Industrial sound systems

[AndrewMeronek]

Not really a trombone question, but an audio system question which maybe some folks here might find interesting to discuss.

Who has experience with installing "warehouse" or "factory" paging systems, where you need to cover a pretty large area that has potentially a lot of ambient noise, but where that noise level can vary a lot over time and by location?

[Jimkinkella]

I've done a couple, what's the question?

[AndrewMeronek]

I've done a couple, what's the question?

Lots. I'm in a position of being able to lots of research but not being able to experiment and see what actually works. I guess a good place to start would be to ask what you've done and what worked and what didn't.

Thanks for replying, I wasn't sure if anyone on this forum would, not being typical in the trombone-music world.

[Jimkinkella]

This stuff is part of my day job

Couple of basics -
-Speakers should be mounted above head height angled down into the space, but definitely not at the ceiling pointed straight down.
-"Column" type devices work best to cover the larger spaces more evenly.
--The larger the space intended to cover, the taller the column should be, with devices spaced further apart.
- You want just a little bit of overlap from one device to the other (-6dB in between devices around 2kHz should be fine) - In spaces like that intelligibility is more important than consistency of SPL.
-- If there's to much overlap intelligibility / precedence gets confusing.
-You can get fancy with ambient sense microphones and DSP to vary levels according to situation, but they're performance is just ok, not great.
-There are a few prediction packages out there, including directly from the manufacturers, most are reasonably accurate
- quick note - powered loudspeakers might seem like a neat idea, but the additional weight and infrastructure end up making it significantly more expensive, unless you just have one or two..

Let me know if you're curious about anything specific.

Jim

[AndrewMeronek]

This stuff is part of my day job

Couple of basics -
-Speakers should be mounted above head height angled down into the space, but definitely not at the ceiling pointed straight down.

Right, for "horn" speakers the general convention seems to be to angle them 60 degrees away from the floor and place them at a height (depending on the horn) so that the decibel level at head level in front of the horn is about 10 decibels louder than potential ambient noise. In my case, I'm not entirely sure just what that is, except that I know that with everything running it can be fairly loud due to some pretty hefty fans running.

-"Column" type devices work best to cover the larger spaces more evenly.

Oh, interesting. I hadn't considered these kinds of speakers.

--The larger the space intended to cover, the taller the column should be, with devices spaced further apart.

At what height? It seems like these would be distinctly different than the more directional horn speakers.

- You want just a little bit of overlap from one device to the other (-6dB in between devices around 2kHz should be fine) - In spaces like that intelligibility is more important than consistency of SPL.
-- If there's to much overlap intelligibility / precedence gets confusing.
-You can get fancy with ambient sense microphones and DSP to vary levels according to situation, but they're performance is just ok, not great.

Sure, makes sense to me.

-There are a few prediction packages out there, including directly from the manufacturers, most are reasonably accurate

What is a prediction package?

- quick note - powered loudspeakers might seem like a neat idea, but the additional weight and infrastructure end up making it significantly more expensive, unless you just have one or two..

Let me know if you're curious about anything specific.

Jim

Yeah, I know a small amount about acoustics and speakers - more than the average voter, probably. But a paging system is dedicated to human speech and beeps, not appropriate for music, and a speaker system with "deep bass" seems to be ingrained into American culture somehow.

[sungfw]

What is a prediction package?

It's a software package for predicting acoustic performance in an existing or planned space.

Typically, you make a 3D model of the space, then make a series of measurments in the actual space (or assign frequency dependent acoustic properties to all internal surfaces if still n the planning/design phase), then start experimenting with speaker placements to optimize for varios performance metrics like reverb times and speech intelligibility.

In my previous job with an architectural firm we used it to improve the acoustics in existing church sanctuary and during the design phase for another church, and both turned out better than we anticipated.

[harrisonreed]

Sort of on the same topic -- are architects for acoustic spaces relatively common? Could I have a "back yard in-law suite" (or "workshop") designed so that it was really a great acoustic space for producing/recording music, but if I ever sold I could just pass off as an in-law hut (or workshop)? I've got about ten years before I can settle down and stop moving and have been toying with this idea.

[elmsandr]

Sort of on the same topic -- are architects for acoustic spaces relatively common?
...

Not really. They are becoming more popular for community spaces; Universities, corporate campuses, gov't buildings. But still not always a part of the process. They are out there, I'd love to hear more from somebody in the building industry to see how prevalent they truly are, but I get the impression that it is not yet a majority consideration in design and construction.

Cheers,
Andy

[AndrewMeronek]

Does anyone have some experiences with specific amplifiers, good or bad? There's lots of choices out there, and one thing I need to at least get a basic understanding of is which amps are reasonably decent and don't add unnecessary noise, while being a reasonable price for what they can do. These would be amplifiers specific for having something like 125W/70V channels?

I know this will be distinctly different than using local, small (probably built-in) amps per speaker as would happen with speakers using wi-fi or PoE (Power over Ethernet).

[timothy42b]

This sounds a bit like a Mass Notification System, required by UFC and Life Safety Codes.

