how much comes from 7.1 rear speakers?

[tomagardner]

Howdy, newbie here.

We are doing the big basement remodel and I get to do the speakers, etc. Are there a lot of 7.1 out there? And how much sound comes from the 7.1 rear speakers? I am trying to decided whether to get really good rear speakers or just some in-walls.

Cheers, Tom

[Chris D]

Tom, I'd recommend that you use the same speakers for side surround as you do the rears, and that those be timbre matched to the fronts. You don't want to have a sound change as it moves from one speaker to another.

I'd say most movies today are put out as 6.1 or 7.1, using rear speakers. And if it's not, you can use Dolby Pro Logic IIx on ANY source, whether speech, music or movie, to create a 7.1 soundfield. I highly recommend this, as it works great.

[tomagardner]

Thanks for the help! Getting identical front, side and rear speakers it is.

[Chris D]

Well, you CAN get identical speakers for all 7. I think that'd be better than buying different speakers here and there that are not going to match sonically. The rear 4 speakers generally all have the same purpose, so they can be identical, designed for surround sound. What's best, though, is to get front main speakers and a center that are specifically designed for each of those purposes, and overall buy all 7 speakers from the same manufacturer that SPECIFICALLY DESIGN them to match up with each other.

But again, all 7 same speakers works too, just not "optimal".

[naughty]

i would not use all speakers identical - i would use conventional speakers for the fronts and stick to the following unwritten rules

1) front speakers to have tweeters as close as possible to ear level when seated
2) rear speakers as high as possible
3) if possible and also keeping in mind the need to have similar drivers for the rear speakers as in the front speakers - it would be nice to have dipole or bipole speakers for the rear and surround speakers - again to make the sounds diffuse
4) use the autosetup on your receiver
5) do as much room treatment as you can - this will help your speakers to play really well

[tomagardner]

Well, you CAN get identical speakers for all 7. I think that'd be better than buying different speakers here and there that are not going to match sonically. The rear 4 speakers generally all have the same purpose, so they can be identical, designed for surround sound. What's best, though, is to get front main speakers and a center that are specifically designed for each of those purposes, and overall buy all 7 speakers from the same manufacturer that SPECIFICALLY DESIGN them to match up with each other.

But again, all 7 same speakers works too, just not "optimal".

Why wouldn't 7 identical speakers be optimal?
Thanks, Tom

[baniels]

I think in a perfect world, identical speakers all around would be ideal. No question of timbre matching, and could even simplify bass management depending on your hardware.

The downside is that if you plan to get 7 identical speakers you have to either:
a) Spend extra on the surrounds to match the more important and ideally good quality front stage (L,C,R).
b) Get a poorer front stage so you can afford identical speakers all around.

If budgeting is part of the equation (as it usually is), I would suggest investing more in the front stage rather than spreading the budget evenly all around. I would take a superb front stage with NO surrounds, over mediocrity all around me any day. I'm sure you can find a balance that works.

I'm guessing it was from the wallet perspective that Chris meant it was not optimal.

[tomagardner]

Gotcha. I will be building 3-way RC3R kits from Selah Audio http://selahaudio.com/id15.html
He has similar speakers with the same woofer and tweeter. I have an E-mail in to him. Think that would be good? They would certainly be installed more easily.

While we're on the subject I am hoping to mount these "in-wall". Rick knows that and will adjust the BSC appropriately. They won't be mounted to the wall, just in the same plane of the wall. They will all be attached to the concrete foundation behind them and any other necessary support below them. They will be level with the plane of the wall and the space between the speaker and the drywall will be caulked.

Whatcha think?

[Chris D]

yeah, I might not have made that clear in my post. Actually, the reason I say that it WORKS to have 7 identical speakers, but it is not IDEAL, is that different speakers are made for different functions. If you get 7 identical speakers, then several of them are going to be doing their job by putting out sound, but doing it in a manner that is not consistent with the design of that particular channel.

Here's what I mean, touching on the fundamentals of multichannel design:

The front MAIN (left, right) speakers should be virtually full-range, as music and effects are primarily carried in these channels, as well as ambient sound in the front of the soundfield. These speakers should be "direct radiating", where they project the sound directly at the listener, making their sound localized. This means the listener can readily tell what direction the sound is coming from.

