Question-------------------------
Followup To
Question -
I have been put in charge of setting up a medical office in a converted victorian house. the doctor wants ceiling speakers in 4 rooms. What stereo equipment do I need to power the speakers?
Answer -
Dear Chris,
You need the following:
The "in-wall" ceiling speakers. There are loads of excellent makers including Boston Acoustics, Polk Audio, B&W, and so on. If the application is mainly background music, modestly sized and priced speakers from Boston Acoustics and Polk Audio would be your best bet.
Don't forget that you'll need "in wall" speaker wire. This is essential because it is (1) shielded from house wire electrical interference and (2) is constructed to withstand years of neglect buried inside of a wall/ceiling. For your application 16AWG in-wall wire at Radio Shack will be fine.
You need also (1) power, (2) distribution, and (3) a sound source. We'll treat each in turn.
The most cost effective power source is a receiver, which contains a tuner (radio), preamplifier (sound source selection), and power amplifier. If you intend to have just one speaker in each of the rooms, you need a receiver with "A/B" capability (sometimes called "dual zone") capability. This allows you to send the same signal to two sets of stereo speakers OR four sets of mono speakers. See? If you have four mono speakers, one in each room, you simply wire the speakers to the receiver and set the receiver's output signal to "MONO". Each speaker will carry the full range of the sound source in mono.
If you want stereo sound in each room (two speakers per room), you'll need a receiver that also has a "PREAMP OUT" circuit and a second receiver that has a "PREAMP IN" capability. The "preamp out" carries the sound source signal to the other receiver. If each receiver has "A/B" capabilities, then one receiver powers two pairs of stereo speakers, and the other receiver powers the other two pairs.
The preceding paragraph is in essence "distribution". A dealer may recommend a "slave amplifier", which is essentially the same thing as a second receiver. The key is that the primary receiver have a "preamp out" circuit and the secondary receiver/slave amplifier have a "preamp in" circuit.
For your likely application (background sound in mono), the one receiver will be enough--no matter what the salesman tells you.
The sound source can simply be the tuner/radio that comes with the receiver. You can also attach a cassette tape player or a CD player. If the doctor subscribes to a satellite radio service (XM or Sirius), then its output can also act as a sound source. The great thing about satellite radio is that it is commercial free.
If the building is wired for cable or satellite television, several of those providers also offer commercial free music channels.
One last advisory. In applications like these, it's fairly common to put the receiver (and sound source) in a closet or a cabinet--anywhere that can't be seen. Make sure that the receiver has adequate ventilation. If necessary install a small fan to circulate the air in an enclosed space. You'd hate to go to all that work and have the receiver burn out on you due to overheating. In "house office" applications, I've found that the "paper" room where the copier, computer server, and fax machines are located is perfect for sound equipment because it doesn't matter that it sits on a counter, etc.
There you go: four speakers, a "A/B" capable receiver, and (if necessary) an external sound source.
Good luck. And thanks for choosing allexperts.com!
Kindest regards,
Kevin
Kevin,
Thank you so much for your response, your explanation for the equipment required is both very clear and concise and greatly appreciated.
How much difference is there between mono(one speaker) and stereo (two speakers) for background sound?
One website talked about hooking up a speaker selector box to the receiver. Is this same thing as a "slave amplifier"?
What do I look for i.e. # of watt or watts per channel when choosing the speakers and receiver?
Most of the rooms are small 8'x 10' except the reception area 13'x15' all with 10' celings
Thank you once again for your all your help. What a great website.
With my greatest appreciation,
Chris
AnswerDear Chris,
Stereo sound is preferable when you want to involve the listener in the musical experience, but as background music is wasted. In fact, it could be argued that stereo reproduction in a venue like a physician's office would be more distracting than soothing, but I'll leave that one to the psychoacoustic guys. A monaural (mono) background should be just fine.
A speaker selector box is essentially an "A/B"--and sometimes an "A/B/C" switch box which chooses one set of speakers over another(s). And, no, it's not a slave amplifier/second receiver. It's just a switch box.
What I'm suggesting is that you get a receiver with "A/B" front channel/stereo speaker capability and run both the A and B speakers at the same time in mono. Four speakers = four rooms with monaural sound.
Anything with 50 watts RMS per channel--check out the specifications in the back of the user's manual--or greater should be sufficient to power your application. I'd counsel against less, and more can't harm you. Since this is for background music, it's not like you're going to play it all that loudly.
Sony just introduced its STR-DE197 stereo receiver. Two channels at 100 watts RMS per channel with A/B capability. $149.99--just what the, er, doctor ordered. Really, that's all you need. Just add speakers, wire, and a sound source (other than the built in tuner/radio), and you're in business.
Glad to be of help. Feel free to write back with any question any time.
Kindest regards,
Kevin
