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Old 04-14-2008, 10:57 PM   #1 (permalink)
Chromy
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Join Date: Dec 2001
Location: Greater Seattle Area, WA
Chromy's Home Theater -- v4

Well, with all the whining about posting pictures, it occured to me that I've probably changed enough stuff, than rather than to update the old thread, it's time to just create a new one.



Threads on old systems can be found at:
- v1
- v2
- v3



While v3 focused on getting into a bigger room, integrating the screen, front speakers, and subwoofers into the front of the room without it looking ghastly, as well as to be more "responsible" about how the lighting interacts with the screen. v4 continues to refine the system in the existing room. With this version of the theater I've made the following changes
  • Installed some backlighting for the projection screen to improve apparent on-screen contrast.
  • Added Xbox 360/HD-DVD, PS3/Blu-Ray, Tivo Series 3 and a Windows Home Server for media hosting.
  • Added another M&K K7 speaker so that I have 4. Using these mounted on the walls as side and back speakers.
  • Moved the electronics to the back to get rid of the visual distraction.
  • Eliminated the side panels in an effort to move the speakers closer to the screen boundaries.
  • Added the glorious new B&W speakers accross the front.
  • Added acoustical treatement (in a haphazard way) -- Taxi helped, so I blame this on him...


The adventure begins: new front trio
I'm a big fan of having identical speakers accross the front of the room. No matter how well 'timbre-matched' a speaker line is, there are still (very) audible differences as sounds move accross the room. That said, evidently many people don't feel the same way, as it's nigh impossible to find a quality set of LCR (Left, Center, or Right).

I listened to a multitude of speakers in my price range (< $800 each) and the B&W 600 series fit the bill perfectly. I was able to get a local shop to hook up 2 HTM61 speakers for me to listen to and I was sold.

In the image below, you can see that I've re-configured the front of the room a bit. Screen has been raised up a bit, to get the speakers closer to ear level (wishing I had an acoustically transparent screen now). I'm using ghetto speaker stands now (thanks Ikea), till I can re-build the front of the room to hold the speakers.


Backing up a bit
Below is a shot from the back of the theater. Speaker grills are on, room lights are up full, and the Tivo is playing some music over the network. Firehawk screen has fairly good ambient light rejection, and you can see how the lights have been positioned so that they illuminate the floor, but barely hit the walls or screen.



Speaker dance
With the addition of a 4th speaker, the M&K speakers were moved from front and center to surround side and back duty. Paradigm bi-polar towers were moved out. This freed up some floor space. It's amazing how much wider the room felt without these behemoths next to the seating position. I'm able to run 6.1 and 7.1 surround mixes now. With 21 mid & high frequency drivers in the room, the room seemed bright, so I focused on tuning/equalizing my dual SVS subwoofers and eventually added another subwoofer (built around a 12" NHT driver I had sitting around). I was able to push an insane amount of volume in the room, but it just sounded... annoying...

Argh! Everything is so loud!
Everything should sound great, but it didn't. What was going on here? You mean besides the fact that you could clap your hands in the room and listen to it reflect aroud for 1/2 a second? I figgured that my problem was acoustical. After researching different options available, and deciding that everything was WAY to expensive (especially with a baby on the way, and having just dropped 2k on LCR speakers) I decided on accoustical foam. Auralex (and probably others) are starting to make "designer" foam (DST-112 and DST-114). I picked up a few 'kits' of this from a local guitar/keyboards store along with a box of 2" 'Wedges' and installed this on the walls and ceiling.

In the picture below, you can see how I structured the kits on the wall to create 'theateresque' patterns and designs.



Now I had a problem with bass...

Without the subwoofers on, there was too much bass in the room. A drawback to foam (and really, anthing that's thin) is that it doesn't absorb low frequencies. I had lost about 6db of reflections in the highs and mid frequencies with no attenuation in the bass frequencies. This resulted in the room sounding very muddy. There is one way to correct this... add more accoustical treatment.

After some research on the internet I found a few ways to do this. Thicker/solid open cell foam suspended out in the room can help absorb bass. I went down to a local crafts shop and picked up a 2'x9' sheet of 5" foam and mounted it 1/2 of the way between the floor and ceiling, back behind the screen. Because the screen sits on an acoustically transparent wall 18" away from the front wall of the room, this gave me 5" of foam, sitting 18" out in the room. This helped a lot, but still wasn't what I was expecting...

Bass traps

Bass is especially effective at gathering and reflecting from the corners of rooms. You can avoid this by putting something in the corners of the room that absorbes sound. I bought some batts of rockwool, and cut them in 1/2 to create squares, and then into 1/4 to create triangles. I stacked these in the front corners from the floor to ceiling, and then sealed them with 2' x 9' frames, wrapped with burlap on both sides, and filled with more rockwool. Bass is now tight and controlled.

In the picture below, you can see the bass trap standing up in the corner behind the right speaker.



Lighting
I had added can lights (with polished black aluminum inserts) that as you can see in the pictures are very directional... they do a great job of lighting up the floor and not much else. However, I've always been a fan of backlighting and decided to give it a spin with the home theater. To accomplish this, I mounted LED light bars behind the screen, so that the light spills out around the edges of the screen. This keeps the iris in your eye clamped down a bit more, and results in less fatigue when watching for long hours at a time.

In the picture below you can see the projector doing 'black' with no room lights, with the backlighting on. It was a challenge to keep the backlighting from coming through the back of the screen.


Here is a shot from the back of the room with a movie playing...



Back of the room
Added a media shelf in the back of the room, and moved the equipment back there. Here is a wide shot of the room from the screen looking back.
http://forums.dvdfile.com/attachment...-v4-back-1.jpg

I ditched the last rack that I made, are re-purposed some spare parts I had laying around to build a flexi-rack to hold my gear. HD-DVD player is borrowed from a guy at work, and PS3 is hanging out in the bedroom till it goes back to him.





Equipment List

Electronics
Receiver: B&K AVR 307
DVD: Denon 2900
Blu Ray: PS3
HD-DVD: Xbox 360
Projector: Dwin TransVision 3
Screen: 92" Stewart Firehawk
DVR: Tivo Series 3 (x2, networked)
Subwoofer Amp: PV-4C
Subwoofer Compressor: dbx 266XL

Speakers
Left/Right/Center: B&W HTM 61 (x3)
Surround Side/Surround Back: M&K K7 (x4)
Subwoofers: SVS 25-31 CS (x2), Custom enclosure w NHT 1259 12" sub driver.




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I'm like a lightbulb... without a continual input of fresh power, I grow dim

My Home Theater!

Last edited by Chromy : 04-15-2008 at 12:36 AM.
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