This means input clipping? If set too low a level and the input signal music/movie was many times greater for the input it would start to distort. With the volume being at higher level there is less chances of clipping happening.
BMWCCA
Those links were very helpful.
that is funny quote "11"
Nigel Tufnel: The numbers all go to eleven. Look, right across the board, eleven, eleven, eleven and...
Marty DiBergi: Oh, I see. And most amps go up to ten?
Nigel Tufnel: Exactly.
Marty DiBergi: Does that mean it's louder? Is it any louder?
Nigel Tufnel: Well, it's one louder, isn't it? It's not ten. You see, most blokes, you know, will be playing at ten. You're on ten here, all the way up, all the way up, all the way up, you're on ten on your guitar. Where can you go from there? Where?
Marty DiBergi: I don't know.
Nigel Tufnel: Nowhere. Exactly. What we do is, if we need that extra push over the cliff, you know what we do?
Marty DiBergi: Put it up to eleven.
Nigel Tufnel: Eleven. Exactly. One louder.
Marty DiBergi: Why don't you just make ten louder and make ten be the top number and make that a little louder?
Nigel Tufnel: [pause] These go to eleven.
I can’t find the old JBL cinema manual in pdf form for the 1993 edition which I have in paper form only.
JBL 4675
108db @ 1m
82db @ 20 meters
Noise floor
24db @ 1 meter
-2db @ 20 meters
The image is from the 2003 edition
Crown SPL db calculator
http://www.crownaudio.com/apps_htm/designtools/elect-pwr-req.htm
SPL db calculator
http://myhometheater.homestead.com/splcalculator.html
When I worked for Snell & Wilcox, one of the lads in engineering had hand-built a noise generator with a knob where the numbers rotated beneath a little window, 1-10 like normal. One day I had it on 10 and noticed that there was an 11 visible after the 10! The potentiometer would not turn that far, so I guess it would need a special "11" pot to get that far...
Mike Scott in SJ, CA
Drive 'em to the Xmax!
Just as another example, I worked another show with the guys from Southard Audio yesterday(www.southardaudio.com), and all of the amps in all of the many, many amp racks (football stadium show to a crowd of thousands) were specifically pre-set at less-than-wide-open, balanced to get the most from the mixer/crossover/loudspeaker management they were grouped with.
I don't think you'd get much work on Broadway with that philosophy. Professional-level dramatic & musical theater productions absolutely demand silent systems.If any one is worried about amplifier or mixer noise in a live situation they should get another hobby.
Allan.
je
As the original poster, I believe I get it, running the amps full up decreases the chance of a rare clipping incident while increasing the possibility of floor noise. However when I had my L300s (with a Crown DC300-home system) I was in the habit of running the amp full and having the pre at 1/3 to 1/2 when I was often impressing myself with the L300s punch and clarity. I am now using L166s with another DC300, generally running the amp at 2/3s with the pre at a little better than 1/3.
No, running them at full actually has nothing whatsoever to do with preventing clipping. The amp will produce full power regardless and if you set the attenuators correctly you'll actually decrease the possibility of someone coming in and cranking the system into clipping, not the opposite. The noise floor isn't a possibility, it's a reality. Setting the amp correctly in relation to the pre-amp just keeps the noise floor as low as possible.
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
A lot of the power amps that I deal with do not have attenuators. The only time I can think that I would use an attenuator is when I have an amp failure and I need to replace it with somthing larger. Most of the current generation rack gear and mixers have unbeleivable noise figures and so do the amplifiers. Feel free though to do as you wish. I have only been doing live sound reinforcement since 1981 so what would I know. I can't think why I would want any work on broadway though.......
Not necessarily so. It is not the amp output stages clipping that is of concern but the preamp overloading the input stages and this causing the clipping, just as the master volume is supposed to do on a guitar amp.
Taken it to the extreme, set the amp at "1" such that you have to turn the preamp up so far that its output will clip the input stage of the amp and the amp will never see its full power.
Thats what I thot when I acquired the amp ....in reality, I find that it makes NO difference....its quiet anywhere that its set, and that is after a lot of experimentation.
The only benefit that I've found to setting the amp lower (more attenuated) is that there is now more granularity to the preamp volume control.
As for stray hands hitting the volume control on the preamp ?? There are only 2 of us here and she knows better than to touch the stereo.
dead-on right....many do NOT have more than just a power switch.
Some kind of happiness is measured out in miles
And many cars have only three, four, or five forward gears, too. Doesn't mean you won't use sixth gear in a car that has one.
I know we're picking at nits on this now but the original question was about the proper way to use the "gain controls" on a Crown amp. I believe that question has been answered. For those unfortunate enough not to have input attenuators on your power amps, you'll just have to muddle along in blissful ignorance, content that your life is so simple!
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
And the first thing one reaches for when they need to put the accelerator down? The gearstick/attenuator. If you are talking about using the attenuators in a home theatre system as safety devices I can see the merit but why not set the internal levels in your amp so that the masters cant run any harder than what you want to be a maximum level. I dont want to have to remember where poweramp levels have to be set when turning a system on and off and I certainly dont want to put marks on the gear where it should be set. I also never mark the desk so I know what channel is what, but that is another subject.
Allan.
I was referring to the fact that the Crowns have attenuators indicating one might want to actually use them. It's not a clutch-shift-throttle analogy, but if you want to play it that way, fine! But it doesn't work even if you consider different final-drive ratios, or whether or not the transmission is an overdrive box, or not.
And why would you have to move the input attenuators on the amp every time you turned it on? Are you just looking for reasons to disagree?
Again, the original question was about how to use the attenuators on a Crown amp. If your amp doesn't have them, then by all means don't waste your time contemplating your navel: You just don't have them. If a Crown owner doesn't want to use them properly, then just crank them wide open and have fun using that 1/4 of the range of your pre-amp's volume pot that you'll ever use. To each their own.
Now if you're just wanting to "buy and argument" in the best Monty Python manner, we'll just have to see how high up on that tree you can pee, won't we?
http://www.youtube.com/watch?v=kQFKt...eature=related
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
I use my input attenuators to help manage the S/N in my active system. When you have compression drivers running at over 110db it certainly helps if you can adjust the amps sensitivity to help keep the noise down. It would be a problem for me if they didn't have them.
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Rob
"I could be arguing in my spare time"
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