Audio Source Switching

[Caleb Williams]

That Behringer X32 Rack 40-channel Rackmount Digital Mixer is AWESOME. Sick find! Wish I had a cool $800 to buy it for myself lol.

The output from the IMS2000 is digital, so you would need to keep the DAX602 for the analog conversion.

When I searched online for "Odyssey DA6-3" I couldn't find any conclusive information about it. Is it some kind of mixer or equilizer?

Ultimately, the Behringer X32 would do what you need it to, but be extremely overkill I think. You'd have a lot of channels to play with. You could add a sound board and have a mic input and add any number of other things to the venue, and mix/automate each channel to your heart's content. You might need a computer in the middle to handle automation commands, since the IMS can only handle binary/ascii messaging natively.

One note on the bobwire solution - I would not use the automatic sense function at all. Any little bit of noise on the rca input could cause the channel to switch over in the middle of a film, and there's no direct control to switch it back in that mode, aside from pulling the offending input. In cinema, you're much better off sticking with deterministic configurations, ie. it doesn't change inputs unless you explicitly tell it to (via the Jnior or the IMS GPO). It's a little more setup, but can save you headaches down the line.

The IMS2000 GPO has a 5v DC output available, and a ground. The Bobwire requires 3-12V with a 5mA draw to switch inputs. The IMS2000 can handle up to 200mA draw, so GPO is up to the task. It would be a little safer probably to use the Jnior instead, because it can handle higher currents, its relays are electrically and mechanically isolated, and it is cheaper to replace if the bobwire box blows up for some reason.

[Steve Guttag]

I wouldn't touch an ECI-60 with a 10-foot pole. It was a hack of a product. The communication on it was flaky, to say the least.

You mention that "there’s A LOT of signal loss currently." From where? The DAX-602 is a D to A converter. The Odyssey DA6-3 is a passive mixer, specifically for drive-ins to get the 5.1 channel audio mixed down to 2-channels for your FM transmitter. That is only 2 boxes and while you could do the mixing actively, you are going to have those two steps in your final system...somewhere. I don't see where you are getting "loss." From the passive mix down? Is the level not sufficient for your FM transmitter?

If you are good with used stuff, locating a JSD-60 would be a decent choice since it combines many things for a Drive-In and has a Drive-In mode available. Plug your server into its AES3 inputs. Connect your FM transmitter to its outputs and it will take care of the D-A and mix down. You can have a separate output for your concession area/restrooms and whatnot that track with the volume control while leaving your FM with the full signal (people can control the volume via their radios).

[Tj Hopland]

I didn't catch the line about there being a lot of loss in the current setup. As Steve said is a bit of a curious statement given the equipment involved. Where are the LR projector and LR PC RCA's? Are they between the DAX and DI6? OR are they between the DA6 and transmitter? And the current switching is just a manual consumer RCA switch box? Or plug swapping? If the RCA's are between the DAX and DA6 I'm wondering if maybe there is an issue with how the balanced lines there are being handled with the unbalanced RCA jacks.

Also there is a not very well known feature that the DAX602 has a web interface and from that interface you can adjust the output levels. For this (and most) applications that feature should not be needed but its something to check if levels just don't seem right. Maybe there are issues with the balanced unbalanced, often level loss and someone boosted the L and R in the DAX to try and compensate? The DI6's passive mix likely slightly favors the center over the other stereo channels so that could confuse things and people.


Glad to hear from Steve that I'm not the only one that had issues with the network control on the ECI. I'm pretty sure I had one working fine with QSYS when I just had a test this module design running and it was just the ECI and Core on my bench but when it got to the site with a full design running it rarely (maybe never) worked. I wasn't using the RS232 port on the core and the ECI and Core were in the same rack so I was able to switch the control to RS232 and that has been reliable. Jnior should be able to reliably control one over RS232 too.


I do/did like the JSD60 and used many of them including in drive ins and one would for sure do the job. The reason I didn't suggest it is they have not seemed to age well so I would hate to see someone pay a premium price for one and then have issues and if you are getting one cheap its likely because it already has issues like fader, power supply, and front panel.

