THX OR 7.1???? I Need help

[Deadbolt]

Hello all. Need help! I have A set of JBL C37's , Set of 1989 Altec 511's as seen in pic 5' tall. Pair of Polk's centers. Polk's rear's, JBL 450 watt 15" powered sub. 250 watt 12" JBL powered sub and many more speaker's if needed , but these are the main one I was going with. Also 4 Hafler 9290 amp's, Pic's also. I know I will be getting a new Receiver or pre amp for this project, Also I have a 2800 lumens 1080p HD Projector with a long throw len's. I want to build a great 7.1 or THX HOME THEATRE. How would you set this up????Best layout??? The best way to hook itup?? The room is 21' x 15'. I need all the pro's here to help me.. Thank's Deadbolt

[Rolf]

Maybe I don't understand, ... but what is the question? 7.1? THX?

THX is standard regarding spl as far as I know. Why do you want 7.1? what is on the marked is not 7.1.

Rolf

[hjames]

Maybe I don't understand, ... but what is the question? 7.1? THX?

THX is a standard regarding spl as far as I know.
Why do you want 7.1? What is on the market is not 7.1.

Rolf

Actually the Harman Kardon receivers do 7.1, as do a number of other brands. I run my receiver in 5.1 mode for movies and TV because its a small room and I'm not sure where I'd put another pair of speakers - tho I'd probably toss a pair of L20Ts in as surrounds to match the rears. I generally play music in conventional stereo.

According to Wikipedia: THX sets strict standards for high quality sound and images. THX-certified systems provide a high-quality, predictable playback environment to ensure that any film (http://en.wikipedia.org/wiki/Film) mixed (http://en.wikipedia.org/wiki/Mixing) in THX will sound as near as possible to the intentions of the mixing engineer. THX also provides certified theaters with a special crossover (http://en.wikipedia.org/wiki/Audio_crossover) circuit (http://en.wikipedia.org/wiki/Electronic_circuit) whose use is part of the standard. Certification of an auditorium entails specific acoustic (http://en.wikipedia.org/wiki/Acoustics) and other technical requirements; architectural requirements include a floating floor (http://en.wikipedia.org/wiki/Floating_floor), baffled (http://en.wikipedia.org/w/index.php?title=Baffled_wall&action=edit) and acoustically treated (http://en.wikipedia.org/w/index.php?title=Acoustical_treatment&action=edit) walls, no parallel walls (to reduce standing waves (http://en.wikipedia.org/wiki/Standing_wave)), a perforated screen (to allow center channel (http://en.wikipedia.org/w/index.php?title=Center_channel&action=edit) continuity (http://en.wikipedia.org/w/index.php?title=Acoustic_continuity&action=edit)), and NC30 rating (http://en.wikipedia.org/w/index.php?title=NC30_rating&action=edit) for background noise (http://en.wikipedia.org/wiki/Background_noise).

THX Ltd. started a licensing program for home screening rooms in 2005, which requires standards similar in concept, though not in detail, to its cinema certification program.

[Titanium Dome]

In technical terms it's possible to have a 5.1 THX set up or a 6.1 THX set up or a 7.1 THX set up. As others have noted, the THX standard refers to the system's ability to meet certain technical standards, and those standards can be applied to multichannel sound systems. (We won't talk about video, here.)

Rolf is correct that there is little 7.1 source material out there, though it does in fact exist. However, it would be fair to say you're not going to find any movies or TV shows that you've ever heard of that will have 7.1 sound per se. There is 6.1 source material, too, as well as the ubiquitous 5.1.

Regardless of the number of channels in the source material, you can get equipment that will produce the technical standards for reproducing THX sound. Many of them will have "THX" prominently displayed if they've taken the time and spent the money to get the certification. There are also many pieces of equipment that can meet or exceed THX standard that don't bother with the certification. Nevertheless, if you know the basics of THX, you can assemble a system that can meet those standards anyway. This would include things like being able to set the LF crossover so that everything below 80Hz goes to a sub that can meet THX requirments, having a minimum power ratinge per channel, etc.

