With DSP enabled amplifiers being the prevailing power source for line arrays, are you guys setting these up to link limiter gain reductions between the individual limiters in each amplifier? If there is gain shading employed within the array, the limiters will engage at different times, essentially changing the characteristic pattern of the array. Thoughts?
Limiting Within Line Arrays
- Thread starter David Sturzenbecher
- Start date
Re: Limiting Within Line Arrays
My basic thought is that if you're substantially into the limiters you have other issues that are more important than what happens to your shading... like keeping your rig intact.
My basic thought is that if you're substantially into the limiters you have other issues that are more important than what happens to your shading... like keeping your rig intact.
Re: Limiting Within Line Arrays
The goal of limiters is to be there "just in case" something get out of hand-or an accident happens etc.
As others have said-you should not PLAN on running the system into limiting.
If the excuse is "well I'm not being paid enough to bring a bigger rig", then don't worry about what happens to the coverage. The person who won't pay you more doesn't care.
The goal of limiters is to be there "just in case" something get out of hand-or an accident happens etc.
As others have said-you should not PLAN on running the system into limiting.
If the excuse is "well I'm not being paid enough to bring a bigger rig", then don't worry about what happens to the coverage. The person who won't pay you more doesn't care.
Re: Limiting Within Line Arrays
Just to add some thoughts-about limiters in general. It is often discussed as to what is the best "sounding" limiter? WHO CARES. In fact-a BAD- HORRIBLE sounding limiter is probably better. At least that way-some (not all) operators will actually TURN IT DOWN when it hear it sounding bad-realizing this is the limit-HINT HINT!!!!!!!!!!!!!!!! The other operators will keep turning it up because they think that is way it is "supposed" to sound-since that is all they have been exposed to.
Limiters should be there to PROTECT-NOT as a creative sound tool. Compressors are creative tools-so how they react sonically IS a big deal.
Looking for good sounding limiters is like a girl asking if her new car has PINK AIRBAGS. WHO CARES what color they are-if they protect your life! You should never have to use them-they are "just in case" thing. Bring a bigger rig so you don't have to push it so hard!
Now maybe having a "nice sounding" compressor that kicks in a little bit before you hit the limiters (to give a bit of a cushion) is not a bad idea-but that is a different topic.
But it seems that these days-people are forgetting the whole purpose of limiters. Probably because they don't have a good understanding of how they work-how to set them-what the differences are and so forth. Hell- how many people ACTUALLY MEASURE what the limiters are doing-where they "kick in", how they respond etc? I be VERY VERY few do. I have been spending a lot of time lately looking at how various limiters react-and trust me people-it is NOT what the "simple numbers" on them say it is.
You may "think" that it is doing one thing-but is it really? Just because a couple of flashing LED's go off-does it really mean anything-or mean what you think it means?
MEASURE AND CONFIRM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! (and the same goes for the rest of the specs on other products-SPECIFICALLY loudspeakers-but we go there-yet) DON'T just take somebodies word for it.
I bet if you were to ask most people what the differences are (in settings-where to set the threshold-attack and release times etc) between different types and what type is better (power compression-peak-"music power" etc) they could not give you a correct answer. But that doesn't stop them from "talking about them" as if they know what is going on
And why would you choose one type over another-for a particular situation-if you only had one type. For certain types of music (if you only had one limiter and you could adjust it anyway you wanted), I would choose one over another. Change music styles and I would probably want a different type. Depending on the music-the system available-how hard it is going to be pushed and the likely hood of actually hitting the limiters and so forth.
There is no SIMPLE answer! It ALL depends.
If you don't understand the tool and how to use it-it will very often be MISUSED. And then the tool or some other aspect gets blamed. When you bend a nail because you are a lousy carpenter-it is REAL easy to blame the hammer or the nail or the wood it is going into. But if you UNDERSTOOD the parameters around the situation-then YOU would have a much better idea of how to deal with it-and get the nail in nice and straight-with the head right where it needs to be for a particular wood, purpose of nail etc. Finish nails in hardwood floor are very different than nails in a deck. Yet the basic tools (hammer-wood-nails) are the same. How they are used and the intended final usage is what makes you choose a different approach for each one.
