Film-Tech Forum ARCHIVE: Qsc DCM

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Posted by Antonio Marcheselli (Member # 373) on 03-07-2003, 09:52 AM:

Hi

I've download the DCM manager from QSC, just to see how it works (I have no amp connected) and I receive a "type mysmatch" when I try to run it. I'm running Windows XP and in win95 compatibile mode I have the same error. This happens because there is no amps connected?

I didn't knoe that there is a monitor/crosover by QSC. Seems a great device, with laptop controls...

What do you think about it?

Bye
Antonio

Posted by Tom Sauter (Member # 616) on 03-07-2003, 05:48 PM:

The DCM software runs OK on my XP machine, just configured a system last week. Maybe there is a problem accessing the correct serial port on your laptop... DCM commander wants to use COM1 when first installed.

The DCM is nice when used with QSC amplifiers and a cinema processor with a DB25 connector for its outputs (CP650). Makes rack wiring a breeze with easy cabling... no splicing, no soldering. "Plug and Play" as they say. Nice if you're wiring up a multiplex, you can at least set up the crossover frequency once and then just upload it to the other zillion screens with the same setup. (Not a substitute for careful time alignment, though).

I wouldn't consider a DCM if I wasn't installing QSC amplifiers, you'll spend a LOT of time wiring up DB-15 connectors with little tiny solder pins. If time is not an issue then it may make sense if upgrading from passive to active crossovers.

Posted by Antonio Marcheselli (Member # 373) on 03-07-2003, 06:42 PM:

Thanks Tom,

I saw a multiplex build with QSC DCA, I didn't knwo that QSC monitor was crossover too and pc configurable!!

Yes, in this case the cabling of the rack is a fun!

I'll check my serials.

Bye
Antonio

Posted by Gordon McLeod (Member # 33) on 03-07-2003, 07:11 PM:

I always make my own cables as I find good cable dress hard to achive with off the shelf vga cables
Also it is bad habit to upload common settings into multiple screens

Posted by John Gordon (Member # 523) on 03-10-2003, 06:24 PM:

Antonio,
Did you have trouble with the download of the DCM software, or are you having issues with your computer? I can see from Tom’s post, there should be no issue with running XP.

Yes indeed, the DCM is a DSP based crossover, with time delay, parametric EQ, screen EQ, CD horn EQ, HPF for subs with a choice of Q settings, and it comes with a booth monitor as well. And of course it works well with or DCA amps as you have noted with the simple hook up via our DataPort connector (VGA style connector).

You can get DataPort cable from us in lengths of 1ft, 2ft, 3ft, 4ft, 5ft, 6ft, 10ft or we can do customs lengths as well. But Gordon, if you choose to make your own cables, you can do that as well.

Gordon, I will have to disagree with you on the “uploading common settings into multiple screens” in one respect. If you tune a room with the DCM and you have similar size rooms, with same speakers, etc, you can indeed upload the information from the tuned room as a starting point to speed things up. But of course you should tune each and every room. The uploading of common settings is only a starting point.

Posted by Mark Gulbrandsen (Member # 72) on 03-10-2003, 06:37 PM:

I agree on the VGA cable use, and I feel that the use of VGA cables is getting out of hand. On these expensive electronics products this is really the bottle neck to getting the maximum performance out of them.

Nothing compares to using high quality Mogami, or other great wires that are available and as were widely used till the stupid VGA cable idea came along...Even Belden 8451 is still alot better cable. Keep in mind that nothing good comes easy!!
Mark @ CLACO

Posted by John Gordon (Member # 523) on 03-11-2003, 01:06 PM:

Nothing good comes easy, hmmm? I have to disagree, to a point of course. Take VGA cables for example. They are widely used in highly critical computer applications, and they were easy to install. And for the past 3 - 4 years, our DataPort cables as well as VGA style cables have been used with the QSC DCM and DCA amplifiers. To my knowledge, there has never been an issue with the use of our DataPort cables, or a VGA style cable.

Now, if someone has a preference for a certain type or brand of cable, more power to them. If someone prefers to make custom cables, that is fine as well. But, there is nothing wrong with using a good quality VGA style cable. We have accessory DataPort cables for use with the DCM Crossover/Monitor and DCA amplifiers--as well as for our networking components--and anyone can purchase them if they desire. You can also pick up VGA style cables at your favorite electronic outlet, though you must make sure the cable has all 15 pins.

