the two signals are causing motion of the one cutting stylus.

Another reason the LP sounds as good as it does --- look at the equivalent IPS speed of the groove past the stylus. It's close to 15 IPS which is the same speed as the master tape. I say "equivalent" because although the speed of the LP platter remains constant at 33 1/3 RPM the velocity of the groove moving past the stylus changes as you move into the disc. The velocity is greatest at the outside of the disc and reduces as the tracking moves toward the center of the disc. Since this will cause the fidelity to be compromised as the velocity slows, a compensation EQ is applied to the signal at the time of cutting to make up for the loss in speed. This is all automatically done so you never hear it.

The opposite thing happens with the CD. The laser starts reading the CD at the center and moves outward. It starts at the center because this is where the surface of the CD is most flat. Manufacturing tolerances of the CD hold it flat all over its surface to a given tolerance, but as the laser moves toward the outside of the disc, the CD becomes less flat and thus more susceptible to mis-tracing due to the disc not being as flat or changing in distance from the laser due to warping. Taking advantage of the flatness toward the center, all music (or pictures, or files) start with the best tracing at the center and as the song advances, along with the tracing laser advancing, the tracing becomes more susceptible to error correction due to the un-flatness of the outer edges of the disc.

Further, unlike the steady RPM of the LP, the CD changes rotational speed as it the laser moves outward. The speed of the CD is faster when the laser is tracing at the inside of the disc, but as it advances toward to outside the CD is slowed. All this is very precisely controlled by the player mechanism. 

You may also find it of interest that the CD or DVD actually has three dedicated (so-called) tracks or pathways of information. That is, one song is actually represented by three independent pathways on the disc. Each is read and the processor, called a comparitor, looks to see if the information from each of the three readings is the same. If not (due to dust or a scratch) the comparitor will take any two sets of information and discard the third. Since these pathways are in different parts of the surface of the CD, a scratch at one point on the surface will not effect the reading of the same information from one of the other pathways since they are at different areas of the disc. So the comparitor takes any two matching sets of information (bits). If the comparitor cannot read two signals that are equal, it will makeup the missing bits by a process call extrapolation. For extrapolation, the processor looks at the bits right before and right after the missing information and assumes or creates bits that are kind of an average between the two. Thus, the missing data is added back by assumption. All this is call "error correction." There are programs which tell you the error correction rate as you play a CD. On a dirty CD, or one that has be mis-handled by its user, the error correction rate can be quite high, but you never hear it.

Error correction takes time. We humans never hear it, but it does take microseconds to be processed. Error correction requires that the tracing information first be stored so it can be compared. Back when files were being traded for free a case was brought against the file traders with the ruling of the court that no CD could be copied as it violated the copyright law. Technicians and engineers laughed at that ruling since it would mean that you could not play a CD. The court had to change the law to accommodate error correction, because for error correction to work, the CD data must be stored in the player (or recorded). 

Sometimes our law makers don't quite realize what they are doing. Like the case against Microsoft in which they ruled that information had to be erased. It took Bill Gates testifying in-front of a committee of Senators for them to be educated that their ruling did little. As Gates said, erasing in computer terms is just changing the first bit (or letter) of a given document into a bit that tells the computer to disregard the following string of data. Removing a file or document from a computer is more than erasing. It take a special program to wipe all the data from memory.  This is why computer experts can go back into a computer and retrieve date the user thinks was erased. In cases of top-secret information or child pornography being stored on a computer and then erased, actually it is still on the computer and can be retrieved by disregarding the first bit. The same for a cell phone.  This is how hackers can look back into files and get information, like passcodes or your social security number from files you thought were erased.  So be careful.

 
~swd

Pages: 1 2 3 4 5 [6] 7 8 9 10
gfx
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.082 seconds with 18 queries.
Helios Multi design by Bloc
gfx
Powered by MySQL Powered by PHP Valid XHTML 1.0! Valid CSS!