Having trouble optimally locating speakers... help please.

[ThA tRiXtA]

The above picture is a topographical view of my current room layout. As you can see, the rear center channels of my 7.1 setup have unfortunately no choice but to be mounted very close to the middle of the room because of the doorway into the room.

From the center point of the back wall, the left and right center speakers will be mounted about 15 inches to the side of the speaker enclosure, therefore totalling 30" between the two, inside face to inside face.

Will this do anything to a 7.1 soundstage or cause imaging/panning to sound messed up? If you have any ideas, feedback or suggestions for these speakers, or anything else in the room I'd be glad to hear your comments.

One other question I have.

I have two subs to go into this room, and based on the audioholics article that suggests placing multiple subs in the middle of the wall front and back or on either side, I was hoping to place them on the front and back wall right in the middle.

Unfortunately my center channel and the stand it sits on will obviously prevent this.

So would there be any issue with placing like I have placed sub 1 and 2 in the diagram above, or would I want to opt for placement as sub 3 and 4 shows?

Please note, I only have 2 subs, I just labled them as "1 and 2" and 3 and 4" for simplicity sake.

If you are going to place the sub in the middle of the front and back wall, would the optimally be directly opposing each other or will it not matter if they are a little off axis to each other.

Again, any comments, suggestions or criticisms are greatly appreciated.

Thanks.

 

[TLS Guy]

The above picture is a topographical view of my current room layout. As you can see, the rear center channels of my 7.1 setup have unfortunately no choice but to be mounted very close to the middle of the room because of the doorway into the room.

From the center point of the back wall, the left and right center speakers will be mounted about 15 inches to the side of the speaker enclosure, therefore totalling 30" between the two, inside face to inside face.

Will this do anything to a 7.1 soundstage or cause imaging/panning to sound messed up? If you have any ideas, feedback or suggestions for these speakers, or anything else in the room I'd be glad to hear your comments.

One other question I have.

I have two subs to go into this room, and based on the audioholics article that suggests placing multiple subs in the middle of the wall front and back or on either side, I was hoping to place them on the front and back wall right in the middle.

Unfortunately my center channel and the stand it sits on will obviously prevent this.

So would there be any issue with placing like I have placed sub 1 and 2 in the diagram above, or would I want to opt for placement as sub 3 and 4 shows?

Please note, I only have 2 subs, I just labled them as "1 and 2" and 3 and 4" for simplicity sake.

If you are going to place the sub in the middle of the front and back wall, would the optimally be directly opposing each other or will it not matter if they are a little off axis to each other.

Again, any comments, suggestions or criticisms are greatly appreciated.

Thanks.

Your position of the rear centers is your only practical solution. It will only be an issue if your are planning to play SACD discs with a lot of antiphonal program. As ambiance channels I don't see a problem.

I would try both sub layouts and see which is best. You will have room gain with the 3/4 set up which may or may not be a good thing. See which sounds best.

 

[mike c]

and how try to locate the couch away from the center of the room ... ideal number is 38% distance from the back of the room.

personally, i'd try: sub1 and sub2 OR sub1 and to the right of the center channel

 

[Exit]

Your layout looks closer to recommended than mine. I would go with your layout. If you have the ceiling height I would put the surrounds at about six foot high. Aside from the sound, it keeps them high enough that most people will not bump into them when walking around the couch. I have only got 5.1 so I am not certain about the rear speakers height, but I think I would raise them to six feet high also.

For subwoofer placement I think you are ok with sub 1 and 2 locations. If you put the subs in the corners you are going to increase bass reinforcement or bass volume. Some people don’t like the sound of corner placement of subs and some do, but you could always try it and see if it is for you. If it is too much bass you can adjust it by moving the subs out of the corners more towards the middle of the wall. I think the idea is to keep the subs the same distance from the corner on the front and back walls.

 

[ThA tRiXtA]

Your position of the rear centers is your only practical solution. It will only be an issue if your are planning to play SACD discs with a lot of antiphonal program. As ambiance channels I don't see a problem.

I would try both sub layouts and see which is best. You will have room gain with the 3/4 set up which may or may not be a good thing. See which sounds best.

Thanks for your input TLS, I just wanted to make sure that sound presence back there wouldn't be all mangled.

The media I peruse is roughly 80% movies and 20% 2.1 channel CD music.

In regards to room gain... I would rather avoid that if at all possible (obviously there is always room gain present to a degree unless you really have went out of your way with acoustic treatments and the like.)

