Digital Recreation of a Big PA System

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Hi community.

I'm a composer, producer & sound-obsessed "mastering engineer".

I'm developing a particular mastering style where I'm essentially trying to recreate the sound of a big PA system, but at a digital level. Please let me explain:

So my top reference for how I want music to sound is the way I heard it through different systems in a few nightclubs mainly, but also some other speakers I've come across. I always paid attention to the characteristics of the sound and tried to make as many mental notes about it as I could. What I'm trying to do now is to recreate those characteristics as close as possible but within a digital audio workstation, that is by splitting the signal into different bands and filtering/eqing each of them as if they were a subwoofer, woofer, tweeter, etc.

Now, I understand this is something I could never truly recreate because of the simple fact that the sound wouldn't be coming out of that actual speaker. I also understand in the process I'm limited by my own listening environment, in this case KRK Rokit 8 inch studio monitors in a 3x7 metre apartment.

Still, I'm on this obsessive mission to fully design a chain of separate driver emulators and in the process somewhat recreate how it would sound (to me) through this ideal big PA system.

It's driving me insane. Not only because I don't know exactly how these ideal speaker drivers would be set up, their frequency ranges, crossovers, etc. but also because I don't know how to emulate the same filtering they have. I've researched and in some cases guessed regions in the frequency spectrum where the bands may be split, but it's the filtering which is driving me the craziest. The plugins I know and have tried alter the sound in a way I don't want. They are not truly customizable as they don't have the curves you would find in a speaker crossover but most importantly they are not truly clean, they squash the sound, they create pressure instead of liberating it, they just don't do what I want them to do basically...

So my first question to you all is if you know of a software that's designed to create speakers, with filters, ranges, crossovers, etc. but that actually processes an audio signal in the software itself, a digital rendering of what the speaker setup would be later on.

I know this may not make much sense, but it could also be a plugin that you know works in the "same" way a physical crossover in a loudspeaker would, not necessarily one specifically designed for building speakers.

The second question would be if you know of a good list with all the values: frequency ranges, crossover points, slopes, etc. for a big PA system that sounds very clean, very airy, but beautifully full and immersive. A system that blasts the sound at you but never tires your ears, that plays back the bass in your face & yet constantly breathes and feels like a soft cushiony mattress under your feet, that plays back shimmery highs that never sound strident. There's never a buildup of energy, no matter what. This is somewhat the description I can think of for this ideal system I want to recreate.

A third question: recently I came to the conclusion that in these systems I liked some parts of the frequency spectrum felt somewhat removed, especially around 200hz. It's the only way I found to create some of this breathiness I mentioned. Still, limited by the way plugins work I can't seem to find the perfect spot, and thought I'd ask if anyone has any info on this point specifically.

Well, thank you so much for reading & for whatever answers you may have. Also, please let me know if I should post this in another section :)

David
 
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If you want a big PA theres no software that gives you the dynamic headroom and low distortion of multiple quality drivers and cabinets with proper amplification and processing. You either spend the money for it, because you can’t duplicate it on the cheap with lesser drivers, cabinets , and amps no matter what the software is.
 
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There's no speaker emulator plugin that I know of. PA systems typically shed a bit of upper bass to midbass energy that is prevalent in home audio, i.e baffle step. I'm not aware of any other major changes, and that might be reasonable starting point - a mild shelf in the <700Hz range, not by more than 1-1.5dB.

So you can't have both.
 
If you want a big PA theres no software that gives you the dynamic headroom and low distortion of multiple quality drivers and cabinets with proper amplification and processing. You either spend the money for it, because you can’t duplicate it on the cheap with lesser drivers, cabinets , and amps no matter what the software is.

Thanks for the reply ticknpop. I may not have explained myself properly. I don't actually want a big PA, this isn't for listening purposes, but actually for mastering music in a particular way so that the sound resembles the tonal characteristics of how it would sound to me through a big PA. My question was if there was a software that can process sound with the actual curve and crossover points that would be later applied to a real speaker (not actually emulate what the speaker itself physically does) so that I can experiment with those filters instead of the ones designed for music production.
 
