本文由 hua 在 2002-12-11 發表於 "錄音、音樂製作精華" 討論區
相對於Stereo只有兩軌, 5.1的成品總共有六軌, 分別送到前面三只喇叭後面兩只, 加上一只woofer. 至於一到六軌到底是送到哪一只喇叭, 有film, DTS, SMTPE/ITU 等規格, 可參考protools的使用說明( digidesign 網站上能免費下載). 錄音的部分和一般Stereo並沒有太大的不同. mix的部分, 當然先是需要支援的軟硬體(O2R, Protools, nuendo...), 然後利用它們的surround pan, 讓使用者自由的在五個聲道間放置聲音.
5.1 surround 以前在這板有一兩個相關討論,,,,hua 可以找一下,,,,,
Surround mixing 個人覺得一個標準的monitoring system,proper setting sound field,,,,,是一個基礎起點,,or The surround mix will only "sound"s like what had done in mixing on the same room,,,,,,,,....
while Bi-speaker sound system are already complicate enough to giving hard time on acoustic measure,the speaker monitoring systems in surround field are just similar to digital media formats(96 or 192,,,16 or 24 or 28..) in recording term......,under a very high demanding ref,,you could not found a couple of rooms or speakers are exactly the same,,,even through a same DSP setting of multi chs monitoring,,,,,
in my pratical terms,most(or just say all of what I have been experiences,,,) DAW type surround mixing out-puts buses,could not even merely line up the SPL dynamic field properly with a "Jellyfish" surround metering measure,,,room acoustic,speakers placements setting,Frequency cross-over setting among 6 speakers...Hey !!??? are in each processing??,,the only gear so far is qualify to me,which make sounds move follows like the level bar and heart-shaped phase zone in a Jellyfish,is the Solid State Logic XL-9K.....which are very few globaly,,,,,,,
on the other hand,I personally found it it is quite handy to use surround buses while applying in a concert's front of house mixing,,..some surround paning efxs just drive audiences crazy easily,,,,,,
When Surround sound is still very sensational to every one,I guess your old colleague might just due to the excitement of new experience,so might be a bit carry away,,fair enough isn't it??......,however,result is always less important then question in durring,,,if he did found some Q??? then he might about to finding the real start point later,,,,
let me put it in this way,,.......
98,99,My mate Peter was mixing the surround format of "The Beatles,Yellow Submarine",,,use a SSL 9K ,,,,,arround 30 speakers in tota for 3 Stereo couples,and 4 combin set srround monitoring,,,,,the Abbey Road Studio 3 was fill up with speakers, so a convinced acoustic is so hard to reached,,,and between engineer and producer........ and lately,Sir George Martin,,,,(even he is not quite able to hear mere Stereo )),,,,,,they all had very different thought about how surround should sounds like ??....the discussing subjects from balance,moving sound field,,,,listen positions or the speakers' angles,,,just about everything,,,
when the DVD released,no one was cunfidently convinced when they played back at other place rather than studio 3 Abbey Road,,...but it is understoodable,isn't it ??
People older than 40 in age ,might still remember there was once the “四聲道音響" so be called the hi end audio system,..but it only exited for some like 5 year ,then vanished due to fail in market,,Nowaday same like Dolby surround,THX,YAMAHA cinema,DTS,5.1,,,,,Yes,,They are all there,,,and some might stay,some might just transorm into some where,,,,,
Firstly,Please accept me to leave my massage in English,,....It is easier for me......
Folks,,,before we start to enjoy any formats' surround entertainment stuff,,or making surround stuff works correctly,,...it is better to understand some bore eletronic theory.....especially on the differences of "stereo matrix" and "surround matrix",,,
# A nice article by Mr David Griesinger explains how Multichannel Matrix Surround Decoders for two-eared listeners.pdf file can be download from here:
We normally think of a "2 channel stereo recording" as consisting of a separate "left" and "right" channel.,,,, But "stereo" can be processed in another fashion.!!,,,,,
Two channel stereo can also consist of a mono "sum" channel ...(which contains the sum of the left and right audio channels) along with a "difference" channel ...(which contains the imaging and ambiance information).,,,, Depending on how we superimpose this difference channel upon the sum channel, we can derive either the left or right channels of sound.,,,,, The industry has developed designations for these channels. The mono "sum" channel is designated as the "L+R" (Left+Right) channel. The difference channel is designated as the "L-R" (Left-Right) channel.,,,,,
"Surround sound encoded movies" take advantage of this sum/difference channel relationship to deliver music and other audio effects to the rear speakers of your home or in the theater.
