Importance of matching rear speakers to front?

brj · « **on:** 10 Jun 2005, 07:56 pm »

There seems to be a general consensus that you really want to match the sonics of your center channel to your mains (dialog, panning and whatnot). I haven't heard as much about matching the rears, however.

What are people's thoughts on the importance of matching the rear speakers to the mains/center for:

a) home theater
b) multi-channel audio (presumably more important than HT)

For reference, my focus is on 2 channel audio at the moment, so I'm putting my money into my mains instead of into a larger number of less expensive speakers. I'm asking this with the expectation that I might want to add rear channels a couple of years down the line, when there is an increased chance that those added speakers will be a different brand/model, or even built into a wall.

Thanks for your thoughts!

bubba966 · « **Reply #1 on:** 10 Jun 2005, 08:12 pm »

For MC audio, you really should have matching speaks all the way around.

For HT, it's most important to have the front array be identical speaks. Matching the front to the rear is great if possible. But if you can at least keep the rears the same brand/line of speaker that's ok. As there's not much info in the rears very often, and when there is there's not much that pans from front to rear. So it's not quite as critical to have identical speaks in the front & rear. As long as the rears have the same sonic characteristics to them that the fronts do then you're fine.

warnerwh · « **Reply #2 on:** 10 Jun 2005, 08:12 pm »

My home theater speakers:
Legacy Classics for Mains
VMPS 626 center
Polk Rti 25's for rears

The difference is noticeable and I'd not want to do multi channel music with this set up. For movies it's fine. I should say that I'm not as fussy as most people when it comes to HT. IF you're going to have a integrated HT music system then I'd do what you're doing and buy good mains.
Also I've got a friend who's using:
VMPS Supertower/R's for mains
VMPS LRC Center
RM 1's for rears.
The Supertowers have a totally different planar midrange and dome tweeters rather than ribbons than the rest of the speakers and this is subtly noticeable and the owner doesn't even know it exists. He's ecstatic with his system. Told me the Vmps LRC must be the best center channel in the world, this after he winced on spending four figures for his center channel. The center channel is hugely important. I'd definitely match the front three if possible but spend the money on the mains right now. You'll be glad you did. Hope this helps.

rbrb · « **Reply #3 on:** 10 Jun 2005, 08:20 pm »

My system used to consist of floor standing speakers for my fronts and the matching center and matching bookshelfs for the rears. When I replaced the center speaker and the rears with the exact same floor standing speakers all around the performance of my system increased 10 fold. I was floored at the difference it made. Surroundsound had a cohesiveness that I never experienced before. Well worth the effort and expense IMO.

An added benefit for me is not having to use apply any electronic bass management.

ctviggen · « **Reply #4 on:** 10 Jun 2005, 08:44 pm »

I'm using VMPS RM40s as my main speakers, an RM30C as my center channel, and Linn 5140s are my surrounds. I honestly don't notice much of a difference between the fronts and rears for movies or music, but I only listen to DVD-type of multichannel music, and that rarely (I think I have 5-6 DVD videos of musicians -- SRV, Big Head Todd, Clapton). I think that having 5 of the same speaker would be nice, but I couldn't see having 5 RM40s. The WAF on that setup might be negative! (It's barely above zero as it is, with two RM40s.) Not to mention that the RM40s are huge and really are overkill for rear surrounds. I should note that I got all the same options on my RM30C as I got on my RM40s and that I try to match them using the level controls on the speakers.

nathanm · « **Reply #5 on:** 10 Jun 2005, 08:59 pm »

What are the dimensions of your room, brj? Where do you sit in relation to the walls?

brj · « **Reply #6 on:** 10 Jun 2005, 10:12 pm »

Thanks to everyone for all of the responses so far! Obviously, this is an issue that people have thought about a bit...

Quote from: nathanm

What are the dimensions of your room, brj? Where do you sit in relation to the walls?

Since I don't anticipate getting rear channels anytime soon, I was really was asking the question in the general sense in order to aid future planning and in the hopes that the answer would serve others. However, since you ask...

My current living room is roughly 18x18x12 with angled corners or openings and a partially sloped ceiling. It opens up completely into a dining area and partially into a foyer and kitchen. There is tile in the kitchen and foyer, and wall-to-wall carpeting everywhere else. Large leather couch at the listening position with other large furniture in the room as well. All windows run from almost the floor up to almost the 8 foot height and have 2 inch blinds on them (not that this has any acoustic benefit).

I just uploaded the floorplan to the gallery. The long dotted line that traverses the image vertically separates the flat 12' ceiling on the right from the sloped portion on the left. The sloped portion drops from 12' to 8' over a 6' span, ending at the "window wall". Main speakers will be in front of the living room windows toward the bottom of the image and pulled out a bit. The front edge of the couch will be positioned roughly at the right-most edge of the ceiling fan as it appears in the image. This gives me some room behind the listening position, but most of it will be walkway. I could conceivably put stand mounted rears there if they weren't too large and could be kept close to the wall. In-wall speakers (or the nifty new picture speakers from Odyssey Audio) would probably be an easier fit.

Again, all of this is somewhat nebulous for me at this point. I'm just starting my system from scratch, and my investment is aimed at 2 channel at this point (although I'll bite the bullet and get the center channel at the same time as the mains to make sure they match both sonically and visually). By the time I get around to adding rear channels, I may well have moved into another house in another part of the country. (WI summers beat TX summers any day the week, Nathan!

)

Thanks again to everyone for all of the feedback!

nathanm · « **Reply #7 on:** 11 Jun 2005, 03:29 am »

Hmmm...this is not gonna be easy. I tried to find a good placement but nothing quick and easy comes to mind.

