5.1 vs 7.1

[bernernj]

I am curious how much of a difference many of you notice between 5.1 and 7.1 DDTrue HD or DTS MA on Blu Ray with good speakers(assuming its one of the few disks that have 7.1)

 

[Seth=L]

For medium to smaller size rooms it won't likely make much of an impact to have 6.1 or 7.1 sound. A standard 5.1 system can be very involving if set up correctly and in medium to smaller rooms sizes is hard to differentiate from a 6.1 or 7.1 sound system. If you do have a larger room you may want to give 7.1 a shot.

 

[Jack Hammer]

The movies that are recorded with 7.1 sound amazing with a 7.1 setup. The movies that are recorded with a 5.1 soundtrack are hit or miss with 7.1 speakers.

Jack (running a 7.2 setup)

 

[mtrycrafts]

The movies that are recorded with 7.1 sound amazing with a 7.1 setup. The movies that are recorded with a 5.1 soundtrack are hit or miss with 7.1 speakers.

Jack (running a 7.2 setup)

Are there movies in theater with 7.1 soundtracks? How do you tell from the display boards there?

 

[darien87]

The movies that are recorded with 7.1 sound amazing with a 7.1 setup. The movies that are recorded with a 5.1 soundtrack are hit or miss with 7.1 speakers.

Jack (running a 7.2 setup)

If you have your system set up for 7.1, which surround speakers are used when playing a 5.1 soundtrack, the sides or rears? Or does the receiver try to matrix all 4 surround speakers via DSP?

 

[Jack Hammer]

Are there movies in theater with 7.1 soundtracks? How do you tell from the display boards there?

I could care less about how many channels are at the theaters. We are talking about watching movies on BD in a home theater and opinions of the differences experienced between 5.1 and 7.1 tracks.

Jack

 

[Jack Hammer]

If you have your system set up for 7.1, which surround speakers are used when playing a 5.1 soundtrack, the sides or rears? Or does the receiver try to matrix all 4 surround speakers via DSP?

It really depends on the movie. Some play mainly from the sides, some from the rear, but most are a combo of all four. I haven't really figured out why that is. I usually listen in Dolby Plxii.

Jack

 

[bernernj]

can anyone else actually tell me if they notice a big difference or not with true 7.1 soundtracks....and of course I mean in a home theater

 

[AcuDefTechGuy]

can anyone else actually tell me if they notice a big difference or not with true 7.1 soundtracks....and of course I mean in a home theater

I have tried both 5.1 & 7.1. I have listened to 7.1 LPCM soundtracks vs 5.1 LPCM soundtrack of the same movie (War). I cannot tell any difference whatsoever.

I think it's cool to have 7.1, but the difference from 5.1 is insignificant.

This makes sense when you realize that most of the movie soundtrack is in the front 3 channels. The surround channels are mainly for ambience effects, so 5.1 vs. 7.1 vs 9.1 vs 11.1 is all the same.

Also realize that the surround channels are there to "support" the main front 3 channels by creating this ambience and panning effects. The surround channels are not there to DOMINATE and take over the entire soundtrack. Thus, be careful not to make the surround channels a DISTRACTION.

 

[ThA tRiXtA]

Wait a second, can some one please explain to me why during a 5.1 soundtracked movie I would be hearing audio coming from the rear surrounds at all?

If it is only a 5.1 soundtrack, the only speakers that should have any information routed to them are the front left, center, front right, left surround and right surround?

Why would you want your receiver to matrix out two more channels that aren't supposed to be there?

 

[AcuDefTechGuy]

Wait a second, can some one please explain to me why during a 5.1 soundtracked movie I would be hearing audio coming from the rear surrounds at all?

If it is only a 5.1 soundtrack, the only speakers that should have any information routed to them are the front left, center, front right, left surround and right surround?

Why would you want your receiver to matrix out two more channels that aren't supposed to be there?

Some people think it's cool to hear sound from all speakers, and there is nothing wrong with that. Coolness is important since this is a hobby.

I think if Dolby comes out with a Matrix 9.1, GlocksRock would buy 2 more Definitive surround speakers just to make it a 9.1 HT.