And that is another thing that REALLY gets me going-about how LITTLE "the industry" really understands about the gear-what its parameters are-and how gulible they are to marketing-that just seems to totally ignore any real specifications and how many "assumptions" users make based on this "pack of lies".
It is truly amazing to me how some manufactures can throw out a "saying" or a simple single number-and then people "assume" that is correct across the intended usage and how "everything all plays nice and pretty together-so let's all hold hands and smile and have a wonderful day".
It doesn't work that way people.
OK time to get down before I really say what I really think/mean----------------------------------------------------------
Just to add some thoughts-about limiters in general. It is often discussed as to what is the best "sounding" limiter? WHO CARES. In fact-a BAD- HORRIBLE sounding limiter is probably better. At least that way-some (not all) operators will actually TURN IT DOWN when it hear it sounding bad-realizing this is the limit-HINT HINT!!!!!!!!!!!!!!!! The other operators will keep turning it up because they think that is way it is "supposed" to sound-since that is all they have been exposed to.
Limiters should be there to PROTECT-NOT as a creative sound tool. Compressors are creative tools-so how they react sonically IS a big deal.
Looking for good sounding limiters is like a girl asking if her new car has PINK AIRBAGS. WHO CARES what color they are-if they protect your life! You should never have to use them-they are "just in case" thing. Bring a bigger rig so you don't have to push it so hard!
Now maybe having a "nice sounding" compressor that kicks in a little bit before you hit the limiters (to give a bit of a cushion) is not a bad idea-but that is a different topic.
But it seems that these days-people are forgetting the whole purpose of limiters. Probably because they don't have a good understanding of how they work-how to set them-what the differences are and so forth. Hell- how many people ACTUALLY MEASURE what the limiters are doing-where they "kick in", how they respond etc? I be VERY VERY few do. I have been spending a lot of time lately looking at how various limiters react-and trust me people-it is NOT what the "simple numbers" on them say it is.
You may "think" that it is doing one thing-but is it really? Just because a couple of flashing LED's go off-does it really mean anything-or mean what you think it means?
MEASURE AND CONFIRM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! (and the same goes for the rest of the specs on other products-SPECIFICALLY loudspeakers-but we go there-yet) DON'T just take somebodies word for it.
I bet if you were to ask most people what the differences are (in settings-where to set the threshold-attack and release times etc) between different types and what type is better (power compression-peak-"music power" etc) they could not give you a correct answer. But that doesn't stop them from "talking about them" as if they know what is going on
And why would you choose one type over another-for a particular situation-if you only had one type. For certain types of music (if you only had one limiter and you could adjust it anyway you wanted), I would choose one over another. Change music styles and I would probably want a different type. Depending on the music-the system available-how hard it is going to be pushed and the likely hood of actually hitting the limiters and so forth.
There is no SIMPLE answer! It ALL depends.
If you don't understand the tool and how to use it-it will very often be MISUSED. And then the tool or some other aspect gets blamed. When you bend a nail because you are a lousy carpenter-it is REAL easy to blame the hammer or the nail or the wood it is going into. But if you UNDERSTOOD the parameters around the situation-then YOU would have a much better idea of how to deal with it-and get the nail in nice and straight-with the head right where it needs to be for a particular wood, purpose of nail etc. Finish nails in hardwood floor are very different than nails in a deck. Yet the basic tools (hammer-wood-nails) are the same. How they are used and the intended final usage is what makes you choose a different approach for each one.
And that is another thing that REALLY gets me going-about how LITTLE "the industry" really understands about the gear-what its parameters are-and how gulible they are to marketing-that just seems to totally ignore any real specifications and how many "assumptions" users make based on this "pack of lies".
It is truly amazing to me how some manufactures can throw out a "saying" or a simple single number-and then people "assume" that is correct across the intended usage and how "everything all plays nice and pretty together-so let's all hold hands and smile and have a wonderful day".
It doesn't work that way people.