There's no speaker emulator plugin that I know of. PA systems typically shed a bit of upper bass to midbass energy that is prevalent in home audio, i.e baffle step. I'm not aware of any other major changes, and that might be reasonable starting point - a mild shelf in the <700Hz range, not by more than 1-1.5dB.

So you can't have both.

Thanks Sangram. I just looked it up and couldn't find a connection between 700hz and the baffle step...

From what I understood the baffle step is to compensate for the way the sound travels physically within the enclosure and is different for every speaker, which in my case wouldn't be relevant since I'm not literally building a speaker.

Or do you mean that PA systems usually have an EQ with a shelf at around 700hz that is meant to change the way the music sounds?

Thanks again!
 
Don´t worry too much speakers themselves, that part is easy, you don´t need to model individual speakers, crossover elements, etc. just apply a generic "PA speaker system" EQ.
In the quest for efficiency and SPL their designers do not worry too much about distortion so at least mid/highs will be harsh, nor deep bass nor extended transparent highs and to boot at least at mid/high frequencies multiple drivers side by side will cause huge peaks and dips because of comb filtering.
Line arrays try to minimize that, keep phase coherent, etc. butbthatbis achieved at large shows.
The typical Club/small theater/school/church/local band show/etc. will often be the conventional type, just a few cabinets stacked the best way possible.

What you call "PA Sound", which you remember and try to emulate, is HEAVILY filtered by inadequate (and large) rooms, chock full of resonances all over the place, combined to looonnnnggg reverberation times and signal bouncing all over the place.

So your quest is part in the EQ domain and part in the *time* domain.

I´ve lived surrounded by live sound for over 50 years now so know very well what you are trying to achieve, it´s definitely a *unique* sound.

EDIT:
My question was if there was a software that can process sound with the actual curve and crossover points that would be later applied to a real speaker
That´s not the way, read my description above.

and: maaaayyyybbbbeeeee somebody wrote a plugin which simulates that, who knows?

Again: room modes and time problems are WAY more important than actual speaker response.
 
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Some notes:

- PA systems operated at sensible volumes will likely have lower distortion levels than your monitors.
- PA systems sometimes have LF boosts built-in. Search online for "low frequency haystack". I've heard of people putting <80Hz +10dB over the rest of the range. I keep my PA systems flat. YMMV.
- Controlled directivity will be a big aspect of the PA system sound. Most PAs are designed for audience coverage, and specifically to avoid throwing sounds at the walls and ceilings.


In short, I don't think there's a way to reproduce that sound with EQ alone. There's too much going on which isn't related to the frequency response.

Chris
 
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Thanks Sangram. I just looked it up and couldn't find a connection between 700hz and the baffle step...

Baffle step (I should have specified it as Baffle Step Loss, which is probably more accurate) is the change in radiation from 4pi to 2pi, which affects the acoustic output above and below the step frequency by 6dB.

This is compensated for in almost all speakers using some kind of circuitry, either active or passive. The size of the driver and size of the baffle affect this, from memory an 8" woofer on a 9-10" baffle would be about 700Hz. The reason the compensation is less than 6dB is because of expected boundary gain, which will boost the LF output a bit.

Of all the PA systems I've come across, this compensation is almost never used as it reduces between 1.5 and 3.5dB of raw acoustic output due to losses within the crossover. It is one of the most pronounced acoustic signatures I've learnt to hear. Some engineers will dial back some of the step boost with active EQ, but some won't.

Speakers sound very different between having this compensation and not (and varying levels, distance to boundary, driver size, among other things). I'm not saying it will be exactly what you are looking for, but it's a starting point. As mentioned the distortion is also a factor, when trying to approximate output levels between PA speakers and studio monitors, even big ones like the KRKs.

The closest recording I can think of is In Square Circle, but even that is not exactly it. Maybe Give in to Me and One (Metallica) also remind me of that specific live sound.
 