Your couch\chair would be the center of each colored circle. The brown one would be about where it is now. I tried two other wider circles...but uh, if I were you I'd stick with 2-channel and spare yourself the headache!

This whole surround thing is a real cock up because they want the speakers arranged in a circle, but everybody's room is a rectangle. If we all lived in grain silos it would be no problem but getting a decent separation for the mains and still finding room for the rears is really challenging.

brj · « **Reply #8 on:** 11 Jun 2005, 01:02 pm »

Nice work, Nathan - thanks!

Starting with your brown circle, my plan for the front 3 speakers was to have them just in front of the windows with the left speaker just next to the fireplace. If I ever get to the point of setting up this current room with rear speakers, they would have to go up against the rear (bottom in the image) wall in each "corner". (This isn't much of a corner, since the ajoining wall on each side is only about 6 inches long and angled outward.)

Obviously, this puts the rears really at the rear, and not out the sides like your circles show. I haven't done much research into HT or MC audio speaker placement yet since I've been focusing on 2 channel, so I don't know how much of an issue this would be. I did figure that I could handle the different distances to the listening position with timing delays set in whatever pre-pro I'd use.

Anyway... I guess if the placement of the rears is really that critical to HT and MC audio, then my forced use of "poor" positioning might make any differences in front to rear channels seem to be a smaller problem than I imagined.

bubba966, ctviggen and rbrb, you make a good point about identical speakers being valuable in MC audio, but is it really that critical? I mean, except for some specialty discs, isn't most of the rear channel content still going to be ambiance effects?

Warner, is your friend's VMPS setup aimed at MC audio or HT? I'm assuming that might make some difference.

Thanks again to all for the comments!

warnerwh · « **Reply #9 on:** 11 Jun 2005, 04:16 pm »

"Warner, is your friend's VMPS setup aimed at MC audio or HT? I'm assuming that might make some difference."

His setup is 50/50. He's not an audiophile but loves music and movies. He doesn't know multi channel recordings exist so for music it's used as a stereo in which case the difference of speakers doesn't matter at all. On movies the difference is only noticeable to people like us and it's really not that noticeable unless you listen for it.

nathanm · « **Reply #10 on:** 11 Jun 2005, 06:39 pm »

Quote

did figure that I could handle the different distances to the listening position with timing delays set in whatever pre-pro I'd use.

Subjectively I would say that having the rears further away than the recommended setup would be preferable than having them closer with preamp delay. In mine I decided that the recommended setup as shown in my diagram just wasn't going to work. So my rears are at 90 degrees and almost twice as close to me as the three mains with digital delay. It's just not the same thing unfortunately, the rears are still right on top of you.

Here's what they want:

But this is what I have. The red box is a rough approximation of my room's walls. The problem arises because the distance of the Main Left and Right which sounds great for stereo means that the rears would have to be placed in the hallway outside! *doh*! The only way I could squeeze the whole Dolby circle inside my room would be to have an extreme nearfield setup, which is just impractical even for a single guy with no aesthetic spousal goals to contend with! Sometime I should try it just for kicks.

I think they should make dolby 5.1 area rugs with speaker placement lines incorporated into the pattern. That'd make things really easy!

Mag · « **Reply #11 on:** 12 Jun 2005, 11:29 pm »

I wouldn't know where to place two speakers in your room let alone MC configuration. Whenever I've been to other peoples homes I try to figure out where I would place speakers and like yours most homes have'nt got an appropriate room. My living room is an L shape, I can make it work but where the door is located would be the best place for the tv and center. The best solution I found for this room was to approach the main portion of the room as a rectangle and then place two speakers in the other corners of the L to fill the sound gap. I have since moved my system to the basement. This room isn't ideal either but at least it rectangular I have found the best solution for it. My room is 11'x25'x7', originally I had my MC set up using the room the long way with surrounds behind listening position which was in the middle of the room. This was okay at first but overtime I realized that I wasn't getting good stereo imaging. And being that the room was narrow I couldn't place any speakers off to the sides. That's when I got a brainstorm to try using the room width wise. So I placed two speakers on each side of the listening position which worked not to bad, but there was a noticable gap in the center soundfield between the speakers. So I placed two bookshelves and a center channel in the center which did the trick. Although these speakers are closer than the speakers off to the sides I find that sound coming from the sides dominates sound coming from the front field. So it a merges together to give me an even soundfield. I also hear way more detail than I was before.
Recently I upgraded my rear and center speaker to match the treble/tweeters to my front mains, I listen to music in MC stereo. The result being that the soundfield is balanced 180 degrees and my ears aren't drawn-in to focus on the front mains. So for MC stereo having matching speakers all around is ideal. I don't think having matching rears for surround sound for movies is that important.
With a good room 2 speakers well placed could probably be just as effective as MC stereo. MC however can solve many room deficiantcies, but since very few homes have an ideal room we have to make comprimizes to an ideal setup. So experiment with your room and you'll come up with a working solution. And don't worry about what the rest of us thinks.

csero · « **Reply #12 on:** 13 Jun 2005, 02:18 pm »

In my experience it is much better to have lots of (4-8 ) lower quality real channel speakers sctattered all around the back and above, than just a matching higher quality rear pair. The ear's freq response is very different from behind.

ctviggen · « **Reply #13 on:** 13 Jun 2005, 03:17 pm »

I personally don't notice the difference between my rear and front channel speakers for movies or multichannel DVDs (not SACD or DVD-audio, neither of which I have; well, I used to have DVD-A but was inimpressed). I think that for movies, I'd rather have speakers that don't act like point sources. Sometimes I can localize my rear speakers.