Check out this easy to read page:

http://www.timefordvd.com/tutorial/THX.shtml

As you'll see, having all THX components and source material will not give you the complete THX experience if the room is not right. So bear that in mind as well. The room must be set up and treated properly.

As for 5.1 vs 6.1 vs. 7.1, the best, most natural sounds IMO come from well-rendered 7.1 multichannel systems. Systems such as Harman's Logic7 or Dolby's PLIIx do a fantastic job when properly calibrated. Many OFs don't like this new-fangled approach and prefer two-channel sound. They can live in the past if they want to; sometimes I like to do that, too. It's very nostalgic and comforting.

Inasmuch as my usual interest in listening to music is to have the best experience, I use 7.1 at least 80% of the time.

[Rolf]

Thank you Titanium Dome for the explanation. I am not very good at this, just listen to music, judging bu that.

Just now listen to NightWish ... ever heard about them? A Finnish group I believe

Roolf

[DieCastMan]

Interesting and pretty accurate responses.

The only thing I'd add is that if your room is quite long from front to back and you have multiple rows of seating then the 7.1 would be a good idea. Side speakers located next to the front row of seats in addition to rear speakers located along side or better yet behind the rear row of seats is the ideal setup for 7.1. A room like that would be more akin to a theater.

Most living rooms can't take full advantage of 7.1 because most rooms don't accomodate multiple rows of seats. If yours does then it is definitely worth doing 7.1.

As previously stated, THX is more of a standard than a type of system. It started years ago when George Lucas went to see & listen to one of his films and hated the way it sounded. Then he developed minimum requirements for db level and bandwidth. Limiting dispersion was key too to get the upper mids and highs to cut through the dozens of rows of seats to get to the folks in the back of the theater.

Remember the first generation JBL Synthesis systems? They used hi freq. horns for theater then switched to 035tia's for music to obtain the optimum dispersion for both theater and music.

OK....that's my two cents worth...you guys already had it well in hand before I chimed in.

Ray

[Titanium Dome]

Thank you Titanium Dome for the explanation. I am not very good at this, just listen to music, judging bu that.

Just now listen to NightWish ... ever heard about them? A Finnish group I believe

Roolf

Rolf

Haven't heard of them before, but I will check them out. :)

[ChopsMX5]

Interesting and pretty accurate responses.

The only thing I'd add is that if your room is quite long from front to back and you have multiple rows of seating then the 7.1 would be a good idea. Side speakers located next to the front row of seats in addition to rear speakers located along side or better yet behind the rear row of seats is the ideal setup for 7.1. A room like that would be more akin to a theater.

Most living rooms can't take full advantage of 7.1 because most rooms don't accomodate multiple rows of seats. If yours does then it is definitely worth doing 7.1.

Ray


Actually, I run a 7.1 setup in my small 13'x17' room with quite excellent results.

It's not that it makes things sound further back in the room or anything, but it certainly does "open up" the room. The back two channels make my room sound much larger than it really is, and to me, that's a nice improvement to me.

[JBL 4645]

There isn’t any practical Dolby dts 7.1 encoded material that’s readily available to the home cinema consumer market place as of yet! And until there is an abundant supply I’d wait until there is.

[MJC]

Most living rooms can't take full advantage of 7.1 because most rooms don't accomodate multiple rows of seats. If yours does then it is definitely worth doing 7.1.


I wouldn't say most. If the room's only seating is up against the back wall, then yes, 7.1 is next to useless. That's my experience listening to such setups, including a HT showroom in a local HT shop.
I sat down on the sofa and they had a small back speakers right next to the ends of the sofa. It was just WAY TOO close.
In my HT I have one row of seating and the back speakers are over 7' behind. The outside seats are about 5' to the side surrounds. So there is plenty of space all around, as it should be.
Multi rows of seating is not the main criteria for having 7.1, having enough space is.
But people have to work with what they've got, and sometimes they have to compromise.

[ChopsMX5]

There isn’t any practical Dolby dts 7.1 encoded material that’s readily available to the home cinema consumer market place as of yet! And until there is an abundant supply I’d wait until there is.


