Quick Question About Speakers (1 Viewer)

[Mark.D]

Is this correct?
5.1 Dolby means: 6 speakers total
Front Right
Front Center
Front Left
Subwoofer
Rear Right Surround
Rear Left Surround
6.1 means that you have: 7 speakers total
Front Right
Front Center
Front Left
Subwoofer
Rear Right Surround
Rear Center
Rear Left Surround
7.1 means that you have: 8 speakers total
Front Right
Front Center
Front Left
Subwoofer
Right Side Surround
Left Side Surround
Rear Surround Right
Rear Surround Left
So the only diff between 6.1 and 7.1 is that 7.1 now has side speakers and does away with the rear center?
And one more question... I'm gonna go with the M&K 750THX speakers and set up 6.1 as above (I'll have to buy an additional rear center), but I will wire for 7.1 for future use... I'm going to be using the Denon AVR-4802 receiver, the next one up in line that supports 7.1 is like double the price!
So my question is, do you think that 12ga wire from Home Depot is sufficient? Or do you think that I really need to spend the cash for the "THX" certified wire?
And my last question is that I've been hearing a lot of debate on the rear center 6.1 speaker or the 7.1 rear speakers as "dipole" or "mono's"... what does "dipole" mean? Does that mean one speaker box, but it houses TWO individual speakers?
Thanks,
Mark

 

[Mark.D]

Arghhh!
This is so confusing, I'm reading Denon's flyer that lists the tech specs on the AVR 4802 receiver:
Audio Outputs:
Front L/R
Center
Surround L/R
Surround Back L/R
Subwoofer
That's 8 speakers total... does this mean it supports 7.1?
All it says in the description isit supports DTS-ES 6.1 + THX Post Processing, DTS-ES 6.1 Decoding, DTS NEO:6 Decoding, Dolby Pro Logic II Decoding, THX Surround EX Decoding... It doesnt say anything about 7.1 though?
Hmmmm...
Glad I have a year and a half to sort all this stuff out... ya know, I think researching, designing and building my Home Theater will be about as much fun as watching my first movie on the Big Screen!
M.

 

[John Garcia]

6.1 and 7.1 are essentially the same, with the exception that 7.1 has two rear centers.

Yes, a dipole/bipole is a single speaker enclosure with drivers equivalent to two speakers, usually facing 180 degrees apart, but may also be angled.

 

[Mark.D]

Okay, I found the Denon AVR 4802 at http://www.reliableaudiovideo.com/denavnewmod.html for $1695.00, and according to them: 7.1-channel preamp in/out ... so I guess it does support 7.1.
Looking at the back of the receiver, there are 9 speaker connections... I'm guessin there are 9 so the user may set up for 6.1 or 7.1, right?
Okay, so here's the next question...
M&K THX750 speakers, $1999 from http://www.superaudiovideo.com:
Link Removed
This THX package system is a 5.1 set up, for 6.1 I'll need one more center speaker for the rear...
So, the additiona center speaker lists for $425. Is the rear center speaker the same as the front center speaker, does it matter?
If I choose to do a 7.1 set up, I forgo the rear center speaker and then just add a pair of surround speakers for the sides... the side speakers list for $695 a pair. Are the side surround speakers the same as the rears? Does this matter if the side speakers are the same exact speakers as the rears?
I'm thinking that for a few hundred dollars more, why wouldnt I want to do a 7.1 set up as opposed to 6.1?
M.

 

[Mark.D]

AND...

Lets say I go with the 7.1 set-up...

When I have my HT room built, I'm going to have the front screen wall built 3ft from the concrete wall. This will make a nice space in which I can access the wiring/connections of the components from behind the wall... its my intent to have the builder make cut-outs for the components and speakers (including the sub) so that all are flush with the wall.

The rear and side walls, I was planning on the builder using 2x10's so that the rear and side speakers could be flush with the wall as well...

