PC Speakers:
(x/y) x=number of front speaker, y=number of surround
2.1 (2) Left, Right
4.1 (2/2)Left, Right, Surround Left Surround Right.
5.1 (3/2)Left Adds Front Center
6.1 (3/3)Adds a Back Center.
7.1 (3/4) Splits Back into Back Left and Back Right
The .1 represents the fact that the sub woofer which doesn't have its own channel Instead the frequencies below the crossover frequency are redirected from other sources. This can be done by a sound card, receiver/decoder or the sound cards. Never redirect LFE more than once!
Low frequencies are perceived as unidirectional so this is adequate for home theater use.
Home Theater Standards:
(Analog)
Stereo = 2.1 (Left,Right)
Dolby Surround = 3.1(3/1)(Left,Right,Rear)
Dolby Pro Logic =4.1(3/1) (Left,Center,Right,Rear)
(Digital)
Stereo = 2.1 (Left,Right)
Dolby Pro Logic 2 =4.1 Same as Pro Logic but digital.
Dolby Digital(AC3) = 5.1(3/2), DTS same at higher bit-rate.
Dolby Digital Ex = 6.1ch (3/3), DTS ES same at higher bit-rate).
Theater Standards:
Dolby Stereo (Analog) originally 4.1 (3/1) now 5.1
Dolby Digital/DTS 6 (3/2)+1 (real sub woofer channel)
Sony Dynamic Digital Sound 8 (5/3)+1 (7.1 with sub woofer channel)
SSDS names the speakers differently than Home Theater 7.1. (left=left center, right=right center, left surround = left, right surround = right, back left = surround left, back right = surround right)
Home Theater Experience:
What happens when your decoder supports more speakers than the source?
5.1->6.1 Create Back Center from Surround Left and Right.
6.1-7.1 Back Center Channel is played through both back speakers. (All current DVDs are 6.1 or less)
Is 5.1->6.1 an improvement? Slightly if you have a large living room.
Is 5.1->6.1 ever worse? Most people feel its always better, others argue it varies on a case by case basis. Many receivers have an option to ignore the 6th speaker when you have a 5.1 source.
Is 6.1->6.1 an improvement? Yes, if the 6th channel is really discrete and not them just mixing the surround channels for you. Otherwise it really just 5.1->6.1.
Is 6.1->7.1 an improvement? Not really, it does give you an extra speaker to fill a extra large room. If your room is large enough that you feel the need 2 Left and 2 Right Speaker then 7.1 is probably for you.
Is 7.1->7.1 an improvement? Doesn't exits for home use.
Thats why they have 7.1 "ready" receivers rather than actual 7.1. If a home theater version of SDDS is released (or a 7.1 of Dolby Digital or DTS) then owners of a 7.1 receiver will have to buy add a 7.1 decoder to use it.
My guess it that we won't see this until blue-laser video disc are released.
PC vs Home Theater System:
Obviously it makes no sense to have a high end sound card/receiver and use low quality speakers.
A high end PC sound card will simply never sound as good as a mid-ranged receiver because there is simply too much electromagnetic interference inside your computer.
A $300 to $700 professional audio interface (costs too much to call them sound cards) are able to compensate for all this noise, but at a price. Plus you get no 5.1 and horrible game support.
A high end sound card with high end speakers may well sound better than the cheapest home theater kits, but will be far less powerful.
A digital connection to an external digital speakers (digital decoder using PC speakers), will eliminate the interference. A downside is high end PC speakers can be just as expensive, sound no better and provide far less power when compared to mid range Home Theater Speakers. On the plus side you save money because you have to buy a $400 digital receiver before you can take advantage of those wonderful home theater speakers.
An analog connection to a receiver gives your PC the power (and potential quality) of a home theater speakers, but you still have the interference.
A digital connection to a digital receiver gives you the best possible sound, since you can pass the signal directly to the receiver for Decoding.
Even a cheap integrated sound card with digital out will render perfect DVD sound when connected to a digital receiver.
Of course the cheapness of the card will come back to haunt you when you are playing a game, in which case the card still has to do considerable audio processing, just no digital to analog conversion.
