View Full Version : Need Ideas for 10,000 sq ft Warehouse Sound System
03-07-2011, 03:20 PM
I have an electrical background (but no sound reinforcement) so am helping a friend install a sound system in a 10,000 square foot warehouse. This store has about 15 feet ceilings, "open beam", i.e. no dropped ceiling, completely open, no walls. He would like something louder than a simple background system. Loud enough that a "customer might tap their foot while shopping".
In the little I have researched so far, it appears I need a 70v system (I expect the longest speaker runs to be 100 feet).
As a start (and I realize there are alot of variables here)...but since this area is so open -- it would be easy to install more or move speakers around...what would be some speakers that could be recommended and wattage of the amp.
03-07-2011, 04:05 PM
I will be more than happy to assist you with this project. Please feel free to contact me at 866-366-4909 ext 135 so we can discuss this in more detail.
03-09-2011, 01:13 PM
You're right, there are several variables. One of the most important ones is the speaker you choose to do the project.
Well designed ceiling speakers provide a 180 degree pattern with minimal drop-off at the edges of the speaker pattern. If you visualize a triangle, the farther away from the center line you move to the left or right, the farther you are from the top of the triangle. In the case of a speaker, the farther left or right of center, the farther away you are from the "sweet spot" and the sound level will drop off. Most manufacturers forget to remind you of this.
Also, the size of the speaker is important. A 4" speaker has a wider coverage pattern in most cases than an 8" speaker. However, for music the 8" speaker is going to sound way better than the 4". I frequently use a 4" speaker and then enhance it by adding a ceiling mounted sub at intervals around the room and in the corners.
A few questions:
Is there presently a system in place that you want to enhance, or is this a greefield design? If something is in place you'll need to know if it's a 70v system and how they are tapped.
Is the ambient noise in the space typical of a grocery store, or is there additional noise typical of machinery? Ideally you probably want to have the potential to provide your music/ paging etc. about 10dB above the ambient noise.
You mentioned you want toes tapping, is this the primary goal to provide background music with paging/ announcements being a secondary function? The paging will typically require the 10dB above ambient while music can easily get away with 1/2 that and still cause some folks to go into kareoke mode. In fact you likely won't want the music that loud. I'd choose an amp with mixing at the input so you can adjust accordingly.
Very important! Will the speakers be flush mouted in the ceiling, or do you need pendant style speakers? Flush mounted, typical of a recessed ceiling speaker will provide you the best coverage for the least cost. If you require pendant speakers, everything models very differently. (And please, don't even think about mounting a few horns around the corners of the room, that's going to sound like toes tapping on a tin can.)
I'm sure the folks at Parts Express will take good care of you, but I ran some numbers for you.
Your building is 100' by 100' with 15' open ceilings.
Your goal is high background music against an ambient sound level of around 70dB. This would be typical of a noisy supermarket or retail store.
Listener height is about 5' above finished floor.
Your target should be to achieve at least 10dB SPL above ambient noise.
I modeled a 70v system using 4" speakers with a 180 degree pattern that achieve 93dB SPL (1w1m) using a 6 watt tap.
I modeled with JBL 8124 speakers. I'm sure John will recommend something equal or better than that speaker (it won't be too hard). It's a basic contractor grade speaker with a frequency range of 60Hz to 18kHz and would do fine in your application.
I modeled a square pattern with three rows of three speakers about 14' off of the side walls and spaced about 36' apart for a total of nine speakers. This will provide average SPL coverage in the mid 80's with a 4.5dB overlap between speakers at the listener height. If the speakers are lower than 15' the quantity of speakers increases to return to 4.5dB overlap. (The width of the cone pattern from the speaker decreases as you either make people taller, or the ceiling lower).
For the model above, you could get away with an amp in the 70watt range, but I'd probably go for something in the 100watt range to get some more headroom.
If you really want to rock the house, you could add a few subwoofers. That however, would be a separate system and I'd suggest a separate amp to drive them.
Good Luck with your project!
03-10-2011, 11:14 PM
This sounds like an awesome project! Good luck, if you post pics and details here, I will be sure to follow!
03-11-2011, 05:23 PM
Before beginning any system like this, where voice evacuation notification is a potential use, make sure to know what local codes and state and federal laws are in force pertaining to voice evacuation systems. Most cities and towns have regulations that reference industry standards from organizations like NFPA and ANSI, regarding the level that must be achievable by the system relative to background noise, where speaker wires are run (cable must be plenum-rated for use in breathing air spaces), how speaker wires are run (in rigid metal conduit, usually), and so on. If you aren't cognizant of the regulations that affect BGM/paging system installations, your system could fail an inspection (which really adds to the total price tag due to the required rework or additional materials) or otherwise put you at risk (as the designer and installer responsible for the quality of the system design) of liability if the system fails or underperforms during an emergency where lives are in danger.
You may want to hire a sound company in your area that does installations as part of their business to do acoustic studies, specify equipment, and handle installation in a safe manner. This will be more expensive than doing it yourself, but you reduce the risk of having to pay to do it all over again if the solution you come up with doesn't cut it. Tom, from the questions you've already asked, you haven't even scratched the surface of the body of knowledge you'll need in order to design and properly (safely) install a large distributed audio system like what you're talking about, so you should think for a moment about whether you're really doing your friend or even yourself a favor by attempting this job and putting your reputation on the line.
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