I'm not sure if this helps or not but I'll provide it anyway.

A live recording done well may at least hint of what you are after, in this case my reference is a concert I attended and I have listened to the recordings many times after and it is very well done and actually rather representative if played back trough a capable system and at a similar level, though it will never be the same with regards to the dynamics and physical sensation it is at the very least close enough for some real enjoyment.

The Pink Floyd Pulse -94 tour used Turbosound flashlight, and it is to this day the best concert sound I have ever heard, period, and the record captures some of that, but being a recording it has been a fair bit polished and compressed but with a balance that still retains very much of the feel and sound of the live event it self, only the sheer physical sensation of the sound is missing, it is one of these records that really takes me back to the event it self in a very good way.

Maybe that record can in some way help, if at the very least to give you an idea, high quality PA systems, if used properly and with a skilled tech. will give you goosebumps beyond what one might think is possible, it is really impressive and being live it puts most of all other music reproduction systems to shame in my opinion.
 
not sure why you want to do that....
i'm currently looking into the possibility of auralizing sims as a loudspeaker development tool but that's a world away from what your attempting to do.


it would be possible to emulate an EQ curve that's representative of a PA system but that ignores the contribution of the source sounds on stage and the acoustic environment.
 
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Can't one get an "effect" made from an impulse and convolution of a real acoustic space, in this case a real PA in a specific venue?
That may be the way, if the impulse is recorded not 1 meter in front of speaker as most are but, say, 15/20 meters away, where an average audience seat would be.
In that case it will include room resonances, even part of that slapback echo that Chris mentions, sound absorption by audience body and clothes, etc.
Good idea since by definition it will simulate/reproduce what that particular seat owner hears.
 
Thank you JMFahey :)

Don´t worry too much speakers themselves, that part is easy, you don´t need to model individual speakers, crossover elements, etc. just apply a generic "PA speaker system" EQ.

Part of the reason I feel the need to split the signal is because I end up wanting to make different effects to the different bands, something I can't do when I'm dealing with the music as just one signal. The main reason though is because my perception & the info I find online tells me that in a speaker each driver functions differently and they literally express the signal each with its own characteristics, so again, this is what I'm trying to mimic in the box, and I can't think of any other way than to split the signal and design the crossovers, etc.

Still, I wasn't aware of a generic PA system eq, so I looked it up and found one which could really help me, at least to affect the entire signal before splitting, which is what would happen in a real venue. Thanks!!

In the quest for efficiency and SPL their designers do not worry too much about distortion so at least mid/highs will be harsh, nor deep bass nor extended transparent highs and to boot at least at mid/high frequencies multiple drivers side by side will cause huge peaks and dips because of comb filtering.
Line arrays try to minimize that, keep phase coherent, etc. butbthatbis achieved at large shows.
The typical Club/small theater/school/church/local band show/etc. will often be the conventional type, just a few cabinets stacked the best way possible.

I got a bit lost here, I'm completely ignorant about all this... I didn't understand the relationship between this and the digital realm in which I'm working.

What you call "PA Sound", which you remember and try to emulate, is HEAVILY filtered by inadequate (and large) rooms, chock full of resonances all over the place, combined to looonnnnggg reverberation times and signal bouncing all over the place.

It's funny you should say this, because actually the references I have for this perfect listening experience were all outdoors, where there was almost no reverb, and I was able to focus much better to analyze what it was I liked so much about the way it sounded. In fact I have a really difficult time listening to music at higher volumes anywhere indoors but especially nightclubs because the acoustics drive me crazy (except when the music is very well produced/mastered and the DJ is limiting or EQ'ing in a particular way that makes everything sound nice and comfortable).

I admit I'm a bit excessively sensitive & picky with this :p In fact now at home I suffer headaches from extreme highs and plugged ears from lows, as I literally feel the soundwaves hitting my ears, changing the atmospheric pressure around me. It's as if once I become aware of these things I'm cursed to experience them all the time. This is why it's difficult for me to listen to music without starting to feel it has too much of this or too much of that, which is what led me to this mission :D

Thanks again JMFahey

By the way, soy de Buenos Aires también!
 
