giomania
Member
Hi, I am commencing construction of a dedicated home theater featuring Martin Logan Vantage, Stage, and Ascent i speakers. I am wondering if there are any special considerations to take into account during the design phase. I have posted excerpts from a thread I started on AVS Forum below. Since the first poster tried to talk me out of the Logan's, I thought it best to seek assistance here.
If you want to view the thread on AVS, it is located at: http://www.avsforum.com/avs-vb/showthread.php?t=731210
CineMark IV Design & Construction
-------------------------------------------------------------------
Introduction
Welcome to the CineMark IV design & construction thread. Before I get accused of stealing the name for my theater, let me explain. A long time ago in a galaxy far, far, away (Germany), I purchased my first projector—a Sony VPL VW 10HT—and screen. A friend of mine came over and remarked “Wow! It’s like a cinema…it’s CineMark!”.
I have moved several times since then—currently in southwest suburbs of Chicago—and every time I just added a Roman numeral at the end to reflect the new location. I actually constructed a quasi-dedicated theater room for the third location when I finished my basement. I am finishing my basement again, and this implementation of the theater shall be named “CineMark IV”.
Design philosophy
I notice a popular trend is to design and build home theaters which look like the real thing. While I think that is totally cool, it is not the direction which I am heading. My primary goal is audio/video performance…aesthetics is secondary. For example, I have Martin Logan Electrostatic speakers which need to be placed out into the room (away from the room boundaries) for optimal performance. As a result, speaker columns along the walls—a big part of the theater look—would not be an option for my theater, unfortunately.
I know that many will disagree with this philosophy, and that is fine…it takes all kinds to make the world go ‘round. That said; please feel free to chime in with advice—despite your design philosophy—as I welcome all opinions. I cannot think of and/or consider everything, and am always willing to learn.
General thoughts about the room
Room Size
Roughly 28’ Long, 20’ Wide, and ~7’-7” High; I have to plug these dimensions into the room mode calculator spreadsheet and adjust them as necessary. I want the ceiling to be a continuous flat surface for acoustic purposes, so the finished height will need to be just under the ever-present structural steel I-beam and HVAC trunk lines running through the middle of the room’s length.
Lighting
I was initially thinking to just install wall sconce lighting, but I like the idea of multiple-zone lighting with a Grafik Eye controller. The problem is that electrical code where I live requires metal conduit, which is much more difficult and tedious to install than romex.
I am doing the electrical myself, so light placement might be limited by my skill in bending the conduit. Then there is all the extra work building light boxes to limit the flanking noise…if I want to be that ambitious. However, it would appear that code allows flexible metal conduit (aka BX) for a maximum of six feet. So, perhaps I can do this…who knows. I need to do some more checking.
Sound Isolation
I want to try to keep the sound inside, naturally. The room will be bordered on three sides by the poured concrete basement walls. They are insulated on the exterior with 2 inch thick XPS (per the Building Sciences Corp. recommendations), so the insulation in the stud walls will be for sound isolation purposes only. On the wall which will be shared with the remainder of the basement, I was thinking of either a double wall or a staggered stud wall. I plan to install two solid-core exterior doors on this wall, creating an air lock for the theater entry.
I would like to go with a room within a room design with isolated ceiling joists. The only problem is that I have a steel I-beam and HVAC trunk lines to work around; I cannot span the entire width of the room with the isolated ceiling joists. I’m planning on 24” O.C. stud walls, as there is no load to bear. I’m not sure if there is a need for multiple drywall layers with Green Glue, since I’m planning on the room within a room isolation technique. I recall that Russ Hershelmann (spelling?) used to advocate using one layer of ½’ drywall to assist with bass absorbption, but that doesn’t seem to be very popular here.
Acoustic Treatments
I’m definitely interested in home-made bass traps. The electrostatic speakers utilize reflective surfaces, so there may not be a need for any other treated surfaces in the room. I could use some help in this area.
Power Conditioning
EquiTech 10WQ balanced power wall panel
Sort of like a 200 amp sub panel with an isolated transformer and balanced power output. Balanced power has 60 volts on the “hot” and 60 volts on the “neutral” lines, 180 degrees out of phase with each other.
Conclusion
While my equipment list suggests otherwise, I am not wealthy. I am just an average guy who lucked out with a real estate transaction. I applied the windfall to some screaming deals I got while employed at Tweeter.
Mark
10-03-06, 06:50 AM #2 (Print)
bpape
Wearer of Many Hats
Join Date: Dec 2000
Location: St. Louis(Wildwood), MO
Posts: 6,687 Congrats on starting your project. Looks like you're going to have a nice setup.
Just a couple of comments.
- I would seriously recommend using something else for speakers in a home theater. Many have tried the Logans and almost all have moved on to something else. They're great for music but just don't get it for HT.
- You will most certainly need additional treatments in the room. I do not say that because we are in that business. I say it because you'll need to deal with decay times in the room.
- Back to #1 - treating the front wall in a multi-channel environment is extremely important to eliminate reflections from the surrounds bouncing back off the front and messing up the soundstage. Also important to assist in dealing with SBIR issues. That said, this is contrary to proper function and output of most planar/open baffle speakers - especially those with rear firing woofers.
