Help with the path of our sound

[Tj Hopland]

Is this venue really expecting a lot of SRD? Or 35mm DTS? If not maybe an easy way to get started would be find just about any of the older analog processors, even a 50 would do it and use that for the optical preamp / changeover / and NR. You then send that into the non sync inputs of the 950 and set it to upmix to 5.1.

That covers you for mono, A, and SR if its a later processor. 70 DTS could be done digital to the 950 if you got a XD10 or 20. That seems like it would cover you for a lot of titles and its not like you can't play an SRD title in SR if you got one. You could probably even get the 950 to do 35 dts, DTS would be the AES input and the fallback would be NS which is the optical. The XD10 doesn't know or care, its just sending those pulses when it needs to fall back you just need something like a Jnior to read the pulse from the XD and convert that to the network command for the 950. If you can get the discs that would likely cover you for a vast majority of the SRD titles then too.

I have done the old processor into the non sync thing several times for various reasons and it sounds pretty good. The DSP matrix in the 950 is likely better than any of the old analog processors anyway. Only catch I can think of with the 950 is I don't know of you can set up the non sync to for sure keep everything in the center for mono. One venue I did that in they sometimes had issues with mono prints sort of drifting around the front channels sometimes likely due to some printing or tracking issues. It wasn't terrible but you sometimes noticed it. Luckily in this venue the 'head' processor allowed me to mute the other channels so we had both the standard 5.1 button for stereo and then a mono button that muted the other channels. If the amps are in the booth just shutting the other channels could be an option, just have to remember to do it and then turn em back on before a stereo show.

You do have to pick the right processor and tap in the right place so it can still control the academy filter and NR, basically you want to tap in before the matrix section. Some processors even have terminals on the backplane so no soldering need. Doesn't always work that way sometimes those terminals are before the NR which isn't what you want in this case.

[Ryan Gallagher]

Is this venue really expecting a lot of SRD? Or 35mm DTS? If not maybe an easy way to get started would be find just about any of the older analog processors, even a 50 would do it and use that for the optical preamp / changeover / and NR. You then send that into the non sync inputs of the 950 and set it to upmix to 5.1.

If you are in the back catalogs, or expecting 35mm first runs (the few that remain), then SRD is definitely nice to have. From Brian's prior post it sounded like they already were doing 35mm and 70mm and angling for mag eventually. Sounded like the CP650 is already in use there, so SRD is already accounted for (with that method)? Or maybe I'm misreading and he was speaking of intentions after the DP70 comes into play?

I would agree there are diminishing returns on 70mm mag availability these days. But it really depends on who is doing the booking. Our programmer often doesn't even ask and I have to prompt him to check with the distributor which soundtrack we are getting. Ran a few mag blow ups that had gorgeous color still, "Streets of Fire" being one that comes to mind. Until I forced their hand and said no more mag until we get our noisy Ampex head replaced. Had one 70mm lined up last summer we had to pivot on after I made him check which format sound we were expecting.

And I did secure a Teccon head, it just has a non-century wiring harness I'll have to sort when I'm ready to tackle all the mag A-Chain. The mount is correct though.

[Tj Hopland]

I guess we will have to wait for clarification but the way I read it is the film installation is new or at a minimum hasn't been used since the 950 was installed so at the moment there is no way to run any film sound. They can't even do a physical manual patch into the amps because its bi-amp and the crossovers are currently only in the 950. I'm assuming the 950 is up and daily running various digital content and it sounds like they are happy with it in that capacity.

[Brian Mendelssohn]

Sorry for the confusion on my end. We took over a historic theater and essentially rebuilt it. We are also installing all new equipment, screen, etc. Nothing was left behind. I installed a Christie 4435 laser for my digital with the CP950 for the audio. I have a lot of alt content formats. I got all of this portion complete in October 2025. Now I'm adding the two Norelco, so this is also a new install. I was led to believe the path my installer was on, everything was great and all the equipment we had was great. Then came Friday when I was informed they had no way of making the sound work. Since this is my theater, I'm stepping in to figure out how to make the sound work from the film projectors to our house system. Our house system is 6 QSC DCA amps connected to JBL speakers in 7.1 format. My first film show is this Friday, so I'm in a panic mode, but also, I want to have a really good permanent solution.

We show 50% new titles and 50% rep. the rep we show DCP, blu-ray, vhs, laser disc, and we hope to have an extensive film program in 35mm and 70mm. We want to show new releases in those formats, but also want to show classic 70mm prints and eventually in a few years have a 70mm festival. I hope this clears things up.

[Steve Guttag]

I would think that the vast majority of prints that people are going to get, nowadays, will have the SR*D track on them. Stuff before the early 1990s, that didn't get a remix would be just optical. Still, not having SR*D, in my mind would be a bad design. DTS for 35mm would depend on getting discs/thumb drives. I don't see them going out for 35mm prints...just 70mm so, again, SR*D is the format of choice for 35mm and discrete audio.

So, I come back to... a CP65/DA20 combination is a good one and would accept up through a CP650 to handle 35mm prints. For 70mm, if just concerned about DTS-70, then any means of getting the audio into the host processor (analog or digital) is sufficient.

