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Discussion Starter · #1 ·
I'm trying to decide whether to install a 5.1 system or a 7.1 system for HT. Assuming the same total price, should I put the money into better quality speakers or buy the additional pair? The receiver will support 7.1, but would it improve the sound to bi-amp the left and right fronts? The space is about 12'x15' with one side open to another room.
 

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takes advantage of anything more than 5.1, so better speakers would be the way to go IMO. You could easily add 2 speakers down the road once the material becomes more available.
 

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Your room is also very small. I'd stick with 5.1, with some nice surrounds that disperse really well. I've had direct radiating surrounds, di-poles and bi-poles, but by far the best surround speakers I've used are my current Axiom QS8's.


If I had bought the QS8's before I already bought the amp and rears for 7.1, I'd probably stayed with 5.1 and saved myself some good money.
 

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Discussion Starter · #4 ·
Assuming a 7.1 receiver (which I'm getting for other features), what do you think about using the extra two channels to bi-amp the front L&R?
 

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Quote:
Originally posted by Grampa
The receiver will support 7.1, but would it improve the sound to bi-amp the left and right fronts?
My personal experience is that bi-amping the front speakers will yield negligible results compared to going 7.1, which will give you distinct and stable left vs right vs rear imaging of the surround content (which isn't really possible with only 2 surround speakers).
Quote:
The space is about 12'x15' with one side open to another room.
More important than the room size is where you'll be sitting. If your couch is flush against the back wall, then a 7.1 layout will be difficult to pull off (no room behind you for the rear speakers). Could you give us a description of the room; i.e., on which wall is the TV, where is the couch, which side is the opening, etc?


Best,

Sanjay
 

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You can not use the extra channels of a 7.1 receiver to bi-amp the front left and right speakers. That is not how bi-amping works. You would be sending the wrong channel information to the speaker terminals. The amplifier in a 7.1 receiver is hard wired internally to each channel.


First, let make sure we are talking about bi amping and not bi-wiring. Connecting two amplifiers is called bi-amping, and connecting two sets of cables is called bi-wiring. A speaker set up for bi-wiring or bi-amping offers a separate connection to the speaker for the upper frequency driver or drivers and a second connection for the lower frequency driver. Speakers that can be bi-wired can generally be bi-amped as the crossover is essentially two or more separate circuits isolated from one another (when the links are removed). One theory behind offering this type of connection is that one kind of amplifier or cable may be better suited for reproducing the upper frequencies of the signal and a different amp or cable is better for reproducing the lower frequencies. Another point of view is that by dividing the demands placed on a single amplifier or cable, that two amps or two cables will perform better than one, optimizing performance.


Bi-Amping,as I stated above, is when you connect the high and low speaker connections each to their own amplified connection on the receiver or amplifier. This is connected either to receivers which accept bi-amping, but most commonly in systems that use separates. Giving the highs and the lows each their own dedicated amplifier DOES improve clarity, bass, and transparency.


There are trade-offs to how you go about bi-amping your speakers. You can use one 2-channel amplifier to power both the high and low signals of a single speaker, or you can use completely separate amps for each connection.


The single 2-channel amplifier solution gives the most accurate sound for stereo imaging since the speaker's sound is driven by one consistent unit, but this offers less efficiency. Using two separate amps give the best efficiency, but sacrifices some accuracy.


Pass on bi-wiring, but if you have bi-amping capability go for it. You can save bi-amping as a nice future upgrade path if your budget doesn't allow for the extra amps and speaker cable needed. Pay special attention not to tremendously overpower your speakers when bi-amping, or you run the risk of damaging them.


Like with cable, you can choose different amplifiers that excel in different frequency bands. You may wish to use a high powered amp to give

good control on the bass while using something smaller and sweeter on the treble where power is not such an issue. However in practice it is generally better to use exactly the same type of amp for both treble and

bass as this will eliminate issues of varying gain, phase and coloration between different amplifiers. Unlike bi-wiring, the load to each amplifier is different from that using a single amplifier full range. The voltage demands on each amplifier remain the same (each is still fed a full-range input and gives a full-range output), but the current demands are reduced. This of itself can improve the amplifier's ability to deliver the signal to the speaker.


There are two methods of bi-amplification - passive and active. Passive bi-amping is fairly simple: split the audio signal coming from the outputs on your pre-amp (preouts on your 7.1 receiver) using a Y-adapter (some pre-amps may even have two outputs so a Y-adapter is not necessary), then connect one of the split connectors from each channel to one amplifier and the other split connector from each channel to the second amplifier with interconnect cables , finally run speaker wire from your bass amp to the low frequency connections on your speaker using good quality speaker wire and do the same from the midrange/treble amp to the high frequency inputs on your speakers. Be sure you take off the connector plate or wire on your speakers that binds the high and low frequency inputs. In this type of arrangement you are using the passive crossover in your speakers to split the signals for the amplifiers thus the passive moniker for this form of bi-amping. Also, the amplifiers you use must have the same gain - this is very important, if the gain is different then the bass and midrange/treble will be amplified at different levels (one louder than the other).


