Jonathan's Toys

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. 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 timings. 

At first, my preference was to go with a digital projector. DLP technology seemed like a better value, although D-ILA did seem to have many advantages.

I decided to go with the Sharp Notevision7 in early 2000, this was fine for a while. But the lack of deep blacks and saturated colors kept me wishing for something better. I had stayed away from CRT's initially due to high cost (> $15K for anything decent) and complexity. However, by late 2001 used CRTs in good condition were priced right (< $7K), so I decided to give them a try.
Boy was I surprised! The improvement in quality was just astounding. True blacks, perfect color and saturation, high-rez (1600x1200) and selectable refresh rates.

I wound up with a Sony G70Q, a unit that had retailed for $20K a few years ago. 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 2007) digitals have come a long way, I still have no burning desire to swap out the CRT, it's that good.

HDTV from satellite is eye-popping good. Music concerts on HDNet (usually accompanied by a DD 5.1 soundtrack) are impressive...

I drive the G70 with a Home Theater PC (HTPC) for DVD playback. Using the power of its ATI Radeon video card, I run it at a resolution of 1440x960. This works out to a perfect 2x factor of the native DVD image data. The refresh rate is set at 72Hz, which is a perfect 3x multiple of the 24 Fps of film sources. However, best results on film are obtained by using a 48hz refresh, a 2x multiple of film rate. While it might seem the screen flickers more, it's not noticeable during movies, and color is improved due to longer retrace timings energizing the phosphors more on each pass. Fewer motion artifacts is another plus.

As for where to project, I went with a front projection 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.

To handle widescreen movies, I keep several memories in the PJ, some for 4x3 and others for anamorphic 16:9 (squeezing vSize).
I figured that if the G70 max V resolution is 1200 lines, then a squeezed 960 is actually at (or slight above) the max resolvable resolution for the raster and phosphor.
I preferred to make the PJ do the anamorphic compression rather than let the DVD software play bit games (and introduce errors) even if I could run a higher rez such as 1080.

 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).

Further video source selection is done via a JVC-S700 IR controllable S-Video switcher. this feds the S-Video input of the H3D card in the HTPC for scaling.

I recently added a Moome DVI-D input card with HDCP to the G70 so I could hook up the HD-DVD and the new HD DVR's. this card has two inputs, a component input (now fed from the HD TiVo) and a DVI-D. The DVI is fed from the outputs of the Monoprice 5x1 HDMI switcher via a 35' HDMI to DVI cable. This works really nice, as I now can switch up to 5 HDMI's, one component and two RGB (via the Altinex) video inputs into the PJ. So far, this accommodates all the sources in the rig

HTPC

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 7 - for DVD and DivX file playback
Immersive H3D scaler + ffdshow - for scaling SD video

Hush Box

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 massive amount of heat my computers, 15 channels of amps and sixteen other pieces of audio gear generate in addition to 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 5 years.

Here’s a pic of the old digital in the ceiling mount (which is right behind / over the couch):

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