[Steve Guttag]

I don't want to get into finger pointing but whomever "designed" the system, if they knew it had to support 35/70mm film, blew it. Push come to shove, it might be a bit pricey, but get some A-D converters for your CP650 (typically available in 2-channel, so 3 of them for non-EX or 4 of them for EX) and convert your CP650 outputs to digital. Then patch in either the CP650 or your DCP as needed for the show. I don't know if they still make it, but Kramer had one called the 6420N. RDL has their HR-ADC1. I'm sure there are others too. Something like that is bound to be a fast solution. That, or one of the various processors, other than the CP950 is another...but that would add in the time to rewire the b-chain and tune it. The ADCs avoid that.

[Ryan Gallagher]

Sorry for the confusion on my end. We took over a historic theater and essentially rebuilt it. We are also installing all new equipment, screen, etc. Nothing was left behind. I installed a Christie 4435 laser for my digital with the CP950 for the audio. I have a lot of alt content formats. I got all of this portion complete in October 2025. Now I'm adding the two Norelco, so this is also a new install. I was led to believe the path my installer was on, everything was great and all the equipment we had was great. Then came Friday when I was informed they had no way of making the sound work. Since this is my theater, I'm stepping in to figure out how to make the sound work from the film projectors to our house system. Our house system is 6 QSC DCA amps connected to JBL speakers in 7.1 format. My first film show is this Friday, so I'm in a panic mode, but also, I want to have a really good permanent solution.

We show 50% new titles and 50% rep. the rep we show DCP, blu-ray, vhs, laser disc, and we hope to have an extensive film program in 35mm and 70mm. We want to show new releases in those formats, but also want to show classic 70mm prints and eventually in a few years have a 70mm festival. I hope this clears things up.

Helpful context! Ideals aside, it sounds like a CAT778 digital output board on the CP650 you already have is going to be the most direct method for Friday, maybe someone has one you can borrow in a jam? You could swap the digital inputs at the CP950 for film mode if you had one.

Dedicated hardware to handle 8 analog channels into AES/EBU is pretty pricey if you try to do it with a separate box. There might be a slightly cheaper clever way with dante as the intermediary utilizing their AV/IO adapters and a dante network, but you still have to convert physically from their more common XLR or BNC AES to the 8 chan RJ45 inputs on the CP950 or 3 chan BNCs. Or maybe figuring out how to embed analog into a 5.1 or 7.1 HDMI signal and trying that method, like you originally suggested.

Even those two channel A/D boxes Steve suggested are nearly 800$ each (or at least the RDL one is). AJA made/makes a 4ch unit that is more resonable? ( https://www.bhphotovideo.com/c/produ...audio_a_d.html )

The Dante AVIOs are like $200 each (but you'd need 6 of them minimum), and the analog to dante ones will have general utility if you ever re-do this and have a dante network elsewhere? Even the AES ones might be pretty resalable because they are kinda industry "gig bag" type items.

Also note the Dante AVIO method requires a network with POE capabilities.

[Ryan Gallagher]

Note if you opt to explore the HDMI embedded analog audio method. The more professional options are going to be embedding audio into SDI first. (AJA/BlackMagic Devices etc)... once you've got SDI with the correct channels and ordering embedded, most SDI to HDMI boxes are going to be able to pass all those channels through, the 950 should be able to handle the PCM audio as it claims they are HDMI 2.0 ports, what it does with it is probably channel config dependent.

Unlike the AJA 4 channel box, the Blackmagic one lets you specify the channel group via dip switches, so daisy chaining two of them properly configured gets you 8 channels of analog input on 1/4in jacks, so still some physical adapting to do and the interlinks.
https://www.sweetwater.com/store/det...audio-to-sdi-2

The AJA might too but is maybe a software change via their USB config. AJA unit has the benfit of being bi-directional and including an XLR break in/out.

Then I'd recommend a Decimator MD-LX (or MD-HX if you have one) in the final conversion to HDMI. The AJA ones are good too, but I find the black-magic hdmi converters to be less reliable on honoring EDID and color spaces of connected hardware.

[Marco Giustini]

. It has 1/12 octave graphic EQ

Doesn't it feature the same EQ the 850 has? I thought it was more than a 1/12 octave EQ. Also, that should be a LAKE EQ so a bit better than the average EQ.

they forgot to low-pass the subwoofer.

This is so annoying. Of course nobody applies a crossover to it and most people still rely on the SPL to set the LFE level...

someone that knows how to tune

The important bit

Cat 778: I'll hold on mine then, I suspected it was valuable!

[Tj Hopland]

Yikes, by Friday is a fun twist. I would guess from the 3 new choices the DPM30-H would be your best shot in a hurry. Decent chance QSC would have one in stock or a big dealer like Strong or MIT. And is the one of the 3 that doesn't require some special set up hardware other than the DPC cables if you don't already have em or DDI-11? break out boards.