In addition to deriving the front left and right channels,.....a surround sound system takes this (L- R) difference channel and plays this channel thru the "rear" speakers.,,,,"rear speakers" are often located behind the listener....... However, they could also be located to the sides of the listening area...... In any case, nearly all matrix surround sound systems use an additional pair of speakers located at or near the back of the listening environment.
Surround sound is especially good at unmasking the reflected sound from a recording.,,,, "Reflected sound" is the sound you hear from the wall reflections of any acoustic environment.,,,,(Contrast this with the direct sound you would hear from the stage and performers themselves....),,,.Often you are not consciously aware of the reflected sound but it makes a huge difference in your perception of the sonic event.,,,,,, For example, a symphony orchestra playing out in an open field would sound far different from the same players in Carnegie Hall....... Because of the nature of reflected sound, (much of it is out of phase from the direct sound), it ends up in the Left - Right difference channel of a stereo recording.......Surround sound allows this ambient sound to be directed to you from behind (or from the sides of) your listening environment.,,Precisely as it would in "real life". Thru the use of rear speakers, the ambient sound is no longer masked out by the louder direct sound coming from your two front speakers.
One of the big advantages of matrix surround sound systems is "the realism of the sound reproduction". There is nothing artificial added to matrix surround..... If the recording was done in a small space, the ambiance reproduced will be small. If the recording was done in a large concert hall that had considerable reverberations, then the surround sound speakers will reproduce that effect quite clearly. Of course, unlike the concert hall, at home you can adjust the surround speaker volume. This allows you to "dial in" the amount of reflective sound you desire. In a sense, you can move closer or further away from the performing stage, by controlling the amount of reflective sound you wish to hear.,,,,,,
As I mentioned earlier,,there are quite a bit ref standdard at moment,,...Which and How of them is the most demanding directly relates to your working results,,,Surround mixing can be done roughly but make no sense to others ref at all,,,,but you could still call that is a "Surround Mix" as you like,,...
Some people works on DVD surround stuff here in Taiwan only base on "6 speakers monotoring" without any proven ref,,It is ridiculous and none sense to me at all,,,Honestly,,If you do listen to "A-Mei"s and "F4"s DVD surround mix ..(which I don't recommand at all),,,,,,You might shocked that "F4" is much better surround efx in all prospects than "A-Mei"s' fake surround,,,
It is not necessary indeed,,,but at this early stage of developing,,,,Some film people had found "sticks" is a easy option rather than fader to locate a "sound" in purpose,,,,however,it is not the best to convince all,,,yet some better inventions are coming up along while in-put devices options are rapidly progressing in all direction,,,,
感謝提供許多觀念上的想法，會再好好研究研究，您這方面的知識真是取之不竭用之不盡.... </font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">The mono "sum" channel is designated as the "L+R"
(Left+Right) channel. The difference channel
is designated as the "L-R" (Left-Right) channel.,, </pre>[/QUOTE]所以其實L+R mono sum儘管打及左跟及右, 再加些shift或其他小把戲, 實際上是不能做到L-R的....一般家用音響擴大機上, 有個pan可L or R, 也只是L+R mono sum的概念?....I guess...
I bet it is just a "stereo pan" like you will find on common mixers ,,,,, though I have no ideal where you are headind to with this path ??.....
Yes ! You could,,,,,
however,if 'L-R" is what you want to do.....,,Reverse one side's phase ,,either L or R ,,,then equally sum together will be a equivalent fact..
or,.........,if you are trying the "Surround DIY",,like to fool around your brain and ears,,,,,It might be cool to starts with 4 speakers,,....
#1 same Stereo L&R to 2 couple,,,reverse one of the surround speakers' "Red" and "Black" connect ports....
#2 or you just happen to have one spare M/S stereo encoder,,....you become "seed player" ,,send the stereo source to 1 pair speakers,and fed the other pair Mid & Side....... the Mid speaker could either be the center channel or throught "low pass" filter as a sub low speaker...
When more extra freak gears or more speakers join the line,,..more funs come up along,,,,,.some special personal requests also help...says like PC games,Alesis "Airfx",graphic projector,.. a day-off next day..,,,,
and this DIY will be great fun and unique surround experience,,,,