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does flipping the room make sense

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Posted on August 23, 2009 at 15:39:43
Patster
Audiophile

Posts: 333
Location: Canada
Joined: November 2, 2004



I've posted here before with a similar layout and had some very good suggestions
My wife has now given me the green light to move my speakers to the short wall and I need advice if this is such a good idea !!
please view pics of my current setup along the long wall

I now want to position the speakers along the short wall and have the spakers firing along the long part of the room
the issue I have is the left speaker the front wall will be fairly close (approx 18 inches away) and the side walls will be close as well 24 inches

I also will have the staircase underneath my listening positon and this will further complicate things

Does it make sense to make the change or leave things as is ?

Alternatively I could move the 36 inch television and leave the room as is does having the tv in between the speakers make a big difference in what i'm hearing

how about flipping the speakers 360 degrees around, posted on August 25, 2009 at 17:13:07
Patster
Audiophile

Posts: 333
Location: Canada
Joined: November 2, 2004



Here's the wall i'm thinking of moving my speakers to
The space is fairly open with no wall obstructions
The only downside I can see is my listening postion (opposite wall) the ceiling is fairly low

The L shaped couch is going to another room and space will be cleared out to allow for this change to happen
I have posted pics of the opposite wall where my listening seat will reside below


Comments/Opinions on whether this is a good move is very much appreciated !

RE: how about flipping the speakers 360 degrees around, posted on August 25, 2009 at 17:16:59
Patster
Audiophile

Posts: 333
Location: Canada
Joined: November 2, 2004



view of the wall where my listening seat will be situated if I rotate my speakers a full 360 around

See the low ceiling and funky duct work ..Is this a problem

RE: how about flipping the speakers 360 degrees around, posted on August 25, 2009 at 18:36:59
David Aiken
Audiophile

Posts: 5109
Location: Brisbane
Joined: September 25, 1999
 The basic consensus is that if you're going to have the ceiling low at one end of the room and high at the other, it's best to have it low at the speaker end. That's with a sloping ceiling becuase having the ceiling slope up to the rear can result in eliminating the first ceiling reflection.

In your case you've got a flat ceiling with several steps. I'd rather have the low steps in front of me than behind me because of the chance of creating a fairly early, and therefore strong, reflection from behind with sound striking the front of one of the steps, reflecting up to the ceiling and then back forward to the listening position. Whether or not this would happen will depend on speaker and listening position placement relative to the various steps in the ceiling. On the other hand, I could also run the argument that it's better to have those steps behind me since our hearing isn't as good on direction to the rear as it is to the front so messy reflections from the rear may do less harm than messy reflections from the front.

The fact is that the room is so complex in shape, and so asymmetrical, that no one is going to be able to predict how it will sound with the setup reversed. The only way to find out is to try it and see which you prefer but, as I said previously, in an asymmetric room my best advice is to go for a setup that keeps the speakers and listening position as far from reflective surfaces as possible and which also keeps the direct path as short as possible and the paths of the first reflections as long as possible relative to the length of the direct path. That kind of setup minimises room effects as much as possible and that makes any remaining problems easier to deal with.


David Aiken
RE: how about flipping the speakers 360 degrees around, posted on August 25, 2009 at 19:07:24
Patster
Audiophile

Posts: 333
Location: Canada
Joined: November 2, 2004
 Thanks David
I like the current setup and when I tested it the room is fairly even
My main worry is the staircase to the left is smearing imaging
What can I do to test if this is in fact happening

RE: how about flipping the speakers 360 degrees around, posted on August 26, 2009 at 00:22:55
David Aiken
Audiophile

Posts: 5109
Location: Brisbane
Joined: September 25, 1999
 The only way to test for imaging problems is to listen. If you can't hear any, there's nothing to worry about. There are no measurement tests for imaging because imaging is a psychoacoustic effect, it happens between our ears rather than in the room.

The main things to listen for are basically the centre image and whether it is centred—use a mono signal for this—and then for an evenly spread soundstage without gaps. Strong lateral reflections can pull images further towards the side than they should be and even create a gap in the soundstage between the speaker and the centre image.

The other thing that can happen with imaging is effects on the size of the image. I find diffusion in the centre of the wall behind the speakers tends to spread the images in my system and I end up with singers with mouths that are a foot or two wide which I don't like. On the other hand, I really enjoy what happens to orchestral music with that setup but, since I listen to very little orchestral music, I don't use diffusion in that location.

There really are no "standards" for imaging, but then there's no "standard" for it in real life. People say you don't get precise imaging in real life but you definitely can, if you're quite close to the performers and they and you are a fair way from walls. If you stop and think about it, you can quite easily localise speakers around the dinner table while you've got your eyes closed, which is exactly the same thing. In a concert hall you probably are never going to be in a location where the direct sound is strong enough, and the indirect sound weak enough, to hear good imaging but that doesn't mean that you can't get good imaging in real life. It's just extremely rare in most live music setups and, of course, you'll never get it if they're using sound reinforcement because the speakers around the hall are all being fed the same mono signal.

So as far as imaging goes, the best imaging is the sort of imaging you like. I like it fairly precise and lifelike in scale for small groups. Others like virtually none and a similar kind of presentation to that which they hear from around mid-hall in a concert setting. It's just like picking where you want to sit in a concert hall—the sound will be different in different locations. They're all "accurate sound" and all just as "true to life" as each other. It's just that one sound is what you get in one location and another is what you get in another location. When you have a choice, you pick the one you prefer. That's the only sensible way to go when it comes to dealing with imaging and your system.



