CurtPalme.com Home Theater Forum

km987654 · Posted: Fri May 02, 2008 10:17 am Post subject: RGB Bandwidth

Two projectors both capable of the same resolution but one has a higher RGB bandwidth. Is there a visible difference in image quality?

Thanks

KM

kschmit2 · Posted: Fri May 02, 2008 11:11 am Post subject:

if the bandwidth difference is real and not just in the specs then the PJ with higher bandwidth should be better (all else being equal, i.e. same source, resolution, refresh rate, tubes)

Person99 · Joined: 09 Mar 2006 Posts: 4899 Location: Flower Mound, TX

Higher bandwidth is always better (if true bandwidth as was said). If the difference in bandwidth is minor though, you may not notice the increase as other factors come into play also.

**kal** · Posted: Fri May 02, 2008 7:50 pm Post subject:

If you feed both projectors a signal that is lower in bandwidth than the bandwidth of both machines then not so much, otherwise yes.

Kal

Person99 · Joined: 09 Mar 2006 Posts: 4899 Location: Flower Mound, TX

ecrabb · Posted: Fri May 02, 2008 8:27 pm Post subject:

Yeah, Dave, but Kal said if you feed both projectors a signal that is LOWER in bandwidth, then "not so much". As in, if the signal is below rated bandwidth, you probably won't be able to actually tell the difference. For instance, you might need to measuring equipment to tell the difference, or other factors will contributed more to any softening than bandwidth alone: lenses, setup, focus, wear, etc.

What happened to that guy, anyway? Chiem, was it? Did he just move on to other projects or did something happen to him? He was just going nuts with all things CRT - electronics, optics... then POOF! Gone.

SC

Person99 · Joined: 09 Mar 2006 Posts: 4899 Location: Flower Mound, TX

km987654 · Posted: Sat May 03, 2008 3:19 am Post subject:

Thanks for the responses. It seems that greater bandwidth is better in any circumstance from a technical perspective. I am really interested in real world performance i.e will you see the difference. In the computer world more bandwidth for say a network connection means more data transfer in any given time and this is noticable in real world terms. Anyway I intend to substitute parts in my PJ for increased bandwidth based on your responses.

secstate · Joined: 20 Mar 2006 Posts: 720

I have used both the 75 MHz Barco neckboards and 120 MHz Barco neckboards in my Barco Data 808s with P16 tubes and the difference was so small at 1080i and 720p, I could only tell near the screen with test patterns. At normal viewing distance and/or video I could see NO difference. The only difference I could see on video was the small amount of banding from bright objects on nearly black backgrounds that is common to the 75 MHz boards. I had a raster flickering problem with the 120 MHz neckboards so I went back to the 75 MHz and given the small difference in quality have not bothered to get to the bottom of the raster flickering (I think it might be related to the splitter).

stefuel · Posted: Sun May 04, 2008 6:57 pm Post subject:

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

Do they twist speaker wire the "other" way down under? Shocked

**AnalogRocks** · Posted: Sun May 04, 2008 7:09 pm Post subject:

Gino · Posted: Tue May 06, 2008 2:19 am Post subject:

I agree with Dave, 'excess' bandwidth is a good thing. It plays into other factors, sharpness, background details, intrascene contrast and colours. If you only notice a small difference, it's because there are other factors which are weaker in your chain, ie. tubes, sources, lens, focus yokes etc...

deronmoped · Joined: 03 Nov 2006 Posts: 1154 Location: San Diego

Out of all the things I changed and messed with, it's the one thing that is out of our control that makes the biggest difference, the source material. I found this to be true back in the 70's with records, tapes and it's still the same now with DVD's and CD's.

Deron.