Realistically with two decent subs in such a small room I think I can afford to forgo any amplified response (and the problems that come with it) caused by corner loading of the subs. I should have way more power, headroom and impact out of those two subs even in a neutral placement, hence why I want to be able to go middle wall placement if I can.

and how try to locate the couch away from the center of the room ... ideal number is 38% distance from the back of the room.

personally, i'd try: sub1 and sub2 OR sub1 and to the right of the center channel

Thanks for the comments Mike.

When you say the couch should ideally be 38% of the total length of the room from the back wall I am going to assume that we actually want our ears to be that magic distance, and not just the couch?

I came across a picture one time that showed a typical HT room and is stated that in the center of the room there was an area which typically was plagued by a null in the bass frequencies... was this why you are suggesting the 38% placement idea? Please see my horrible rendition of this image I described. The grey wavy area is the proposed nullified region.

As for the sub placement, you would place both upfront flanking either side of the center channel?

 

[mike c]

yes, if sub 1 and sub 2 location yields you a crappy FR.

yes, the center of the room gives you a lot of nulls which is why i suggested you move back the couch (if you can) and yes, its actually the ears that should be moved back and not just the couch

 

[ThA tRiXtA]

I'm curious, regarding that 38% from the back wall idea, does anyone have any research that actually shows it to be ideal or have any truth to it?

Also, does placing your speakers farther into the room make a difference in this equation? Obviously you're not going to ram your floor standing towers right up against the wall.

 

[bpape]

The 38% (or 62%) is simply a starting point rule of thumb based on the place where you're in the fewest axial modes of the length of the room. Rearlistically, it changes slightly sometimes due to the fact that real rooms aren't perfectly rectangular nor perfectly rigid.

In practice, the best position almost always ends up between 62 and 66% from the front wall of the room to the seated ear position.

As for sub placement, centered on the front and rear wall is optimal. If you can build a stand that would straddle the sub and allow both it and the center to occupy the middle of the wall, that'd be great. Also remember that sitting centered on each SIDE wall also helps the same types of issues that sitting centered on the front and back wall does.

Bryan

 

[ThA tRiXtA]

Nice info, thanks for the reply Bryan.

So, it doesn't look like I will get to place both my center and the front wall sub in the middle, it would force me to place my display much higher than I had wanted to... I considered placing the center channel on top of the sub, but the sub and the center together would stand about 38.5" high...so obviously the sub is going to get pushed out.

In the original diagram, I had sub 1 just to the left of the center channel and sub 2 at the middle of the back wall. It looks like sub 1 will flank the left main tower speaker on the left side, so the subs will not be in line with each other whatsoever.

What will this placement do (good or bad) in terms of integrating them both in the room? If I place sub 1 on the left side of the left tower, should I move sub 2 diagonally across in the back right corner to keep them equal or would it be fine to keep it in the middle? I'd rather keep the back one in the middle if I can get away with it.

Cheers.

 

[jostenmeat]

Trixta,

IIRC, for certain settings (perhaps Ultra2), I've actually seen that the rears were recommended to be within 5 feet. In any case, I wouldn't sweat it. Exit sort of brings up an interesting point. While I believe that ear-level is best, I do find that many setups are compromised because furniture is blocking ear-height speakers. Hence, I have bookshelves on very tall stands. If this was a non-issue I would have got towers for surrounds.

I've heard plenty of different recommendations for sub placement. You name it! Some have found that both or most subs in the front sound best. Some will say 1/3 wall length (perhaps a similar thing with 38% listener distance, eh?). What many CAN agree on is using your ears, or equipment, or both. Try "crawling for bass". Put a sub AT the l.p. and start crawling around. The places on the floor that sound best to you may prove to be viable.

I don't know if you diagram is to scale, which I doubt, but if it is... do you find that the speakers are ideally placed for stereo reproduction? A general starting point could be making an equilateral triangle between you and the two speakers. Have tweeters firing to outside of each ear, and fine-tweak from there.

Best of luck, although I don't think your going to need it... Im sure it should sound great when done!

 

[ThA tRiXtA]

Thanks for your input Josten.

No, my diagram is not to scale. I just drew it up quickly for a cheap reference point.

My ear height while sitting on my couch is 42 inches, I was going to place the surrounds and rears at about 66 inches. Do you think I should go higher? I am only concerned about the sound quality and imaging of the surround channels, not looks or anything else, so I want to find the optimal position. In a 7.1 set up, do the rear centers typically sit at the same height that the side surrounds do?

