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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 2013, 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 2009) 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 1080i and 720p from all sources, as scaled by the excellent Realta XT in the Denon preamp via an HDMI 1.3a link.

How does one get a 14+ year old CRT to have HDMI inputs? Well, a Gentleman in Taiwan named Moome makes some awesome cards for these projectors, and his latest versions include Gamma controls, which really give one the ability to fine-tune the image.

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

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.


2010 Note: While the HTPC functions are 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.

With full Digital audio links via HDMI to the preamp, this is now able to deliver pretty good audio and video experience. But in terms of convenience, the dedicated hardware is better.

The Radeon 5750 video card I use is one of the first to support multichannel PCM over HDMI as well as full support for bitstreamed codecs like DoblyTrueHD and DTS-MA.

Software used is:

Windows7 Ultimate (w/MCE)
FooBar 2000  - for music

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. So after few years 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:

Cover Hush box

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. 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:

Fan and Variac

And finally, here is a rear view of it. Note how it straddles the Dais and provides a convenient 'table' for the sofa.

Rear view of HushBox

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 11 years.

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

Ceiling projector Box


G70Sony G70 CRT

Video Diagram

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