Trezl's Upstairs HT build planning

T

Trezl

Junior Audioholic
It's been a few years since I've had a proper movie space, and we are putting a 2nd story on our house next year. I have the opportunity to build a home theater in the back half over the garage. I'm working through preliminary planning and was wondering what advice folks might have so that I make the right decisions.

I've attached a diagram of the basic layout. Here are some points:

  • Room approx 15ft E-W
  • Approx 13ft N-S
  • North, East walls are exterior
  • South wall is a bedroom closet
  • West wall is bathroom
  • All walls will be foam insulated
  • Plan for 7.2.4 Atmos speaker system
  • Faux wall in front, 2 feet from the east wall. Front channels and sub woofers behind screen
  • The room won't be a perfect rectangle, as the hall leading to it requires that 45degree angled opening.

I know the room is a bit small for multi-tier seating, so I'd rather just optimize it for one big couch/theater seating with the option of bean bags in front.

My open questions:
  • How to best optimize couch location and screen size?
    • It looks to me I need to have it at least up enough to be full in front of the door.
  • A/V system in the N/W corner best?
  • Would a double wall help on the south side, even with foam insulation?
  • Is having the faux wall at 2 feet creating a square room acoustically? Will this cause me sound issues? Is 2 feet the right distance? I could probably just squeeze the south wall and make the bedroom closet bigger if it is going to make a large difference, but I can't go longer than 15ft E-W
  • Any other things I should be thinking about?
Thank you all for any help.

Home Theater edit1 (2).png
 
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TheWarrior

TheWarrior

Audioholic Ninja
My open questions:
  • How to best optimize couch location and screen size?
    • It looks to me I need to have it at least up enough to be full in front of the door.
  • A/V system in the N/W corner best?
  • Would a double wall help on the south side, even with foam insulation?
  • Is having the faux wall at 2 feet creating a square room acoustically? Will this cause me sound issues? Is 2 feet the right distance? I could probably just squeeze the south wall and make the bedroom closet bigger if it is going to make a large difference, but I can't go longer than 15ft E-W
  • Any other things I should be thinking about?
Thank you all for any help.
I think this room is a bit small for the number of speakers you want to put in there. I would suggest you start with getting the highest quality front - L, C, R you can, and start with just 2 surrounds on the back wall for a 5 channel surround system - or bi/dipole speakers on the sides. I wouldn't seek full range tower speakers in this room, but a quality 3-way that can get below 60 hz would be excellent. Let the subs control the bass, and I'd start with two. The internet direct companies are as good as anything available today.

Couch: I project on to a 96" screen from 13' giving me a ratio of 1.6. This is the low end of the THX spec, meaning a ratio of 1.2, for example, would mean an even larger screen for the same viewing distance. At 1.6, I am moving my eyes to see everything, 1.2 would mean moving my head. So the further back you sit, the bigger the screen could be, I would just try to keep at least 3-4 feet from surround speakers.

A/V location: I would try to have at least two 15A circuits in this room. You'll need outlets for subwoofer locations, unless you go passive. Big TV's or powerful projectors ideally get their own circuit too.

Faux wall: should not be a studded wall, use an acoustically transparent fabric and take the grill covers off of the speakers. Use minimal framing for screen/display. Distance depends on from speakers used.
 
T

Trezl

Junior Audioholic
I think this room is a bit small for the number of speakers you want to put in there. I would suggest you start with getting the highest quality front - L, C, R you can, and start with just 2 surrounds on the back wall for a 5 channel surround system - or bi/dipole speakers on the sides. I wouldn't seek full range tower speakers in this room, but a quality 3-way that can get below 60 hz would be excellent. Let the subs control the bass, and I'd start with two. The internet direct companies are as good as anything available today.

Couch: I project on to a 96" screen from 13' giving me a ratio of 1.6. This is the low end of the THX spec, meaning a ratio of 1.2, for example, would mean an even larger screen for the same viewing distance. At 1.6, I am moving my eyes to see everything, 1.2 would mean moving my head. So the further back you sit, the bigger the screen could be, I would just try to keep at least 3-4 feet from surround speakers.

A/V location: I would try to have at least two 15A circuits in this room. You'll need outlets for subwoofer locations, unless you go passive. Big TV's or powerful projectors ideally get their own circuit too.