The second more complex method of bi-amplifying is active in which you will not use the crossover built into your speakers. Instead you will use an active electronic crossover. This crossover should sit in the signal path between your pre-amp and your amplifiers. It will split the signal to high-frequency and low-frequency pieces sending only the highs to one amp and only the lows to another (in passive bi-amping each amplifier still receives the full frequency spectrum). You will also need to disengage the crossover network in your speaker, which may require you to take out the crossover and work on - this is best left to a professional A/V installer. Otherwise the connection method is the same from amplifiers to inputs. Active bi-amping allows you to set the crossover point you use, but be careful in doing so as the point used by the speaker designer was carefully selected. You may wish to simply use the same crossover point as the speaker designer did with your speakers but use the active setup to get the advantages of driving your amps with only a portion of the frequency spectrum and a direct connection from the bass amp to the bass driver(s).


Sorry about the long explanation...Can you tell I'm an engineer? I hope it helps.
 

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Discussion Starter · #9 ·
Wow!! It does help, but mostly it lets me know I can't do what I was thinking about doing. The speakers I had been looking at are "bi-wirable," and the receiver has two channels that aren't going to be used. I thought I might simply be able to connect the two unused channels to the second pair of posts on the speakers. I understand now that this will not work.


As for the room, my basement is essentially an "L," with the top of the "L" being north. My HT room is the short leg of the "L," and the screen will be on the north wall of this leg (i.e., the right front speaker will have the east wall on the right, but the left front speaker will not have a wall on the left). The space is about 12' wide, not including the additional 8' or so where the room opens to the long leg of the "L," and about 16' deep. In addition, there are counters and cupboards lining the south and east walls, as well as a closet door and a bathroom door on either side of the screen (by day, the room is an office). Because of the built-ins, seating is only about 10' -12' back from the screen, and about 4' - 6' from the back wall.


It is a difficult space, and I'm pretty much limited to in-ceiling speakers. I've read all the warnings, but I really don't have a choice, and so now I'm looking at much more expensive in-ceilings (Triads).


Thanks for your help.


Doug
 

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I agree with the others, if you have room to do "7.1", feel free to go for it. But, if you're sitting against a backwall or lack space behind the listening position, then don't kill yourself trying to squeeze in those extra speakers. A properly placed and situated 5.1 setup will easily outperform a poorly implemented "7.1" setup.


Even if you have the room, your budget is better served by getting better speakers all around. Most DVD soundtracks are either 2.0 or 5.1. 6.1 constitutes less than 0.5% of the titles on the market, and "7.1" is nothing more than marketing BS because there are no true 7.1 audio formats available for home use. It's for the same reason that I don't call Dolby Pro Logic a 5.0 or 4.0 format.
 

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Quote:
"7.1" is nothing more than marketing BS because there are no true 7.1 audio formats available for home use.
Why do people keep saying this. All it does is more thoroughly confuse people.


YOu are 100% correct that there is no 7.1 format. What there is though, is extended 5.1, and a sprinkling of discrete 6.1 (DTS-ES discrete) titles. Furthermore ALL 5.1 discs can be manually processed to get you extended 5.1(this is also erroneously and casually called 6.1, at the very least people should call it extended 5.1, or at least use some scare quotes: "6.1")


And when people talk about "6.1" or 6.1, the most effective setup is with 7.1 speakers, and there is very good reason for this, which is to eliminate the reversal effect by just having one speaker behind your head. The other processing system that actually provide different sound to those two rear back speakers in a "7.1" speaker setup go furthermore, such as with Logic7.


Quote:
6.1 constitutes less than 0.5% of the titles on the market,
You are technically right, but what is the number of regular 5.1 titles? Thousands upon thousands im sure. ALL of those can be played back in 6.1 just the same, and to correctly do that requires dual rear backs, thus a 7.1 speaker setup.


While moving to 6.1/7.1 setups can show some improvement, IMO, i agree that in some situations and rooms, it's not worth it unless you do it right. But don't mislead people by saying that 6.1/7.1 is practically useless and "marketing BS."

Quote:
The amplifier in a 7.1 receiver is hard wired internally to each channel.
As for this, it is true in most cases, but there are some recievers out there so you can assign channels to do different things, like assign the fronts to power the two back surrounds, if say, you have an outboard amp for your fronts, or may have multi-zone capabilities that can assign those amps to the rear backs. I wouldn't be surprised if there is a reciever that lets you bi-amp the fronts like you want, I'm not sure.
 

