Video
With a totally dedicated and light managed
room (no windows), the
home theater features a front projection system. The screen is a
100" diagonal (80"x60")
Stewart Studiotek 130 THX Microperf (acoustically transparent)
fixed screen. Firing onto this is a
Sony G70 CRT projector.
OK, it's 2009, why a CRT?
Well, I tried digitals when I first built the theater in 2000,
but was horribly disappointed at the price/performance of the units
of that time.
So I looked at CRT as an option, and sure enough, in mid-2000, some
high-quality used CRT's were appearing on the market at reasonable
prices.
I wound up with a
Sony G70Q, a unit that had retailed for $18K
in '98.
Got a nice low-hours (600+hrs) used one from a local contact who was
nice enough to come to my place and do initial setup.
Once these devices are well focused and converged. The resulting
image is outstanding. And while modern (circa 2008) digitals have
come a long way, I still have no burning desire to swap out the CRT,
it's that good.
The CRT is run at 1440x960 @48Hz from
the HTPC for movies and at 1400x1050@60hz for standard def sources.
For the HD sources, it runs standard
1080i@60hz and 720p timings via
the HDMI link.
HDTV from BluRay and satellite is eye-popping good. Music concerts on HDNet
(usually accompanied by a DD 5.1 soundtrack) are impressive...
As for where to project, I went with a professional 100"
diagonal 4:3 screen in a fixed mount configuration. I selected the
Stewart Filmscreen
Studiotek 130 Microperf. The microperf is key, since I need an
acoustically transparent screen to allow the massive Martin Logan
SL3XC center to play through
it.
The fact that it's a 4:3 screen reflects that I bought it in
2000, when most of the content I watched was 4:3 from the Satellite
DVRs.
Now that most things are 16:9, there is some 'unused' screen, but
it's not objectionable.
A 16:9 screen is still not practical due to the big center back
there
There is an
Altinex DA1916SX switcher to handle splitting the video so I can
have an extra CRT monitor in the equipment room when I want to
preview or adjust things and not turn on the big PJ (or have to run
back and forth).
In the main room, I also have a 21.5" 16:9 LCD monitor plugged
into the second HDMI output of the Denon AVP so I also don't have to
fire up the CRT just to see the menus and GUI feedback from the
preamp.
There is a Moome
HDMI
input card with HDCP installed in the G70 so I could hook up the
high definition sources. With the Denon AVP providing all the
switching and scaling duties, it's a great way to extend the life of
this awesome projector.
2009 Note: While the HTPC is still around, it's rarely used for
DVD playback or for scaling. Since the Denon AVP's scaler is much
superior, and has an HDMI link to the PJ, much of what the HTPC did
is moot.
I still time-shift DVD's on it, plus for watching a 4:3 formatted
DVD, this is the box to play it on and get full resolution.
A Home Theater PC is a computer dedicated to providing video
source services in the HT. The primary use is to provide DVD
playback that maintains the video signal totally in the digital
domain. Any video manipulation, such as scaling, doubling, etc. can
be accomplished with the original digital data stream, thus reducing
any potential artifacts and maintaining color purity.
An HTPC can also be equipped with various signal tuners (ATSC or
NTSC TV) and video capture devices to enable the PC to act as the
'TV tuner". Some cards enable a Digital VCR type function, where the
incoming video is recorded to the PCs hard drive.
Some cards enable S-Video input up-scaling. In my case, I use an
Immersive Holo3DGraph hardware and software to de-interlace and
scale video sources.
The H3D is able to take component, S-Video or DVI inputs and
de-interlace them with its Faroudja processor before the video card
scales the resulting image for the projector. The results are the
very best achievable with a PC, reaching true >$2K dedicated scaler
performance.
Combine with additional
FFDshow
processing (noise reduction and / or smoothing), the resulting image
quality, even blowing up so-so SD DirectTV signals to 100" is quite
impressive. The Faroudja scaling in the H3D make a huge difference.
Most HTPC systems will also feature a digital audio output from
their sound cards to feed the main audio system. This enables them
to feed Dolby Digital 5.1 or DTS 5.1 signals to the surround
processor. Since most sound cards also have sophisticated audio
processing chips and software, there are many audio processing
tricks an HTPC can perform. Equalization is the least of them.
The audio is sent to the surround process via SPDIF coaxial out from
the Asus MoBo. This board also features Dolby Digital
encoding; therefore,
multichannel sources in WM9 can be encoded and sent to the
Meridian in digital quality for
further processing.
The current configuration is designed to handle WM9 High
Definition sources, such as the HD content on the T2 Extreme DVD. It
sure takes a lot of horsepower to do it, but this config runs
glitch-free through the entire movie.
Current HTPC configuration
The HTPC is driving the highly flexible
Sony G70 CRT projector,
providing it with various output resolutions and frequencies to best
match the source material. Currently configured resolutions are:
- 1440x960@72hz for DVDs. This is 2x size of
DVD native rez (720x480) and 3x frame rate of film based sources
- 1440x960@48hz for DVDs. This is 2x the
frame rate of film sources. Provides real theater like
experience. Deeper color saturation as well due to longer
retrace timings, the CRT phosphor is energized more on each
pass.
- 1080i and 540P @ 60hz. This matches the
output of the HR20 HD-DVR and the HiDef DirecTiVo tuners as well
as the HD-DVD Toshiba HD-A1.
