Speaker Placement Tradeoffs

If you are serious about 2 channel listening, I'd keep them out in the room and leave them there for HT too. I do this and am very happy with both situations. There are some potential line of sight issues depending on seating distance, screen width, layout etc.


Also remember that (opening a can of worms here) a room set up and treated for best 2 channel listening is not the same as 1 designed for multichannel. There are some tradeoffs to be made. In either case, the front wall should be totally absorbant.


I don't think you'll find soundstaging anything close to 'spectacular' with them recessed - sorry. If you are a 2 channel nut, you know the difference even just moving them out from the wall a couple feet and how that opens things up and lets them 'breathe.' It also gets kind of tricky to play with any kind of toe-in when you're trying to build them into a wall that is flat.


Home theater setups are generally meant to localize the image within the screen dimensions and help lock it to what your eyes are seeing. In 2 channel, the goal is to get it as wide as possible while still localizing specific sounds using just aural cues.


There are some speaker designs that are meant to use a 'wide baffle.' Think about the old Boston Acoustics A-400's for example. They were designed to be put against a wall.


You CAN have both work well with some minor tradeoffs. The other option is to build an acoustically transparent wall and build the speakers flush with that. You'll still be dealing acoustically with the screen in the middle but the'll have some room to breath and spread the image at the cost of 18-24" of floorspace. This also offers a way to hide any treatments behind this virtual wall as well as a place to put a sub (if it works there) where it might be more obtrusive in the visible portion of the room.


Just some thoughts.

Quote:
The second sentence is a certain amount of non-sense. Assuming you're using an 80Hz cross over for low frequencies, front speakers can be as close as about 36" to move the notch frequency below 80Hz (depending on cabinet design). Sub-woofers (below 80Hz) are moved closer to the wall to place the notch frequency above 80Hz. If you're using full range speakers and need to avoid these problems, then place your audiophile full range speakers on the order of 15' from any wall or surface.


Back to the front speakers and wall proximity. Knowing, or measuring the affect of SBIR as an LCR moves near a boundary will allow that boundary to be treated (perhaps along with some parametric EQ) to avoid near boundary effects of the speakers.


The real issue is room decay time and how surfaces are treated in a two-channel vs multi-channel room. If you're going to use your room as a surround processor (which is exactly what you're doing with two-channel playback), delay times must increase and you must have adequate means of getting non-direct sound to the back and side of the room without leaving too many early reflections.


To suggest that a proper HT speaker set up doesn't require excellent imaging, or is attempting to "focus" rather than image, is incorrect. Multi-channel installations must produce front sound stage imaging to the same degree as a two channel environment.

I'm glad to see we're at least somewhat in agreement Dennis. In 2 channel mode, you are, as you say, using the room as a surround processor and delay times should increase.


I was not suggesting that there is no 'imaging' in a surround arrangement and associated treatments. However, while there is good lateral placement within the boundaries of the screen, there is not a lot outside of it and there is usually very little 'depth' behind the speakers when using inwall or recessed speakers. The 'depth' in a surround configuration is delivered directly via the additional channels and is spread throughout the actual room. In 2 channel, with proper alignment, treatment, and spacing, aural cues can also suggest sounds are coming from farther away than the front wall of the room. I don't hear that from inwalls in general.


I'm confused as to your statement that the mains can be moved 'as close as 36" to the wall to move the notch below the xover point. However, you then say that recessing them will not cause an issue that can't be treated with an EQ. In my mind, that tells me that I AM introducing issues that are now going to require additional equalization or specialized treatment that keeping them out into the room would not. Now I've treated my room for this speaker and in a year I change to something else. Now I need to change my front wall treatment because this one acts differently as it approaches a boundary?


You stated that the effect proximity has is related to cabinet design. My point is that when you recess speakers into a wall, you are changing the design that went into the speaker baffle. You are in fact, making the whole front wall the speaker baffle. Additionally, as I said before, it also makes it very difficult to provide any toe in that a speaker may require at a given listening distance.