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Quote:
Originally posted by ChrisWiggles
Why do people keep saying this. All it does is more thoroughly confuse people.


YOu are 100% correct that there is no 7.1 format. What there is though, is extended 5.1, and a sprinkling of discrete 6.1 (DTS-ES discrete) titles. Furthermore ALL 5.1 discs can be manually processed to get you extended 5.1(this is also erroneously and casually called 6.1, at the very least people should call it extended 5.1, or at least use some scare quotes: "6.1")


And when people talk about "6.1" or 6.1, the most effective setup is with 7.1 speakers, and there is very good reason for this, which is to eliminate the reversal effect by just having one speaker behind your head. The other processing system that actually provide different sound to those two rear back speakers in a "7.1" speaker setup go furthermore, such as with Logic7.


You are technically right, but what is the number of regular 5.1 titles? Thousands upon thousands im sure. ALL of those can be played back in 6.1 just the same, and to correctly do that requires dual rear backs, thus a 7.1 speaker setup.


While moving to 6.1/7.1 setups can show some improvement, IMO, i agree that in some situations and rooms, it's not worth it unless you do it right. But don't mislead people by saying that 6.1/7.1 is practically useless and "marketing BS."

I should have prefaced my comments better. The problem I have with the casual usage of "7.1" is that people mix and match the terminology as if a 7.1 system implies that you're getting discrete channels as part of the format, when that's not true. You correctly differentiate your use of the term for a speaker setup, but the usage of that terminology for a receiver/processor is just not correct because it's not part of the original format encoding.


As I cited in my example, people did not go around calling their Dolby Surround and Pro Logic systems "4.0" or "5.0" systems, so why is the 7.1 parlance suddenly catching on, other than to create a perception in the market that it is somehow bigger and better than what came before? Yamaha's latest flagship receivers have two additional outputs for high mounted effect speakers, so is it correct of them to call that system 9.1? Or because that receiver has an A/B speaker selector, to call it 11.1? Or calling a two-speaker monophonic system "stereo" just because it uses two speakers (and this is a good analogy to "7.1" systems because the two back surround outputs are identical)?


There are technical merits to using two back surround speakers with 6.1 and 5.1 matrixed material, but again calling that 7.1 just because it's played back in that type of speaker configuration is what I take issue with. And the usage of the back surround speakers for all 5.1 material is not always a good idea if it was not originally mixed with at least a matrixed back surround channel. This is because the surround channels in a lot of 5.1 mixes are done with minimal channel separation. Turning on the 6.1 decoder in this example collapses the sound into the back surrounds and creates holes in the side imaging. Some DSP processors might correct this, but in most of my listening I try to go with as little postprocessing as possible.


And just to clarify, I NEVER said that 6.1 was useless marketing B.S., so there's nothing misleading or confusing there. I should have said that the usage of the 7.1 terminology is marketing B.S., and it's this widespread and inconsistent usage of the terminology that creates more confusion than my objections do. How else do you explain the occasional newbie question inquiring into 7.1 DVDs?
 

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Doug,
Quote:
Because of the built-ins, seating is only about 10' -12' back from the screen, and about 4' - 6' from the back wall.


It is a difficult space, and I'm pretty much limited to in-ceiling speakers. I've read all the warnings, but I really don't have a choice, and so now I'm looking at much more expensive in-ceilings (Triads).
Since you're going to place them in/on the ceiling, the surround-back speakers will be more than 4 to 6 feet away. That's a pretty good distance behind the listeners' ears, so I think a 7.1-speaker layout is quite do-able in your room.


Even with ceiling mounted speakers, you'll still get the benifits of a 7.1 system. Don't worry so much about the missing wall to the left, just try to place your speakers as symetrically as possible around the listening area. Put the side speakers as far apart as you can, so that left/right surround content appears to come more from the sides than directly above. For similar reasons, place the rears as far back as you can; this will also help to give you more distinct side vs rear separation (one of the major advantages of 7.1).


The end result should translate to good stability in the surround field. For example: no matter where you sit on your couch, sounds intended to come from behind you will always appear to come from behind you (not some side-ish, rear-ish direction). The fact that you have physically placed a couple of speakers back there makes it difficult for those sounds to appear from any other direction. Make sense?


Good Luck,

Sanjay
 

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" I should have said that the usage of the 7.1 terminology is marketing B.S., and it's this widespread and inconsistent usage of the terminology that creates more confusion "


Agreed 100%. I perhaps shouldn't have phrased my remarks so hotly, because we both agree.


And you're right, applying "6.1" processing (EX/ES) to 5.1 DVDs that aren't labeled or purposefully mixed for DD-EX or DTS-ES matrix can yield mixed results. I find that on many DVDs it is beneficial, but of course, it's just like applying Pro logic or PL II to older movies that were mixed before the advent of PL/PLII. Most often it can yield a more pleasing experience, but sometimes it does not come out well at all.