[David Ellis]

Thanks everyone! Awesome info and I am going to check into all this

@Caleb I will double check the model number Odyssey DA6-3 and make sure I have that right.

@Steve when I say signal loss... the signal seems to either be getting eaten somewhere or there is a gain adjustment somewhere that I can not find. What is happening is that, rather unscientifically, if you have a radio on a normal level, then switch to our FM station, then you can barely hear it. On our station you have to literally have your radio turned all the way up to hear it well.

@TJ, to be honest, I embarrassingly do not know how to tell if RCAs are balanced vs unbalanced. Is there a way for me to check this? Maybe that is the issue?
@TJ great tip on the DAX602 web interface to adjust the gain! I had NO idea. Maybe that is the issue?

@Everyone, sorry but I got a little confused with the suggestions... Is there anything that can go straight from the IMS2000, and it will mix down to left/right analog? Some say that no matter what I need the DAX602 and Odyssey DA6-3 but then some suggest other equipment, but it is unclear to me what that other equipment would replace, or if it would be in addition to my current setup to give additional control?

[Harold Hallikainen]

I agree it would be good to avoid the ECI, and I helped design it. The JSD-60 will take the AES3 directly from the server and mix the channels to create a stereo feed for the FM transmitter. It has a Drive In configuration that does this.

On low FM modulation, does the transmitter have a modulation indicator? Does it have an audio compressor? The sound tracks have a much wider dynamic range than can be supported by FM transmission. Ideally the transmitter has a compressor or some audio processing. FM stations spend many thousands of dollars on audio processors, so it is unlikely you will be as loud as they are, and you DO want to preserve some dynamics of the soundtrack.

Good luck!

Harold

[Ryan Gallagher]

Thanks everyone! Awesome info and I am going to check into all this

@Everyone, sorry but I got a little confused with the suggestions... Is there anything that can go straight from the IMS2000, and it will mix down to left/right analog? Some say that no matter what I need the DAX602 and Odyssey DA6-3 but then some suggest other equipment, but it is unclear to me what that other equipment would replace, or if it would be in addition to my current setup to give additional control?

I believe the only purpose built cinema gear that has been mentioned with the needed "drive-in" modes that eliminates your other two pieces of equipment is the JSD-60.

You can probably cleverly combine some other things mentioned to change your D2A and Mixdown methods, but not with much less complexity than what you already have.

[David Ellis]

I believe the only purpose built cinema gear that has been mentioned with the needed "drive-in" modes that eliminates your other two pieces of equipment is the JSD-60.

You can probably cleverly combine some other things mentioned to change your D2A and Mixdown methods, but not with much less complexity than what you already have.

Ok awesome. And the JSD-60 is Q-SYS which is usually pretty good right? If it is reliable then I will order one right now

[Harold Hallikainen]

I believe QSC has discontinued it, but you MIGHT be able to find a new unit through a dealer, or a good working used one somewhere (perhaps here!).

[David Ellis]

I know there aren't many drive-ins so this is pretty niche, but it is pretty wild there's only one option that has this function and even it has been discontinued. Sad...

At least there is one though. I will start trying to tack one down. Thanks again!

[Harold Hallikainen]

You can get familiar with it by reviewing the manual at

https://www.qscaudio.com/resource-files/productresources/dn/usl/usl_jsd-60/q_dn_usl_jsd_60_usermanual.pdf

[Tj Hopland]

I forgot to hit send so there has kinda been some answers in the meantime. And the lack of other options for drive ins was why Odyssey made that box. Odyssey was the little box/board/cable problem solver.

JSD-60 was a stand alone processor from USL that came near the end of the main digital rollout so there wasn't as many out there as say the JSD100 or CP750. QSC bought out USL and continued to offer it for a while along side their offerings like the DCP and later the DPM. I think it was end of life with stock remaining in like 2018 ish but they did a bit of a production run in 2020 to support the pop up drive in demand. I think that was the last of em and that was it so 5+ years ago now. What it had that no other cinema gear had was the ability to do custom mixes which was what you needed for a drive in or other wacky setups. This means you would not need the Odyssey box because you could do what that box is doing and more internally inside the JSD using the PC setup app. The JSD60 being D cinema gear would take the signal direct from the Dolby server so with this you also would not need the DAX.