Faux wall: should not be a studded wall, use an acoustically transparent fabric and take the grill covers off of the speakers. Use minimal framing for screen/display. Distance depends on from speakers used.
Thanks for the information.

Yes, I planned on at least 2 circuits with surge protection. I expect to do several lighting scenarios (wall, recessed, probably rope), plus the AV circuit and subwoofers like you mention. It sounds like a 3rd circuit might even be best, which shouldn't be a problem.

I think I had the ratios backward in my head. Distance from is 1.2-1.6x the diagonal size of the screen, right? So if I sit at 9' (108"), I'm looking at a 90" screen at MAX, right?

I think the room is going to be wider than I need compared to the length (and funky doorway in the rear), so I'm probably going to need to think of some ways to make the room feel thinner through decoration or something. 90" screen only requires like 7' of wall, right?
 
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T

Trezl

Junior Audioholic
Also, I agree I don't need full range towers in this space. My plan was for high quality book shelf sized speakers for LCR (and probably side) to start and build out from there.

I know it's a lot of speakers. In your experience will the small space override the immersion of having multiple points for 7.2 + Atmos object based surround sound? I'm trying to do a little bit of future proofing in the design.

I recognize to fill the space with sound, 7.2.4 might be overkill, but is your contention that too many speakers will muddle the ability to do Atmos style surround in such a small space? Something along those lines? Or just that I might be spending more money than is necessary?

Thanks again!
 
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William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
Just to clarify, the second , and third numbers in the 7.4.2 designation you list, I believe you mean 2subs right? That goes into the second digit location. So 7(channel).2(subs). 4(atmos speakers). In any case, I think you’ll be best served by going5.2.4. The rear surrounds don’t really add much, and considering the size of the room, I don’t see a need for 7 bed channel speakers. As you said, I think it would just congest the room. Sometimes less is more.
 
T

Trezl

Junior Audioholic
Just to clarify, the second , and third numbers in the 7.4.2 designation you list, I believe you mean 2subs right? That goes into the second digit location. So 7(channel).2(subs). 4(atmos speakers). In any case, I think you’ll be best served by going5.2.4. The rear surrounds don’t really add much, and considering the size of the room, I don’t see a need for 7 bed channel speakers. As you said, I think it would just congest the room. Sometimes less is more.
Yes, I messed that up. (Will correct in original post). Thanks for the explanation. That makes sense as to why less is more. :)
 
TheWarrior

TheWarrior

Audioholic Ninja
Thanks for the information.

Yes, I planned on at least 2 circuits with surge protection. I expect to do several lighting scenarios (wall, recessed, probably rope), plus the AV circuit and subwoofers like you mention. It sounds like a 3rd circuit might even be best, which shouldn't be a problem.

I think I had the ratios backward in my head. Distance from is 1.2-1.6x the diagonal size of the screen, right? So if I sit at 9' (108"), I'm looking at a 90" screen at MAX, right?

I think the room is going to be wider than I need compared to the length (and funky doorway in the rear), so I'm probably going to need to think of some ways to make the room feel thinner through decoration or something. 90" screen only requires like 7' of wall, right?
If you've got enough breakers available, do 3, it's easy to do when you're already there, rather than deciding to do it later.

A 108" viewing distance divided by a 90" screen equals 1.2 - MAX, you are correct!

Likewise 108" divided by 1.2 = 90" (for the peanut gallery)

Do you already have the couch? If not, I'd get the biggest one you can, you'll always have seating, and there's a comfortable amount of walking room on either side - I wish I had that! Plus, you'll have less than 3 feet on either side of your screen, great place for artwork, sculptures can be natural diffusers, for example.


Also, I agree I don't need full range towers in this space. My plan was for high quality book shelf sized speakers for LCR (and probably side) to start and build out from there.

I know it's a lot of speakers. In your experience will the small space override the immersion of having multiple points for 7.2 + Atmos object based surround sound? I'm trying to do a little bit of future proofing in the design.

I recognize to fill the space with sound, 7.2.4 might be overkill, but is your contention that too many speakers will muddle the ability to do Atmos style surround in such a small space? Something along those lines? Or just that I might be spending more money than is necessary?

