Members DJ Swydez Posted March 1, 2007 Members Share Posted March 1, 2007 Is this statement accurate? I was reading online and came across, wondering whether it is true or not? "As a general rule, the best performance of Crown, QSC, Peavey, American Audio, and most of the other current amplifiers is best utilized at the higher settings on the amplifier, with the mixer to 'control' the level." Any thoughts? Link to comment Share on other sites More sharing options...
Members tlbonehead Posted March 1, 2007 Members Share Posted March 1, 2007 I don't know. I ordinarily just set my amps' gains wide open or close to it and control with the board. Link to comment Share on other sites More sharing options...
Members Mogwix Posted March 1, 2007 Members Share Posted March 1, 2007 No idea. I heard it's better for the amps to run them wide open and let the mixer do the attenuation. Which in my view can only benefit by giving you more headroom at the mixer (ie. you don't have to crank the output of the mixer into clip, sending a distorted signal to the amps which in turn can blow your speakers). Link to comment Share on other sites More sharing options...
Members tremendo Posted March 1, 2007 Members Share Posted March 1, 2007 Yeah, that's what I've understood. Your better running the amps near full, since they won't overdrive anything, as long as the input is not too high. That allows you to keep the input lower and cleaner. That being said, I normally run my powered Yorkvilles volume control at 75% for gigs, 50% for practice. I just don't want them wide open in case a cable pops or something. Link to comment Share on other sites More sharing options...
Members Phil Clark Posted March 2, 2007 Members Share Posted March 2, 2007 The potential danger of not running the amps full open is someone playing sound expert and turning them up on you, which in the best situations you notice and drop the volume of the overal mix at the board before you do any damage to the amps or anyone's hearing. In the worst situations the sudden jump in volume blows your drivers on your horns. And lest you say "people don't do that" it happened to me. Although safely since we always run the amps attenuators full open and control the overall levels from the board so what the person did was simply turn down the mids on one side of the rig. Annoying, yes... damaging, no. Link to comment Share on other sites More sharing options...
Members 6Imzadi Posted March 2, 2007 Members Share Posted March 2, 2007 Use this link as a reminder of past discussions about this subject. Link to comment Share on other sites More sharing options...
Members agedhorse Posted March 2, 2007 Members Share Posted March 2, 2007 The disadvantage of running amps with the attenuators way down is that you run the chance of clipping your drive electronics before the limiters actuate, or you reduce the amount of drive headroom available for the limiter to use in the limiting process. Link to comment Share on other sites More sharing options...
Members stvcmty Posted March 2, 2007 Members Share Posted March 2, 2007 The potential danger of not running the amps full open is someone playing sound expert and turning them up on you, which in the best situations you notice and drop the volume of the overal mix at the board before you do any damage to the amps or anyone's hearing. In the worst situations the sudden jump in volume blows your drivers on your horns. I like the crown CE series way of dealing with that possibility. The knobs are removable with caps to cover the holes. Right now, I have my amps set so when the mixer peaks, the amps clip. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted March 2, 2007 Members Share Posted March 2, 2007 If your amps have good limiters, I think it actually sounds good to size and set your system so that the limiters get exercised somewhat. Link to comment Share on other sites More sharing options...
Members DJ Swydez Posted March 2, 2007 Author Members Share Posted March 2, 2007 I have all of the knobs set on my mixer, and have their settings memorized, so I know exactly where the mixer clips. I have the gain on channel 5-6 and slightly past the detent and the master output knob at the detent when I run my mixer full open. If I take it past the detent on the master knob, all of the yellow lights become solid on my output meter, and if I go past there the begins to clip mixer clips. I have tried to clip the mixer the way I have it set with all sorts of inputs from my laptop, CD players, iPod, etc. at full volume and cannot get the mixer to clip unless really I really crank up the bass (+9 or 10 dB I believe... which I never do!) so I think I am pretty safe. I usually set my amp to a certain position (usually about 12 o'clock) and then use the mixer to control my gain. If I need more power, I slowly turn down the mixer's master knob while raising the 2 amp knobs and then use the mixer to control accordingly. I personally like having the gain on my mixer up a little higher at gigs because it provides a nice light show that moves to the beat of the music on top of my work station which people often look at. To each his own. Thanks for the input guys! Link to comment Share on other sites More sharing options...
Members agedhorse Posted March 2, 2007 Members Share Posted March 2, 2007 Right now, I have my amps set so when the mixer peaks, the amps clip. Which on the CE amps doesn't matter since there are no limiters. But, on amps with limiters, this is a terrible way to run things in that you would not be using the limiters in the amps at all. You need the amp to limit BEFORE the mixer (or drive electronics) clip, and the difference between the clip point of the amp and the clip point of the mixer is called the compliance range. For live audio, 12dB is the minimum that I find as reasonable. This way you can hit the limiters on peaks and not worry about distorting your drive signal. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted March 2, 2007 Members Share Posted March 2, 2007 Which on the CE amps doesn't matter since there are no limiters.But, on amps with limiters, this is a terrible way to run things in that you would not be using the limiters in the amps at all. You need the amp to limit BEFORE the mixer (or drive electronics) clip, and the difference between the clip point of the amp and the clip point of the mixer is called the compliance range. For live audio, 12dB is the minimum that I find as reasonable. This way you can hit the limiters on peaks and not worry about distorting your drive signal. Exactly! Use your limiting options to their best or wherever they are located. Link to comment Share on other sites More sharing options...
Members les_rokr Posted March 2, 2007 Members Share Posted March 2, 2007 Makes sense to me.. Link to comment Share on other sites More sharing options...