OK time to get down before I really say what I really think/mean----------------------------------------------------------
Re: Limiting Within Line Arrays
Some things that are JUST STUPID!!!!!!! OH-but "so and so" said it-so it MUST be true-NOT!! It is just propaganda to meet a certain objective. That does NOT mean it is correct. But to the unknowing lemmings who follow-they swallow it up every time. They act like zombies and just wander around----------------
Heck-anybody can write an article and get it published in a magazine-that does not mean it is right OR SAFE (how the guy who believes you can change the polarity of subs by swapping the hot and neutral AC legs-yes there was an article about that).
QUESTION EVERYTHING!
Can you say "drink the kool aid"?
I'm sorry-but I see crap all the time in the way of ads/articles and various things that people (many who should know better) that just throw out garbage. ANd they expect people to "believe it"-just because they are "so and so".
Some things that are JUST STUPID!!!!!!! OH-but "so and so" said it-so it MUST be true-NOT!! It is just propaganda to meet a certain objective. That does NOT mean it is correct. But to the unknowing lemmings who follow-they swallow it up every time. They act like zombies and just wander around----------------
Heck-anybody can write an article and get it published in a magazine-that does not mean it is right OR SAFE (how the guy who believes you can change the polarity of subs by swapping the hot and neutral AC legs-yes there was an article about that).
QUESTION EVERYTHING!
Can you say "drink the kool aid"?
Re: Limiting Within Line Arrays
David,
This is an excellent question, and one that explains a lot about why large high end systems are deployed the way they are. I have come to believe that most audio systems, certainly loudspeakers and amplifiers, are characterized by their behavior in limiting... whether it be a tenth of a dB or ten dB. It's a question that's very hard to find the end of, too: gain shading is one thing, but what about the HF boost I applied to the top half of the array to compensate for air loss? What about the wide LF cut I'm using for steering? In cardioid subwoofers, if I only use two I generally need to turn down the rear one - but then the pattern goes all funny in limit.
While sometimes the answer is as simple as "bring more, identical gear" the catch 22 is that the people who will be spending the most time in limit are the ones who can't or won't bring more gear. I am also unaware of any system that allows you to chain gain reduction between elements, so limiting in many line arrays can be one of those "well, do you want it right 90% of the time, or wrong but consistently wrong?". Certainly there are many system decisions where I choose to be consistently wrong, but of course there's always more than one dimension to that decision.
If you figure it out, let me know.
David,
This is an excellent question, and one that explains a lot about why large high end systems are deployed the way they are. I have come to believe that most audio systems, certainly loudspeakers and amplifiers, are characterized by their behavior in limiting... whether it be a tenth of a dB or ten dB. It's a question that's very hard to find the end of, too: gain shading is one thing, but what about the HF boost I applied to the top half of the array to compensate for air loss? What about the wide LF cut I'm using for steering? In cardioid subwoofers, if I only use two I generally need to turn down the rear one - but then the pattern goes all funny in limit.
While sometimes the answer is as simple as "bring more, identical gear" the catch 22 is that the people who will be spending the most time in limit are the ones who can't or won't bring more gear. I am also unaware of any system that allows you to chain gain reduction between elements, so limiting in many line arrays can be one of those "well, do you want it right 90% of the time, or wrong but consistently wrong?". Certainly there are many system decisions where I choose to be consistently wrong, but of course there's always more than one dimension to that decision.
If you figure it out, let me know.
Re: Limiting Within Line Arrays
Bingo! And I'll add to that... the operators (BEs, typically) that do this either like the way the system limiter crunch the dynamics or don't have the clout to get a promoter to hire Enough Rig for the Gig®.
We have a competitor that routinely brings too little because "that's what the client paid for." He has frequent repair and maintenance issues with his speakers. We pass on gigs that we can't do "right" or that would put our rigs in jeopardy. Someone else can do them and spend the profit buying HF diaphragms and reconing speakers.
Bingo! And I'll add to that... the operators (BEs, typically) that do this either like the way the system limiter crunch the dynamics or don't have the clout to get a promoter to hire Enough Rig for the Gig®.
We have a competitor that routinely brings too little because "that's what the client paid for." He has frequent repair and maintenance issues with his speakers. We pass on gigs that we can't do "right" or that would put our rigs in jeopardy. Someone else can do them and spend the profit buying HF diaphragms and reconing speakers.
