Film-Tech Forum ARCHIVE: Sound setup questions

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Posted by Paul Looker (Member # 5420) on 04-24-2014, 01:19 PM:

Sometimes I get embarrassed when I post the details of our setup, this being 2014 and all. This is one of those times, but hopefully someone can help me make it better. We are dealing with our last two film projectors. I have a red light reader that puts out two pairs of wires labeled left and right (lt, rt which I assume is left and right). They run to our ultra stereo processor and take up two of the four inputs lt and rt again. Lt and rt on input 1. There is also a pair of inputs for lt and rt 2. Outputs from this processor include left center right and sub. What channels of output are even available coming in from that lt and rt from the reader? I'll try and give more information if needed but I'll need to know what else you would need to know.

And just as an aside so you know what I'm hoping to do here. I've got these awesome sounding digital houses but I still have to open the biggest movies on film because they are available on film and we need to save the digital houses for the stuff that isn't. People are starting to get unhappy about the difference in sound quality now that they have had a taste of something better. Since it is going to be at least a couple of months before we can convert these last two houses I was hoping to at least get some better sound in there. At the moment the surround speakers up on the left and right walls do nothing. There is one speaker behind the screen for the center channel output on this processor. I'm hoping to get left and right up on the wall and put in the sub but are all of these channels even coming in from the red light reader?

Posted by Steve Moore (Member # 4753) on 04-24-2014, 02:35 PM:

The left and right from the reader is yes left and right.

The ultra stereo should (assuming in is working and model dependent) decode left, centre, right, and a mono surround from the left and right input (and maybe a LFE subwoofer output too if it has that ability).

If the processor has never been aligned it may give you some mis-balanced sound, so to speak, but then again it might sound better than just centre (which is what i think you mean you currently have)??

Perhaps you could provide more detail? Processor model and if you have amps etc?

Posted by Monte L Fullmer (Member # 2797) on 04-24-2014, 03:33 PM:

Sounds like you have a USL JS-95/195 unit

Maybe we can point towards the source than the target, being: that the optics are getting bad, which is a common occurrence to reverse scan LED units.

The LED array has either one or two rows of LEDS in which each row contains a good dozen of single LEDS in the one string. What happens is that one or more LED's in the string could be dying, or have died across the string.

When this happens, it's not getting all of the sound track information sent to the pickup camera, thus sound quality suffers.

An easy way to check: grab a chunk of black film, preferably from a leader, fold it in half where the two halves each contains a black frame.

Hold this film against the LED array as it's illuminating and you can safely see the LED array through the black frames and the individual LEDs in each or the single string.

If you see some dark areas - like burnt out LED(s) - in the string, the entire LED array needs to be replaced.

If all is normal, then a service tech needs to come out and give your location a thorough "tune-up".

-Good luck .. Monte