For ceiling isolation, you'll probably want to use RSIC-1 clips and hat channel if you can't do your own joists. Also decouple the new inner walls with DC-04 clips.
Bryan
__________________
I am serious...and don't call me Shirley.
GIK Acoustics
10-03-06, 08:44 AM #3 (Print)
giomania
Vini, Vidi, Vici
AVS CLUB MEMBER
Join Date: Nov 2001
Location: Chicago, Illinois
Posts: 143
Bryan, thanks for visiting. I know you have helped many others, so I am glad you chimed in. I have heard that about the Logans, but was also thinking that maybe the others didn't spend alot of time on speaker placement or wanted them against the walls. Have you had any personal experience attempting to set up a Logan theater?
I'm not married to the Logan theater idea, because I know I can recoup my investment in the speakers. My previous setup--which I still have-- was a Mirage Omnipolar theater. I had four OM-7's, two OM-5's, and four BPSS-210 subs. I was happy with that setup, but was really looking to up the performance level. I fell in love with the Logan's while at Tweeter, but they were in a 2-channel setup in a very large room.
It would seem the problem is that room design is vastly different for traditional direct radiation speakers versus bipolar or dipolar radiation designs. Do you think the choice has to be made at this juncture or can the room be designed to go either way?
Regarding decoupling the walls with DC-04 clips, I assume you are talking about decoupling the four walls from each other with the clips at the corner intersections?
Thanks for your help.
Mark
__________________
Check out my design & construction thread:
http://www.avsforum.com/avs-vb/showthread.php?t=731210
Report Post
Edit Post Click anywhere outside this box, to cancel editing.
10-03-06, 10:48 AM #4 (Print)
Kevin_Wadsworth
Member
Join Date: Dec 2002
Location: Columbus, OH
Posts: 166 Quote:
I think he is referring to decoupling the top of the walls from the joists with the DC-04's.
Report Post
10-03-06, 11:41 AM #5 (Print)
giomania
Vini, Vidi, Vici
AVS CLUB MEMBER
Join Date: Nov 2001
Location: Chicago, Illinois
Posts: 143 Quote:
Hmmm...my understanding of a room within a room design is that the walls will never touch the existing joists above. There enough distance between the bottom of the I-beam and the bottom of the existing joists so that the isolated 2x6 joists will never touch them. That is on the outide perimeter of the room.
Where the I-beam and HVAC trunk lines run, I need to use DC-04 clips to suspend the isolated 2x6 joists from the existing joists, as I cannot build a wall (that sits on the ground) to support them.
I'm not sure if this is making sense or not.
Mark
If you want to view the thread on AVS, it is located at: http://www.avsforum.com/avs-vb/showthread.php?t=731210
CineMark IV Design & Construction
-------------------------------------------------------------------
Introduction
Welcome to the CineMark IV design & construction thread. Before I get accused of stealing the name for my theater, let me explain. A long time ago in a galaxy far, far, away (Germany), I purchased my first projector—a Sony VPL VW 10HT—and screen. A friend of mine came over and remarked “Wow! It’s like a cinema…it’s CineMark!”.
I have moved several times since then—currently in southwest suburbs of Chicago—and every time I just added a Roman numeral at the end to reflect the new location. I actually constructed a quasi-dedicated theater room for the third location when I finished my basement. I am finishing my basement again, and this implementation of the theater shall be named “CineMark IV”.
Design philosophy
I notice a popular trend is to design and build home theaters which look like the real thing. While I think that is totally cool, it is not the direction which I am heading. My primary goal is audio/video performance…aesthetics is secondary. For example, I have Martin Logan Electrostatic speakers which need to be placed out into the room (away from the room boundaries) for optimal performance. As a result, speaker columns along the walls—a big part of the theater look—would not be an option for my theater, unfortunately.
I know that many will disagree with this philosophy, and that is fine…it takes all kinds to make the world go ‘round. That said; please feel free to chime in with advice—despite your design philosophy—as I welcome all opinions. I cannot think of and/or consider everything, and am always willing to learn.
General thoughts about the room
Room Size
Roughly 28’ Long, 20’ Wide, and ~7’-7” High; I have to plug these dimensions into the room mode calculator spreadsheet and adjust them as necessary. I want the ceiling to be a continuous flat surface for acoustic purposes, so the finished height will need to be just under the ever-present structural steel I-beam and HVAC trunk lines running through the middle of the room’s length.
Lighting
I was initially thinking to just install wall sconce lighting, but I like the idea of multiple-zone lighting with a Grafik Eye controller. The problem is that electrical code where I live requires metal conduit, which is much more difficult and tedious to install than romex.
I am doing the electrical myself, so light placement might be limited by my skill in bending the conduit. Then there is all the extra work building light boxes to limit the flanking noise…if I want to be that ambitious. However, it would appear that code allows flexible metal conduit (aka BX) for a maximum of six feet. So, perhaps I can do this…who knows. I need to do some more checking.