It's not about right or wrong. It's about what makes you happy.

 

[GlocksRock]

I think many movies would be in 7.1 if more people's rooms would be able to handle it, but only in the past few years have 7.1 receivers been available. And with Dolby Pro Logic IIx you can take any 2 channel, or 5.1 or whatever source and make it 7.1. I have found that the PLIIx decoder does a very good job with 5.1 material, it makes the pans much smoother and movies more realistic. For instance if you only have a 5.1 setup with the surrounds mounted on the side walls, and a plane flies over front to back, or vice versa, when it goes behind you really you should hear the sound coming from that direction, and with PLIIx, it will. Plus it works really well for video games because you can hear exactly where people are coming from, and say you walk under a waterfall and you turn around, you can hear the water coming from every direction. The reason why 7.1 is not as favorable for someone like acudeftechguy is that his setup is all analog, so he doesn't have PLIIx capabilites, and since there aren't that many movies in 7.1 there isn't much point in having those extra speakers, but for someone who uses a receiver that has those decoders built in, it makes a world of difference.

 

[Pyrrho]

Wait a second, can some one please explain to me why during a 5.1 soundtracked movie I would be hearing audio coming from the rear surrounds at all?

If it is only a 5.1 soundtrack, the only speakers that should have any information routed to them are the front left, center, front right, left surround and right surround?

Why would you want your receiver to matrix out two more channels that aren't supposed to be there?

As AcuDefTechGuy says, some people like it. And they are free to use it, if they have it. I generally like to reproduce what was recorded, and do not like redirected (actually, misdirected) audio from other channels. That is why I use DPL (not DPL II or DPL IIx) on DPL encoded films.

For anyone interested in how DPL (Dolby Pro Logic) works, you can view a pdf at:

http://www.dolby.com/assets/pdf/tech...ic_Decoder.pdf

As one can see there, the original encoding for DPL is with 4 channels and with limited frequency response at the rear. Consequently, any "decoding" that results in 5 (or more) channels and without limited frequencies to the rear is altering the original material. So, if you want to be able to hear exactly what was encoded, you need the original DPL. If you do not care whether you hear what was encoded or not, you can do whatever processing you want that your equipment can do.

Of course, I much prefer discrete 5.1 to DPL, and slightly prefer 6.1 to 5.1. And I prefer multi-channel discrete audio (e.g., 5.1 SACD, etc.) to 2 channel. But I do not like to artificially create extra channels, because, in my opinion, it never sounds right to do so. Other people, of course, have their own opinions on this matter, and, as I have already said, they are free to use whatever processing that they have and want to use.

 

[Jack Hammer]

You guys are forgetting one other difference. Some people are not able to mount their side surrounds in ideal locations and the extra rear channels can help balance those discreet surround effects.

Jack

 

[ThA tRiXtA]

Well I'm with Pyrrho, I want to hear what I was intended to hear. If it's a 5.1 movie, even though my receiver can do 7.1 I still just want the 5.1

One thing Pyrrho, I am interested in reading your dolby link but it seems to be broken... got a fix?

On a side note, what's a "discreet channel?" Does that mean say in a 5.1 format, all 5 channels have their own significant audio programmed to them as opposed to having the same audio signal split up and divided over multiple channels?

Also, what is the preferable decoder for PS3 games? I am upgrading my PS2 shortly, and was wondering what the buzz is for the audio reproduction lately.

 

[AcuDefTechGuy]

As one can see there, the original encoding for DPL is with 4 channels and with limited frequency response at the rear. Consequently, any "decoding" that results in 5 (or more) channels and without limited frequencies to the rear is altering the original material. So, if you want to be able to hear exactly what was encoded, you need the original DPL. If you do not care whether you hear what was encoded or not, you can do whatever processing you want that your equipment can do.

Of course, I much prefer discrete 5.1 to DPL, and slightly prefer 6.1 to 5.1. And I prefer multi-channel discrete audio (e.g., 5.1 SACD, etc.) to 2 channel. But I do not like to artificially create extra channels, because, in my opinion, it never sounds right to do so.