I think that in general, surround sound formats and processing is EXTREMELY confusing to average folk, and thus I try to be as thorough as possible, and to try to use correct terminology, or explain things that may not be related, just to cover all the bases so that people just reading a post aren't further confused. I know when I first started learning about all this stuff, there were MANY resources on the net that were just flat-out wrong, or out of date, and that leads to even MORE confusion. I think it is important to be clear that when people say "7.1" (if they know what they are talking about), they mean a 7.1 speaker system, NOT, of course, a discrete format. Then what makes THIS even more confusing, is, is this like a Logic 7 setup? Or just "6.1"/6.1 with 7.1 speakers.


And the last thing that I find very confusing too, is when I start rambling in my posts and forget the point i was trying to make. :D
 

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Quote:
Originally posted by ChrisWiggles
I think that in general, surround sound formats and processing is EXTREMELY confusing to average folk, and thus I try to be as thorough as possible, and to try to use correct terminology, or explain things that may not be related, just to cover all the bases so that people just reading a post aren't further confused. I know when I first started learning about all this stuff, there were MANY resources on the net that were just flat-out wrong, or out of date, and that leads to even MORE confusion. I think it is important to be clear that when people say "7.1" (if they know what they are talking about), they mean a 7.1 speaker system, NOT, of course, a discrete format. Then what makes THIS even more confusing, is, is this like a Logic 7 setup? Or just "6.1"/6.1 with 7.1 speakers.


And the last thing that I find very confusing too, is when I start rambling in my posts and forget the point i was trying to make. :D
Been there done that ... well, at least the confusing myself part!


I can see this whole confusion getting even worse if various proposed schemes to try and convey height information start to catch on. It's already happening to a limited extent with multichannel music. Chesky Records includes a 6.0 mix with some of their DVD-As. But, this does not use the familiar 5.1 or 6.1 home theatre configuration, but rather it removes the center and subwoofer channels and substitutes two high mounted effect speaker outputs angled at 55 degrees in their place.


I believe that either Telarc or DMP have been experimenting with overhead height effect speakers that would also substitute either the center or the subwoofer channel. In that case, it would still be a 5.1 system, but the information playing through the center channel actually needs to go through a speaker mounted overhead. How's that for confusion?


Or how about if an actual 7.1 system like SDDS gets adapted for home use? (Strictly hypothetical since I heard that Sony's pretty much quit developing and marketing that format) That system would actually require five speakers up front to go with two surrounds. Ugh, maybe I should just stick with headphones...
 

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Discussion Starter · #16 ·
Quote:
Originally posted by sdurani
Doug, Since you're going to place them in/on the ceiling, the surround-back speakers will be more than 4 to 6 feet away. That's a pretty good distance behind the listeners' ears, so I think a 7.1-speaker layout is quite do-able in your room.
Sanjay, I probably can't get away with that because there are overhead built-in cupboards that effectively reduce the size of the ceiling area. If the surrounds are one foot from these cupboards, they would be only about a foot and a half behind my head when I sit at a 12' distance from the screen. True, they would be further away from my ears because of being on the ceiling, but it is a low ceiling. I think I'll stick with five speakers, and get better ones.


As to the correct terminology, I fully admit to being uneducated. I mainly wanted to know whether seven speakers would sound better than five, assuming the total cost is equal. I also didn't want to waste the other two channels on the receiver, but I can always decide to create another zone and use them there.


Thanks, all.
 

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Quote:
Originally posted by Grampa
If the surrounds are one foot from these cupboards, they would be only about a foot and a half behind my head when I sit at a 12' distance from the screen. True, they would be further away from my ears because of being on the ceiling, but it is a low ceiling.
In that case, surround-back content will image overhead; not quite what was intended (though some people have done it).


Best,

Sanjay
 

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Your room is fairly small for a 7.1 setup so I would use your extra two channels for a zone 2 audio system. I'm going to use mine to power inwalls on my main floor.
 

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"It's hard to be surrounded by sound, with just 2 speakers" (Russ Hershellman, one of CEDIA's founding fathers. From his '95 seminar "Home Theatre:Essential Elements")

Go with a 8-channel design. You will be glad when the software comes out with discrete 7.1 sound. Til then get a Lexicon prepro and use 5.1 Film Logic 7 for a 7.1 ride of your life.
 

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It might be worthwhile to consider what movies you watch. Our taste tends toward the classic and romantic - and on most of them, there's precious little information in the surround channels to begin with. There is very little difference between 5-ch and 2-ch for these. Of course, if your tastes are the new stuff, it might be a more useful proposition...
 
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