Product
Overview and Description
MS4 is a sound system developed to improve
the speech intelligibility in rooms with poor acoustics by amplifying the
level of speech in relation to the background noise. Its applications are
unlimited due to its uncomplicated installation. The system can be used
in classrooms, conference rooms, town halls, community centers, museums,
and hotels.
Product
Use and Procedure
MS4 makes the speech signal 10-20 db louder than the background noise. The
result is clear speech even in rooms with poor acoustics. Furthermore, speakers
avoid straining their voice and can focus more on their speech.
Features
and Benefits
The column loudspeaker
consists of 4 loudspeaker units placed on top of each other with an FM receiver
built in. The speaker wears a wireless microphone, which transmits the speech
to the speaker and thus increases the signal-to-noise ratio. Using the on/off
switch can interrupt the transmission. In situations where MS4 is placed
in a large room, an auxiliary "slave" loudspeaker may be added.
There are 40 channels available for MS4, which are compatible with those
used with Personal FM systems.
Frequently
Asked Questions
| Q: |
How
does the system work? |
| A: |
: In the same way
that sitting close to the teacher results in a positive signal-to-noise
ratio and strong speech discrimination, a wireless sound field system
delivers a clear, intelligible speech signal by reducing key distances.
First, the
teacher wears a small wireless transmitter with a microphone placed
within 11cm/6in of his or her mouth (or connected from a receiver
directly to a VCR, CD player, etc. for a surround sound kids love).
His or her
voice signal is transmitted across the room through radio wave or
infrared light, bypassing the effects of distance, noise, and reverberation.
The teacher's
voice signal is then brought close to students' ears through speakers
placed around the room. Sound field uses the advantages of close proximity
to the sound source twice - first by placing the microphone close
to the teacher's mouth where it picks up a strong signal nearly free
from background noise, and second by placing speakers closer to the
students. In effect, the teacher is never more than a few feet from
students, and a gentle amplification brings the signal-to-noise ratio
above the 6db requirement.
As an added
benefit, amplification eases teacher vocal fatigue by allowing him
or her to speak in a normal voice. Moreover, these amplification systems
are wireless, so the teacher can move freely around the room or turn
to face the chalkboard while effortlessly maintaining the level of
his or her voice to the students.
|
| Q: |
Does
it really work? |
| A: |
Since the 1970's
over 50 studies have been conducted to find out just how much difference
sound field systems make.
Putnam County,
Ohio added 60 sound field systems to its classrooms between 1985 and
1990. The number if students placed into LD programs has since declined
nearly 40%. This meant significant savings, since the annual cost
of placing a child in Special Ed in 1990 was $2,600.
Other studies
have found:
 |
Vocabulary
test scores improved by 12% with sound field.
|
|
Spelling test
scores of 3rd, 4th, and 5th graders have been shown to improve
by 14,5%, 9%, and 22,4% respectively when using amplification.
|
|
Comparative
results from project MARRS (Mainstream Amplification Resource
Room Study) indicated that students in an amplified classroom
showed significant improvements in Scholastic Reading Achievement
scores. |
Teachers benefit
too. Sound field has been shown to reduce the cost of substitute
teacher pay. A school could recoup the cost of a sound field system
in the savings from just 9 to 13 days worth of substitute pay.
"Students
in the classrooms with an FM sound field system achieved greater
literacy gains than control students. Twice as many students achieved
up to 7 reading levels of literacy growing compared to the control
students".
|
Technical
Specifications
| Loudspeaker |
| Sensitivity: |
93.5
dB |
| Frequency
response: |
200
— 16 kHz |
| Output: |
Nominal
30w |
| Units: |
4
VIFA - units, type S09FD-09-08 |
| Directionality
index: |
12,6
dB (2000 Hz) |
| Directionality
factor: |
18
(2000Hz) |
| Dimensions
(HxWxD): |
880
x 150 x 70 mm-34.5 x 5.9 x 2.8 in |
| Weight: |
4000
g-141 oz |
| Standard
Color: |
Black/gray |
| Material: |
Aluminum
(front)
Painted iron plate (cabinet) |
| Receiver
in Loudspeaker |
| Frequency
stability: |
+/-
200 Hz 0° to 50° C |
| Modulation: |
FM
narrow-band |
| AF
frequency response: |
100
Hz to 10 kHz +/- 3dB |
| Auxiliary
input level: |
100
mV |
| Auxiliary
input impedance: |
>/=
10 k ohm |
| Signal-to-noise: |
>
60 dB |
| THD: |
<
2% |
| Nominal
deviation: |
+/-
3.6 kHz |
| Maximum
deviation: |
+/-
10 kHz |
| Squelch: |
RSSI-type |
| Squelch
level: |
1uV
at 20 dB SINAD |
| Power
Supply: |
16.5
VDC at 1.2A |
| User
controls: |
On,
Off, Vol, FM Vol, Aux Vol and Tone |
| Displays: |
LEDs
for "On" and "No FM" |
| Transmitter |
| Transmitting
frequency: |
72
to 76 MHz, 140, or 173 MHz |
| Channels: |
40
channels available |
| Modulation: |
FM
narrow-band |
| Operation
range: |
Up
to 50m/160ft |
| User
controls: |
Off/On |
| Inputs/outputs: |
3.5
mm auxiliary input jack
2.5 mm microphone input jack |
| Battery
life: |
16
Hr (AA alkaline), 8 Hr (AA NiCad) |
| Dimensions: |
2.5
x 9.4 x 5.6 cm- 1 x 3.7 x 2.2 in |
| Weight: |
80
g-2.8 oz |
| Color: |
Gray |
| Material: |
ABS
plastic |
Warranty
ONE YEAR LIMITED WARRANTY: This warranty
is extended to the original purchaser of the instrument, by Maico, through
the Distributor from whom it was purchased. The warranty covers defects
in material and workmanship for a period of one year from date of delivery
of the instrument to the original purchaser. Accessories, which are purchased
from Maico at the same time as the instrument, are covered for one year
from the date of purchase. For additional information contact School Health
Corporation, your authorized Maico distributor.
Product
Ordering Information
| SH
Catalog # |
Product
Name |
| 51085 |
Maico
MS4 Wireless Sound System |
|