Actually, both Dolby ProLogic and Dolby ProLogic II takes the original 2-channel stereo signal and MATRIX them into multi-channel (4, 6, etc.).

So personally I would never use anything except the true discrete sounds - DD/TrueHD, DTS/DTS-MA, MLP (DVD-A), and DSD (SACD).

When you MATRIX anything, you are using DSP, which increases distortion.

I think the sound from a good receiver can be very clean if you BYPASS all DSPs, Tone Controls, and Equalizations.

Hey, I know they make Pure Direct Modes for 2-Ch, but do they make Pure Direct Modes for 5.1/7.1?

 

[GlocksRock]

If matrixing is so bad, they why are there movies encoded in 5.1 EX? They are meant to be that way, so there is obviously no harm in having some of the surround info sent to the surround back speakers. To each his own, but I've never heard anything odd or bad while using the PLIIx or DD EX decoders on my 7.1 system, I only get a greater surround field. The logarithms used by the decoders are very good, after all the decoders are made by dolby, and you are listening to a dolby digital track most of the time, so I don't see where there would be any problems or issues with sound coming from somewhere it shouldn't.

I wouldn't say using a PLIIx or EX/ES decoder is adding distortion since it's a DSP, it's not like you are using the Cinema DSP found in yamaha receivers, which do add reverb and other undesireable effects, those decoders just redirect some of the sounds to where they ought to be, but aren't. The only difference between PLIIx and the DD EX decoder is that the PLIIx decoder will create a stereo surround back whereas the DD EX decoder plays the same sounds from both rear speakers in a 7.1 setup.

The first 3 Star Wars movies are all encoded in 5.1 EX so if you want to hear them how the director intended them to be, then I guess you need to get a rear center channel and use something with a DD EX decoder, and since the flags don't work proplerly on those discs, you have to manually turn them on, which doesn't add anything artificial to the original DD track.

 

[AcuDefTechGuy]

Well I'm with Pyrrho, I want to hear what I was intended to hear. If it's a 5.1 movie, even though my receiver can do 7.1 I still just want the 5.1

One thing Pyrrho, I am interested in reading your dolby link but it seems to be broken... got a fix?

On a side note, what's a "discreet channel?" Does that mean say in a 5.1 format, all 5 channels have their own significant audio programmed to them as opposed to having the same audio signal split up and divided over multiple channels?

Also, what is the preferable decoder for PS3 games? I am upgrading my PS2 shortly, and was wondering what the buzz is for the audio reproduction lately.

Discrete means that the original soundtrack was recorded in 5.1 (6 channels) or 7.1 (8 channels), not 2-Ch stereo and then matrixed later into 5.1/7.1.

For PS3, I would use whatever is the original soundtrack. I think most are in DD.

 

[AcuDefTechGuy]

The first 3 Star Wars movies are all encoded in 5.1 EX so if you want to hear them how the director intended them to be, then I guess you need to get a rear center channel and use something with a DD EX decoder, and since the flags don't work proplerly on those discs, you have to manually turn them on, which doesn't add anything artificial to the original DD track.

You mean Episodes I, II, & 3 are only in 5.1 EX? That sucks.

I thought it was 6.1 EX, which is also discrete?

Or did you mean Episodes IV, V, & VI?

I thought when they record the original soundtracks (at least the new digital ones), it is in LPCM 8 or 10 channels. Then when they soundmix for the DVDs or Blu-rays, they make it into 5.1 or 7.1.

 

[GlocksRock]

I mean the first ones, Phantom Menace, AOTC, ROTS. But after looking at the dvd details on the trilogy, it looks like those are also all done in 5.1 EX.

http://www.imdb.com/title/tt0120915/dvd you can see where it says Dolby Digital EX.

There is no dolby 6.1 discrete, dts es 6.1 discreet is the only discrete 6.1 audio format, all 6.1 dolby digital is just 5.1 with the rear surround channel matrixed in, no real discrete rear channel. even dts has a matrixed rear surround channel, it's call dts-es which is different than dts-es discrete 6.1

http://www.timefordvd.com/ref/dts-ES.shtml