It doesn't matter.

If the HT processor has 7.1 capability, it also most likely has the ability to "matrix" the back two channels and still provide a better feeling of "space" in a smaller room.

All I can say is there is a notable difference/improvement in my system with the rear channels activated, even if it isn't "true" 7.1.

Don't knock it till you try it. ;)

[CONVERGENCE]

How about separate channels .Denon has a separate 7.1 pre amp
with balance outputs. The model is the DNA 7100 The price is more reasonable than the McIntosh model.


Highlights
7.1 Balanced Line Level XLR Outputs (+4dB/-10dB - switchable)
Balanced XLR Auxiliary Audio Input (+4dB/-10dB - switchable)
HDMI Video Switching (ver. 1.1) (2 sources)
192kHz/24 bit Crystal® DAC for all 8 Channels
32 bit Digital Surround Processing Chipsets
Set-up menu via Video Outputs (Composite, S-Video, Component)
Video Convert Feature (Composite/S-Video to Component)
Dolby Digital EX, Dolby Digital, DTS ES (Discrete 6.1, Matrix 6.1, Neo:6) Decoding
Dolby Pro Logic IIx (Movie, Music, Game)
Circle Surround II (Movie, Music, Mono)
HDCD Decoding
RS-232C Terminal for System Control
XM Ready

[JBL 4645]

Using the matrix circuitry to move or place centralized phantom signals in different locations is easy.

You can get two extra channels of directional support just be re-plugging the left front and rear left with a matrix decoder, because sometimes there’s often two signals that sound kinder outer place, disorientating you’re not sure if its suppose to be placed slightly up front or slightly to the back?

A few films that I have come across over the years like “Flight Plan” “Saving Private Ryan” “E.T.” have this type of sound or effect, and all it needs is an array of matching loudspeakers for the surrounds and several matrix decoders amplifiers and a lot of patience in setting it up.

Heck I’ve even figured a way to make the surrounds to move around with split-surround films only and providing the stereo surrounds have been mixed well, you can trick the surrounds to move around in five-ways that is.

Left side surrounds
Left half surrounds
Centre back surrounds
Right half surrounds
Right side surrounds

A bit like the like the (SDDS 8) five-screen array easy, and all you need is a simple Dolby dts 5.1 AVR a few extra decoders a bit of imagination and you can transform your home cinema into something different rather than following the rest of the sheep.:p

[ChopsMX5]

Using the matrix circuitry to move or place centralized phantom signals in different locations is easy.

You can get two extra channels of directional support just be re-plugging the left front and rear left with a matrix decoder, because sometimes there’s often two signals that sound kinder outer place, disorientating you’re not sure if its suppose to be placed slightly up front or slightly to the back?

A few films that I have come across over the years like “Flight Plan” “Saving Private Ryan” “E.T.” have this type of sound or effect, and all it needs is an array of matching loudspeakers for the surrounds and several matrix decoders amplifiers and a lot of patience in setting it up.

Heck I’ve even figured a way to make the surrounds to move around with split-surround films only and providing the stereo surrounds have been mixed well, you can trick the surrounds to move around in five-ways that is.

Left side surrounds
Left half surrounds
Centre back surrounds
Right half surrounds
Right side surrounds

A bit like the like the (SDDS 8) five-screen array easy, and all you need is a simple Dolby dts 5.1 AVR a few extra decoders a bit of imagination and you can transform your home cinema into something different rather than following the rest of the sheep.:p

I don't understand... You argue about setting up a 7.1 system as being useless, yet you have this thread about your own system... :blink:

http://www.audioheritage.org/vbulletin/showthread.php?t=11167

I mean, seriously, upper and lower center channels PLUS left and right center channels?! Not to mention the 101 side and rear surround speakers?! And all in a room which appears to be smaller than my room?! :blink:

Don't get me wrong. I'm not bashing your system at all or anything of the kind. I'm just trying to figure out how you are so against people wanting 7.1 setups in their homes when you have all the stuff you have. :blink: