Members DJ Swydez Posted January 28, 2007 Members Share Posted January 28, 2007 Okay, here is how my current setup goes: Laptop Computer --> Mackie Microseries 1202 Mixer --> QSC RMX-2450 Amplifier --> Yamaha Speakers I am using a 1/8 Stereo --> Dual Mono 1/4" Cable to connect my laptop to channels 5 and 6 (the first stereo channel) of my Mackie Mixer. I then connect my Mackie Mixer to my QSC RMX-2450 using a Dual 1/4" Unbalanced cable. Now I have been reading in some posts that using unbalanced cables, I am losing 6 dB of sound in the transfer of sound from my mixer to my amp, is this correct? I also understand that if I were to use a Dual TRS balanced cable in place of my Dual 1/4" unbalanced cable, I would gain 6 dB of sound, correct? My question is: if I run my Mackie mixer at +10 dB vs. the recommended +4dB, would I be getting the same amount of output that I would get using Balanced TRS cables with the mixer running at +4 dB? Would this in effect give me the same sound and setup as using TRS cables? Am I correct? Or is my theory on this wrong? Is there an problem or anything wrong with this setup? Please comment. Thanks. Link to comment Share on other sites More sharing options...
Members Not Serial Posted January 28, 2007 Members Share Posted January 28, 2007 this either holds/doesnt hold water based on whether or not the QSC amp has a differential amp in its input section. the mackie output does have this BTW. you should use balanced in either case IMHO. Link to comment Share on other sites More sharing options...
Members DJ Swydez Posted January 28, 2007 Author Members Share Posted January 28, 2007 this either holds/doesnt hold water based on whether or not the QSC amp has a differential amp in its input section.the mackie output does have this BTW.you should use balanced in either case IMHO. I know the my Mackie mixer can send either a balanced or unbalanced signal, depending on which type of cable is connected. I also know the QSC amp can receive either a balanced or unbalanced input, depending on which type of cable is connected. How will I know if my amp has a "differential amp"? Would that be on a spec sheet or in the owner's manual? Does anyone know if my QSC RMX amp would have a "differential amp"? If not, would I be losing any sound/signal in the process turning up the mixer and using the above setup? (Btw, I know where to set the gain knobs on my Mackie mixer to achieve either level of output. And I have tested that setting with all different types of music from my computer and have established that it will not clip the mixer at either setting. I also have my software set to restrict the gain from the music to be no more than +0 dB at all times leaving my computer, so there would not be any unexpected "peaks" in the music because my computer restricts the level.) Link to comment Share on other sites More sharing options...
Members Not Serial Posted January 28, 2007 Members Share Posted January 28, 2007 i am pretty sure the qsc does. even the the most cheepy amps i have available to me have unbalanced/balanced inputs. sometimes its called a servo balance something or other. i dont think your losing any sound doing it unbalanced. i have one peice of equipment that will not output to an unbalanced input. its a white 4200 and if i put it into an unbalanced input i get zero sound. nada. not applicable to you, but perhaps interesting. i beleive when the chain is reversed (unbalanced output into balanced input) this would refer to your OP. sound would pass at a lower level. i think your fine with your qsc/mackie unbalanced connection. but i still would go balanced. i'm just like that. Link to comment Share on other sites More sharing options...
Members DJ Swydez Posted January 28, 2007 Author Members Share Posted January 28, 2007 but i still would go balanced. i'm just like that. Okay good, so I am not losing any signal using my setup and it will work. And btw, I will eventually pick up a balanced cable, I just don't feel like driving 1 hour round trip to go to GC or spending more money on my rig right now if my current setup works. Thanks for your help and input! Link to comment Share on other sites More sharing options...
Members DJ Swydez Posted January 28, 2007 Author Members Share Posted January 28, 2007 Two last questions. Which would be better to buy when I eventually do buy a new cable: a Balanced Dual TRS-TRS cable or a Balanced Dual TRS-XLR(M) Cable? Does it really make a difference which I get? Is one better or worse than the other? And this way when I get a balanced cable, I can have my current unbalanced cable as a backup cable. Also, does it matter if I run my mixer in the +6 dB to +10 dB range vs. the recommended +0 dB to +4 dB range? Which is better? Link to comment Share on other sites More sharing options...
