Film-Tech Forum ARCHIVE: Static Sound (DTS?)

This is topic Static Sound (DTS?) in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=007485

Posted by Richard Edward Wells III (Member # 2990) on 10-01-2005, 01:26 PM:

I have have sooo many problems with sound in this booth. We are running on the new DTS units (XD10P) and for many of the projectors, when they run on analog sound, they have a really poor quality sound with scratching and static. I have tried cleaning the optics and LEDs.. and it seems to do nothing. Is there a problem with the readers, LEDs, or the analog component on the DTS?

Posted by Mike Babb (Member # 1379) on 10-01-2005, 01:42 PM:

Check for scratches on the analog soundtracks of the film.

Posted by Gordon McLeod (Member # 33) on 10-01-2005, 01:50 PM:

Sounds like either the A chain alignments or damaged film

Posted by Richard Edward Wells III (Member # 2990) on 10-01-2005, 02:06 PM:

but its projector specific... only theaters 8,9, and sometimes 10 have that sound problem

Posted by Adam Martin (Member # 641) on 10-01-2005, 02:37 PM:

This could also be a loose connection anywhere between the solar cell and the amps. Please list the other equipment involved.

Posted by Michael Schaffer (Member # 1204) on 10-01-2005, 02:58 PM:

Or - worn sound drum bearings or belts. These problems can cause a constant background shifting, crackling sound.

Since you have the still fairly new XD10Ps, the installation apparently isn't that old. There isn't that much field experience with the unit yet. I took part in the beta testing and it worked very nicely. Still, if this is not a mechanical or alignment problem, you should contact DTS. But they too will want to know if the A chain has been properly aligned. So, if you don't have the tools to do so, you should call in a technician. Even if the problem turns out to be the sound drum bearings, it would be better if you had somebody there with the equipment and knowledge required for A chains. With many machines, you have to take the LED bracket off to gain access to the inner life of the sound drum. Even though you can "earball" the positioning of the LED when you have the Cat.No.69T loop, it is not a good idea.

Posted by Richard Edward Wells III (Member # 2990) on 10-01-2005, 02:58 PM:

Well, we use Simplex 5 Star Soundheads, and QSC DCA amps

oh, and Paul Curro says "hi" from the Roxy 11 in Camarillo

Posted by Andy Summers (Member # 3207) on 10-01-2005, 04:05 PM:

Yeah I noticed this poor quality from the “ODEON Westover Road Screen # 1 Bournemouth, they have the new “DTS XD10Ps” with there poor loudspeakers placed behind the screen ALTEC A4 what a joke and the poor frequency response and range with “Batman Beings” was sickening to listen too, with a scratch high sound always popping in and out the whole duration of the film.

I won’t be going there again, there behind the times…. [puke]

I mean whats wrong with the older DTS models…

Posted by Brad Miller (Member # 2) on 10-01-2005, 04:18 PM:

Andy, it wasn't the XD10 that caused the problem. They could've put a Dolby Digital or SDDS player in that same auditorium and had the same poor quality sound. Now you figure the rest of it out.

Richard, what kind of sound processor are you using and what kind of red led is in the soundheads?

Posted by Richard Edward Wells III (Member # 2990) on 10-01-2005, 04:52 PM:

Its the XD10P processor, and a red L.E.D. light source

Posted by Brad Miller (Member # 2) on 10-01-2005, 04:54 PM:

An XD10 is not the processor. Also we KNOW it's a red led. What BRAND and/or model is it?

Posted by Andy Summers (Member # 3207) on 10-01-2005, 05:00 PM:

What about a defect in part of the design packaging, does all the parts come from different manufactures, maybe the fault can be traced back to where it original came from.

I like to rule out the possibility of “Electrical Gremlins” though sometimes they do get in and tracing it to the source can be tricky… [Roll Eyes]

Posted by Michael Schaffer (Member # 1204) on 10-01-2005, 05:50 PM:

I would say if you have really crappy speakers like you said, maybe ("wild guess") that may have something to do with the crappy sound you are experiencing?

Like I said, I haven't worked extensively enough with the XD10P - the new analog (though internally digital) processor DTS developed together with UltaStereo, and which is also available from USL - to form a solid opinion, but my first impressions so far have been very good. We also used it in an open air cinema installation at the San Diego County Fair. Obviously, open air does not give you a realistic idea of sound quality. But we set up a huge playback chain (all QSC components, QSControl.net, DCA series amps, and cinema speakers) and blasted the venue with tons of sound at very high levels, and the XD10P performed very well, with basically no audible distortion even at very high playback levels. It also ran for many months in a regular cinema installation with no problems. I like it. It is a nice well designed unit, quick and easy to set up, not the most versatile processor out there, but with all the options you need for a normal cinema installation.

Posted by Richard Edward Wells III (Member # 2990) on 10-01-2005, 05:53 PM:

the XD10P is the processor, we have the XD10 unit as well, but the other is the processor.. its supposed to be "brand new" But the LED reader only says "Cinequip" on it, if that helps at all..

The digital sounds fine, though... it sounds great, actually, but when it plays in stereo (in a few of our theaters) it is terrible

Posted by Michael Schaffer (Member # 1204) on 10-01-2005, 06:07 PM:

One thing you can do right now to check if there are any problems with the preamplifier is to move the optical input from projector 1 to projector 2 on the back panel, then jumper "c/o" to "common" right next to the automation input to change over to projector 2 input. This would be for testing only since you would need to set slit loss and level for that input. If you have at least the Dolby tone loop, the setup software and the authorization to work on the unit, then you could simply copy the slit loss value from input 1 and set the analog level with the level test film.
But just to test if there are any problems with the optical preamp for input 1 - not to play shows on it -, follow the simple steps above. The sound will be a bit more muffled and possibly low, but you will be able to test if you still have the same nasty noise.
Also check if the wires are all connected properly to the processor. Breakout boards with terminal boards into which you wire the optical sound wiring are fairly common these days. I have found that if the wiring is not connected propely or the connector is not sitting nicely on the input, you can have such problems too.

Posted by Mark Gulbrandsen (Member # 72) on 10-01-2005, 06:20 PM:

The XD-10P is similar to the new USL processor and in fact is made for DTS by USL. We have little experience with the new JSD 80 because its muting scheme is not interfacing well with the fire alarm systems that the local contractors are installing in new builds. The unit goes into mute but touching any format button tales it back out of mute and the inspectors in this area will not allow that sort of scheme. We have one or two of them installed so far and no major problems to report..... other than the analog section just isn't very good. To me analog is as important as digital!!

Mark

Posted by Steve Guttag (Member # 268) on 10-01-2005, 09:10 PM:

If you've got an A-4 that sounds bad, then you have an A-4 that doesn't have proper parts or is not kept up in the slightest. The frequency response is easily 40Hz - 16KHz and is one of the better sounding speakers out there (subject to your own opinion, for sure). However, they are still used in many high-profile venues and doing just fine, even in the digital era. I'll put an A-4 up against ANY speaker made today in a large venue (or an A-5 in a medium venue).