Originally Posted by GEP
The sub-frame system is the way the DLP chip works and not unique to Mitsubishi. It is the design of the chip by Texas Instruments. It provides for a very smooth picture with little to no visible pixel structure and a smaller, less expensive chip that only requires ½ the number of mirrors.
Thanks GEP, excellent info!
I believe this technique is also referred to as "wobulation". Some more info here:http://en.wikipedia.org/wiki/Wobulation
I think this technique works well in practice, and doesn't have the same downsides as traditional interlacing. However I also think it is misleading for Mitsubishi to advertise this as if it is a feature, i.e. "Smooth120". I fell for it myself. When I saw 120Hz in the specs, I assumed that this was a 120Hz TV. It really isn't. I'm pretty sure it still has to apply 3:2 pulldown for 24p content.
I just got my 73640 today, and here are some observations. Overall I have mixed feelings about it. On the upside, it does have a nice picture, and in terms of bang-for-the-buck it can't be beat. However, my impression is that this TV was specifically engineered to give maximum screen inches per dollar, so quality and features were sacrificed to achieve that design goal.
Cost cutting measures:
- Remote is very basic, only controls TV, no backlight. Get a Harmony.
- TV has very limited input and output connections.
- Built-in speakers are not very good.
- Screen mounting mechanism is crap.
I think most of the screen issues that have been discussed in this thread are due to a poor design, not the fault of the delivery guys. Looking at my screen, there is uneven spacing between the bezel and screen along the sides and top. If I push on edge of the screen with my finger, it deflects very easily and is not securely attached to the bezel. There is enough inconsistency on the right edge that image distortion is noticeable. Tightening the screws on the back of the bezel will not correct this problem. I peeked inside and it is constructed like this:
1) Screen is attached to the bezel via internal screws. There are internal mounting strips (for lack of a better word) which are screwed into the back of the bezel, sandwiching the screen between the strips and the bezel.
2) The bezel is then attached to the frame via the externally accessible screws. These screws only attach the bezel to the frame of TV, and do not secure the screen to the bezel.
The source of the problem is item 1. The screen is not secured tightly or uniformly between the mounting strips and bezel.
For comparison, I also have a JVC LCoS RPTV. On that TV, the screen is much more rigid, and is perfectly attached to the bezel with no gaps or distortions. It is obviously a higher quality screen assembly. Granted the JVC cost twice what the Mitsubishi did, but in my opinion there still no excuse for such a poor screen mounting design in the Mitsubishi. In my case it does cause some distortion of the picture. In my case it's fairly minor, and some people wouldn't notice it, but it's definitely there.
I'm also disappointed with the quality of the built-in speakers. One advantage of a thick TV like this is that there is room for decent speakers. In comparison, my old JVC has much better audio quality. Mitsubishi also complicates the ability to add external speakers by only providing a coax digital audio out. No analog or optical audio out. You have to upgrade all the way to the 840 series to get analog audio outputs.
My TV has a build date of Nov 2011, and came with firmware ver 13.04, which is the latest version at this time.
There is a problem with handling of Dolby Digital audio on the HDMI inputs. I have a Tivo HD connected directly via HDMI. Whenever I change channels, and often when I pause or fast forward, I get a brief static-like noise in the audio. Changing the Tivo to output PCM instead of Dolby Digital cures the problem. I've never had this issue with any other TV.
Power consumption is good for a TV of this size, but not quite as good as I expected. With the lamp set to the normal 156 watt mode, my TV draws about 206 watts, so the non-lamp parts of the TV draw about 50 watts. Note also that it continues to draw 25 watts or so for about 10 min after you turn it off, even after the lamp and fans are off. Not sure what it's doing. It eventually settles down to 1 watt at idle.
Fan noise is much less than on my JVC. I think very few people will find it objectionable.
Black level is noticeably better than on my old JVC. Otherwise I don't think there's a huge difference in PQ. I didn't compare side-by side though.
This TV sucks a a computer monitor, as probably all RPTVs do. There is lots of overscan, so the edges of the PC screen get cut off, unless you switch to PC mode which scales the image down. The geometry imperfections are noticeable, and text is not very sharp. Suffice it to say that if you want to use your TV as a computer monitor very often, then you are probably better off with an LCD.
I don't mean to be too negative here. I do still think this is a good TV, and a very good one for the money. There is no "perfect" TV technology. I just think Mitsubishi cut a few too many corners on quality. Personally I would have been happier if it cost a little more but had better speakers and screen mounting.