As for the subs, it is finalized that my subs will sit where subs 2 and 3 sit in the diagram. I would love to use position 1 and 2 but my display height prevents my sub from sitting underneath it.

I hope I am not compromising anything by having one sub sit fairly far into the corner as opposed to the other that is middle wall placement.

It's funny you talked about the stereo imaging of the two front towers... I was just thinking about that today. I have always had the towers face straight out, but I see that a lot of people toe in their front mains slightly... should this be something I look into?

I read a guide regarding center channel alignment on AH one time, where it recommends that you get a laser pointer and use it to help focus the tweeter of the center channel to the listener. Would it be similarly the same for the two mains? Tape the laser pointer at tweeter level and toe in each speaker till the tweeter is at the desired point?

Does anyone know if AH happens to have a guide on getting appropriate stereo imaging or toeing in speakers?

Thanks in advance.

 

[jostenmeat]

My ear height while sitting on my couch is 42 inches, I was going to place the surrounds and rears at about 66 inches. Do you think I should go higher? I am only concerned about the sound quality and imaging of the surround channels, not looks or anything else, so I want to find the optimal position. In a 7.1 set up, do the rear centers typically sit at the same height that the side surrounds do?

My advice is to keep them as close to ear level as possible, while still "clearing" any furniture. If you mount them very high, it would actually be best to then angle the speakers toward the listener. I suppose with the greater the number of viewers that higher mounting might help to clear everyone's heads, but I am speculating.

I hope I am not compromising anything by having one sub sit fairly far into the corner as opposed to the other that is middle wall placement.

Well, you're already ahead in the game with multiple subs to even modes. You can only do your best, right? Don't kill yourself over it, hehe. After all some folks do prefer corner loading, even if I don't. Ok, ok, ok it appears you are pretty serious here. Perhaps even a bigger deal than corner-loading or not, is the use of room treatments since you don't care about looks. You can look at my other recent posts in this particular sub-forum for a start if you are newer to this. HT setups are desired to be pretty dead acoustically, even more so than 2-ch rooms from what I have learned. Then you can also add EQ, anything from Behringer setups (search WmAx's posts) to the pricier SMS-1. Or run Audyssey for now, and set sub's gain to taste afterwards if you like it hotter as many prefer. Or a $5,000 sub-PARC, lol.

It's funny you talked about the stereo imaging of the two front towers... I was just thinking about that today. I have always had the towers face straight out, but I see that a lot of people toe in their front mains slightly... should this be something I look into?

It was actually this portion of your post that got me thinking about treatments for you. Many have found that they are given much more freedom in positioning their speakers after using treatments, as one doesn't have to worry about all of the reflections and their effect as much. In the end, whether you have treatments or not, it really will depend on your perceptions, particular speakers, and particular room. You'll just have to play around a lot. I don't think there really is any better solution. Some folks have spent a very, very long time in finalizing their speaker placements. Just try that equilateral triangle thing and see what you think. You might hate it, you might love it, but some of the best setups I've probably heard were placed in this kind of arrangement.

btw, thanks for that cool 1080p graph you made the other day.

jostenmeat

 

[mike c]

this JL audio F113 manual might help ... it's got sub positioning and listening positioning stuff...

http://www.soundoctor.com/pdf/JLAudio_Fathom_f112-113_UsersManual.pdf

 

[ThA tRiXtA]

Thanks again Josten, I guess I have some playing around to do after I get it all set up

As for that graph, I am glad you like it and I hope it works out well for you, but for me I unfortunately have distanced myself too far due to the 62/38% rule, so that renders me 11 feet back and theoretically unable to discern any 1080p benefits...

I don't know whether I want to make the compromise of sitting in a null or sitting beyond the 1080p range. Thoughts?

this JL audio F113 manual might help ... it's got sub positioning and listening positioning stuff...

http://www.soundoctor.com/pdf/JLAudio_Fathom_f112-113_UsersManual.pdf

Thanks Spider-Dad! I read that manual, it seems I should be ok if sub 3 is not rammed right into the corner even if sub 2 is in the middle of the wall.

BTW, the sub that you linked the manual for looks really nice... drool.

 

[jostenmeat]

You're very welcome T.T.

Nothing is more important than the display in HT. Hmmmm... the search for the perfect balance....

Maybe 38% from the front wall? Greater visual immersion + easier accomodation of getting an eq triangle with mains? Less need for greater amp as well.