Things you may want to consider regarding VGA style cables:
Any of the D-Shell connectors are far better cables than most standard audio cables. This includes VGA cables. Reasons?
1) The shell of the connector is guaranteed to make contact before any conductor does, greatly reducing the chance of static discharge into the audio system.
2) The connector itself is far more robust than most standard audio cables.
3) In general, VGA cables are designed to carry signals of much higher bandwidth than audio. Video contains much higher frequency content than audio, and the VGA cable works great for monitors.
Now, we do understand that audio quality can degrade if the cable length of a standard VGA cable gets longer than about 2 meters. QSC has engineered an audio specific VGA cable for longer runs, or where extremely high audio performance is required. The QSC Custom DataPort cable individually shields the audio signals from a DCM (or other DataPort equipped piece of hardware) to the amplifier. This shielding is in ADDITION to the normal heavy duty shield around the entire cable. So, we end up with two individually twisted pairs, each pair shielded from the other, and the other 11 DataPort signals. All of these signals are then shielded from outside interference. The result? Pristine audio quality.

Posted by Daryl C. W. O'Shea (Member # 1303) on 03-11-2003, 01:25 PM:

FWIW, Digidesign (Protools) says that you can use standard DB25-based cables for their analog audio interface. They make no mention of using a higher grade or custom cable.

Posted by John Gordon (Member # 523) on 03-11-2003, 01:30 PM:

Antonio,
Regarding your “type mismatch” issue. The reason for this is more than likely the region coding of periods and commas. I’m assuming you have your region options set to Italian. If you want to open the DCM Manager software, here is two simple ways to do so:
1) In Control Panel, click on “Regional Options.” On the General tab, change the “your locale” to “English (United States).”
or
2) In the “Regional Options,” if you are set for Italian, you can click on the Numbers tab, change “Decimal symbol” to a period (.), and change “Digit grouping symbol” to a comma (,).
In either case above, you may want to make sure you put your Regional Options settings back to their original settings when finished using the DCM software.

Posted by Daryl C. W. O'Shea (Member # 1303) on 03-11-2003, 01:35 PM:

Antonio, don't forget you can install/enable multiple 'Input Locals' under the 'Input Locals' tab in the Region Settings control applet. Defining multiple locals will allow you to switch back and forth using the system tray input local icon that will appear.

Posted by Antonio Marcheselli (Member # 373) on 03-11-2003, 02:15 PM:

Daryl and John

Thanks, it worked!!

Bye
Antonio

Posted by Steve Guttag (Member # 268) on 03-11-2003, 07:13 PM:

I've used the dataport cables...once...I'm sticking with higher quality conntectors...XLR (which are more robust than VGA). The dataport is less sensitive than the other inputs. With the HD-15 you are combining high-level and low-level signals within a common shield and depending on the source, are forced into some rather silly channel groupings.

If you like the VGA cable solution...more power to you, it certainly works and I know of no one that uses them that dislikes them I just don't find them to be the best way to go about wiring sound systems.

Steve

Posted by Dave Macaulay (Member # 813) on 03-12-2003, 09:47 PM:

I don't know if there would be a problem at audio frequencies, but I've had VGA cables used as VGA cables that are CRAP. I use a KVM switch that naturally requires an extra VGA cable for each computer. I bought el-cheapo cables and got an image that was unusable because of the extreme ghosting. Replacing the unbranded ones with Belkin VGA cables produced undegraded images.

Posted by Mark Gulbrandsen (Member # 72) on 03-13-2003, 06:12 AM:

"Now, we do understand that audio quality can degrade if the cable length of a standard VGA cable gets longer than about 2 meters."
______________________________________________________________

John,
That line in your reply makes me want to question the use of them even more.....
If a good quality VGA cable cannot pass audio and remain acceptable on runs of more than 2 meters thats not doing too good. Now it really has me thinking that these cables are marginal performers!! Because a cable is good at high frequencies doesn't necessarily mean it will work well in an entire different bandwidth situation, a situation that the cable was not designed for in the first place. It may be adaquate, but adaquate is not good enough for me, nor is it for the perspective customers I would be selling expensive systems to.

I certainly like the quickness associated with them but it all still leaves me feeling a bit negative on the whole thing due to what is looking more and more like questionable wire. Also just because Protools has facilities built in for using DB connectors, and or VGA cables for audio doesn't mean its the best route to go when cabling up a system, or designing a piece of audio gear. I have no problem with DB connectors for audio use, except that they are not sturdy, and can be difficult to wire up. Hard wiring is still IMHO the most effective quality oriented route to go. Had Phoenix connectors been implemented at least along with DB connectors on alot of really nice "high End" cinema audio gear that has appeared of lately I'd feel a bit better about it all. To each his own then.
It seems retro-progresive that there are a number of fine designs appearing using this built in cabling bottleneck. Using DB to Phoenix adaptors is another possibility but more connectors can also lead to more problems, and systems that are simply not sturdily built.
Mark

Posted by Steve Guttag (Member # 268) on 03-14-2003, 07:15 AM:

Personally...I have no problem with D connectors...but...when one must have several wires comming off of one D-Sub pin...they are not the right tool for the job. If they are strictly 1-to-1 then bring them on...they make for a very neat connector and I can wire them fast.

Steve