Help putting playback system together, please?

[sfxGuy]

Hi guys,

Been lurking around here a little over a year. This is my first real post.

I've been working with a community theater for just over two years now. I've designed and/or engineered 11 shows for them. When I first started, all I had was a Mackie 1604 VLZ, a CD player and a mini-disk player. Summer of 2011, I was given a 6 year old PC, running XP with a decent Creative Labs card capable of 7.1 output. I made unbalanced 1/8" stereo to 1/4" cables to get into the Mackie. I bought a copy of SCS and off I went. We do suffer through slight, occasional noise that has been narrowed down to the playback computer and/or cables (probably the internal D/As). It's noticeable sometimes but not obnoxious.

We also do a lot of fundraising events like sing-a-long Sound of Music or Wizard of Oz and also an interactive Rocky Horror. We license and screen the material and actually do a fun interactive plan. I'm sure you guys know what I'm talking about. We didn't invent it... At first, I only had an old DVD player with RCA stereo outs to the Mackie. Over a year ago, we bought a new Blu-Ray player (when we replaced the projector) and continued using the RCA stereo outs. We also do collaborative events with local filmmakers where we show their film, then have a Q&A afterwards.

Last May, we had the old FOH stereo system replaced with E-V L/C/R/Subs, amps and processors. It was a huge improvement! But we were still driving it with the Mackie or a rented console for musicals, usually a Venice 320. Last November, a nice elderly lady approached the theater wondering if we were in need of any equipment, large or small, to "make the experience better". Was she kidding? We asked for a new console and got a Pro1! I rewired the patch cables for my setup with XLRs and there I was.

Last Summer I discovered QLab. I was blown away. I love it! But it's Mac only. This past Christmas, my uncle gave me his old MacMini (Mid-2010, core 2 duo) when he bought 2 new ones. Now I have a Mac! My dad's willing to help me put a QLab system together (meaning help pay for it. He's lucky to find the on/off button on a computer =P ). Sooo...

I've decided on an Echo AudioFire12. It maximizes my channels while skipping mic pres, etc. I have a Pro1. What do I need Echo's pres for? I seldom do any recording anyway, beyond maybe a recorded announcement, etc. This gives me a basic QLab system, with 12 outs!

About 10 of us have been getting together at the theater to watch SAG screeners and it got me thinking... I'd really love to do something different with A/V playback. I have a good L/C/R/Subs system. Why not use it for screenings too? For the last film, I popped the DVD into the old PC, configured the Creative driver for 3.1 playback. I'm assuming the driver decodes the audio stream and intelligently down-mixes the 6 channels to 4. Please correct me if I'm understanding this wrong. It sounded really good, except for the occasional noise that was much more apparent while watching a movie. I'm not looking for surround sound. I've got 4 wedges that I can use for surround. But I don't think they're enough to cover all 400 seats. So, I'm looking for 3.1 sound.

Wow. This is getting long. I just wanted to share some background...

After reading endlessly through forums on the net, I think I've answered some of my questions:

The MacMini will not be a good playback device, especially for Blu-Ray material. I don't think an external USB optical drive is reliable enough. And I don't think any Mac software will decode DVD and Blu-Ray audio and down-mix it to 3.1. A Blu-Ray drive, even with 7.1 analog outs, I don't think will down-mix the audio to 3.1. Besides, commercial Blu-Ray drives are really pricey.

I can take the old PC (originally dual-core, 2 GB ram), which I've already upgraded to 4 GB and Win7, pop a new video card in the PCIe slot (like a Geforce 640) for HDMI conectivity and swap a Blu_Ray/DVD Combo drive for the DVD drive. I can pop a good 1394a card in the PCI slot to move the AudioFire over. But that will bypass the Creative driver, meaning, I don't think I'll have anything to decode and down-mix the audio stream. And I don't know of any video playback software that will both decode and down-mix audio.

Questions:

Is there PC video software that will decode and down-mix 5.1 & 7.1 audio to 3.1?

Maybe I can use the SoundBlaster, using the S/PDIF (coax or optical) outs, bypassing the on-board D/As?

Will the Creative driver still decode and down-mix the audio using the S/PDIFs?

Is there an inexpensive, external S/PDIF D/A I can use to connect to the PRO1?

If I go with the EchoFire Pre8, losing 8 analog channels (4x4) but gaining a S/PDIF I/O, will I be able to pass a 3.1 audio feed onto the PRO1?


My HS TD keeps telling me that mixing consumer and commercial equipment will only give me headaches. At first, I didn't believe him. What does he know? He's a lighting guy. ;-) But my head is spinning about now. And I need to give my dad a realistic total for this playback system.

Any suggestions?

Thanks!

Sean

 

[museav]

Before getting too far into how to get a 3.1 signal you may want to first verify that the existing installed speaker system can properly support a 3.1 signal. I don't think the analog mixers you apparently used prior to getting the Pro1 support actual LCR operation and since those are what were in use when the speaker system was installed and the associated processor programmed then it seems unlikely for the system to have been designed and/or programmed as an actual LCR system. Similar for the .1 LFE channel of 5.1 or 3.1 as the installed speaker system would need to be configured to work with a dedicated LFE or subwoofer signal. If you are running aux fed subs you may be in luck on that aspect but if the system uses full range outputs from the mixer then it may not be setup to work with a dedicated signal for the subwoofers.

