5.1 material with 7.1 speakers

[PoorSignal]

I was wondering when you have 5.1 material on 7 speakers does the 2 rear channels go to the very back, or is it played the "mid" surrounds?

[BIslander]

The surround speakers in 5.1 and 7.1 systems are on the sides. 7.1 adds the rear speakers. The surround channels get played from the side speakers in a 7.1 system.

[Fors*]

Originally Posted by PoorSignal

I was wondering when you have 5.1 material on 7 speakers does the 2 rear channels go to the very back, or is it played the "mid" surrounds?

I may be wrong on this, but I believe if you are matrixing the audio trac into 7.1 from the 5.1 audio trac, the rear surrounds will duplicate what is sent to side surrounds to create 7.1.

[eljay]

5.1 on a 7.1 set-up will play in the front three speakers, the (side) surrounds and the sub. Nothing will play in the rear surrounds unless you "matrix" the audio, in which case the audio from the (side) surrounds is also sent to the back.

[BIslander]

Originally Posted by forsberg21

I may be wrong on this, but I believe if you are matrixing the audio trac into 7.1 from the 5.1 audio trac, the rear surrounds will duplicate what is sent to side surrounds to create 7.1.

Matrixing is more sophisticated than simple duplication. But, yes, the audio from the surround channels is used to create four new channels, both of the surrounds and both of the rears.

[aponjon]

1. Speaker Size: He sets eveything to large so that the Sw only gets the .1 channel. However, he uses surround speakers equal in size to his fronts (i.e. towers capable of serious bass). Because the centre is only dialogue / voice, it does not need to send off any freq < 80hz to a sub. He suggests that this is the purest sound with the greatest spatial orientation. There is no additional crossover processing being done by the amp; each speaker is doing what it is intended to do, especially the SW which is only processing LFE. Finally, he said that if you have to use "bookshelf" type surrounds, then set them up as large anyways and route the pre-out for that channel to another SW set up in the rear to play back the bass from those speakers.

This is how my set-up is. For HT and multichannel music. All my 4 speakers, front and back, set to LARGE, are identical full ranger floorstanders that can go down to 45hz -3db. The lone subwoofer, crossed at 45hz, is there simply to AUGMENT and add about 20hz bandwidth from 45db -3db down to 26hz -3db, and 22hz -6db. Excellent integration. It is my philosophy, and shared by fellow enthusiasts in my community, that the subwoofer shouldn't TAKE OVER the woofer function of the main speakers. But to AUGMENT those bottom range that the mains cannot deliver adequately.

Ideally, your main speakers should go down to 20Hz. But we all know it takes $$$ for such a speaker to be made and acquired for the home. An excellent subwoofer dedicated to do the job should be used to make the set-up more cost effective.

And yes, the center channel is for dialogue and the solo vocal in music. Whether there is content below 80hz or not, it would still be a good idea to limit the low end range so as not to impart any boominess on those voices.

There are bookshelf brands and models that do exhibit the ability to go down to the same low ends as many floorstanders. And therefore, they should rightly be set to LARGE. However, most entry level bookshelf speakers do not. The farthest they can go is 60hz -3db. So it is prudent to set them to SMALL. But having said that, I've heard excellent sounding mid-priced bookshelf speakers set to LARGE but whose "natural" roll-off at 60Hz give them excellent crossover seamlessness with the sub that is crossed-over at these natural roll-off points from bookshelves. You just shouldn't play them to the max.

Admittedly this set-up can be "over-kill" for many DVD video materials out there, expecially movies with little special effects or ambiance information. Often the rear channels do not exhibit any sonic acitivity.

But there are DVD materials that do deliver full range sonics all around, maybe not all the time. But when you get the material that has, it's a nice thing to have rear surrounds that accomodate the demands. Many of those DTS and DD-EX encoded blockbusters do deliver full range sonics at the back. And if you get to listen to those DVD-audio and SACD high resolution tracks, you'd be surprised what a benefit to have full range floorstanders all around. Many titles actually don't have LFE or the 0.1 channel for subwoofers. And unless you have bass management (which obviosuly the salesman in your example is reffering to when he said it better that way to have a "purer" sound), you could end up with very thin sound if your bookshelf speakers are crossed at 80hz.

I also would prefer to have a subwoofer at the back. I had a spare cheap subwoofer crossed at 60hz together with some satellite rear speakers in the past connected to the back and I was pleasantly surprised that there was rear subwoofer activity in some DVD materials, like in Saving PRivate Ryan and Pearl Harbor, among others. At the moment I don't have the luxury in space and money to accomodate one. But the 45hz lower limit of my rear monopoles seems adequate enough.

2. 5.1 versu 7.1: He suggests doing an installation based solely on available formats today, not on HW capabilities. He suggests that there are not many 7.1 or 6.1 titles today. He also suggests that in order to put in rear surrounds, you need a large room or the sound will be too muddled. He suggests 5.1 for today; maybe switch in a few years if 7.1 takes off.

Unless your budget is unlimited, you as a consumer may have to put your foot down and draw the line yourself. I don't see the end of this trend. You now have 10.1 receivers. What's next? 12.1, 15.1??? There's this upcoming SDDS from Columbia/Tristar that require 8 channels. Then there are "height" channels. We now have side channels. I wouldn't be surprised if we get ceiling channels in the future (that would be nice for screen shots with hovering helicopters )

The salesman is right in saying there's hardly any DVD material out there that have discreet 7 channel information. But if you like what you hear with 7.1, don't let that stop you. All those new 7.1 receivers can matrix the additional channels. It's what makes you happy in this hobby that counts. Having those extra channels can be a feature that future-proofs your investment today. For me, I am quite happy with my 5.1 set-up at home as I have yet to hear a glorious 7.1 set-up in a proper accoustically set room. Maybe I can consider one within the next 18 months if there are many titles in the new format that I LIKE. A material that I don't like to begin with will not make me like it just because it's in 7.1.

3. Surround speakers should not be di, bi or quad polar type, but should be mono directional so as to give proper positioning of sound and effects. Multi polar speakers were great for plain old pro logic, but not for DD or DTS. Funny, I just purchased several pairs of quad polars from a reputable firm.

Not necessarily accurate. While I have and like my monopoles for the rear identical with my fronts, I've heard excellent ambiance surrounds coming from dipoles and bipoles. And I know of many audiophiles who have both rear dipoles and monopoles that they can select to suit the DVD material they have at the moment. Even that rule that says SACD and DVD-A should have monopoles at the back is not entirely applicable. Many hi-res multichannel mixes don't have discreet instruments for the rear and use ambience of the hall or theater to be delivered at the back channels. In this case, a well located dipole of bipole can deliver the desired effect much better than monopoles can. Remember that ambiance effects are not supposed to be directional or localizable. Monopoles give a sense of directionality to the ambience. This can be pleasing in some but often distracting in many others. A bird chirping in the forest is often not localizable with pinpoint accuracy, just a general direction, if at all. Monopoles can give a pinpont location which is less than realistic.

[BIslander]

Interesting stuff. Is it in response to something in this thread, though?