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Is your theater design ready for prime time?

11K views 152 replies 45 participants last post by  rmerlano 
#1 · (Edited)
Lately, I've been seeing major fundamental Acoustics mistakes in people's builds. So, in an effort to curb costly issues before they are made, post here your drawn room layouts to see if you are on the right or wrong track, and whether you should seek professional assistance...the good kind not the head kind. ;)
 
#4 ·
Looks like he does have the screen dimensions called out. I would take notice of the front row location. Very close to dead middle of the room length, which is certainly to be avoided. By moving both rows forward, you can move the first row out of the middle, and also get the back row further off the rear wall, which is another of the worst locations to be.
 
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#13 ·
You don't have to shrink the screen. There are several issues I see. The proximity of the seats to the side and rear walls. Lots of boundary gain there which will be difficult to filter out without lots of treatment, and if done, will still not sound very good. The door is causing the lopsided aspect to the room. This can be alleviated a bit through increasing distance and SPL, but your bigger issue is the countertop/bar area. If only 42" in height, this won't be as bad, but if you intend to go floor to ceiling, it will cause issues not only in acoustics, but placement of surround speakers. As Adam mentioned, moving your seats out of the center of the room will move you out of the nulls. I would place your speakers and screen in the drawing, and see what that presents to you.
 
#6 ·
Shawn, Wow! just the thought of starting a thread like this by valued members is much appreciated. I have been slowly building my HT for over an year and certainly contemplated the use of professional services at several instances.
But truly, the joy of multi-disciplinary learning and experimenting steered me so far.

After the laborious sound proofing efforts, I have recently completed the stage build. Here is a tentative vision in mind, please provide your valuable feedback

I have procured some raw acoustic materials, OC703 2", sound blanket 1", fabric etc., and started conscious reading on acoustic topics.

Thanks in advance
 

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#8 ·
Welcome! A few thoughts. I would consider using the same speaker for your left and right of possible. If you are using the Welti method of sub arrangements, they should be at the center of the side walls. They look close, but hard to tell. Also, check your angles fir your left and right speaker. They should be at least 45 degrees for the rear row. Are you using multiple side surrounds? Hard to say on Atmos placement without seating. Otherwise, looks good.
 
#7 ·
Greatly appreciate your taking the time and effort to do this! This my most current plan. It is only in Excel (every time I use Google Sketch I end up with something quite bizarre!). The black squares are posts for a support beam. The dark blue are speaker locations. I have not added atmos ceiling locations as of yet and am still undecided on whether to put my left and right mains inside or outside the screen. Maybe you could shed some light on this?
 

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#9 ·
Have you placed your subs yet? With your current configuration, you are looking to do multiple side surrounds. This will require some considederabke knowledge of actually incorporating it using a powerful and moderately priced DSP. What's the distance from screen to seating as well as angles to the screen from the seating and the speakers?
 
#15 · (Edited)
Hi Mark,

Thanks! The Dolby speaker and THX specifications (throw in SMPTE, ITU, etc.) are the two best "start here" templates. Although they have to be tailored to specifics frequently. Only under ideal conditions will they be adhered to fully. As has been mentioned over and over in the past, designing is part science and part art. The art part is understanding where you can compromise due to situations and where you can't. But pretty much every designer starts with the basic THX and Dolby specs and proceeds from there. When you run into a problem that deviates from those specifics, the compromise part takes over. I do recommend enthusiasts who want to design their own rooms take the Home Acoustics Alliance course...all five days. Understanding how things will sound once you manipulate things in a controlled and learned classroom is truly invaluable to apply to your own space.

As an after thought there is a link in my signature that takes you to a sample layout I've done labeled Quest Layout. You can use that to get an idea of angles and how the symmetry of how this all comes together. Might be a good template to use. I've put it up there for all to see.
 
#16 · (Edited)
I've been struggling with room diagrams as well due to the angled corners I have. I'd like to ask a few questions. I added a diagram below showing the rough dimensions (They are all within a couple inches at worst). Back of the back row is 4' from the back wall, MLP from the front row is 10.5' from the screen. Room is 13'1" wide by 21' deep to the screen and 24' to the back wall. Chairs are going to be very close to the side wall. I know having seats right up close to the side wall may not be the best scenario, but we are really wanting the dual loveseat configuration in the front and back. Ceiling height was 100", but I did a 6" drop ceiling to house a 6X10 star ceiling. With the 12" riser, my rear row of seats is only 88" from the ceiling. Pictures below are current. I am wrapping up the ceiling sheetrock right now and about to start on walls. There are a couple lighting and blocking aspects that I need to deal with first, but the mud/tape/painter is scheduled to arrive on the 20th.