So, it was my intent to have the speaker cut-outs the same height as the stands, with the rear speakers being elevated higher than the fronts...

How critical is speaker height placement? At what height would you recommend placing the front L/R, Front center, Surround Side L/R, and Rear Surround L/R speakers... I also plan on the Sub being up front.

M.

 

[Ted Lee]

the whole 6.1/7.1 thing is a PITA. as long as you wire for expansion, you'll be fine. the only major difference between 6 and 7 is an additional rear-center. i don't know specifics of that denon, but all those sound-modes should definitely be enough for ya.
if you have specific questions about that receiver, do a search (then post if necessary) in the a/v sources forum.
regarding speaker placement, i would NOT put those speakers into the wall if i could help it. aesthetics aside, most speakers sound better when placed away from the wall. imagine they need room to "breathe" - if you shove them into an enclosure you're going to stifle them.
speaker height placement is critical. if you put those speakers at the wrong level, all the high-frequency info (which is very directional) will not be pointed at the listener.
again, if you have specific questions aboout those speakers, search (then post) in the speaker forum.
good luck - looks like it's gonna be a sweet setup!
[EDIT] - looks like a similar discussion about sound formats is going on here:
http://www.hometheaterforum.com/htfo...threadid=99537

 

[John Garcia]

The reason the Denon has 9 speaker outputs is because you can have 2 additional sets of surround speakers in an optional, selectable setup: You can have monopoles for multi-channel music and switch to di/bipoles for surround for movies. Of course, that also means you would need that many speakers also.

The rear center does not need to be identical to the front center, but it should be timbre matched to the other surrounds.

In a 7.1 setup, there is plenty of discussion as to whether the rears should be bi/di or monopole. My preference would be monopole, with bi/di side surrounds.

Front L/C/R should be ear level when seated. Bi/dipole sides should be 2-4 ft above the listener, rears also.

The rear and side walls, I was planning on the builder using 2x10's so that the rear and side speakers could be flush with the wall as well...

You cannot have bi/dipole surrounds flush, they have to stick out by definition, since the drivers face front and back and reflect off the other walls.

You can't choose the sub placement until you have it in the room. Sticking it where you think it should go may not be the optimum location within your room due to "room effect" based on how the low frequency waves react with the room size and shape.

 

[Mark.D]

Thanks John, that makes a lot sense. I'll have to check out M&K's website again, I dont recall if they state if their speakers are bi/di... from looking at the pics, I tend to think they're just mono's... for THX speakers they're pretty affordable/cheap too. $1999, I'm guessing that di/bipoles cost more?

 

[ChrisWiggles]

I've had this nagging doubt in my head about this "7.1" thing. There isn't any 7.1 right? I was pretty sure about that, but you know...i get stuff wrong all the time. Now, it was originally my understanding that in a system that touts "7.1" that the rear outputs are in mono, however, i heard that some brands, i think onkyo, prolly others do some kind of "fudgy" processing so that the two rear backs are a little bit different, perhaps they carry a little bit of the signal from the R/L surrounds. Is this right? And if it is right, there isnt any industry standard is there? e.g some kind of DD 7.1 EX.....RIGHT? I just wanna make sure you know

 

[Will Orth]

Just a Reply on the wall thing, if you do decide to do it build massive cabinets-seperate enclosures for your in-wall speakers, i just got my new audio generator today and did find some problems, i can live with them as i don't turn up my system loud enough to hear the vibrations, if you do a in wall deal use the concrete as the main front wall baffle and make the enclosure out of 1" mdf with extensive bracing as i found some nasty vibrations on high spl tests.


Will

 

[John Garcia]

Chris, you are correct, there is no "7.1" material, only 6.1. In 7.1, you have two speakers, but the sound is basically the same. Through procesing, each may get a little more left or right on some processors, but I think the end result is more or less the same. I feel that some advantages of 7.1 are an even number of speakers, and wider dispersion (especially for larger rooms).