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Hi new here. I am a technician in a small cinema we use barco dp2k-6e projector and proyecson pdac11 we have a simple stereo system and not a 5.1 system we mix 5.1 output to stereo but I have a problem with the speech clarity the effects and other sounds sound just fine but the vocals are all muffled you can barely understand them does anyone know what can be the problem?
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I would say for a start something is out phase or polarity with regard to the center channel in your 5.1 mix. If you have a phase flip somewhere in the mix down to 2 channels you'll get cancellation of dialogue which is by nature a mono signal. I would start with flipping the polarity of the speakers.
Listen to the dialogue. If no change, work your way upstream. -
Thank you for the suggestion I’ve already tried that even when I listen to the center channel only the sound is still muffled,is like the mids are way to hi it helps when I make an adjustment on the mixing console but is not enough I had people leave the cinema because they can’t understand the wordsComment
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Have tried other source material not coming from the projector or the Proyecson? Process of elimination you know. Apart from this I have nothing more to contribute. Don't know your processor.
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Take the center channel (which I presume you have as a good center channel, route it, by itself to just Left or Right...does it sound clear? Try the other...see if you have an amplifier or speaker problem. Music won't show it up as much as dialog. Don't discount the possibility of overloading an input somewhere such that you are clipping the center channel even before it gets amplified. If possible try alternate equipment, naturally.Comment
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Can you get a channel ID DCP and test? Also a pink noise DCP. Those are critical tools in setting up a sound system, even a basic one as yours. Music is much more forgiving than dialogues.
The DAC is just a DAC. What happens next? How do you mix 5.1 into Stereo?Comment
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The outputs from the dac goes in a mixing console then the master goes to a dbx driverack Pa processor and then to the hi and lows amplifiers I’ve tested everything the sound is clear with test voices and sound even when we play older movies the sound is clear only with newer titles the problem comes back it’s like the problem is with the movies and not the sound systemComment
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Newer movies will likely have more elaborated soundtracks. More sound from all channels. When they mix up into stereo, the dialogues will probably be drowned by the other channels.
Find the DCPs I mentioned as a start. By running the channel ID, you will be able to subjectively ascertain if the levels are consistent between channels.
Then disable everything but the centre channel from your mixing console. Check the dialogue quality then.
Also, did you check the frequency response in your auditorium?
Are you in bi-amplification - you mentioned Hi and Low. Is there any signal processing applied in the DBX?Comment
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I have studio monitors in the booth with me and they are hooked up straight to the mixer even with only the centre channel on the speech is not clear but the effects on the centre channel are perfectly clear it feels like it’s the dcps fault the voices are boomy with lots of mids and it feels like when they talk lower in the movies that there is something like a gate and it cuts of very low voices the worst so far was with the fast and furious x movie in some parts it was just a muffled mess you couldn’t understand what they where saying, I tried to adjust the eq from the mixing desk and it was a little better but not enoughComment
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May be it's the driverack's compressor/limiter that cut's back the dialogue. I'm sorry, but this is hard to solve from a distance. Also, I never found standard two-way music systems very convincing for cinema dialogue. I hear them all the time on open-air screenings, but, they suck in this application.Comment
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We do this for drive-in installs (use a mixer such as this one to mix 5.1 down to 2.0), and I usually find it necessary to boost the level of the center channel relative to left, right, and surrounds, in order to achieve acceptable dialogue reproduction on a typical FM car radio.Comment
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It's hard to help as your system is a bit patched up - no offence.
There are NO options in a cinema server to tweak the sound - I believe Doremi had level adjustment somewhere but I'd hope it's never used.
If you say that the dialogues are muffled with SERVER - DAC - MIXER - MONITOR (single speaker) in the chain, then I'm not sure. I would still repeat myself and ask you to get a channel ID and Pink Noise clip. Those will give you a massive help in identifying where the issue lies. Those clips are free.
If when running pink noise/ID you still notice that the centre is weird, the next step would be to swap channels. Route the centre to a different channel on the mixer and I think you can also route the centre/LFE digital pair to a different AES output so your centre channel would come out of a different output on the DAC. A final thought, Mixers have EQ as well, make sure this is not your problem.
You need to go in steps, starting from the bare minimum as you did.
But always bear in mind what Carsten said: Stereo mixdown will never sound right in a cinema.Comment
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