System is as follows:
Denon 6300 DVR
Klipsch 7.2.4
Fronts & Center: RP-280F
Subs: 2 X RP-115SW
Front Surrounds: 2 X RP-250S
Rear Surrounds: 2 X Klipsch R-5800W-II
ATMOS in ceiling: 4 X Klipsch CDT-5800-C II

I am already looking to change the subs. One of the RP115SW subs will be placed in the rear by the AV cabinet. One will go out of the theater into my living room. The front subs will be replaced with two Dayton UM18-22 subs in Mini-Marty boxes run by an Inuke 6000DSP.

1) Is having 45 degree angles instead of 90 degree angles problematic or beneficial? All of my "corners" have 45 degree angles. The back side has the door one one side and the AV cabinet on the other. The front of the theater is an ICF turret wall that will be used to recess the front speakers behind an AT screen. The screen will be between 32-36" in from the back wall. How much treatment should I place on the ICF wall behind the speakers? Are bass traps as effective in corners with 45 Degree angles compared to 90 Degree?

2) Regarding the side surrounds. I have two rows of seating, the rear being on a 12" riser. In general, where should the side surrounds be mounted between the seats, and what would the optimum height be? Right now I can foresee both rows being MLP, but I would probably lean towards the front row and being the main.

3) Regarding the rear speakers. I plan to elevate them fairly close to the ceiling and angle them down. Should my main focus be on having a clear line of view from the speakers to the front row listeners?

Thank you very much for the offer to provide your input.
 

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#17 ·
1) Is having 45 degree angles instead of 90 degree angles problematic or beneficial? All of my "corners" have 45 degree angles. The back side has the door one one side and the AV cabinet on the other. The front of the theater is an ICF turret wall that will be used to recess the front speakers behind an AT screen. The screen will be between 32-36" in from the back wall. How much treatment should I place on the ICF wall behind the speakers? Are bass traps as effective in corners with 45 Degree angles compared to 90 Degree?

Whew. Lots of questions. To be honest, you're on the threshold of HIRE A PRO! Since you are creating a false 45 degree angle in the rear, create this as a bass trap. I'll leave that to you to figure out, but generally, you only need one corner bass trap to be effective. You can have more, but if you treat one corner, it has significant effect. No, there is no advantage to having 45 degree angles. 90 degree is preferable primarily due to spacing considerations no from an acoustic point of view...though low frequency modeling assumes a rigid walled rectangular room. Predictability may become a bit of an issue of you tried to model it compared to real world readings.

2) Regarding the side surrounds. I have two rows of seating, the rear being on a 12" riser. In general, where should the side surrounds be mounted between the seats, and what would the optimum height be? Right now I can foresee both rows being MLP, but I would probably lean towards the front row and being the main.

It depends on the speaker types you are using. Bipole/dipole applications are generally mounted exactly between the two rows listeners ears. With your seats being as close to the boundary as you say they are, using direct radiators is not the best approach especially if you are using Atmos. Height of the speakers is variable. I initially start out around 2 feet above the second row ears, but then I take a look at the entire picture. Am I using Atmos? Do I have a clear line of sight for all the listeners to the side and rear surrounds? How close are my seats to the speakers? All of this is a balancing act. Primary above all is to have a clear line of sight to the speakers from all seats. From there, lower and adjust as necessary. I shoot for a slightly higher application if the seats are close to the walls. Always default to 7.1. If you Atmos works given conditions, then consider where to place the atmos speakers. If the surround speakers are too high to meet the primary objective, then consider losing atmos as it just may not work. You can still have a great theater experience using 7.1 only.

3) Regarding the rear speakers. I plan to elevate them fairly close to the ceiling and angle them down. Should my main focus be on having a clear line of view from the speakers to the front row listeners?

Answered above. Consider speakers that already have an angle built into them. Some manufacturers will provide a best angle for you so you can ask them. Procella and some JBL speakers already have an angle built into some of their speakers. Makes mounting easy. Be careful not to get too high as unwanted reflections off the soffit and or ceiling may have to be dealt with.
 