They have to be loud enough to reach everyone, but not loud enough to cause hearing damage in any space, so the design is not trivial. It's usually left to the fire protection engineer.

[AndrewMeronek]

This sounds a bit like a Mass Notification System, required by UFC and Life Safety Codes.

They have to be loud enough to reach everyone, but not loud enough to cause hearing damage in any space, so the design is not trivial. It's usually left to the fire protection engineer.

We would be using such a system for general notices: shift changes, paging, etc. - not for primary use as emergency alerts - although, of course once a system is in place we can probably feed those alerts as well, in addition to the emergency systems that will be separate.

[Jimkinkella]

Couple of quick ones first,

With a software prediction package you create a 3d or even just 2d profile of the space that you're working in, and "install' a virtual loudspeaker or system into the space to investigate the performance of that system in your space.
The everyday generic industry standard is called EASE https://www.afmg.eu/en
Some loudspeaker manufacturers have their own versions, and there are a few other specialty pieces of software for different things; CATT, ODEON, etc.

Yes, acousticians are all over the place if you know where to look.
For a personal space your best bet would be to look up some of the smaller manufacturers of acoustical materials (https://www.gikacoustics.com/faq/)(https://www.atsacoustics.com/recording- ... stics.html)
They all have engineers on staff, and most would be happy to help you with a project.

You only need to worry about fire code for evacuation if the system is specified by the building construction, if it's simply a paging system added into an existing space there's no need to run it past the fire marshal, but you may need a construction permit, that's a question for your facilities manager.

I strongly recommend staying away from POE / wireless distribution / etc.
For a small to medium size space 70V is the way to go, if it's an exceptionally large space you may need to drop down to low impedance, but those spaces are rare.

For professional industrial spaces standard amplifier manufacturers are Crown or QSC, For a smaller space (under 5-6000sqft) you could go with something like TOA.
There are a bunch of other ones out there, but some are absolute garbage.


Now for the long list:

This stuff is part of my day job

Couple of basics -
-Speakers should be mounted above head height angled down into the space, but definitely not at the ceiling pointed straight down.

Right, for "horn" speakers the general convention seems to be to angle them 60 degrees away from the floor and place them at a height (depending on the horn) so that the decibel level at head level in front of the horn is about 10 decibels louder than potential ambient noise. In my case, I'm not entirely sure just what that is, except that I know that with everything running it can be fairly loud due to some pretty hefty fans running.

- It's simple enough to find out the noise level in a space with a smart phone app. They're not clinically accurate, but will give you a general ballpark idea.
In some industrial spaces you'll never be able to overcome the regular ambient noise level, at that point you're really just setting a target based on preference - for paging 95dBa would be pretty darn loud.

-"Column" type devices work best to cover the larger spaces more evenly.

- The appropriate device depends on the space

Oh, interesting. I hadn't considered these kinds of speakers.

--The larger the space intended to cover, the taller the column should be, with devices spaced further apart.

At what height? It seems like these would be distinctly different than the more directional horn speakers.

- The basic function isn't terribly different, but the performance characteristics can help certain applications.
Here's an ok comparison of some different device types, the author's a church applications engineer, but the concepts are the same
https://pro.harman.com/insights/enterpr ... ur-church/

- You want just a little bit of overlap from one device to the other (-6dB in between devices around 2kHz should be fine) - In spaces like that intelligibility is more important than consistency of SPL.
-- If there's to much overlap intelligibility / precedence gets confusing.
-You can get fancy with ambient sense microphones and DSP to vary levels according to situation, but they're performance is just ok, not great.

Sure, makes sense to me.

-There are a few prediction packages out there, including directly from the manufacturers, most are reasonably accurate

What is a prediction package?
See above

- quick note - powered loudspeakers might seem like a neat idea, but the additional weight and infrastructure end up making it significantly more expensive, unless you just have one or two..

Let me know if you're curious about anything specific.

Jim

Yeah, I know a small amount about acoustics and speakers - more than the average voter, probably. But a paging system is dedicated to human speech and beeps, not appropriate for music, and a speaker system with "deep bass" seems to be ingrained into American culture somehow.

[AndrewMeronek]

- The basic function isn't terribly different, but the performance characteristics can help certain applications.
Here's an ok comparison of some different device types, the author's a church applications engineer, but the concepts are the same
https://pro.harman.com/insights/enterpr ... ur-church/

Great link! I think this will be helpful.

Here's another link I've come across that interested readers here may enjoy:

https://www.lowellmfg.com/wp-content/up ... ellPHS.pdf

I like that this one gives some equations so I can have some more specificity with thinking about particular horns.

[andycomb]

An industrial sound system for a warehouse, factory or distribution centre can be used for paging or background music.

Pendant speakers are often used in warehouses as they can be suspended from high ceilings for wide dispersion of sound over a large area.

An effective PA system in a warehouse is essential in order to page staff or communicate break times or shift changes. A door bell alert or telephone system can also be integrated.

A radio tuner playing through a factory sound system needs careful planning to control overall sound levels where ambient noise may already be high, but may help protect employees from potential hearing damage from listening to personal radios or MP3 players at high volumes.
source link: audiospeaks