Members Audiopyle Sound Posted March 2, 2007 Members Share Posted March 2, 2007 I generally do leave the amp gains wide open on my systems, with passband gain and limiting set in the processing ahead of them, only because my systems are operated by others after I set them up. Fortunately, everything I run in front of the amp input is quiet. If you have any noisy gear in your signal chain, then having the amp gain wide open is going to amplify the noisefloor, something to be avoided if possible. For that reason, many people will set the amp gain as low as is reasonable and run the mixer levels hot. Link to comment Share on other sites More sharing options...
Members agedhorse Posted March 2, 2007 Members Share Posted March 2, 2007 For that reason, many people will set the amp gain as low as is reasonable and run the mixer levels hot. The key word in this is "reasonable" Link to comment Share on other sites More sharing options...
Members Crownman Posted March 2, 2007 Members Share Posted March 2, 2007 I run my amps wide open. I rather clip the amp than send a clipped signal to it. Link to comment Share on other sites More sharing options...
Members OMNIFEX Posted March 2, 2007 Members Share Posted March 2, 2007 Is this statement accurate? I was reading online and came across, wondering whether it is true or not?"As a general rule, the best performance of Crown, QSC, Peavey, American Audio, and most of the other current amplifiers is best utilized at the higher settings on the amplifier, with the mixer to 'control' the level."Any thoughts? I own Crown, Peavey, QSC (Among others) and it's far from the truth. The lower the settings the lower the signal to noise ratio. All offer different input sensitvity ratings as well. Link to comment Share on other sites More sharing options...
Members dboomer Posted March 2, 2007 Members Share Posted March 2, 2007 so I know exactly where the mixer clips. Do you really know where your mixer clips ... or do you just know when the lEDs come on. That may not be the same thing. Many mixers will clip internally before there is any indication on the clip lights. Link to comment Share on other sites More sharing options...
Members dboomer Posted March 2, 2007 Members Share Posted March 2, 2007 I generally do leave the amp gains wide open on my systems, with passband gain and limiting set in the processing ahead of them, only because my systems are operated by others after I set them up. If you have the limiting set correctly then there is no reason left to run the amps wide open. You are throwing away sN ratio. Link to comment Share on other sites More sharing options...
Members dboomer Posted March 2, 2007 Members Share Posted March 2, 2007 I own Crown, Peavey, QSC (Among others) and it's far from the truth. The lower the settings the lower the signal to noise ratio. All offer different input sensitvity ratings as well. The thing that nobody has mentioned is if you are using amps that have different gains ... most notably QSC RMX series ... how do you balance the amps? Peavey, Crest and most higher end Crowns have fixed gains but amps that have fixed drive will be all over the map if you are using multiple amps in a bi/tri amped setup. Also anyone using a Driverack or our VSX 26 will want to back the amps down. If there is anything digital in the chain it will need to be driven harder to keep the bit depth up. Digital gear does have a sweet spot and that spot is ...to be driven as close to full scale as possible. Link to comment Share on other sites More sharing options...
Members OMNIFEX Posted March 2, 2007 Members Share Posted March 2, 2007 The thing that nobody has mentioned is if you are using amps that have different gains ... most notably QSC RMX series ... how do you balance the amps? Peavey, Crest and most higher end Crowns have fixed gains but amps that have fixed drive will be all over the map if you are using multiple amps in a bi/tri amped setup. Also anyone using a Driverack or our VSX 26 will want to back the amps down. If there is anything digital in the chain it will need to be driven harder to keep the bit depth up. Digital gear does have a sweet spot and that spot is ...to be driven as close to full scale as possible. Agreed. Whoever DJ Swydez got that quote from is probably using one amplifier. Try using 14+ amplifiers and it's a whole different ball game Link to comment Share on other sites More sharing options...
Members Audiopyle Sound Posted March 2, 2007 Members Share Posted March 2, 2007 If you have the limiting set correctly then there is no reason left to run the amps wide open. You are throwing away sN ratio. The point that I didn't express well is that while others are operating the system, I am gone. If I left the amps with the gains turned down someone could turn them up, thereby defeating my limiting as well as my gain balancing done in the driverack. Link to comment Share on other sites More sharing options...
Members Audiopyle Sound Posted March 2, 2007 Members Share Posted March 2, 2007 Also anyone using a Driverack or our VSX 26 will want to back the amps down. If there is anything digital in the chain it will need to be driven harder to keep the bit depth up. Digital gear does have a sweet spot and that spot is ...to be driven as close to full scale as possible. If one drives the input of the processor with a hot signal, but uses the passband output gain to drop the level to the amplifiers, does that still meet this criteria? Link to comment Share on other sites More sharing options...
Members agedhorse Posted March 2, 2007 Members Share Posted March 2, 2007 Also anyone using a Driverack or our VSX 26 will want to back the amps down. If there is anything digital in the chain it will need to be driven harder to keep the bit depth up. Digital gear does have a sweet spot and that spot is ...to be driven as close to full scale as possible. Provided you have word depth adequate ADC headroom for the limiter to function properly at the maximum amount ot operational limiting that the system is designed around, otherwise the ADC will distort as the limiter limits. Anythime you use a limiter, you must have adequate gain/resolution from which to take gain away from. Link to comment Share on other sites More sharing options...
Members W. M. Hellinger Posted March 2, 2007 Members Share Posted March 2, 2007 Do you really know where your mixer clips ... or do you just know when the lEDs come on. Exactly what I was gonna ask. Link to comment Share on other sites More sharing options...
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