#18 ·
Shawn,

Wow, thank you very much for your response. As you can see in the pictures, I'm fairly committed at this point, but the input you provide on the rears and side surrounds is very helpful. I will be building boxes for the rears that I can easily make changes to in the future if needed. The panels will be mounted at a slight angle. For the sides, that gives me a great starting point. I think I was on the right track there.

I will plan to install 1 bass trap per inside corner. on both the rear and front wall. We will be installing non-functional curtains on the screen wall to the side of the screen, so the bass traps can be hidden behind those.

Once I build the boxes for the Dayton's, I would like to have the room professionally tuned, so I'm hoping for some local availability for that service.

Again, thank you very much!
 
#23 ·
Thanks for your post and offer to help the community Shawn, we all really appreciate your insight!

I humbly submit a design I've been working on that's been pretty fluid lately. It's an update to my existing FROG dedicated theater (finished room over garage). I'm not dead set on anything here and do realize there are some issues with the layout. The ceiling slope and room layout are forcing me to compromise on some things that I realize are not ideal, but regardless this is what I have so far.

General Points:
- 7.2 surround system design for now. May go with Atmos eventually but it's not in the plan for now due to budget reasons.
- Room is staying open to stairway with sealed door and acoustic treatments in stairwell. This initially caused confusion as to where the true length null of the room would be. Measurements with REW show the length mode null point is roughly between 1st and second rows (indicated by dashed datum line in drawing)
- (3) JBL 4722n on front stage
- (4) Volt 10lx coaxial speakers for side and rear surrounds
- (4) HST-18 subs close('ish) to front 1/4 points of room
- proper amps to run all above equipment
- 144" diagonal 2.35:1 screen. Targeting the same viewing angles that I have now, which I'm quite happy with
- Listening angle of LR speakers is not optimal atm, measuring at 42.5 degrees

Acoustic Treatments:
- dead front wall: 2" OC703 or Linacoustic with plastic barrier on front / side wall area and ceiling behind screen. Additionally will add 12"x12"x2" foam wedges in alternating pattern on top
- ceiling: 4" OC703 w/ 4" air gap at first reflection points for fr and rr rows
- side walls: 4" OC703 with air gap at first reflection points of LR speakers
- rear walls: 4" OC703 with diffusor plates
- corner bass traps behind screen tuned to focus on 125Hz and below
- corner bass traps in mid and rear room corners (
 

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#24 ·
Thanks for your post and offer to help the community Shawn, we all really appreciate your insight!

I humbly submit a design I've been working on that's been pretty fluid lately. It's an update to my existing FROG dedicated theater (finished room over garage). I'm not dead set on anything here and do realize there are some issues with the layout. The ceiling slope and room layout are forcing me to compromise on some things that I realize are not ideal, but regardless this is what I have so far.

General Points:
- 7.2 surround system design for now. May go with Atmos eventually but it's not in the plan for now due to budget reasons.
- Room is staying open to stairway with sealed door and acoustic treatments in stairwell. This initially caused confusion as to where the true length null of the room would be. Measurements with REW show the length mode null point is roughly between 1st and second rows (indicated by dashed datum line in drawing)
- (3) JBL 4722n on front stage
- (4) Volt 10lx coaxial speakers for side and rear surrounds
- (4) HST-18 subs close('ish) to front 1/4 points of room
- proper amps to run all above equipment
- 144" diagonal 2.35:1 screen. Targeting the same viewing angles that I have now, which I'm quite happy with
- Listening angle of LR speakers is not optimal atm, measuring at 42.5 degrees

Acoustic Treatments:
- dead front wall: 2" OC703 or Linacoustic with plastic barrier on front / side wall area and ceiling behind screen. Additionally will add 12"x12"x2" foam wedges in alternating pattern on top
- ceiling: 4" OC703 w/ 4" air gap at first reflection points for fr and rr rows
- side walls: 4" OC703 with air gap at first reflection points of LR speakers
- rear walls: 4" OC703 with diffusor plates
- corner bass traps behind screen tuned to focus on 125Hz and below
- corner bass traps in mid and rear room corners (
 
#25 ·
27' x 14'6" x 9'. Thinking about doing a raised floor with rubber sheet on slab, then pressure treated 2x4s laying flat on rubber, then OSB or plywood sheets, bringing room height down to ~8'9".