David Aiken
RE: does flipping the room make sense, posted on August 24, 2009 at 00:08:12
David Aiken
Audiophile

Posts: 5109
Location: Brisbane
Joined: September 25, 1999
 I seem to remember your earlier post. The room has a complex shape and if I remember correctly there's a dining area behind the point from which the picture was taken.

Possibly the best thing you can do in an asymmetrical room, especially one with a complex shape, is to keep the speakers and listening position as far from the walls as possible, and the listening position as close to the speakers as possible. A near field listening setup is the extreme version of that but even if you can't get close enough to the speakers to be in the actual acoustic near field the advantage of making the first reflection paths as long as possible relative to the length of the direct path is that you reduce the strength of the first reflections relative to the level of the direct sound. Strong first reflections can cause spreading and smearing of the stereo image and other problems.

Moving the TV out from between the speakers may eliminate another source of a strong early reflection but whether or not it does depends on the location of the TV relative to the speakers and listening position. Of course if the speakers are being used with the TV as well as for music, then you have no option but to have it between the speakers but you could consider covering it with some sort of sound absorbing cover like a couple of layers of thick blanket or a quilt when listening to music.

You've got a difficult room and it it is also used as a living room and/or for watching TV then you are in the position of having to juggle the layout demands of what might deliver the best sound and what physically works best for the activities the room is used for. I'd probably lean a bit towards what works best physically since a layout that works awkwardly will annoy you and frustrate you every time you use the room and I know I don't enjoy listening to music as much when I'm annoyed or irritated. I'd rather trade some acoustic performance for having a room I feel comfortable in so I can be relaxed when I listen. I figure the plusses from that are probably more than what I could gain in sound performance by going for a better layout if it was one that I found annoying or frustrated.

So my suggestions are not to swap to another layout if it either makes the first reflections stronger relative to the direct sound by reducing the length of the first reflection path relative to the length of the direct path, or if the swap makes the room more awkward or uncomfortable to use. If a swap does both of those things, I'd say definitely avoid it.


David Aiken
RE: does flipping the room make sense, posted on August 29, 2009 at 15:50:05
Patster
Audiophile

Posts: 333
Location: Canada
Joined: November 2, 2004
 Daid by placing the speakers along the short wall and having them fire down the long part of the room
does this make the first reflections stronger
I'm thinking of going with an equalateral triangle 6.0 feet all around

What to do with the angled wall would placing absorption on this help

RE: does flipping the room make sense, posted on August 31, 2009 at 20:57:36
David Aiken
Audiophile

Posts: 5109
Location: Brisbane
Joined: September 25, 1999
 How strong a first reflection is depends on 2 things, how much longer the first reflection path is than the direct path, and how reflective the room surface at the reflection point is. The longer the first reflection path is relative to the direct path, the weaker the reflection will be,

One of the things that determines how much longer the first reflection path will be is distance of the speaker from the side wall. If the length of the direct path stays constant, the further the side wall is from the speaker the longer the first reflection path will be. So, if you're sitting the same distance from the speakers as you were before you rotated the layout and the speakers are closer to the wall, the first reflection will be stronger. If the speakers are the same distance from the side wall, the reflections should be equal and if they are further from the side wall then the reflection should be weaker than it was. Of course one of the things that is going to affect how far speakers are from side walls is going to be how far apart they are since that distance takes up some of the width of the room and the rest of the width is taken up by the distance between each speaker and its respective side wall.

Angled walls change the direction of the reflection of sound striking them. Depending on the angle of the wall and where the angled section is, you may actually avoid getting a first reflection or you may end up getting one from a different location than it would come from if the wall wasn't angled. What happens is going to depend on the geometry of your room and the placement of your speakers and listening position. There's no simple rule.

If you do have a problem reflection from the angled wall, then placing absorption at the reflection point will help, just as it helps with normal reflections that are problems for you.

One thing to consider is that each speaker actually has a first reflection point on each side wall. If the angled wall eliminates the first reflection point on that side for one of the speakers, then you may well benefit by placing absorption at the equivalent first reflection point on the other wall. For example, I have an angled wall section on my right wall and that actually eliminates the right wall first reflection from my left speaker. In order to balance the centre image and soundstage, I actually need to place absorption at the first reflection point for my right speaker on the left wall.

With asymmetric rooms there are no simple rules because everything is governed by the geometry of sound waves. It's a matter of working out what's going on in your room with your specific speaker and listening position placement in that room, identifying the problems and then dealing with them. If you change the speaker and listening position placement you're back to square one and you need to go through that process again, simply because the asymmetry guarantees that the way sound waves behave in the room will have changed with the setup change. The change may make things better or worse but they won't be the same.



David Aiken
RE: does flipping the room make sense, posted on September 2, 2009 at 10:56:29
Patster
Audiophile

Posts: 333
Location: Canada
Joined: November 2, 2004
 Thanks David for you insight into my dilemna
I'm starting to realize that none of this exercise is straight forward
I Guess I have to make the changes and hope for a better sound

RE: does flipping the room make sense, posted on August 24, 2009 at 10:35:08
Patster
Audiophile

Posts: 333
Location: Canada
Joined: November 2, 2004



Thanks David
I'm going to remove the television from this space all together and move my stand and equipment in between the speakers this should open up the left side of the room and perhaps help with soundstaging

I've also moved the black leather seat from the room this has opened up a bit more space for the family to move around and does help with imaging

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