sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging Large PA system installation

Ed -

1/4 Watt per speaker is kind of low. is this all "quiet" office space? Is the system for general announcements or for more serious stuff? What's the spacing on the speakers?

sam

Sam, yes it is very quiet office space with very few hard surfaces. The speakers are ridiculously close to each other in my opinion, but that is what they want. In most areas, they are no more than 25 feet apart. The system will never be used for general daily paging; it will only be used on very rare occasions.

90% of the offices are modular furniture, so the space is almost all open.

The similar setup in one of their other buildings has never been used in ten years except for monthly testing.

OK. Usually we set small closed offices for 1/4 watt and open "bull-pens" went for 1 Watt. (At JFK we had the bathrooms set at 2 Watts, the Gates at 4, Corridors at 8 and outdoors, machine rooms and whatever went 15W. Speakers out by the runways went at 30W!)

Wall mount speakers generally don't project farther then 25 feet, so the spacing is good (These are wall mount, right?) Horns might push 35' but have practically no bass and sound like sh*t.

One important thing with wall mount speakers is that they should not be directly facing each other. If you have them on opposite walls then they should be staggered. Usually we try to keep them pointing in the same direction.

For ceiling speakers, the rule of thumb we used was: Twice as far apart as the distance from the speaker to the ground - for ADEQUATE coverage (10' ceiling=20' apart). For BETTER coverage we used twice as far apart as the distance from the speaker to the ears of the person hearing it (10' ceiling in classroom=13' apart. 10 ceiling in hallway=9' apart).

Hope this makes sense.

Sam

Reading all this reminds me of the "good old days," when this site was a lot busier.

I have learned more from this one thread than all the other "media" I ingested in the past week combined.

You guys are awesome.

As B/4,
Jim

I agree with you, Jim. I've learned a lot here in a short period of time. When my boss presented me with this project for pricing, I scoffed at it. Then I thought, let me check with my friends here and get their feedback. Now I'm not so concerned about it. Besides, if I get into a pinch, I can drag Sam out of retirement to come down and manage it for me!