Members Not Serial Posted January 28, 2007 Members Share Posted January 28, 2007 one is not better than the other. i prefer XLR because they lock and maintain a connection for a longer period of time (in terms of many years without being removed - perhaps argueable in either case) if you are putting up, running a few hours, tearing down; a TRS - TRS should work fine. does your QSC also have XLR inputs? in that case i would get a pair of XLR mic cables. Link to comment Share on other sites More sharing options...
Members DJ Swydez Posted January 28, 2007 Author Members Share Posted January 28, 2007 does your QSC also have XLR inputs? in that case i would get a pair of XLR mic cables. Yes. My QSC has both XLR(F) inputs and 1/4" or TRS inputs, which is why I was also asking about XLR inputs. Only problem with using XLR mic cables is that I can't use them. My Mackie mixer only has 1/4" outputs, which are both unbalanced and balanced. Whichever cable I get has to have 1/4" or TRS jacks on one side of it. Too bad tho... that would be an easy solution. Also, if I wanted to connect another amp to power some subs, could I run a set of XLR-XLR cables from the QSC's inputs to the inputs of the other amp? The QSC's XLR and 1/4" inputs are connected. Would this work? Link to comment Share on other sites More sharing options...
Members Not Serial Posted January 28, 2007 Members Share Posted January 28, 2007 your 1202 has no xlr outs? wow. we have four or so at one of my jobs and they all have xlr outs. thats interesting. (i have a 1604 that does NOT have xlr outs) i beleive the two sets of inputs on your amp are paralleled - usually that kind of setup is. which qsc amp do you have if you dont mind? i use 1802's and 3402's a lot and i do not recall seeing a TRS input in them, but i only hook speakons to them as they stay racked and wired to a crossover. Link to comment Share on other sites More sharing options...
Members Not Serial Posted January 28, 2007 Members Share Posted January 28, 2007 Also, does it matter if I run my mixer in the +6 dB to +10 dB range vs. the recommended +0 dB to +4 dB range? Which is better? sorry i missed this one. i dont know. i have long been suspect of mackie's placement of zero. i have no hard evidence to back this up but it seems low to me compared to allen&heath mixers. it could very well be in the correct spot. Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 28, 2007 Members Share Posted January 28, 2007 edit for duplicate post Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 28, 2007 Members Share Posted January 28, 2007 I have one peice of equipment that will not output to an unbalanced input. its a white 4200 and if i put it into an unbalanced input i get zero sound. nada. That's because it most likely has either a transformer balanced output, which requires pin 1 to be connected to either pin 2 or pin 3 (depending on polarity) or it has an unbalanced (or ground compensated) output on a "balanced" input connector (or term strip) and if it's pin 3 hot, connecting pin 1 to pin 2 for example. Link to comment Share on other sites More sharing options...
Members DJ Swydez Posted January 28, 2007 Author Members Share Posted January 28, 2007 your 1202 has no xlr outs? wow. we have four or so at one of my jobs and they all have xlr outs. thats interesting. (i have a 1604 that does NOT have xlr outs)i beleive the two sets of inputs on your amp are paralleled - usually that kind of setup is.which qsc amp do you have if you dont mind? i use 1802's and 3402's a lot and i do not recall seeing a TRS input in them, but i only hook speakons to them as they stay racked and wired to a crossover. Yea, I am using a Microseries 1202, which is an older discontinued model, which does not have XLR outs. I use a QSC RMX-2450, which has XLR, barrier strip, and 1/4" (TRS) inputs and has Speakon and Binding Post Outputs. Link to comment Share on other sites More sharing options...
Members boomerweps Posted January 28, 2007 Members Share Posted January 28, 2007 Balanced cable is balanced cable, TRS or XLR and both should be twisted pair + shield. The only advantage of the XLR is a latching connector on most gear. In your case with the TRS only option on your mixer, get whichever saves you $ between TRS to TRS and TRS to XLR. It's the receiving gear that determines the +6dB increase in INPUT GAIN on that receiving gear, accepting a balanced signal. The purpose of balanced cable and connections is getting rid of NOISE and keeping it out. That said, PA's ran unbalanced for a long time and you are stuck with TR returns on older snakes. If you don't have noise that's objectionable, unbalanced is fine. Balanced just helps prevent noise in those electrically noisy enviroments. I just looked over the RMX manual and it only references sending OUT an input signal in PARALLEL or BRIDGED mode using the second side's input. Yes, the XLR & TR/TRS inputs are electrically paralleled. I'd ask over at the www.QSC.com forum about it to KNOW for sure. Boomerweps Link to comment Share on other sites More sharing options...
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