Sound Isolation
I want to try to keep the sound inside, naturally. The room will be bordered on three sides by the poured concrete basement walls. They are insulated on the exterior with 2 inch thick XPS (per the Building Sciences Corp. recommendations), so the insulation in the stud walls will be for sound isolation purposes only. On the wall which will be shared with the remainder of the basement, I was thinking of either a double wall or a staggered stud wall. I plan to install two solid-core exterior doors on this wall, creating an air lock for the theater entry.
I would like to go with a room within a room design with isolated ceiling joists. The only problem is that I have a steel I-beam and HVAC trunk lines to work around; I cannot span the entire width of the room with the isolated ceiling joists. I’m planning on 24” O.C. stud walls, as there is no load to bear. I’m not sure if there is a need for multiple drywall layers with Green Glue, since I’m planning on the room within a room isolation technique. I recall that Russ Hershelmann (spelling?) used to advocate using one layer of ½’ drywall to assist with bass absorbption, but that doesn’t seem to be very popular here.
Acoustic Treatments
I’m definitely interested in home-made bass traps. The electrostatic speakers utilize reflective surfaces, so there may not be a need for any other treated surfaces in the room. I could use some help in this area.
Power Conditioning
EquiTech 10WQ balanced power wall panel
Sort of like a 200 amp sub panel with an isolated transformer and balanced power output. Balanced power has 60 volts on the “hot” and 60 volts on the “neutral” lines, 180 degrees out of phase with each other.
Conclusion
While my equipment list suggests otherwise, I am not wealthy. I am just an average guy who lucked out with a real estate transaction. I applied the windfall to some screaming deals I got while employed at Tweeter.
Mark
10-03-06, 06:50 AM #2 (Print)
bpape
Wearer of Many Hats
Join Date: Dec 2000
Location: St. Louis(Wildwood), MO
Posts: 6,687 Congrats on starting your project. Looks like you're going to have a nice setup.
Just a couple of comments.
- I would seriously recommend using something else for speakers in a home theater. Many have tried the Logans and almost all have moved on to something else. They're great for music but just don't get it for HT.
- You will most certainly need additional treatments in the room. I do not say that because we are in that business. I say it because you'll need to deal with decay times in the room.
- Back to #1 - treating the front wall in a multi-channel environment is extremely important to eliminate reflections from the surrounds bouncing back off the front and messing up the soundstage. Also important to assist in dealing with SBIR issues. That said, this is contrary to proper function and output of most planar/open baffle speakers - especially those with rear firing woofers.
For ceiling isolation, you'll probably want to use RSIC-1 clips and hat channel if you can't do your own joists. Also decouple the new inner walls with DC-04 clips.
Bryan
__________________
I am serious...and don't call me Shirley.
GIK Acoustics
10-03-06, 08:44 AM #3 (Print)
giomania
Vini, Vidi, Vici
AVS CLUB MEMBER
Join Date: Nov 2001
Location: Chicago, Illinois
Posts: 143
Bryan, thanks for visiting. I know you have helped many others, so I am glad you chimed in. I have heard that about the Logans, but was also thinking that maybe the others didn't spend alot of time on speaker placement or wanted them against the walls. Have you had any personal experience attempting to set up a Logan theater?
I'm not married to the Logan theater idea, because I know I can recoup my investment in the speakers. My previous setup--which I still have-- was a Mirage Omnipolar theater. I had four OM-7's, two OM-5's, and four BPSS-210 subs. I was happy with that setup, but was really looking to up the performance level. I fell in love with the Logan's while at Tweeter, but they were in a 2-channel setup in a very large room.
It would seem the problem is that room design is vastly different for traditional direct radiation speakers versus bipolar or dipolar radiation designs. Do you think the choice has to be made at this juncture or can the room be designed to go either way?
Regarding decoupling the walls with DC-04 clips, I assume you are talking about decoupling the four walls from each other with the clips at the corner intersections?
Thanks for your help.
Mark
__________________
Check out my design & construction thread:
http://www.avsforum.com/avs-vb/showthread.php?t=731210
Report Post
Edit Post Click anywhere outside this box, to cancel editing.
10-03-06, 10:48 AM #4 (Print)
Kevin_Wadsworth
Member
Join Date: Dec 2002
Location: Columbus, OH
Posts: 166 Quote:
I think he is referring to decoupling the top of the walls from the joists with the DC-04's.
Report Post
10-03-06, 11:41 AM #5 (Print)
giomania
Vini, Vidi, Vici
AVS CLUB MEMBER
Join Date: Nov 2001
Location: Chicago, Illinois
Posts: 143 Quote:
Hmmm...my understanding of a room within a room design is that the walls will never touch the existing joists above. There enough distance between the bottom of the I-beam and the bottom of the existing joists so that the isolated 2x6 joists will never touch them. That is on the outide perimeter of the room.
Where the I-beam and HVAC trunk lines run, I need to use DC-04 clips to suspend the isolated 2x6 joists from the existing joists, as I cannot build a wall (that sits on the ground) to support them.
I'm not sure if this is making sense or not.
Mark