Re: Limiting Within Line Arrays
It is far more profitable to bring a larger/stronger rig and let it "cruise", than to push a smaller rig to the max-and constantly be blowing drivers.
+1
It is far more profitable to bring a larger/stronger rig and let it "cruise", than to push a smaller rig to the max-and constantly be blowing drivers.
Re: Limiting Within Line Arrays
not to mention it will flat out sound better. in most cases WAY better. IME, a quality rig that is loafing along has a 'sound' to it that is hard to duplicate with anything that is being pushed hard, no matter how high-tech it may be.
In fact, an outdated but oversized, quality rig will outperform a modern but under-sized PA every time. I think for most smaller operations, this is a fact that is overlooked in pursuit of having the 'latest and greatest'.
Obviously, things like rig size and parts availability and lots of other things factor into whether a smaller modern rig is the right tool for the job. But if i were a smaller operation, i'd probably rather have a big ol' pile of KF850s than a 3 or 4 a side 'line array'.
not to mention it will flat out sound better. in most cases WAY better. IME, a quality rig that is loafing along has a 'sound' to it that is hard to duplicate with anything that is being pushed hard, no matter how high-tech it may be.
In fact, an outdated but oversized, quality rig will outperform a modern but under-sized PA every time. I think for most smaller operations, this is a fact that is overlooked in pursuit of having the 'latest and greatest'.
Obviously, things like rig size and parts availability and lots of other things factor into whether a smaller modern rig is the right tool for the job. But if i were a smaller operation, i'd probably rather have a big ol' pile of KF850s than a 3 or 4 a side 'line array'.
Craig Hauber
Sophomore
Re: Limiting Within Line Arrays
OR when there's DJ's and you're not around:x~:-x~
Or the owner's installed more than enough rig, yet to drunk "management" and high "DJ's" they don't realize how they are "boiling those frogs" (attendees) and far exceeding the local noise ordinances! I've learned over the years (in installs) to plan on the limiter used often -even on overbuilt premium setups.
OR when there's DJ's and you're not around:x~:-x~
Or the owner's installed more than enough rig, yet to drunk "management" and high "DJ's" they don't realize how they are "boiling those frogs" (attendees) and far exceeding the local noise ordinances! I've learned over the years (in installs) to plan on the limiter used often -even on overbuilt premium setups.
Re: Limiting Within Line Arrays
I couldn't agree with you more Ivan. Measure a few different limiters and you are likely to be horrified. I think limiter definitions vary even more then parametric filters and their ilk do. It's especially frustrating as a loudspeaker manufacturer, as the second most popular request we receive from customers is "can you recommend limiters for processor/amp X that will protect my system?" The short answer is nearly always "perhaps".
The process to measure and match parametric filters is fairly straightforward. It is a lot of work to support processor du jour, but it's doable. Measuring and accurately characterizing every limiter topology on the market is another matter altogether.
Food for thought: I surveyed approximately twenty processors last year while preparing for an AES presentation. There are a vast assortment of ways to describe each limiter parameter. To wit:
There are also "bonus" parameters found on some limiters:
"rms" and "peak" limiter detectors (the detector circuit, NOT the numeric values found in the GUI) are not strictly defined. For instance, a "peak" detector may be just that, or it may in fact be an rms detector with 3 dB added. If we as an industry cannot come to an agreement on this most basic of limiter functions, how on Earth can we agree what all the other parameters listed above mean?
In short, as Ivan said you have to MEASURE. And you have to measure A LOT of parameters, many of which are interdependent. I don't see how we can realistically talk about how different limiters "sound" when we generally don't even know how they work!
I couldn't agree with you more Ivan. Measure a few different limiters and you are likely to be horrified. I think limiter definitions vary even more then parametric filters and their ilk do. It's especially frustrating as a loudspeaker manufacturer, as the second most popular request we receive from customers is "can you recommend limiters for processor/amp X that will protect my system?" The short answer is nearly always "perhaps".
The process to measure and match parametric filters is fairly straightforward. It is a lot of work to support processor du jour, but it's doable. Measuring and accurately characterizing every limiter topology on the market is another matter altogether.