What if you have a speaker that has it's drivers 'time aligned?' What if you are using a design that has 'open sides or non-flat front surfaces? Things like Thiel, Vandersteen, Snell, etc. come to mind. How do those get correctly recessed into a wall without causing serious cavity effects, early reflections, cancellations, etc?


Lastly, if you are recessing, you are making the assumption that the speakers are not rear ported nor are they any type of bipolar or dipolar design - of which there are quite a few. My Dynaudio's for example have 2 rear ports. Not only would enclosing them change the volume of air the port opens into but it would also cause the cavity to resonate, much like a stage or riser that is not filled.


Voices:


It's really up to what your priorities are. One or the other has to give a little but you can still get good results for both. You have to decide where you are willing to compromise.

Dennis has been very generous in helping to determine whether or not to retain him.


He made it clear from the outset that a room optimized for multi-channel is a room potentially compromised for 2 channel.


The debate here is informative, but I don't want to in any way imply that Dennis has given me specific or formal advice, as I have not compensated him to do so.


He most certainly shouldn't be asked to defend my post. He can no doubt design a glorious sounding home theatre. It is my introduction of compromise that is the problem. He doesn't even know the details of my equipment at this point, so he cannot give any advice that is too specific. His conversation with me was regarding some of the general issues that are faced when asking a room to do many different tasks.


So, hopefully we can steer this back to the issue. If I love 2 channel but also want a great sounding HT room, should I haul the 2 channel speakers in and out while having the multis recessed in the wall, or can I have optimum sounding too channel with recessed speakers, assuming such speakers are designed for in-wall placement?


The approach of having my front 3 channels exposed with my existing Klipsch speakers may be appropriate, but what am I losing practically and aesthetically by exposing the front 3 channels in lieu of in-wall speakers for home theatre?

Sorry. I thought that is what I was addressing - the tradeoffs of recessing your 2 channel system into the walls.


I would not begin to question Dennis' methods nor his designs for a pure HT. He is a well respected professional with hundreds/thousands of satisfied customers. As he said, there are compromises to try to do both HT and 2 channel in the same room as some of the design goals are different. Dennis is very generous on this forum with his advice and his knowledge and it is greatly appreciated. I think we've all benefited from his contributions.


On to the topic...

You are obviously losing some asthetics by having your existing 3 channels exposed for view. Only you can decide if you are willing to make that compromise. Personally, I am. You may not be. That is one of the reasons I suggested the false wall. This can give you the best of both worlds by allowing some spacing, flexibility in position and toe in, etc. and still not see them.


Moving speakers in and out of the room is a compromise that I personally would not be willing to make. It would make sitting down for a listening session something I would probably do less due to the hassle of getting things set up exactly right every time I wanted to do it. You might be.


Can you have 'optimum' 2 channel with speakers designed for in wall use? - maybe so. I have never heard any in-walls including the top Snells, B&W's, and the Triad Platinums image the way I can get something out in the room @ similar costs do. Maybe you can. Dennis sells the Triads. Maybe he knows exactly what to do to the walls to make them really disappear like a good mini-monitor 3-4' out from a wall. Maybe they can throw an image way back behind the front wall. I've heard all of those speakers in various rooms. They do a great job on HT but in my opinion, lack something in terms of being holographic in 2 channel mode. That's my opinion.


Again, it's your priorities that are important and Dennis has been up front with you about it. He has identified some potential issues arising from trying to do both.


My vote, no. You won't get both 2 channel and HT to be optimal in the same room - Dennis would agree and has told you so. You can't have 'optimum' 2 channel and a great sounding HT from built ins. This is especially true with your speakers with rear ports. It's not so much the imaging as it is going to change the low frequency response of your speakers. However, you can have optimum 2 channel and a great sounding HT without speakers built into the wall. Again, just my opinion.

Thanks, bpape, for your response. My apologies for putting you into a defensive posture. I wasn't criticizing you, and your comments are appreciated, I was just making sure Dennis wasn't being criticized because of my mischaracterization of my conversation with him.


Your comment:


"However, you can have optimum 2 channel and a great sounding HT without speakers built into the wall. Again, just my opinion."



