Meyer Sound Amie-Sub, Operating Instructions Manual

Page: 20 / 32

AMIE-SUB OPERATING INSTRUCTIONS
20
2.1 Integration Module Operation
The 2.1 Integration Module (Figure 15) features two input
channels using 3-pin XLR-F connectors (see “Audio Input
(XLR 3-Pin Female)” on page 17) and an additional 3
- pin
XLR-F LFE input.
Two 3-pin XLR - M looping outputs (see “Audio Loop Output
(XLR 3-Pin Male)” on page 17) are provided.
LFE + Bass Management
For the LFE input, there are three controls on the user panel
that affect how this signal is output to the Amie-Sub driver
(see Figure 13):
NOTE: These controls work identically as the
ones described for the 7.1 Integration Module
except there are only two input channels and
no LFE loop output.
•
LFE switch: the user can selectively add 10 dB of gain by
setting this switch to the “+10 dB” position.
•
LFE + Base Management dial: the user can add ±6 dB
gain/attenuation to the output of the loudspeaker by
rotating this dial to the appropriate position.
•
Bass Management: When switched to the Bypass
position, the signal passes from input to the subwoofer
driver without any internal signal processing.
When switched to the ON position, the subwoofer driver
receives a combined signal consisting of both channel
(L and R) inputs summed, low-pass filtered and then
further summed with the (selectively) 10 dB-boosted and
then phase-matched (all
- pass filtered) LFE input.
The result of this last summation may be boosted or
attenuated by the ±6 dB LFE + Bass Management dial.
NOTE: The option to boost the signal by 10 dB
is provided for playback of recorded audio in
situations where the LFE channel was
recorded 10 dB lower than the other channels and
where the source equipment has not already restored
this 10 dB.
NOTE: The purpose of the all-pass filter is to
phase - match the LFE channel signal with the
low - pass filtered and summed L,C, R and
Surround channel signals.
TRUPOWER LIMITING
The Amie-Sub employs Meyer Sound’s advanced
TruPower
® limiting. Conventional limiters assume a constant
driver impedance and set the limiting threshold by
measuring voltage alone. This method is inaccurate,
because driver impedances change as frequency content in
the source material changes, and as thermal values for the
loudspeaker’s voice coil and magnet vary. Consequently,
conventional limiters often begin limiting prematurely, which
reduces system headroom and dynamic range.
In contrast, TruPower limiting anticipates varying driver
impedances by measuring both current and voltage to
compute the actual power dissipation in the voice coil. This
approach improves performance, both before and during
limiting, by allowing the driver to produce the maximum SPL
across its entire frequency range, while also retaining signal
peaks. TruPower limiting also eliminates power
compression at high levels over lengthy periods, which
helps regulate voice coil temperatures, thereby extending
the life of the driver.
Figure 15: 2.1 Integration Module