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Author Topic: CP650 Surround Mixdown Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 07-20-2008 10:05 AM                     quote: Joe Redifer CP650 digital out to a QSC DCM-1 monitor and that feeds digital signals to the amps. Are you absolutely sure you're not an ex Wal-Mart Employee... I am pretty sure that one time I heard a Wal-Mart Employee say that QSC amps only took a digital input signal . Mark  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 07-20-2008 05:10 PM                        Well they plaster the word "digital" everywhere so everything MUST be digital! Anyway there are XLR jacks so I think it would take a McDonald's employee to say they only accepted digital. John, I don't have a Windows laptop or the QSC software.  |  IP: Logged John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 07-20-2008 08:13 PM                     The software is easy to get. I know you area Mac guy; can it emulate Windows? If the DCM is new and has the genaric standard settings, then it probably won't effect you. But I was thinking if it was bought used, then it may have been set up for it's previous install - which might be bad for you now.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 07-20-2008 09:55 PM                        I don't have a Mac laptop, either. I am not really a fan of laptops, and I'm not going to buy one just to mess around with sound equipment here and there (I have absolutely no other use for a laptop). All I want to do is mix the surrounds, I shouldn't be required to hook up a freakin' computer just for that. That would make the QSC unit entirely non-self-sufficient (next thing you know we'll require laptops to change the channel on our TV). I'll just put it to parallel, run the pink noise and see if I get sound from both LS and RS. That will answer my question. Anyway I noticed the VGA cables that come from the QSC DCM that go to the amps seemed pretty gimpy, as if they were made by Belkin or something. The cables are pretty thin. I used to have an extremely similar Belkin cable for a VGA monitor and there was lots of ghosting. Using a real (re: phuggin' thick) VGA cable solved the problem. Could there be similar issues when using these same cables for sound as is the case here?  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 07-20-2008 11:41 PM                     The dataport cables are fine. The ones supplied by QSC are tan or black and thin about the size of a cat5 cable. You won't have any problems with them. Putting the amp in parallel will only take the signal from the left channel input and run it through both sides of the amp. Your best option at this point is to download (QSC calls it upload in their software if I remember correctly) the settings in the DCM-1. I honestly don't know if there is a setting to sum to mono or not. I would never permit this in one of my installations, so if I saw such an option previously when I had the software open, I quickly erased it from my mind. Unfortunately my laptop is in the car and I am feeling too lazy to go outside and get it to look for myself. Sam Hynds from QSC would know, but I wouldn't hold my breath that such an option exists. (It would be funny if the DCM-1 was configured for the wrong speakers though.) If Sam or somebody doesn't chime in I can look tomorrow evening provided you harass me about it. Had you considered burning the building down? That might get it fixed quicker.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 07-20-2008 11:44 PM                        I think the building would flood before it would ever burn. My cables are beige. They are not "dataport" since they send audio in analog form.  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 07-21-2008 05:58 AM                     Joe, Your theater is "really atmospheric". KEN  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 07-21-2008 11:46 AM                     The DCM-1 does nothing to the surrounds except monitor them and, if EX is enabled, turn them into unbalanced (grrrrrr). If you don't want to make a resistor network yourself, you could always buy an RDL STD-10K or STD-600 . They are pre-built (with the price to match) resistor networks (with RF suppression) that will allow you to passively sum balanced outputs to balanced inputs. There are four combination input/outputs. Steve  |  IP: Logged Jon P. Inghram Expert Film Handler Posts: 124 From: Wichita, KS USA Registered: Jan 2007 posted 07-21-2008 01:07 PM                     quote: Joe Redifer My cables are beige. They are not "dataport" since they send audio in analog form. The dataport connections are analog, just like the DB25 output on the CP650.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 07-21-2008 02:45 PM                     quote: Joe Redifer My cables are beige. They are not "dataport" since they send audio in analog form. Dataport is the name QSC gave the cables. When used with A DCM series monitor and DCA and a few other models of QSC amplifiers, the cable carries the audio signals, a power-on signal to the amps (when you power down the monitor the amps go into standby) and the signals for the output of the amps to the monitor. Supposedly, the audio sends in the QSC cables are shielded separately from the other leads...a good idea since close coupling of the input (or feed) to the amp and the output from the speaker lines can cause serious feedback or oscillation. Which is why QSC cautions people to NOT use a standard VGA cable even though it has the same HD15 connector. Since the QSC cables are reasonably priced, not a big deal anyway.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 07-21-2008 06:42 PM                        quote: Tony Bandito Jr Dataport is the name QSC gave the cables. Yes, that's been my point through this whole thing... it's a very misleading name (especially when they are throwing around the word "digital" everywhere as well). Hmmm, maybe I should refer to a Firewire 800 connector as a "patch cable". It would make sense to QSC.  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 07-24-2008 11:11 AM                     Actually most of you are wrong regarding the Dataport as a VGA cable!! All of you think "What the heck is he talking about". Well it goes something like this. VGA Cables usually use Pins 1,2,3 for Hot Red,Green,Blue respectively and pins 6,7,8 for grounds for Red,Green,Blue, 13 and 14 for Horizontal and Vertical sync and pin 10 for common ground for the Horizontal and Vertical. In a VGA Cable this means that on these pins (1,2,3,6,7,8) small coaxial cable is being run through it. Some molded VGA cables even have 6,7,8 shorted together since it is all ground. It is WRONG to use a VGA cable and not a certified Dataport cable or if you are too lazy and can't be bothered to buy one you should see the pinout diagram in the DCM manual to create one and spend countless hours over a magnifying glass to solder all 15 pins. Dataport cable basically carries three balanced cables and data cables all in one form from the monitor to the amplifiers. Anyone who has been using VGA cables bought from the local Radioshack or whatever you call it is simply WRONG!! The only common thing these cables have with the VGA cables is the 15 pin socket they use to connect. Demetris  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 07-24-2008 02:31 PM                     Well, something else that VGA cables have in common with QSC dataport cables is ... they work just fine as dataport cables. There's likely some difference in the way the cables are shielded and probably really cheapo VGA cables may cause problems... but they are not some completely different cable that happens to use the same connector.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 07-24-2008 05:01 PM                        So what kind of "data" goes through these dataport cables? I seriously want to slap someone over this name.  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 07-25-2008 06:21 AM                     On the Dataport cable the balanced shielded pairs are Pin 1 for Channel 1 Minus Pin 7 for Channel 1 Plus Pin 6 for Hard Ground Pin 8 for Channel 2 Plus Pin 11 for Channel 2 Minus This means that analog signal is passed from the all Digital DCM monitor down to the amplifiers! From what I realise, there are cable connections for standby control, clip protect e.t.c. I believe (but I could be wrong) that the amplifier simply shorts a pin with the ground to indicate the state of the amplifier if its on/off, clip e.t.c. Even though a VGA cable might work, it is still wrong to use it instead of the Dataport cable which uses completely different shielded cable combinations. Demetris  |  IP: Logged

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