[HTbuph]

I am just starting construction of my HT. This should be fun and alot of work. I just thought that I'd relay what I am doing to everybody as a learning experience, primarily for me, but also for anybody else who might drop by. Please feel free to critique what I have done and guide me as much or as little as you like.


Let me just start by saying that I do not have a digital camera or scanner that would allow me to post pictures, although I am taking them as I proceed. I am sorry, but you'll have to rely on my descriptive abilities.


First let me describe the space. It is in an unfinished portion of the basement in a townhome. It is about 19 feet between the two neighboring townhomes which means two of the walls (walls A and B) are firewall. It is about 10 feet wide with one side concrete (wall C), and the other facing the rest of the basement(wall D). It is 8'3" between the concrete and above floor joists. Wall D is basically delineated by a large, structure supporting I-beam in the ceiling. The bottom of the I-beam is about 7.5' from the concrete floor with supporting members (4" diameter) on either end of the space. Along the ceiling, under the joists, running parallel for about 10-11' of the I-beam on the unfinished side (i.e. in my future HT space) is a large section of box ductwork which branches into several smaller ducts distributed to various places in the house. About 10' of wall D is open into the laundry room, 3.5' of it is the opening to a hallway in the basement (where the door will be), and 5' of it is already walled off from a closet and steps. Wall A has the waste water line coming down it, about in the middle, and going into the concrete about a foot out from the wall. There is nothing along walls C and B that I have to contend with. There are two lighting fixtures in the ceiling, one above each half of the space.


Now, I have already built the wall framing. I built a staggered frame under the I-beam along wall D with 2X6 sole and top plate. The studs are 16" OC on either side of the sole and plate, meaning there is a stud every 8" OC. I have not yet framed the doorway, and the other section of wall D only has the pre-existing framing and drywall. Walls A, B, and C are all framed 16"OC. The top plates for walls A and C are secured to the ceiling joists with 16d nails, and with liquid nails for wall B. The top plate for the staggered framing of wall D was secured to the I-beam with liquid nails. The sole of all framing that I put up was secured to the concrete with concrete nails.


The space enclosed by the framing is 18'6" X 10'2" X 8'3". The door frame will jut into the room by about 5".


That is where I am now.


The equipment I have that will be in the room is as follows:

NEC 6pg+

FR, C, FL speakers....NHT super ones

RS, LS....Definitive BP2

2 Subwoofers....homemade, heavily braced, HDF boxes (3' cubic) w/ 12" Audio concepts DV12s


I plan on putting a component closet in the laundry room so that none will be in the room. This means I intend to have an IR repeater to allow control of the components.


I envision the seating positions to be about 10' and 16' from the screen. I am not sure about putting the screen on either wall A or B. The screen will be a 16:9 screen.


I will post descriptions of what I've done, as I go.


Tim

 

[Shaun Pressley]

Should be a nice room, Tim. What are you going to do for acoustical treatments? Have you picked out colors of fabric, etc? Are you going to build a proscenium on the screen wall? How about a riser for the rear seating position?


Have you decided on a screen size for your room?


I look forward to following your progress.

 

[HTbuph]

Thanks Shaun!


I do intend to have a proscenium and a riser. In fact, I already have the 2X6s, while originally intended for sole and top plates all the way around for staggered framing, could be used for a riser. I realized that staggered framing wouldn't really be beneficial on walls A,B, and C. So I have them left over. On the other hand, a 6" riser probably wouldn't be enough. Maybe I could use them for the proscenium and get 2X12s for the riser. The riser and proscenium won't be started until the drywall is up.


BTW, I intend to double layer the drywall, probably both 5/8" and 1/2" with one layer perpendicular to the other. I've seen some glue at HD that advertises as being a substitute for screws, and would aid in sound absorption. Any opinion on the stuff for use with drywall?