11.2 setup. Two 18" freestanding subs at the front corners will act as one subwoofer, and then four 18" drivers using the rear closet as an enclosure will act as the second. Those drivers can span across horizontally or be stacked vertically - I am leaning vertical. Audyssey will try to make them all play nice.

Primary seat ~15'5" back from front wall.

Rear seats on 1' riser that can be stuffed and ported to act as bass trap.

Acoustically transparent screen to cover LCR and heights. Stretch velvet to cover the rest of the front false wall.

Corner bass traps, absorption panels on the side walls, front walls, and ceiling with alternating 4" thick 703 and 4" thick acoustic wedge foam, and absorption/diffusion panels on the back wall with 4" thick acoustic pyramid foam.



Am I overlooking something?
 

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#28 ·
Ok, lot's of issues I see here. Subs chosen are too large for the room, seats in poor placement, LCR speakers not separated enough. Velvet will not likely be a good choice for fabric. Are those height speakers depicted in the corner? If so, no need for them. Your planned isolation is eating a lot of room as well. I hate to be a party pooper, but just from what you have shown me here, the room will struggle acoustically. Further, your room does not appear to be able to accommodate 4" panels. I would recommend considering to either get acoustical consulting or possibly a design to use your space a bit more to your advantage.
 
#26 ·
Here is my layout:



The two circles in the middle are the heads. Green is height speakers.

Room is 12x12x8.5'

Speakers are Monitor Audio GSLCR, GS20, GS10 and GSFX. Subwoofer is SVS PB13 Ultra.

The right/left/front soffit will be used as a massive bass trap 12"x24".
 
#29 ·
I like that you put your angle lines! Are you able to place the actual values in as well? This is my opinion, but you may wish to consider condensing the speakers down a bit. The GSFX speakers are either monopole or dipole mode. You will want to use them in monopole configuration. I would consider arranging the rear surrounds a bit different. They don't need to be angled toward you unless the tweeter dispersion of off axis response are very poor. This is also my opinion, but at this time, I do not see the need for height and wide speakers. It opens a whole can of worms with especially the wides that are unnecessary. You can achieve virtually the same thing using only proper treatment in those locations. You're on the right track though! Just tweak a few things, consider rearranging your atmos speakers (4 is plenty for this room actually for only two people and room dimensions) , and keep going!
 
#37 ·
Ok so this should be fun. OK so the room is roughly 13' x 25' not counting where the tv is. That is I think about 3.5' x 19' give or take 8' celings. Windows with curtains behind TV, along wall on far left on both sides of the corner. Doors and couches are roughly as placed. There is a 3' circular glass coffee table in front of couch and there are hardwood floors no rugs or carpet. There is a framed painting behind couch and love seat. Circles represent speakers front left right and surrounds, center is in front of the tv. There is a sub on either side of the tv behind the front channels. The black hoops are the main listening positions, although the couch is more centered on the tv. First try at Sketchup haha. The coffee table as well as a dinner table are the black objects. there is honestly very little chance of moving things around just due to the way outlets are placed. Just curious how god awful this set up actually is lol. Honestly doesn't bother me all that much the way it is but wondering what a professional might say, other than are you insane.
 

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#43 ·
Ok, finally able to get back on track here. Very long day. Things that could improve your sound: 1) the corner placement of the Right front speaker will cause SBIR and likely boundary gain issues. Treat behind and along the side wall with a thickness appropriate to deal with these issues. 2) The coffee table will cause either blocking of the center speaker sound, or unwanted reflections. Suggest moving it and put an ottoman or something there. 3). Obviously the lopsided nature of the room is going to cause several acoustic issues. Too many to really dive into. 4). Move the couch at least a foot off the back wall. Hope this helps. I would try to at least move the TV down the sidewall a bit, but obviously before the door.
 
#41 ·
Hi Shawn, I'd love any advice you could give on my small dedicated room, but this might be a bit of a challenge!

13 foot long x 9 foot wide x 7 foot high!

Four sealed 12" subs stacked behind the screen and four sealed under rear riser.

The front row (yes, I've two rows of seats in there!!) is the MLP, the back row is just additional seating and helps make it look more like a cinema!!

4 rows of seats on each row - What can I say, it's cosy but we like it!

