New theater help needed (1 Viewer)

[drobbins]

This is my first post to this forum. I have been lurking here for weeks and the information provided here has been very helpful in designing and building my home theater. Thank you for all the info. I still have a few questions.
First of all, a description of my theater. I am finishing my basement and the dimensions are 13’ wide by 14’ deep, plus an entryway. I have put in the sub floor, framed out the walls, run all the speaker wires and put up the sheet rock. I have not started the spackling yet. I have already purchased the sound system. A Yamaha 5740 receiver with a JBL SCS160SI 6.1 speaker system is including an 8” subwoofer.
1. I am planning to purchase (thanks to this forum) an Infocus 4805 projector. I already ran a s-video cable for it through the walls and ceiling. After my wife spent 3 hours in BestBuy black Friday checkout line, I found that my receiver does not have a s-video output. Only the standard video output. I can get an adapter. Will the adapter work fine, or should I run new wire? I can take down the sheet rock before I finish the walls to do it, but I would rather not.
2. I also already ran the subwoofer wire using standard speaker wire. Will attaching the RCA plugs to the standard speaker wire work for the LFE connection?
3. The 14’ room depth is a little small. How close can, I sit before I get the “screen-door” effect? Will making the screen size smaller help?
4. I am in fear of the “rainbow” effect. I always have to set my computer monitors refresh rate to 85 hertz so I don’t see the screen flickering. There are no stores with-in 2 hours of home that I can preview any projector. Do you think I will see the rainbow effect?
5. I already own a Sony 12” subwoofer. Is there any advantage to using 2 subwoofers? If not, I would keep the other upstairs with my stereo. The JBL has an 8” facing down and the Sony has a 12” facing forward.
Thank you again for all your help.

 

[Dave Milne]

drobbins,
Welcome and good luck on your project

1. There are no s-video to composite adapters that I know of. Can you run the s-video straight from your DVD to the projector? This could be a simple solution if you use the projector for DVDs almost exclusively (like I do). Otherwise, I would bite the bullet and do a little drywall hacking. But don't do it to to install a composite video cable - that's going backwards! You'll be sorry later when you want to upgrade to RGBHV, DVI or HDMI video connection systems. Instead, install a 2" PVC conduit from your equipment area to the PJ ceiling mount. Then you can upgrade to your heart's content!

2. Don't use standard speaker wire for a line-level subwoofer connection. It will prone to noise and hum pickup. You really need to use coax. Ordinary RG59 or RG6 from Home Depot works fine - just get some crimp- or solder-type RCA connectors for it (Parts Express or Radio Shack sells these if you can't find them at Home Depot). 'Sounds like another reason to do some drywall hacking!

3. DLP projectors, like the 4805, are not prone to "screen door" effects like LCD PJs. Nevertheless, if you get too close, you'll see pixellation - or whatever the DLP term for this is (I'm a CRT PJ kind of guy). 14' is not that bad. At 13' throw distance, your projector can scale the image size from 79 - 95" diagonal. The lower end of this is probably fine.

4. Rainbow effect is not quite the same as flickering. People have varying levels of sensitivity to rainbows. I'm somewhere in the middle: On some DLP setups I can see them; on others I can't. I've never been annoyed to the point that I couldn't watch one, however. I would strongly suggest trying to see one before you buy. Of course, a CRT projector eliminates this problem!

5. Two subwoofers will provide more bass but if they're not in phase and placed in the same location, they can interact in wierd and not-so-wonderful ways. Best just to experiment and stick with what sounds good to you.