Thanks again!
Yes, larger speakers can typically play lower frequencies better, but high and mid range drivers need very little space to operate. Check out Dennis Murphy's BMR Monitor http://www.philharmonicaudio.com for an example of a 3-way speaker that can anchor the front end of a multichannel system and then be quite capable even with out a subwoofer for 2 channel music listening. Dennis is on this forum and I can speak for his work!

My contention is, in that size space, more satisfaction will be derived from higher quality speakers, rather than a higher quantity of speakers. I would start there, and then as time and money allows add more. ATMOS is only the beginning, the new 16 channel processors are already way down in price :D
 
T

Trezl

Junior Audioholic
If you've got enough breakers available, do 3, it's easy to do when you're already there, rather than deciding to do it later.

A 108" viewing distance divided by a 90" screen equals 1.2 - MAX, you are correct!

Likewise 108" divided by 1.2 = 90" (for the peanut gallery)

Do you already have the couch? If not, I'd get the biggest one you can, you'll always have seating, and there's a comfortable amount of walking room on either side - I wish I had that! Plus, you'll have less than 3 feet on either side of your screen, great place for artwork, sculptures can be natural diffusers, for example.




Yes, larger speakers can typically play lower frequencies better, but high and mid range drivers need very little space to operate. Check out Dennis Murphy's BMR Monitor http://www.philharmonicaudio.com for an example of a 3-way speaker that can anchor the front end of a multichannel system and then be quite capable even with out a subwoofer for 2 channel music listening. Dennis is on this forum and I can speak for his work!

My contention is, in that size space, more satisfaction will be derived from higher quality speakers, rather than a higher quantity of speakers. I would start there, and then as time and money allows add more. ATMOS is only the beginning, the new 16 channel processors are already way down in price :D
Awesome information, thanks again!

As for what I'm going to PUT in the room, I'm still working on the details. But since this is a completely new build, I have every opportunity to wire it right. So while I might only install 5.2.4 at first, I'll probably wire at least 7.2.4 so I can add those speakers later if the budget allows or technology changes.

16 speakers though? Any diagrams on how that's supposed to lay out??? That's honestly new to me! :)

Thanks again for all the help!
 
T

Trezl

Junior Audioholic
Oh, and yes - for couch I plan on getting as long a couch as possible. Most likely home theater recliners eventually that can be built one seat at a time. I think I'll be able to go at least 5 wide if I don't do arm rests every seat (which I prefer - better for snuggling next to the missus). ;)
 
TheWarrior

TheWarrior

Audioholic Ninja
Awesome information, thanks again!

As for what I'm going to PUT in the room, I'm still working on the details. But since this is a completely new build, I have every opportunity to wire it right. So while I might only install 5.2.4 at first, I'll probably wire at least 7.2.4 so I can add those speakers later if the budget allows or technology changes.

16 speakers though? Any diagrams on how that's supposed to lay out??? That's honestly new to me! :)

Thanks again for all the help!

http://www.audioholics.com/av-preamp-processor-reviews/emotiva-rmc-1-atmos-dts-x-av-processor

Not yet available, but I cite it as the example of prices coming down. There's always the JBL SDP-75 which is a rebuild of the Trinnov Altitude 32. I think both of these cost above $15k. JBL didn't like a lot of the additional processing Trinnov uses, I am told, but the bare bones were the perfect start.

Anyway, my only point is that I'd start with the best possible 5 speakers you can afford before diving head long in to these new surround formats, cause they're already about to change as the above examples become more widely available.

With prewiring, just be sure to keep A/V cabling minimum 12" away from electrical, if they need to cross, make it perpendicular. Prewiring before drywall makes like effortless, I'd do as much as you're willing.

I would definitely prewire for side surrounds in a 7 channel configuration, just be SURE of where your couch is going to be.



Oh, and yes - for couch I plan on getting as long a couch as possible. Most likely home theater recliners eventually that can be built one seat at a time. I think I'll be able to go at least 5 wide if I don't do arm rests every seat (which I prefer - better for snuggling next to the missus). ;)
Be very critical of the dimensions of the couch. I'm over 6 feet tall, so I prefer a deep couch. We scored at Rooms to Go of all places for $400, a huge couch - did the 3M teflon spray myself for $10.