This is key. I think I'm going to hire Dennis to work within the parameters of exposed speakers.


No matter how much research I do, I am not convinced I'm going to be happy without some speaker placement flexibility for 2 channel. Also, I'm not enthused about moving speakers in and out of the room, or trading in the RF-7's for in-wall designed speakers.


Aesthethically, the tradeoff isn't enormous. My speakers are pure black, the stage will likely be very deep with black carpet, and the screen wall will be black. The speakers will be visible, but not obtrusive.


Your comments have been very helpful, bpape.

I think we're all basically saying the same thing. My only point was that IMO, in-walls or speakers built in to a wall are more of a limiting factor to 2 channel playback than having them out in a room is to HT playback (zero other than asthetics and potential line of sight adjustments). Just a lesser of 2 evils thing.


HTG, I can't speak to 8 channel but I can to 6. My room was designed for music listening first and foremost. After determining workable dimensions, I laid out appropriate speaker positions and listening positions. Within those boundaries, I looked at screen sizes that would fit my distance from the wall and PJ throw length and still keep me out of nasty room positions. Adjust, rinse, repeat. I ended up with a 92" Stewart 1.85 screen to go with my XG135. Speakers are 2.5' from rear to rear wall and 4' from the side walls in a 17' wide room. Toe in is about 15 degrees. When I go for HT listening, if there are more than 2 of us, I simply push them back 1' and reduce the toe-in.


I never feel that I compromised my HT experience for 2 channel. I'm still playing with the acoustics to find that 'best' compromise where the room is live enough for my taste and still dead enough for HT. I'm getting pretty close and I could live with it the way it is right now but hey, what fun would that be


Again, the only caveat is that you see everything. I've been an audio nut for years. My wife loves this as it's as organized as my stuff has been for a long time! I guess everything's relative...

I guess it's just a difference in priorities. I just like the ability to be ABLE to move the speakers around to suit my preferences. Yes, we audio heads are habitual tweakers - it's a disease . I routinely move things around - sometimes even from CD to CD to suit my preferences. I can't do that with in-walls (forget building in existing speakers, we obviously agree that's a bad idea). That's a compromise I'm not willing to make - but that's just me. The original poster also seems to have these same reservations. He asked about tradeoffs, flexibility is one.


That's what this thread is all about - a person who has higher priorities for 2 channel but wants great (maybe not perfect) HT at the same time. He was so concerned with 2 channel that he was even considering moving speakers in and out of the room totally to assure the BEST possible 2 channel playback. Pushing a speaker back a foot is much less of a hassle than he was considering tolerating. Depending on his situation, he might find a place where he is happy with both in the same spot, then again, he might not. Having them movable allows this kind of flexibility at the cost of asthetics which may or may not be important to a specific individual.


Having front speakers out in the room and visible should have ZERO negative effect on creating a proper multi-channel soundstage with all other variables the same (discounting the differences in decay time design which is a given in a shared environment) - would you agree? I'm quite sure you'd agree that the difference in acoustic treatments will make much more of a difference than a visible speaker - again depending on your priorities.


Unfortunately, I'm nowhere near Atlanta. I'm sure your demo will be very impressive. I'm sure that the imaging will be very good. I'd love to hear something like Dire Straits - Private Investigations where there is a ton of information that appears to be WAY behind the front wall.


It would also be interesting to hear the same system in an identically constructed room treated for 2 channel and note the differences and drawbacks in each room for both 2 channel and HT. I don't know if you have a room set up for that or not. In either case, Hiring a professional like yourself gives your customers the benefit of knowing exactly what the tradeoffs are and how best to deal with them.

Dennis,


Glad to hear it. I think that's a great idea. I think it will be very informative to let people actually hear what the differences are.


HTG,

Unfortunately, I have neither the space nor the budget for a second room, second system, alimony , etc. I suspect most people don't. Many have a hard time justifying a single space dedicated for either or both.


Realistically, properly treating a room for either is a quantum step forward in quality reproduction from what most people have.