- 1440x1050@60Hz for H3D scaled output from
the SD DirecTivo, S-VHS, Laserdisc and other video sources.
I built my HTPC with the following configuration :
ASUS A7N8X nForce2 Ultra 400, 8x AGP
SPDIF coax out driving processor (for Soundstorm 6ch to DolbyDigital
Athlon XP 3.2Ghz
512MB DDR-3700 RAM
38GB (10K RPM) / 200GB SATA drives
80 GB / 120 GB Ultra-133 drives
ATI Radeon 9600XT, 8x AGP video
Pioneer slot load DVD
M-Audio Audiophile sound card (for music and Movie soundtracks)
Dlink 100MB Ethernet PCI card
Antec P180 case and Antec TruePower IIPS
Wireless keyboard/mouse combo
Software used is:
Windows XP SP2
FooBar 2000 with Bacon visualization plug-in and MilkDrop visualizer
- for music
WindDVD 8 - for DVD and DivX file playback
Immersive H3D scaler + ffdshow - for scaling SD video
Hush boxes are a big part of a successful CRT deployment. They
really add to the enjoyment of the awesome images CRT’s put out by
quieting down the fan noise.
I ran my CRT for a year or so without a hush box and man, the noise
was distracting. I could play over it no problem, but during quiet
passages, it made itself known.
My Sony G70 PJ is floor mounted, as I assumed it would be only there
for three years or less, as digitals allegedly were getting better.
Now, almost five years later, digitals are still not quite there
(the Sony Ruby comes close though). So a few years ago I decided a
hush box was really needed, so the design had to incorporate several
goals:
Not be too large, or at least not look big.
Interesting design, no rectangular box thanks.
Do double duty as the foot rest and remote stand in front of the
couch.
The design features a two part construction to simplify deployment
and to break-up the surfaces. The first half is a bench-like element
in front of the couch with a nice flat surface for putting remotes
or your feet on. The surface facing the couch is sloped away from
the couch to give extra foot room.
The main element that covers most of the PJ is a bit more boxy, but
uses a partially sloping top to break up the big flat surface.
Rounded corners at the front also look better than sharp edges.
The two parts are joined together with a tongue-in-groove type
affair where the foot rest component has edges the slide into the
front box. This effectively seals the airflow.
The interior of the box is lined with fiberglass panels for sound
absorption.
The exterior is finished as follows:
- Top is natural black leather
- Sides are ultrasuede fabric designed for furniture
Airflow is managed by having an 8” AC voltage Patriot fan pull air
out of the box on the side of the footrest box that faces away from
the main theater and entrance. I toyed with ideas for dumping the
air out the bottom to the crawl space under the room, but since
that’s also the ‘rear’ wave of the infinite baffle, I figured not
such a good idea. Plus, this helps negate the need for heating the
room in the winter
The summer is another deal, but then the AC runs regularly in the HT
zone, so no sweat (literally).
All of the above words are useless without pics, so here ya go:
The performance is very good. From a sound perspective, it pretty
much made the PJ silent. There is a bit of noise escaping the front
of the box, and the fan generates a small, but audible in total
silence, bit of noise as well.
I found that once the leather and fabric were applied, the box
itself was more damped.
I’m fully satisfied that given the amount of air I need to move,
this is as quiet as I can get without dumping the air under-floor.
As for cooling, as long as the fan speed is set correctly for the
ambient in the room (lower speed in winter), then it has no problem.
Now that it’s regularly in the 90’s outside and the ambient is kept
at 77 in the HT, the fan speed is high enough that wind noise is 2
to 3 db louder than the winter setting. But still very low.
The interior of the box is baffled to route air to the side of the
G70 that has the exhaust vent so I ensure I’m pulling all the hot
air out.
BTW- The AC fan controlled with a
Variac is a wonderful thing. Nice and quiet electrically and
physically. Triac based fan speed controllers are crap to put close
to a CRT.
Plus it’s appropriately ‘old school’ to use a 1940’s tech such as
the Variac with a CRT
Here is a shot of the unit standing on its side, with view of Fan
and Variac from the inside. Also note the lip that goes into the
front part of the box:
And finally, here is a rear view of it. Note how it straddles the
Dais and provides a convenient 'table' for the sofa.
Heat removal thoughts
What to do with the heat from the hush box? Well, there are two
schools of thought:
1- Get the heat out of the room at all costs
2- Dump the heat into the room and let the zone deal with it.
The one thing adherence to #1 requires is to not dump it outside the
house, as it forces the overall AC system to deal with fresh, hot,
humid air coming in to the house to replace the air you are pumping
out. That’s not efficient.
So in either case, your overall AC system is going to have to deal
with the heat. Now the question is: can the zone in the HT handle
that much heat?
In my case, for the CRT, I decided that yes, it could. My system has
a dedicated zone off of a 5 ton unit and keeps up very well with the
room and the G70.
Plus in the winter, it warms the room nicely. The heater doesn’t
have to run. But after a few hours, the AC does. It’s pretty funny
to have the AC run while it’s in the 40’s outside.
I actually subscribe to both camps, as in the ceiling mount for the
digital PJ, I ducted the air extractor into an adjoining hall. But
then, I haven’t had a digital in 9 years.
Here’s a pic of the old digital in the ceiling mount (which is right
behind / over the couch):