Food for thought: I surveyed approximately twenty processors last year while preparing for an AES presentation. There are a vast assortment of ways to describe each limiter parameter. To wit:
Threshold: dBu, dBFS, VU, volts, watts, Off/-3/-6/12 dB Note that dBu and dBFS are often simply labeled "dB", so you have to decipher the GUI or look at a help file to learn what they are.
Attack: Milliseconds, Seconds, ms/dB, ms/20 dB, Slow/Medium/Fast
Hold: Milliseconds
Release: Milliseconds, Seconds, dB/seconds, ms/dB, ms/20 dB, Slow/Medium/Fast, multiplier of Attack Time, e.g. 4x or 16x
Attack: Milliseconds, Seconds, ms/dB, ms/20 dB, Slow/Medium/Fast
Hold: Milliseconds
Release: Milliseconds, Seconds, dB/seconds, ms/dB, ms/20 dB, Slow/Medium/Fast, multiplier of Attack Time, e.g. 4x or 16x
There are also "bonus" parameters found on some limiters:
Ratio: Values typically 1.2:1 to INF:1
Over Easy: Integer values from 0 to 10
Overshoot: Values typically 2 dB to 6 dB
PeakStop: Values either On/Off or range 0 dB to 6 dB
Soft Knee: Values typically On/Off
Knee: Soft, Medium, Hard
Corner: Values typically 0 dB to -100 dB
Over Easy: Integer values from 0 to 10
Overshoot: Values typically 2 dB to 6 dB
PeakStop: Values either On/Off or range 0 dB to 6 dB
Soft Knee: Values typically On/Off
Knee: Soft, Medium, Hard
Corner: Values typically 0 dB to -100 dB
"rms" and "peak" limiter detectors (the detector circuit, NOT the numeric values found in the GUI) are not strictly defined. For instance, a "peak" detector may be just that, or it may in fact be an rms detector with 3 dB added. If we as an industry cannot come to an agreement on this most basic of limiter functions, how on Earth can we agree what all the other parameters listed above mean?
In short, as Ivan said you have to MEASURE. And you have to measure A LOT of parameters, many of which are interdependent. I don't see how we can realistically talk about how different limiters "sound" when we generally don't even know how they work!
Re: Limiting Within Line Arrays
Agreed! And they "expect" a single-simple number to "protect" their loudspeakers in every situation/usage. There are different types of failures of loudspeakers-caused by different signals applied. Sometimes it is simple to much power for to long. Other times power has nothing to do with it, but rather a large signal for a short duration causing the loudspeaker to move to far and physically damage itself. Sometimes this is a signal that is to low for the loudspeaker, and sometimes it is well within the freq band-just to large.
Sometimes it is a combination of all of the above. And they want a "single" setting to cover all of those situations? Yeah right!
ALl a limiter does is give a bit of protection. If the loudspeaker is not operated within its parameters, then it gets really hard to keep from tearing it up.
When you really dig-loudspeakers and their ratings/limits etc are VERY complicated-with a lot of "depends" applied. They are not light bulbs.
The more people understand how the gear works, what the limits are, the easier it will be to keep it working for a long time.
Of course you can always "clamp down on it" so that you can't damage the loudspeaker. But then you will be missing out on a lot of output capability.
Agreed! And they "expect" a single-simple number to "protect" their loudspeakers in every situation/usage. There are different types of failures of loudspeakers-caused by different signals applied. Sometimes it is simple to much power for to long. Other times power has nothing to do with it, but rather a large signal for a short duration causing the loudspeaker to move to far and physically damage itself. Sometimes this is a signal that is to low for the loudspeaker, and sometimes it is well within the freq band-just to large.
Sometimes it is a combination of all of the above. And they want a "single" setting to cover all of those situations? Yeah right!
ALl a limiter does is give a bit of protection. If the loudspeaker is not operated within its parameters, then it gets really hard to keep from tearing it up.
When you really dig-loudspeakers and their ratings/limits etc are VERY complicated-with a lot of "depends" applied. They are not light bulbs.
The more people understand how the gear works, what the limits are, the easier it will be to keep it working for a long time.
Of course you can always "clamp down on it" so that you can't damage the loudspeaker. But then you will be missing out on a lot of output capability.