Recliners can create their own problems if their linkage starts vibrating in tune with your subwoofers. You may be better off, and have more money for sound equipment, going with a nice fluffy ottoman (just not a massive one that is deeper than the couch, maybe half as deep, you don't want all of that between you and your speakers.)

Post pictures of your theater too, especially the construction, people love watching that! So much has changed in my room that I'll be doing a new thread some time in the future... gotta transfer everything since Photobucket stopped allowing 3rd party hosting.
 
T

Trezl

Junior Audioholic
I've done recliners in the past and liked them, but what I put in there immediately after we build it and what I save up for later will probably be wildly different.

I will definitely post pictures of construction as it goes. I've already worked out with my builder that I will run the A/V wiring myself.

After talking with my wife last night, I flipped the layout of the room to see what it would look like. Not sure which I prefer...

Home Theater edit2.png
 
TheWarrior

TheWarrior

Audioholic Ninja
I've done recliners in the past and liked them, but what I put in there immediately after we build it and what I save up for later will probably be wildly different.

I will definitely post pictures of construction as it goes. I've already worked out with my builder that I will run the A/V wiring myself.

After talking with my wife last night, I flipped the layout of the room to see what it would look like. Not sure which I prefer...

View attachment 22625
Because you have the advantage of space on both sides of the couch, that allows your guests to excuse themselves without crossing in front of the display. With that in mind, I would keep the arrangement the way you had it, with the door in the rear. HT should be a social experience, so allowing people the ease of refilling their beverages without needing to disturb anyone else, would be the ideal!
 
T

Trezl

Junior Audioholic
OK, new question: sound isolation. My current plan was a double wall on the south side to isolate from the southern bedroom.

But I've seen some articles say do a full "room within a room" where I create double walls on all sides. For a home theater, am I really going to need that level of build out, especially if we foam insulate all the walls? I assume it's "better," but is it something I'm going to regret NOT doing?

Thanks!
 
TheWarrior

TheWarrior

Audioholic Ninja
OK, new question: sound isolation. My current plan was a double wall on the south side to isolate from the southern bedroom.

But I've seen some articles say do a full "room within a room" where I create double walls on all sides. For a home theater, am I really going to need that level of build out, especially if we foam insulate all the walls? I assume it's "better," but is it something I'm going to regret NOT doing?

Thanks!
I wouldn't be worried about the exterior walls, windows, however, are not desirable!

A solid core exterior door with all the weather stripping on the frame and floor is a good start. But sound proofing is a rather involved practice. Even the HVAC ductwork can transfer sound, for example.

The key to the room with in a room strategy is the air gap between boundaries. So you have the load bearing wall, and then the interior theater wall, at least 1/2" separated. You are creating two sealed and insulated wall cavities separated by a sealed volume of air.

Double layers of drywall can also work well, but also serves to increase room gain at bass frequencies. Boomy bass can be a result, and only heavy absorption (like: add a second couch, even if it's not meant to sat in) can solve that.

I've seen recording studio treatment plans that needed to control the bass booms for similar reasons, they would add couch-sized foam installations sunk into either the floor or ceiling to get the room to measure to a specified curve.
 
T

Trezl

Junior Audioholic
That's what I figured. I just wanted to make sure I didn't skip a step in creating the room that I can't go back and fix later.

I'm not trying to sound proof the room, necessarily. But I do want to do what I can to increase the STC as best I can within reason for home theater viewing.

No windows in this room, and we will use a solid, weatherstripped door. I plan to do some sort of acoustic treatment to the walls as well and do little things like put subwoofers and speakers on isolation foam platforms (like what Auralex sells).

The room itself will be a process to complete over months or even a couple years as budget allows upgrades.
 
TheWarrior

TheWarrior

Audioholic Ninja
That's what I figured. I just wanted to make sure I didn't skip a step in creating the room that I can't go back and fix later.

I'm not trying to sound proof the room, necessarily. But I do want to do what I can to increase the STC as best I can within reason for home theater viewing.

No windows in this room, and we will use a solid, weatherstripped door. I plan to do some sort of acoustic treatment to the walls as well and do little things like put subwoofers and speakers on isolation foam platforms (like what Auralex sells).