 

[drobbins]

Dave,
You gave me the answers that I expected, but didn't want to hear. I was going to start the spackle tonight. Now I think I will back up and do some re-wiring. Maybe I can unscrew the drywall and put it back up. Can you recommend a good CRT projector for under $1500.00?
Thanks for the advise.
Dave Robbins

 

[Dave Milne]

Sorry that you might have some extra work ahead of you, Dave. But at least you caught it before texture and paint

My rule of thumb when building a theater is: prewire everything!
7 channels of speakers (at least)
Conduit to PJ
Power to PJ
Power and screen trigger for motorized screen
Power and trigger for motorized blinds or draperies
Antenna feed
CATV
Satellite
CAT5E (computer, home networking)
Several subwoofer locations
Extra sub (line level and/or speaker level) line to seating area for bass shakers
Power to seating area for motorized/heated seats or reading lights
Multiple lighting circuits (room fill, accents, sconces, rope lights, lighted movie posters, pathway lighting)
etc, etc...

Wire is so cheap compared to having to rip the room up after the fact!

$1500 is at the very low end of CRT projectors. Of course, we're talking used here - new projectors start at about $30K. I bought a new Dwin HD700 a few years ago for just under $20K (with scaler), but I don't think these are available any more. There are a small number of good used machines in the $1-5K range. A lot of CRT guys hang out at the CRT forum of AVSforum.com. You might also want to check out CRT Cinema

 

[drobbins]

Last night I took the sound system for a test run. Turns out that I changed the location of the sub-woofer also. Good thing I used screws to put up the sheet rock. It wasn't much trouble. I ran the new wire today and started on the spackle. All those ideas on prewiring sound great. I don't think my theater will be that elaborate, but you can never tell what the future will bring. Right now I am finishing off my whole basement with a home theater, utility room and hall for under $8,000.00 including equipment and carpeting. Thanks again.

 

[Adam Gregorich]

There are S video adapters available, but I would bypass the reciever and run it direct. If it's not too late I would at least run a component cable as well, or three runs of RG-6. If you aren't sure about the rainbow effect you can buy the 4805 direct from Infocus and return it with in 30 days (w/ a 15% restocking fee). They may have some refurbs that you could try w/o a restocking fee.

 

[Dr. Anthony Rosalia]

We are having a sale on the 4805 for $1299 shipped if you are interested

See this thread for details.
http://www.hometheaterforum.com/htfo...hreadid=218520

 

[drobbins]

Dr. Anthony Rosalia,
I had visited your web site earlier tonight and was planning to call you on Monday. I understand that I could get a 72" screen also? Is this dimension diagonal or horizontal? If it is horizontal, it is the perfect size for me. I am interested.

 

[Dr. Anthony Rosalia]

drrobins:

You have a pm

 

[Brad E]

drobbins, one thing to keep in mind that I haven't seen mentioned yet is sound treatment.

Acoustically speaking, the worst room to have is a cube. Your room is 13' x 14' and you didn't mention what the height was.

When I built my HT, sound treatment was the last thing on my mind. When I finally finished, I could barely contain my excitement while hooking everything up. When I turned it on I could have cried it sounded so terrible.

Good news is that I was able to fix it with some Owens-corning 703. (great stuff by the way).
But if I had to do it again, I would do things quite a bit differently.

Here's a link that can explain it better than I ever could.
www.ethanwiner.com/acoustics.html

 

[drobbins]

Brad,
I have given some thought to the acoustics. I found a "frequency response calculator" excel spreadsheet that addressed some of the issues. I wish I knew where on the net I found it so I cold post the link. Anyway I entered the dimensions of the room L x W x H and it calculated the number of "peaks and nulls" in all the different frequency ranges. I don't really understand fully what they are, but I know they are bad. By using this spread sheet I adjusted designed the dimensions of the room for the best set up. 168" x 149" x 94". I was surprised how much 1" could make a difference! Also I could place the seating in the worksheet and see the results also. This ensured that seats were not located in a trouble area.
You are right though. The room is still just a box in my basement. I test ran my system the other day and the room was filled with echo. There is still not even carpet down yet. I was hoping that carpet and some wall curtains would do the trick. I glanced at the link you posted and it looks like something that I will read & study carefully. Thank you very much for the link. It will make a big impact on the quality of sound I am sure.

 

[Adam Gregorich]

Here is a link to the spreadsheet:

http://www.ultimateavmag.com/news/10388/index.html