Soundstream Technologies Class A 5.0 - Manual (Page 5)

16
LSE.Q THEORY AND USE (Class A 10.0)
LSE.Q is a unique subwoofer control circuit
i n c l u d e d w i t h t h e S O U N D S T R E A M
REFERENCE Class A 10.0 amplifier. It is
capable of removing subsonic energy in program
material. The circuit consists of two controls.
One adjusts the frequency of operation and the
other adjusts the range of boost. With both
controls adjusted fully counter-clockwise, no
boost is applied and the amplifier is flat in
response down to 30 Hz.
The frequency control (Hz) adjusts the starting point of the subsonic
filter. This high pass filter can be
adjusted from 30 Hz up to a
maximum of 60 Hz. This control
is useful for setting the lowest
frequency that your subwoofer will
see. (See figure 1)
The Q control adjusts the
amount of boost applied at the set
frequency. This is adjustable
from .707 (flat) to 2.8 (+9 dB).
(See figure 2)
When the Q is set to .707
(Butterworth), LSE.Q acts as a
sub-sonic filter only. (See figure
3)
The simple act of removing the
signal below the vented tuning
frequency can improve system
output by as much as 3 dB. With Q values greater than .707, boost is
added to the sub-sonic filter. (see
figure 4)
Application
Woofers in vented enclosures have
good power handling characteristics
above the tuning frequency, but
below the tuning frequency, power
handling drops off considerably.
-10
Frequency (Hz) 10
-30
-25
-15
-20
-5
dB
0
5
10
50 100 200
FIG. 3 Variable High Pass
dB
Frequency (Hz)
-20
-30 10
-25
-15
-10
5
0
-5
10
50 100 200
FIG. 2 Variable “Q”
Q=2.8
Q=0.707
dB
Frequency (Hz)
-20
-30
10
-25
-15
-10
5
0
-5
10
50 100 200
FIG. 4 Variable “Q”
FIG. 1 LSE.Q
5
most amplifiers in the Class A 5.0, and over twelve times in the Class A
10.0! More drive current maintains the amplifiers' performance into low
impedance loads.
•
Drive Delay TM Muted Turn-on/off Circuit - A unique circuit which
completely eliminates any amplifier-related turn-on/off noises.
•
Flexible Dual Input Level Sensitivity accepts 2 voltage ranges; from 200
mV to 2.0 V and from 500 mV to 5.0 V, permitting maximum output from the
amplifier with virtually any source unit.
•
Differential Balanced Input Design for added immunity to noise caused by
component and vehicle electrical system interaction when using Unbalanced
RCA inputs.
•
True Balanced Input for professional-quality performance and noise
cancellation. The 6-pin din plug carries (+) and (-) Signal information for Left
and Right channels, audio ground, and ±15 Vdc to operate the Soundstream
BLT Balanced Line Transmitter.
AIRBASS™ ACCESSORY OPTION
Soundstream's new AIRBASS™ feature can be added to the REFERENCE
Class A amplifiers. This feature allows wireless RF remote control level
adjustment of the amplifier.
NOTE: The AIRBASS™ accessory is intended to be used only while the
REFERENCE Class A amplifiers are driving subwoofers. When the
AIRBASS™ accessory is added to a REFERENCE Class A amplifier, it
automatically configures the amplifier into Bridged Mono mode. (The Coherent
Stereo / Mixed Mono / Bridged Mono switch is bypassed.) Therefore, when
using AIRBASS™, follow the Bridged Mono input and output wiring
Installing AIRBASS™ involves removing the bottom plate of the amplifier,
adding the AIRBASS™ circuit board, and flipping a switch. The switch is
labeled on the amplifier's main circuit board. DO NOT set the AIRBASS™
switch to the "IN" position unless the AIRBASS™ module has been added.
DO NOT move the AIRBASS™ switch while the amplifier is "ON". Doing so
may damage your speakers. (Please refer to the AIRBASS™ owner's /
installation manual for more details.)