The room itself will be a process to complete over months or even a couple years as budget allows upgrades.
If you double wall between other rooms, along with a solid-core entry door, you're going to be pretty close to 'sound proofed'. The Sound Transmission Class won't affect quite so much of what you hear in the HT, although keeping more sound in is good, the real benefit is in how much others won't hear.

Save acoustic treatment for last because doing double walls, heavy padded carpeting and really any furniture creates a lot of absorption, naturally. If you've ever been in a heavily damped room, it is actually uncomfortable to listen in. Room treatment is far from limited to absorption, and is the last step to treating measurable problems at the listening locations.
 
T

Trezl

Junior Audioholic
If you double wall between other rooms, along with a solid-core entry door, you're going to be pretty close to 'sound proofed'. The Sound Transmission Class won't affect quite so much of what you hear in the HT, although keeping more sound in is good, the real benefit is in how much others won't hear.

Save acoustic treatment for last because doing double walls, heavy padded carpeting and really any furniture creates a lot of absorption, naturally. If you've ever been in a heavily damped room, it is actually uncomfortable to listen in. Room treatment is far from limited to absorption, and is the last step to treating measurable problems at the listening locations.
Right, right. First step, as I see it, is isolation so the outside world doesn't hear too much. It sounds like I'm on the right track with doubling the shared walls and isolating speakers from the structure as best I can. HVAC I recognize can be difficult to isolate. I'll need to do some research there as the HVAC will be shared with the upstairs bedrooms (2 of them).

After that, it's acoustics in the room, which can vary greatly based on what else is already in the room.

That said, I planned to look into bass traps and wall absorption treatments behind the front speakers before I close up the faux wall, since I plan to have the speakers/woofers back behind that wall and treating later would be a problem. Thoughts on that?

Thanks!
 
TheWarrior

TheWarrior

Audioholic Ninja
Right, right. First step, as I see it, is isolation so the outside world doesn't hear too much. It sounds like I'm on the right track with doubling the shared walls and isolating speakers from the structure as best I can. HVAC I recognize can be difficult to isolate. I'll need to do some research there as the HVAC will be shared with the upstairs bedrooms (2 of them).

After that, it's acoustics in the room, which can vary greatly based on what else is already in the room.

That said, I planned to look into bass traps and wall absorption treatments behind the front speakers before I close up the faux wall, since I plan to have the speakers/woofers back behind that wall and treating later would be a problem. Thoughts on that?

Thanks!
Just to be clear, that's one fully insulated and drywalled shared wall with another room, 1/2"+ air gap, and then one more fully insulated and drywalled 2x4 stud wall that becomes the new interior boundary of the theater (drywall both sides, no exposed studs, even inside the air gap, it all has to be sealed to work - I'm really trying to emphasize the fact that the new wall has to have drywall on both sides, caulked/putty'd seams with no holes. sorry if it's redundant)

A few key points as I have no idea your construction knowledge:
- Electrical outlets cannot be used in these sound insulating walls - can't seal it if you put a hole in it
- Plan out each wall on paper - care needs to be taken to properly/safely adhere the drywall to the new stud wall on the air gap side.
- The insulating wall must be fully attached to the floor below, and ceiling joists above
- Due to the need to not have holes in the insulating walls, utilize 3/4" thick trim/moulding with a cavity to run cabling where needed
- Attaching the wall securely means it can bear 'some' load, at least in the form of hanging a speaker on one of it's studs

Those sound insulating walls are a tall order! Just really wanting to make sure you're 'hearing' that.

They also serve a function in your endeavor to absorb sound. So will your couch, which I don't think you've purchased yet.

Which means all of the equipment and cabinetry, interior decor items, furniture, all need to be present and accounted for before making any decisions on acoustics. An empty room sounds different, surely you've noticed. So don't waste a DIME on absorbers until you've gotten that far. Because you may find diffusion or a combination is better suited, or that the furnishings of the room and a heavily padded carpet floor are all you need.

The faux wall for you front speakers needs to very well detailed in it's design - putting anything between you and the speaker could corrupt the sound if done incorrectly. You'll also want to allow a way to freely access anything with in it. And you need to know what speakers you are using before designing it, because the depth of the speaker plus rear porting (as an example) means you might not have a deep enough faux wall cavity for the speaker to perform well.
 

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