Originally Posted by Doug Blackburn
I debated for a while about posting this, but I just can't let it pass...
The comments about using a $1500 power cord and power conditioning to "improve" a digital video display... I have a very different experience/result. I have been an audiophile since 1970 and a home theater enthusiast starting not long after that. Everything and anything in the analog domain, audio and video, makes a difference... cables, power conditioning, power cords... everything. In digital audio, the same things make a difference (my guess is because music is a continuous playback process in which TIME is very critical and TIME is analog... anything that alters timing in digital audio produces inescapable audible side effects that carry through to the analog output signal).
Then digital video came along and I assumed for several years that all the same things would be just as effective for digital video as they were for analog audio & video and for digital audio. I never really questioned it until around 2006-2007. At that point I was getting some high-end HDMI cables for review and they were all claiming to make big improvements in image quality. Keep in mind that digital video does not (much) rely on accurate timing for much of anything except lip-sync. Digital video is no different than displaying still photos at the rate of 24, or 30 or 60 images per second. And pixel luminance is determined by 1s and 0s in groups of 8, 8 for red, 8 for green and 8 for blue. As I got to thinking about digital video, it became obvious that to "improve" an image in ANY way, the cable (power cord or HDMI cable) would have to change the 1s and 0s in an intelligent way (like a video processor). You couldn't POSSIBLY expect a passive cable to have any effect on the 1s and 0s the TV uses to illuminate each pixel. So I started doing visual comparisons with still and moving images, experimenting with HDMI cables, power cords, and power conditioning with a wide range of video displays (plasma, LCD, and projectors). In EVERY case, it became quite obvious that NO power cord (up to $2500), NO HDMI cable (up to $1000 for 2m), and NO power conditioning made the slightest difference in image quality, either subjectively or measurement-wise. I used many Monoprice HDMI cables (different models from $4 to $12), a free HDMI cable that came with a disc player, and half a dozen aftermarket HDMI cables selling for $50 to $1000. None of them made the SLIGHTEST difference in image quality. I repeated the same thing with power cords ranging from the stock power cord up to $2500 power cords and none of THOSE made the slightest difference in image quality either.
Then I moved-on to power conditioning. I've reviewed (professionally, for magazines) over 90 different power conditioning products since 1995 and collected quite a few over the years, from $30 filters you plug into an empty electrical outlet anywhere to an $8000 conditioner that is magical for music listening and many intermediate price points. I also have the same IsoTek Mira power conditioner mentioned in a previous post (a 2-outlet device with 1 outlet supposedly optimized for digital video, the other for an audio component). I spent the same amount of time trying to find ANY power conditioner that did ANYTHING to change, let alone, improve, image quality of digital video displays and failed completely. None of them did ANYTHING to change digital video for the better or worse. And it makes sense if you think about it. A pixel that is supposed to illuminate at the 75% luminance (50% stimulus) would have to illuminate at some other level in order for the image to be different (better or worse). For that pixel to illuminate at a different level would require a different sequence of 1s and 0s... and it would have to be a DELICATE difference. For example, if the 8-bit word for a pixel is 10101010 and you change it to 00101010... that would make the pixel MUCH MUCH MUCH dimmer... how could power conditioning, an HDMI cable or power cord do THAT? (they couldn't). To make a more subtle change in the image that would be more acceptable, only the least significant digit could be altered... that means 10101010 could be 10101011 or maybe 10101001. Again, there's no "intelligence" in the power cord or HDMI cable or power conditioner that could make a difference like that. In fact, for a digital image to change, you MUST change the 1s and 0s. For analog video to change EVERYTHING and ANYTHING could change the analog input voltage and improving the "quality" of that signal could make a measurable improvement. Digital video is a completely different beast. I do find differences in the sound quality of HDMI cables when playing music and that's the only difference I hear. And all those cable companies that used to tout that their power cord or HDMI cable were great for improving image quality of digital video displays have backed-off their claims. The IsoTek Mira, in spite of IsoTek's or the importer's claims, did zero to change or improve image quality of anything I used it with.
That said, I still use power conditioning with digital video displays... battery backup (pure sine wave output only, cheaper models have NASTY waveforms with huge amounts of distortion) for displays with projection lamps so the lamp is cooled if power goes off, and good active or passive conditioning for other video displays... but not to improve image quality. I use digital video display power conditioning to improve the sound quality for stereo music playback and movie sound. It keeps any noise generated in the video display's switching power supply isolated from other components.
You can change digital video images with the Darbee box, a Radiance processor, an eeColor box, calibration, test/setup discs, and even with the controls on the TV or projector. But in every case, those change the 1s and 0s that define how bright each pixel should be.
So that's my "truth"... everything matters for everything BUT digital video. For digital video, you have to change the 1s and 0s to see (or measure) a difference in images or test patterns.