S/PDIF can carry two channels of PCM audio or multi-channel compressed audio, such as encoded surround going to a surround sound decoder, but I do not think a S/PDIF audio stream can carry four discrete channels of decoded audio as you seem to be wanting.

 

[sfxGuy]

Before getting too far into how to get a 3.1 signal you may want to first verify that the existing installed speaker system can properly support a 3.1 signal. I don't think the analog mixers you apparently used prior to getting the Pro1 support actual LCR operation and since those are what were in use when the speaker system was installed and the associated processor programmed then it seems unlikely for the system to have been designed and/or programmed as an actual LCR system. Similar for the .1 LFE channel of 5.1 or 3.1 as the installed speaker system would need to be configured to work with a dedicated LFE or subwoofer signal. If you are running aux fed subs you may be in luck on that aspect but if the system uses full range outputs from the mixer then it may not be setup to work with a dedicated signal for the subwoofers.

S/PDIF can carry two channels of PCM audio or multi-channel compressed audio, such as encoded surround going to a surround sound decoder, but I do not think a S/PDIF audio stream can carry four discrete channels of decoded audio as you seem to be wanting.

Thanks, museav. The install company specifically said it's a true L/C/R/Subs install. There are 2 dbx DR260s in the rack. One handles L&R. The other handles C&Subs. Appropriate delay, high pass/low pass and EQ were supposed to be programmed.

With both the Venice 320 & 1604VLZ, I was driving the L&R with the stereo sends, the C with a sub group and the Subs with an Aux. There really isn't a whole lot of low-end in the mix for musicals. As there tends to be more than enough filling the room live. It seemed to work the way it was supposed to. But now you have me questioning myself. I haven't designed or run a musical yet with the Pro1. So it will be a learning experience for me. There's a lot to learn about the Pro1! I hope I'm up to the challenge.

I wondered that about S/PDIF I/O. Since it's the same basic technology as Lightpipe, only different data streams, I was hoping there was some way to make it work.

Is it me? Or does this stuff seem more difficult/expensive to accomplish than it needs to be?

Sean

 

[museav]

Thanks, museav. The install company specifically said it's a true L/C/R/Subs install. There are 2 dbx DR260s in the rack. One handles L&R. The other handles C&Subs. Appropriate delay, high pass/low pass and EQ were supposed to be programmed.

With both the Venice 320 & 1604VLZ, I was driving the L&R with the stereo sends, the C with a sub group and the Subs with an Aux. There really isn't a whole lot of low-end in the mix for musicals. As there tends to be more than enough filling the room live. It seemed to work the way it was supposed to. But now you have me questioning myself.

So what you have been doing is apparently stereo plus mono center, in other words a left/right 'stereo' system along with a mono center cluster with the assignment to one and/or the other via bus assignments. As long as the speakers properly cover the listener area then that should adapt well to true LCR, which the PRO1 does support. And the aux fed subs arrangement should provide a way to address the dedicated subwoofer output.

Using two DR260s rather than single larger matrix DSP is a bit unusual but there may have been a reason for it.

I wondered that about S/PDIF I/O. Since it's the same basic technology as Lightpipe, only different data streams, I was hoping there was some way to make it work.

Actually, while it uses coax/RCA or fiber/TOSLINK, in terms of the signals carried S/PDIF is essentially the consumer version of AES3.

Is it me? Or does this stuff seem more difficult/expensive to accomplish than it needs to be?

It really is not that complex, my understanding is that with most SoundBlaster cards that support surround sound you have the choice of either a) using the internal decoder and the unbalanced, analog outputs on the card run into multiple system inputs or b) taking the encoded, multichannel stream out as a digital signal to an external decoder with the outputs of the decoder then run into multiple system inputs. Whether you can 'downmix' 5.1 or 7.1 encoded content to 3.1 depends on the decoder, some may automatically do this if the speaker system configuration selected has no surround speakers while others may not offer the option at all.

Extron, D&M Pro, Crestron, Dolby, etc. offer professional surround sound decoders but because they are typically used in surround sound applications they may not all support 'downmixing' of 5.1 or 7.1 content to 3.1. I have also seen many systems using relatively inexpensive consumer surround sound preamps or consumer surround sound receivers with line level analog audio outputs. As far as the cost of these decoders keep in mind that they may provide multiple input switching, may include IR/serial/IP control, may have balanced audio outputs , may also address video and so on.

 

[sfxGuy]

Thanks, museav.

According to the EASE data I was shown, 92% of our 399 seats is covered +/- 3dB with L/C/R/Subs the remaining 2% is +/- 5 db. I've run pink noise through all channels separately and my ears tell me it's reasonably even too.

I've been reading manuals for all the Blu-Ray players that I can find with 7.1 analog outs (consumer, all RCA). I may have found a solution to the situation that I can sell to the the theater. If I'm reading the manual correctly, the Panasonic DMP-BDT500 will decode and downmix based on the user's config, ie speaker count, size and location. It requires that I continue to use the RCA to XLR cables that I've been using for the stereo PCM feed. But I have not been unhappy with the results of that. (My godfather tells me that sound guys are seldom truly happy)... B&H has the DMP-BDT500 for $277.49. Can someone confirm that it definitely has this capability? The section regarding this is on page 30. http://service.us.panasonic.com/OPERMANPDF/DMPBDT500-MUL.PDF

I hate to keep bothering you guys. But salespeople seem to be less than helpful.

~Sean