building a new HT

[delhite2]

Hi,

I've a 7.1 rf82 pakcage and an onkyo 705 for which i am looking to build a new HT room of size whd 16' x 9'6" x 25', it is a corner part of a basement that is currently enclosed on 3 sides, i will build a wall on the 4th side to achieve to above room size. i am also using Pt Ax200e and plan on a diy on wall-screen of 160" .

How do i get the best sound in the room? do i need to use some acoustical treatment for my room to get best sound i.e. (sound abosrbers, diffusers, carpets etc).

Thanks

[cornfedksboy]

I just completed a similar HT build. I'm using a "modified" RF-82 7.2 HT. You can see my gear in my sig. My room was considerably more narrow (11 X 24 X 7.5). Mine is also built in the corner of the basement and we finished off one of the long walls. From my experience, here are some important things to consider (listed in chronological order per the construction).

Blueprint: Figure out where you want your entrance and how wide you want it. It needs to have proper in/out clearance and not be in the way of any seating. Where do you want your components? Do you want them next to the screen, in a closet, or in a seperate room? Do you want any common HT architectural features like a soffit, pillars, or tiered seating? With a big room like that, you have the opportunity to make your walls "non-parallel." This is the single best thing you could do to improve accoustics in the HT. I didn't have that luxury, and we wanted to keep expenses down so we kept in simple. Some people build double walls to create an air pocket that works as a great sound absorber. You may want to consider going knock-down texture on the walls and ceiling to decrease light and sound reflectivity. We had low celings so we had basic pad and carpet put down. You have 9.5' ceilings, so you have a little more to play with. In cinema's, they put in elevated floors (something like 4"). This will really help the bass transition smoothly throughout the room. I assume you are on a concrete foundation, so make sure that you put down some type of carpet at a minimum. That is a super echoic material and needs to be covered.

In wall cables. This REALLY tidies the room up! We had studs w/o sheetrock so it was easy to do. Also include an in ceiling HDMI and electrical outlet for your pj. All of the cables and wall plugs can be purchased dirt cheap at monoprice.com and they are very good quality! I used 12 gauge in-wall speaker wire and HDMI 1.4 connectors. All of these connected back to my A/V closet which has a removable panel for easy access from the adjacent unfinished room.

Electrical considerations. Recessed lighting or sconces need to be planned for early. Make sure you get dimmer switches, and you may/may not want remote control access. Also, if you will want any accent lighting (rope light) in a soffit, you will need an outlet or other means of wiring it in. I found that I had plenty of outlets based on required code, but you may want a seperate panel to handle any excess power. This was not a concern for me and hasn't been an issue thus far.

Sound proof insulation. This doesn't really improve the sound of the room, but it does keep the sound IN the room and OUT of the rest of the house. This is rediculously important if you live with anyone else. Beware of air ducts as these will transfer sound. They should get tightly wrapped. I used JohnsManville sound/heat fire-proof insulation in my walls and ceiling, although there are several brands that work great.

Windows and doors: I had three garden windows in my basement (built before scapement windows were required). We framed and sheetrocked around them. Then we placed a 1" board in the opening with styrophone glued to the back. This keeps the windows from vibrating and keeps the neighbors happy. Color matched paint and a simple handle slapped on to the front makes them easily removable for ambient light. If you don't want to go to that extreme, simply use a blackout curtain, although I'm almost positive that my solution was cheaper. Get a solid door. No sense in insulating and using a cheap hollow door for the entry.

Paint and trim: Trim can be expensive, so keep that in mind for the budget. Use dark paint that is flat or matte. The most reflective surface seen from the prime viewing seats in my room (other than the screen) is the RF-82s.

Once you have everything hooked up, THEN look into wall-panels and bass traps. wall-panels can be had fairly cheap on line if you stay monochromatic. More expensive ones can be custom ordered as wall-art.

A few things to consider to improve your theater: Get a second sub. This was a HUGE improvement to the impact of the sound, and with the big room, I'd think you would really want one. Get a 2 or 3 channel power-amp to power the front. This will eleveate the strain on the receiver (which gets super hot anyway) and will really make the front sound stage crisp and clear. Buy an actual screen. The reflective surface will do wonders over the painted screen. I bought my 110" from jamestown for $220.00. Their 130" is only $260.00 and they do build custom sizes. http://www.jamestownhometheaterscreen.com/130_screenDiagonal.html

See my room here if interested: http://community.klipsch.com/forums/t/150426.aspx

[tragusa3]

I highly suggest you visit avsforum.com and browse through the construction thread. Your questions are the focus of that entire forum. Good people.

[cornfedksboy]

I highly suggest you visit avsforum.com and browse through the construction thread. Your questions are the focus of that entire forum. Good people.

You are absolutely correct...but there are SOOOOO many threads! I posted there about six times with questions, and I only got one response. That was after about 4 hours of reading. It's almost too big.

[delhite2]

thanks cornfedksboy,

you mentioned something about un-parallel walls, i mean which side should be narower and by how much,

i.e. should the width be narrower at screen side or seating side, since this is the only possibility.

Also how do i confirm the need for bass traps, and how to figure where to place them.

thanks .

[tragusa3]

you're right, it can be too big...but you can get so much from just reading. I bet I've read for over 1,000 hours!!!