Do you have any sort of big AV company that does big stuff like convention centers or place that does production work and rents cameras and things? A lot of big cities have such places and they often have various converter box types of things. I have no idea if analog to AES is something they would have or use but maybe given the time crunch its worth asking. If they got one maybe you can rent it while you figure out a better solution. Maybe you would get real lucky and they have one that never gets used anymore and they would just sell it cheap? Cheap could still cost you but it could have been a $10k box new sort of thing. AES in pro audio tends to be on XLR cables so you would have to make a XLR to RJ but at least those are common connectors.

Note that in the 650 if there are any of the expansion boards 774, 790 that the surround outputs moves to the option port so its not going to be just a straight cable with any of the new head processor options. Custom cable or Odyssey boards. I have not looked at the pinout for any of those 3 processors so even if you don't have an expansion card it still may not be a straight cable so one more thing to have on the radar especially since you have the time crunch.


A possible snag for any downstream options other than the known crossover issue is how many surround outputs are you using on the 950? Just 4? Or are the 4 split into more zones and or amp channels? How about subs? Any surround subs? That's all stuff a 950 could do that 650 for sure can't.

I was looking at something like the QSC DSP-3 which was the DSP module that plugs into the back of the DCA's. There seems to be several of them for reasonable prices on the used market and on the stage channels those could be set up to be the crossovers and then both inputs could be routed to the crossover so you would have 2 live inputs, one from each processor. That would not work on the subs and surrounds unless you happen to be now running them in parallel or bridge mode. Timing could also be an issue since its not likely that one close seller would have at least 8 of em. They are also old and unsupported but it looks like you could collect several and have spares. Final snag is the programming software may not run well on a current PC and is done over serial which again the more modern you get.

[Ryan Gallagher]

So I forgot about AJA's A/D D/A 4chan boxes (ADA4 Model). Which is another option in the A/D camp. Probably the most economical option?, only two needed. One can generate a 48k or 96k AES sync signal for the other... but they will free-run as a pair since the CP950 can't provide it's own sync.

https://www.aja.com/products/ada4#features

This would do the XLR analog to XLR AES pairs but you'd still have to sort out the physical XLR AES/EBU pairs to RJ45 situation.. If you had XLR breakouts already on your CP650 you'd be half way there.

Note I own almost this whole kit personally, but am struggling to find my CP650 cables (recently reorganized my place).

[Ryan Gallagher]

I found my handful. I would be short a bunch of gender changers personally cause my only 5.1 dolby cable is female XLR and the AJA ADA4s are also female on the input tails, and unless I could repurpose some break ins/outs I lack the male XLR to something that gets you to AES3 on RJ45.

IMG_7105.jpg

Unless this DOREMI analog cable shares the same dolby pinout (I don't think it does).

IMG_7107.jpg

I also have the Odyssey 650-OPTIO-AES-RJ breakout and the 7.1 cabling, which is gendered opposite to my other 5.1 dolby one, cause one of my 650s came with CAT790 config.

Not photographed, I also have a dolby DB25 to 6 unbalanced RCA cable... which would maybe be useful if there was a consumer audio to hdmi embedder attempted.

IMG_7106.jpg

[Tj Hopland]

So how does the sync work with AES? Does every out pair have a sync signal in it? Then does every in pair sync to that or is that where the possible catch is? Not all in chips are created equal? Does a multi channel box assume the incoming pairs will all be in sync and its using say the first pair as the reference?

So forgetting about the likely quality and reliability issues using this case as an example could you go buy 3 of those $20-$50 internet special single pair A to D boxes and stack em to get the needed 6 channels into the 950? Lots of reasons this would not be ideal but would everything sync up and work or would each of the 3 boxes not likely be in sync and something like a 950 is expecting them to be in sync? If the channels do need to be in sync how likely is it that the 1-8 and 9-16 ports also need to be in sync with each other? Or is it likely that the chips handling this come in groups so maybe the groups are 1-8 9-16?

[Ryan Gallagher]

So how does the sync work with AES? I get it if its multi channels in one box, there is a master perhaps the 1/2 pair? and the rest sync to that? So how does it work with multiple boxes? I see those specific boxes have 3 BNC so its 2 2 pairs for the AES and the 3rd is related to sync?

The ADA4 has separate sync loop and output BNC connections (almost out of frame in my picture). The output can be an always on sync source... so one just becomes the free-run clock and feeds the input of the other, unless you ignore the outputs and provide them an alternative world-clock type sync source.

[Ryan Gallagher]

To clarify, none of the BNC's are AES... those are all for sync. The AES output is on the XLRs (in AES/EBU channel pairs), so only half of the output XLRs get used, they aren't plugged into anything in my photo cause I lack the rest of that chain. If you had them in DtoA mode (they are bi-directional) then you'd use half the inputs but all of the outputs.

The rest of the kit that is missing would be a suitable XLR to DB25 cable with dolby pinout... and then a manually wired DB25 to RJ45 that is wired to honor the expected pinout on the 950 AES3 RJ45 ports. You can channel map by replugging XLR, but you still have to get the pins correct relative to the channel boundaries on the adapters.

Unless you are set up for 7.1 on your CP650, then it's definitely a different batch of cables at that end.