Also many 5.1 cards with digital out are not capable of encoding to 5.1. My Sound Blaster 5.1 only sends a 4.1 digital signal to my receiver when playing games. My CMedia only sends a 2.1 signal when it is not simply passing through audio form a DVD.
AC3 DivX:
In theory you can set AC3 filter to pass through without decoding, so it should work just like playing a DVD. In practice it is somehow down mixing to 4.1 Dolby Pro logic (left,center,right,rear). I am not sure what is causing this.
If you have a sound card that supports 5.1 Dolby digital encoding then you can get full 5.1 sound from a DivX by having AC3 filter render it for 5.1 speakers.
Gaming:
True 6.1 makes it a lot easier to locate sounds. 7.1 is also an improvement, but to a lesser extent.
5.1->6.1 is usually an improvement over just 5.1. Since rear sounds are actually coming form behind you.
6.1->7.1 Can't hurt. If you think 6.1->7.1 gives you more accurate positioning then move the back speakers closer.
Gaming 7.1 to 7.1. I hear this help a little, but the effect isn't as great as moving form 5.1 to 6.1.
I wouldn't pay extra for 7.1, but if a 7.1 had better features than a 6.1 I would buy it for those reasons.
Headphones:
Quality Headphone's are great for 3D gaming (your characters virtual head to position sound works just as naturally as moving your actual head in real live. They are definitely the better choice for gaming if you keep your 5.1 speaker centered on your couch.
My Gear:
PC #1 CMedia with optical out connected to Pioneer VSX-D912K 7.1 Receiver, PC #2 SB Live 5.1 coax SPDIF to same receiver. 5.1 Speakers Centered on couch. High quality headsets for gaming.
I used to have an analog connection to a slightly defective low receiver that lacked digital in.
Yesterday was the fist time a played a DVD with DTS sound. It was a religious experience! <P ID="edit"><FONT SIZE=-1><EM>Edited by codesmith on 01/21/04 04:38 PM.</EM></FONT></P>
(x/y) x=number of front speaker, y=number of surround
2.1 (2) Left, Right
4.1 (2/2)Left, Right, Surround Left Surround Right.
5.1 (3/2)Left Adds Front Center
6.1 (3/3)Adds a Back Center.
7.1 (3/4) Splits Back into Back Left and Back Right
The .1 represents the fact that the sub woofer which doesn't have its own channel Instead the frequencies below the crossover frequency are redirected from other sources. This can be done by a sound card, receiver/decoder or the sound cards. Never redirect LFE more than once!
Low frequencies are perceived as unidirectional so this is adequate for home theater use.
Home Theater Standards:
(Analog)
Stereo = 2.1 (Left,Right)
Dolby Surround = 3.1(3/1)(Left,Right,Rear)
Dolby Pro Logic =4.1(3/1) (Left,Center,Right,Rear)
(Digital)
Stereo = 2.1 (Left,Right)
Dolby Pro Logic 2 =4.1 Same as Pro Logic but digital.
Dolby Digital(AC3) = 5.1(3/2), DTS same at higher bit-rate.
Dolby Digital Ex = 6.1ch (3/3), DTS ES same at higher bit-rate).
Theater Standards:
Dolby Stereo (Analog) originally 4.1 (3/1) now 5.1
Dolby Digital/DTS 6 (3/2)+1 (real sub woofer channel)
Sony Dynamic Digital Sound 8 (5/3)+1 (7.1 with sub woofer channel)
SSDS names the speakers differently than Home Theater 7.1. (left=left center, right=right center, left surround = left, right surround = right, back left = surround left, back right = surround right)
Home Theater Experience:
What happens when your decoder supports more speakers than the source?
5.1->6.1 Create Back Center from Surround Left and Right.
6.1-7.1 Back Center Channel is played through both back speakers. (All current DVDs are 6.1 or less)
Is 5.1->6.1 an improvement? Slightly if you have a large living room.
Is 5.1->6.1 ever worse? Most people feel its always better, others argue it varies on a case by case basis. Many receivers have an option to ignore the 6th speaker when you have a 5.1 source.