For sure would do the job I would just say be careful how much you pay and who you buy one from. If your regular dealer / service provider has one they know the history of thats probably a better bet than paying the same price for one from a random online seller. Also note that that front panel problem could come up from one being rattled around during shipping so its possible it was working fine in its original home but ain't gonna be happy after its moved. Had more than one that happened with recently so that's one reason I don't trust em like I used to.


QSYS is a whole ecosystem of products that centers around units called the Core which are literally the core of the system. The cores depending on the model may have no analog inputs or outputs so it depends on other modules from the family to have say some ins and then a Q amp for the outs and you connect those devices with network cables and then program them to do pretty much what ever you want. You can do a system that maybe just has a core in it and and analog amp or two and that's the whole system. You could also do something like a whole cruise ship or international airport. Out of the box they literally do nothing, you have to tell it what you want it to do which is nice because you can pretty much do anything you can think of as far as routing and processing. You can also do custom control interfaces that run on their special touch screens as well as iOS, PC app, or even a web interface. Its actually a pretty slick system but probably overkill and over budget for this sort of application.


As someone else was suggesting your level issues may not be solved by just being able to 'turn up' the inputs. As they said some transmitters have the stuff built in to better manage a source like this and others expect that you would have some sort of proper official processing unit inline before you get to the transmitter. Even the ones that have some built in stuff it tends to be pretty basic and is barely enough to get by so not really the broadcast quality you are likely comparing to. If someone in the past went into the DAX's interface and turned things down it may have been to try and get the best results they could with the transmitter at the time. Has the transmitter changed since the rest of the stuff was installed?

[David Ellis]

Has the transmitter changed since the rest of the stuff was installed?

Thanks for explaining! That is very helpful! Nothing has changed since everything was installed 15 years ago. The problem has existed since then. They have been just dealing with it because it is passable, but it it is a really bad customer experience so I am trying to fix it and some other issues all at once.

Question... does the sever make any difference in regard audio interface/output, or are they all the same? We've been considering upgrading our IMS2000.

[Steve Guttag]

All servers output AES3 audio. Some, now, also offer AES67, which is a network based audio system that I would consider less robust than AES3 (point-to-point). As to upgrading the IMS2000 to something else...my experience has been that the IMS2000 is one of the more reliable servers out there. It's wear points are the OS drive (is an SSD that gets 5ish years) and the HDD or SSD used for the RAID storage. I would place it more reliable than the IMS3000, for instance (which can have boot up issues and a greater tendency to have clock drift). The IMS3000 has a greater feature set (e.g. AES67 output, Dolby Atmos) but your movies won't play any better, sound any different, look any different.

[Tj Hopland]

Thinking about if any of the current server model would offer any possible advantage got me thinking about other ways to maybe attack this.

Anyone, How does the IMS2000 handle the HDMI vs a playlist? I can never remember how which models and software versions do it. I know early on if the server was in HDMI mode a play list would not start. Did that eventually get changed that a playlist switches back to dcp mode or will at least start and you can have a cue at the start that switches it? Possibly said cue has to be on a built in black clip vs a created one? I think that is the trick with Barco, just can't remember if the IMS2K also works that way too.

What I'm thinking is assuming the flow and cuing can be worked out is you hook the music PC to the HDMI port on the IMS. The exact workflow is TBD depending on how the IMS handles the switching. Even if you had to manually trigger the switching that could still possibly be remote controlled one way or another so would not requite someone to be in the booth pressing buttons or swapping cables which sounds like its what you have now. The HDMI port on the server will pass the HDMI audio down the regular path as if it was a DCP. That audio isn't always the optimum format, often just L and R but in this case that all we want anyway.

[Steve Guttag]

You can create an HDMI ("Live") CPL that can be put into a playlist and switch to and out of. If you have a Christie projector, you can have it switch to HDMI or DCP (or SDI) via a suitable Channel/Macro.

I believe you are confusing the Barco ICMP with the absurd situation that if the projector is on an HDMI preset that it will refuse to run a DCP. The ICMP does allow you to put a cue on its special black CPL to switch it to a DCP preset before an actual CPL hits. If you do that, it will run.