Speaker Selection.
Hi,
In a hospital there is a requirement to install a speaker near the bed of each patient to listen the audio of the TV mounted on the wall. The volume of the speakers will be kept very low (audible to that patient with out disturbing others) and at the same time audio quality should be good. Can anybody give me some guidance on the selection of speaker and speaker box?
Use headphones, you can't get good quality at quiet levels (check for loudness compensation).
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A cheap small speaker has a resonance at a fairly high frequency. When it is enclosed in a speaker box then its resonant frequency is increased which creates a "boomy" sound.
Uncle $crooge
Have a look at this small desktop radio, the Boston Acoustics Receptor. It is a good example of how to get very good fidelity from a small speaker in a small housing.
Amazon.com: Boston Acoustics Charcoal High-Fidelity AM/FM Table Radio- BARADIOB: Electronics
The sound is extremely smooth and broad for such a small unit.
RadioRon
Boston Acoustics don't make that nice little radio anymore. They make a similar Solo mono radio and a Duo stereo radio both with 3.5" little speakers.
They probably use bass-boost because they have a Bass-trac system that reduces the bass boost when the volume is turned up.
My computer speakers use a 3" speaker with the biggest magnet I have ever seen on a little speaker. They sound pretty good for a little speaker and have an output of 4W RMS each.
Uncle $crooge
Use a parabolic sound reflector. They use them in the music sections of large stores so the person standing directly underneath can listen to CD selections without disturbing anyone, even the person 5 feet away at the next listening booth. Very effective and adequate fidelity for TV.
Here is a link to one. I am sure there are cheaper versions, the ones at my local store don't look near as nice.
SoundTube FP6020 SoundTube Parabolic Speaker | Full Compass
Last edited by speakerguy79; 16th November 2008 at 10:35 PM.
I don't think a granny in the hospital would want a dome like that over her head.
Uncle $crooge
Tell them it is a hair dryer?
I think all the sick grannies should each have their own chamber (room?) so they can blast the TV sound and the others won't hear it.
I haven't been to a hospital for about 26 years (my son was born) so I don't know if the rooms are not private anymore. Maybe on the other side of the world they have millions of sick grannies in one room.
Uncle $crooge
Hi,
A 3" ordinary speakerbox with a 3" 2W fullrange speaker will do the trick. If more than one patient is there in a single room you can connect them serially or parallely to get the required load resistance. Use a commercially available low rms cheap audio amplifier for this purpose.
The problem is that the sick grannies each watch a different TV show and some grannies are trying to sleep.
Uncle $crooge
We can provide a switch for each speakerbox. When it is switched of insert the corresponding speaker resistance into the circuit!
Some of the speakers will be in rooms. But most of them will be in wards where so many beds will be there in the same hall. So another requirement is that the audio from the speaker near one bed should not cause much disturbance to adjacent patients if they don't want sound. I plan to mount the speaker on the wall with a bent clamp to avoid hindrance to the other movements.Originally Posted by transistor495
Any advice?
I think the "wards" in India are like the "wards" in North America a few hundred years ago. India is in a completely different world or planet.
Uncle $crooge
Hi,
How many sick persons will be ther in a single ward for a maximum?
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