The front CENTER speaker is critical and often not given enough attention in a buyer's system. It should specialize in re-creating human dialogue, as almost all spoken dialogue in a movie is put into the center channel. It should also be direct radiating, ideally placed directly in the middle of the screen. (i.e. behind an acoustically perforated screen, if possible) When a character on screen talks, you don't want to hear his words coming from the general front of the room, you want to hear it coming directly from the screen itself, where you see the character's mouth. This all goes to realism. If you experience a setup where the center channel is a large distance from the middle of the screen (sometimes necessary for a huge screen), you'll see what I mean when you hear sound coming a person's feet or the ceiling, instead of the mouth.

Surround speakers (both side and rear) should be designed for re-creating the ambient environmental sounds and effects that are put into these channels. They ideally should NOT, repeat NOT be "direct radiating". Instead of shooting sound directly at the listener, they should have multiple drivers that put the sound out into the room periphery, where it reflects off walls and objects before reaching the listener. Experience a non-optimal room sometime--direct radiating speakers used as surrounds can be VERY distracting while watching a movie, especially if they're turned up too loud. You want to keep the viewer's attention forward on the screen, with the visuals, not constantly pulling their attention to the sides and rear. A proper surround sound should make the viewer aware of a noise from "somewhere in the right rear of the room", not from one point in space that they can specifically identify.

You've heard it before, where a distinct sound comes from your side or behind you. Your attention gets at least partially diverted there. Make it loud and/or distinct enough, and it will make you turn your head and look at the speaker. Makes for an interesting novelty if it is deliberately done once in a sitting. Done constantly for hours, and it's annoying. Instead, surround channels should provide an ambience that draws the viewer into the environment. Done properly, it ENHANCES the experience. Improperly done, and it is too much, and DETRACTS from the experience.

That's why, out of a 7 channel system, you should ideally buy at least *3* different types of speakers. (mains, center, surrounds) Can you use identical speakers for all 3 front speakers? (mains, center) Yes, this is often done, with not a lot of trade-off, because all 3 channels are direct-radiating. Does this mean that you CAN'T use the same speakers for surrounds? No, people still do it, and it's probably better than not having anything there at all. Not ideal, though. But if you have the choice to buy a new system, buy it RIGHT the first time, and get diffused surround speakers for the surrounds.

didn't mean to draw this one out this long, but just to reiterate the other point, even though you're buying different TYPES of speakers, they still need to match sonically. You don't want the rear of your room to sound completely different in tone and timbre from the front. And if there is a sound "pan", like an aircraft flying overhead, or truck that drive from the rear to the front, or side to side, you don't want the sound to change how it sounds to your ears, from robust to thin, or from smooth to sharp and metallic, or such. That's why you don't want to buy brand X for your mains, and then later on buy brand Y for your surrounds. Not only keep them all the same brand, but research the manufacturer, and find out which surrounds and center channel speaker of their match the mains you choose.

Hope this helps.

[tomagardner]

gotcha, thanks

[onyxbfly]

+1 To Benaiels. Most of your budget should be focused on your main sound stage. The front L and right and the center channels. They should have the same drivers and should be timber matched. If you have any old speakers they can fill in as surrounds until you get your budget up and or get your wife something so that it diverts her attention from your main objective.

Chris has made several points not to sure if I agree with him about the rear/ surround speakers. If your room is properly set up and your speakers are calibrated then you should be set. I do agree with him in regards to bi vs direct surrounds.

[JamesB77]

There are all kinds of conflicting ideas about surround's. Here is an artical comparing direct, bi and di-polar. In the end, I think you have to decide what will work best in your situation.

[Hdale85]

bi/di-polars are kind of designed for crappy room setups. Small spaces where you can't place the surrounds where they should be and what not. Generally the problem with them is they have nulls in the FR in certain area's and what not.

[Chris D]

I disagree. bi/di/tri/whatever-polars are designed to produce diffused sound, which is the design of surround sound speakers. Work better than direct radiating speakers in most any setup where the room is less than maybe 40' wide, and even then, work great.

[Hdale85]

Well it's a long lasting debate have to leave it at that. But there are reasons you rarely see a bi/di-pole DIY build.

[Hdale85]

I mean bi/di-pole surround DIY designs. There are obviously quite a few Di-pole and open baffle mains designs