Some notes:

- PA systems operated at sensible volumes will likely have lower distortion levels than your monitors.
- PA systems sometimes have LF boosts built-in. Search online for "low frequency haystack". I've heard of people putting <80Hz +10dB over the rest of the range. I keep my PA systems flat. YMMV.
- Controlled directivity will be a big aspect of the PA system sound. Most PAs are designed for audience coverage, and specifically to avoid throwing sounds at the walls and ceilings.


In short, I don't think there's a way to reproduce that sound with EQ alone. There's too much going on which isn't related to the frequency response.

Chris

Thanks chris661

I couldn't really understand when I searched "low frequency haystack", though a 10db boost at 80hz would make anything sound with way too much bass. Is that what you were saying?

I agree that EQ alone won't cut it, but I feel would be a start hehe

Thanks again!
 
Baffle step (I should have specified it as Baffle Step Loss, which is probably more accurate) is the change in radiation from 4pi to 2pi, which affects the acoustic output above and below the step frequency by 6dB.

This is compensated for in almost all speakers using some kind of circuitry, either active or passive. The size of the driver and size of the baffle affect this, from memory an 8" woofer on a 9-10" baffle would be about 700Hz. The reason the compensation is less than 6dB is because of expected boundary gain, which will boost the LF output a bit.

Of all the PA systems I've come across, this compensation is almost never used as it reduces between 1.5 and 3.5dB of raw acoustic output due to losses within the crossover. It is one of the most pronounced acoustic signatures I've learnt to hear. Some engineers will dial back some of the step boost with active EQ, but some won't.

Speakers sound very different between having this compensation and not (and varying levels, distance to boundary, driver size, among other things). I'm not saying it will be exactly what you are looking for, but it's a starting point. As mentioned the distortion is also a factor, when trying to approximate output levels between PA speakers and studio monitors, even big ones like the KRKs.

The closest recording I can think of is In Square Circle, but even that is not exactly it. Maybe Give in to Me and One (Metallica) also remind me of that specific live sound.

Thank you very much Sangram, for the detailed explanation & live sound suggestions.
 
I'm not sure if this helps or not but I'll provide it anyway.

A live recording done well may at least hint of what you are after, in this case my reference is a concert I attended and I have listened to the recordings many times after and it is very well done and actually rather representative if played back trough a capable system and at a similar level, though it will never be the same with regards to the dynamics and physical sensation it is at the very least close enough for some real enjoyment.

The Pink Floyd Pulse -94 tour used Turbosound flashlight, and it is to this day the best concert sound I have ever heard, period, and the record captures some of that, but being a recording it has been a fair bit polished and compressed but with a balance that still retains very much of the feel and sound of the live event it self, only the sheer physical sensation of the sound is missing, it is one of these records that really takes me back to the event it self in a very good way.

Maybe that record can in some way help, if at the very least to give you an idea, high quality PA systems, if used properly and with a skilled tech. will give you goosebumps beyond what one might think is possible, it is really impressive and being live it puts most of all other music reproduction systems to shame in my opinion.

Thank you martinsson

A great live sound experience is really what I'm trying to achieve, not in the sense of being in a stadium for example, but in the sense of being totally immersed in an airy physically pleasant way.

Thanks for the suggestion, I will definitely check it out.

And yeah, I agree there's nothing quite like a high quality PA system :)
 
not sure why you want to do that....
i'm currently looking into the possibility of auralizing sims as a loudspeaker development tool but that's a world away from what your attempting to do.


it would be possible to emulate an EQ curve that's representative of a PA system but that ignores the contribution of the source sounds on stage and the acoustic environment.


Interesting, I hadn't heard of the term auralizing. And why do you want to do that?

In my case I'm developing a personal style of mastering basically, to kind of remaster already mastered music in my own way, but also to finally publish my own album, for which I want to create a very specific auditory experience.
 
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