I just want to get as even a bass response as I can with what I have.
 

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#45 ·
Interesting on the second row in a small room. Congrats on getting it in there! In this case, definitely focus on the main row. Your angles are good for the speakers. Only word of caution I could give you is watch the location of the L/R speakers in reference to the edge of the screen. You may want to scoot them in a bit to prevent blocking of the tweeter dispersion pattern. This is important when it comes to lateral reflections off the side wall. Not sure exactly where the other subs are in the riser, so those could be causing issues. Main thing is to make sure your main listening row is not in a null, you treat the room well, and use a DSP to calibrate the subs. These items should help to smooth out most if not all of the issues.
 
#42 ·
Hello Shawn,

Please comment on the ML position. I thinking the front corner wall meets at 20 degree from the MLP center. I am flexible with the L/R position or re position the MLP a bit as i haven't build the riser yet.

Also, the second picture is for the Column build design I have in mind. Any tips or predictions on its acoustical merits/ demerits?

Regards
 

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#46 ·
Just from cursory glance, it looks as if the MLP is a little too far back. See if you can adjust that a little. Since I am unsure what speaker model you are using is, it is hard to comment on your column. I am assuming though you don't intend to put fiberboard in the speaker area.
 
#48 ·
How can I create drawings or schematics like those being posted here? I could use some advice as I have been unable to come up with a solution on my own to a living room set up. Or should I just post pictures of the room......after I clean it up a bit. :eek:
 
#49 ·
The best 'free' software is Sketchup - there is a learning curve, but for modelling pretty much anything in 3D, it's a great resource.

As well as plan view type stuff - you can produce 3d visuals as below....vvvv



X-ray visuals....vvvv



...and cut-aways....vvvv



Loads of tutorials on YouTube and Trimble's (the developers) web-site.

HTH


Should keep you busy for a while! ;)
 

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#51 ·
I see they emailed me, saying that SketchUp Make (whatever this is) is free after 30 days. That's good, as it'll take me a while to get into this program.
 
#56 ·
My main reason for using SketchUp is to plan out my basement remodel (including home theater) and other remodels (two bathrooms, front of house, etc.). I plan on using this to get ideas on "paper", but then paying an expert or more likely experts (one for HT, one for rest of house) to do the final planning. My version should help someone know what we're thinking and what our requirements are. That might help get the end result closer to what we want, in less time than with a blank slate. And, my wife can visualize the configuration and add her ideas. I have the engineering background, but she comes up with a lot of the realistic ideas about how we should actually use the space.
 
#57 · (Edited)
Thanks, I'll look into Sketchup. .......... Just a quick question. Would a 15'8" x 11'4" x 9' room with 1/8" paneling on two walls ( think enclosed porch not done properly w/ single pane window on one and sliding glass dr on the other ) then brick on the other 2 ...... be too small after tearing down and building new walls (not the brick) for 3 JTR Triple 12's, 2 Triple 8's, and 2 118's? If so , then I have no choice but to use the living room and make some compromises I think. The living room is 15' x 21' x 9' BTW with an opening of french doors to the dinning room. Otherwise enclosed.
 
#63 ·
^^^

there are many here that are seeking advice (myself included)

I think you are taking the discussion on a tangent....so can we please move on...perhaps take it to PM, or another thread?
 
#66 ·
Hello,

Here is my room. The front speakers will be behind the screen and the placement of the speakers and the subs can be changed. The surround speakers and the ceiling speakers are already wired. The height of the surround speakers can be adjusted. The atmos speakers on the ceiling were wired at 55 degrees from the listening positions in front and at the back and the angle can be adjusted as we will put them in enclosures (speaker cloud). The only change I plan to make is building 4 ported enclosures for my 18" subs and place them at the correct locations. The room has subwoofer wiring in each corner and I am also able to run wires to the side walls if necessary.

 

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#69 ·
Hi!

Sorry it took me so long to get back to you. It's difficult to read your plan. Only thing I can see that sticks out at me is the screen and the L/R main speaker locations in relation to it. Might want to consider expanding the screen a bit to encompass those main speakers a bit. The main listening position looks to be a bit centered in the room. Consider moving forward or backward, but if you move backward, the distance between the left speaker will have to be expanded. Other than that, without knowing fully what you have there, it is difficult to say, but looks ok so far.
 
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