Is 6.1->6.1 an improvement? Yes, if the 6th channel is really discrete and not them just mixing the surround channels for you. Otherwise it really just 5.1->6.1.
Is 6.1->7.1 an improvement? Not really, it does give you an extra speaker to fill a extra large room. If your room is large enough that you feel the need 2 Left and 2 Right Speaker then 7.1 is probably for you.
Is 7.1->7.1 an improvement? Doesn't exits for home use.
Thats why they have 7.1 "ready" receivers rather than actual 7.1. If a home theater version of SDDS is released (or a 7.1 of Dolby Digital or DTS) then owners of a 7.1 receiver will have to buy add a 7.1 decoder to use it.
My guess it that we won't see this until blue-laser video disc are released.
PC vs Home Theater System:
Obviously it makes no sense to have a high end sound card/receiver and use low quality speakers.
A high end PC sound card will simply never sound as good as a mid-ranged receiver because there is simply too much electromagnetic interference inside your computer.
A $300 to $700 professional audio interface (costs too much to call them sound cards) are able to compensate for all this noise, but at a price. Plus you get no 5.1 and horrible game support.
A high end sound card with high end speakers may well sound better than the cheapest home theater kits, but will be far less powerful.
A digital connection to an external digital speakers (digital decoder using PC speakers), will eliminate the interference. A downside is high end PC speakers can be just as expensive, sound no better and provide far less power when compared to mid range Home Theater Speakers. On the plus side you save money because you have to buy a $400 digital receiver before you can take advantage of those wonderful home theater speakers.
An analog connection to a receiver gives your PC the power (and potential quality) of a home theater speakers, but you still have the interference.
A digital connection to a digital receiver gives you the best possible sound, since you can pass the signal directly to the receiver for Decoding.
Even a cheap integrated sound card with digital out will render perfect DVD sound when connected to a digital receiver.
Of course the cheapness of the card will come back to haunt you when you are playing a game, in which case the card still has to do considerable audio processing, just no digital to analog conversion.
Also many 5.1 cards with digital out are not capable of encoding to 5.1. My Sound Blaster 5.1 only sends a 4.1 digital signal to my receiver when playing games. My CMedia only sends a 2.1 signal when it is not simply passing through audio form a DVD.
AC3 DivX:
In theory you can set AC3 filter to pass through without decoding, so it should work just like playing a DVD. In practice it is somehow down mixing to 4.1 Dolby Pro logic (left,center,right,rear). I am not sure what is causing this.
If you have a sound card that supports 5.1 Dolby digital encoding then you can get full 5.1 sound from a DivX by having AC3 filter render it for 5.1 speakers.
Gaming:
True 6.1 makes it a lot easier to locate sounds. 7.1 is also an improvement, but to a lesser extent.
5.1->6.1 is usually an improvement over just 5.1. Since rear sounds are actually coming form behind you.
6.1->7.1 Can't hurt. If you think 6.1->7.1 gives you more accurate positioning then move the back speakers closer.
Gaming 7.1 to 7.1. I hear this help a little, but the effect isn't as great as moving form 5.1 to 6.1.
I wouldn't pay extra for 7.1, but if a 7.1 had better features than a 6.1 I would buy it for those reasons.
Headphones:
Quality Headphone's are great for 3D gaming (your characters virtual head to position sound works just as naturally as moving your actual head in real live. They are definitely the better choice for gaming if you keep your 5.1 speaker centered on your couch.
My Gear:
PC #1 CMedia with optical out connected to Pioneer VSX-D912K 7.1 Receiver, PC #2 SB Live 5.1 coax SPDIF to same receiver. 5.1 Speakers Centered on couch. High quality headsets for gaming.
I used to have an analog connection to a slightly defective low receiver that lacked digital in.
Yesterday was the fist time a played a DVD with DTS sound. It was a religious experience! <P ID="edit"><FONT SIZE=-1><EM>Edited by codesmith on 01/21/04 04:38 PM.</EM></FONT></P>