I had been thinking about TS+, or an equivalent from Corning, for the wall behind the screen and for a few feet forward from the screen. I'm not sure how difficult it will be to get TS+ or the Corning equivalent. I will have the same around the rest of the walls up to about 4'.


I had also thought about columns along walls C and D to hide the surrounds. However, the first seating position, if the screen is on wall B, will be about even with the door, so a column there wouldn't work....unless I put the surrounds between the two seating positions high on walls C and D. I could put the screen on wall A. In that case the 1st seating position will not have the door next to it. The other consideration is the subs. They are rather large, heavy boxes. I want to put one in the center of wall C, with the driver centered halfway between the ceiling and floor, and the other most likely in the center of the wall under the screen, on either wall A or B. That positioning results from my desire is to even out bass resonance in the room. The positioning of the one sub along wall C will make a column once again problematic.


I want the room to be fairly dark. TS+ is already black. The walls above the acoustic material I was thinking of painting a dark, almost burgundy red using a flat paint. The floors will obviously be carpeted to compliment the rest of the colors in the room.


I was planning on recessed lighting with a couple near the screen, and four over the seats (two over each seating position).


I'm thinking about a 7'-8' wide 16:9 screen. I don't want to overtax the pj by getting too big with the screen, and I want the image to be tolerable from a 10' viewing distance.


I'll start on the door frame most likely tonight or definately some time tomorrow. Its my day off tomorrow, but the "boss" is also taking the day off and we're supposed to go shopping. Hopefully there will be time in there for me to "play".

 

[HTbuph]

Just thought that I'd update everyone on what I have completed since my last post. I took a few weeks off for travel and turkey day, so I'm just starting to get back into it.


I have framed and installed the entry door to the HT. I secured a 32" section of pressure-treated 2X4 to the floor as a footer for the door. There is about a 1/4" gap between the footer and the door which I will deal with later.


I have framed in the component closet in the laundry room. It is about 21" deep and 25" wide. I intend to put a moveable rack, which I'll probably build myself, into the closet that would allow me to role the entire rack out of the closet for access to the back of the components. I ran the satellite, telephone, and one electrical line into the closet. I will be running a second line to the closet specifically for the amplifiers.


I have started modifying the ductwork in the room. I have replaced one section of tin ductwork with flexible, insulated, 6" ductwork and replaced the prior vent with an insulated vent that has an 8"X12" opening. I zig-zagged the flex duct between the two support joists to where the vent was affixed. I want to cut into the box duct and install another section of flexible ductwork for the second vent into the room. Right now the second vent into the room is simply a cutout in the box duct with a vent in it. I will be splicing into an air return and running it into the HT. There are some other tin ducts that don't vent into the room and I wasn't intending to replace them. Would it reduce the background noise level to replace them with the flex duct even thought they don't vent into the room?


That is pretty much where I am at the moment. Hopefully this weekend I will be finished with all the wiring so that I can start insulating the walls prior to putting up the dry wall.


Things are starting to take shape!

 

[SVonhof]

Tim, you may want to re-consider the placement of the subs. From the different things that I have read, the center of a wall is the wrong place to put them because of the sound waves bouncing back from both side walls at the same time and cancelling out each other or something like that.


Anyone out there that can either confirm or shoot down that point? I seem to remember hearing that from an article a while back in AVI that dealt with sub placement.

 

[HTbuph]

I just did a search on SW placement in the special guest area. Russ Herschleman recommended placing them at the 1/4 and 1/2 position on walls if using 2 subs, the one I remember particularly is 1/2 on the front wall and 1/4 on the back wall.


Quote:

Originally posted by SVonhof Tim, you may want to re-consider the placement of the subs. From the different things that I have read, the center of a wall is the wrong place to put them because of the sound waves bouncing back from both side walls at the same time and cancelling out each other or something like that. Anyone out there that can either confirm or shoot down that point? I seem to remember hearing that from an article a while back in AVI that dealt with sub placement.