HX E-33A-100701, Руководство пользователя

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M
AXIMUM
O
UTPUT AND
L
ISTENING
D
ISTANCE
E-33A-100701 is optimized for 1-4m (3.3ft – 13ft) listening distance. It is not recommended to have a listening
distance of less than 1m (3.3ft).
The amplifier sensitivity is 1.4V RMS (5.1 dBu, 2V peak), therefore a 0.5V RMS pink noise with 12dB crest factor
(-3.8dBu, 2V peak) can be safely passed to the loudspeaker without clipping/distortion.
Using pink noise 12dB crest factor as a realistic program material replication, the calculated output (no weighting,
free-space, slow average) can be seen below.
Distance Output using 0.5V RMS Using 1V RMS (onset of
distortion
1m [3.3ft] 95 dB SPL 101 dB SPL
2m [6.6ft] 89 dB SPL 95 dB SPL
4m [13.1ft] 83 dB SPL 89 dB SPL
The acoustic output is also affected by other factors such as:
1. Different compression ratio/crest factor of the audio signal. A more compressed signal (smaller crest factor)
may result in higher SPL.
2. Room will add acoustical gain, up to 3dB.
Warning: The amplifier gain is set to unity! Always start with a low input signal [set the
master fader at -40dBFS or lower!]
Q
UICK
D
IGITAL
O
UTPUT
A
DJUSTMENT
A sound card/audio interface maximum output is usually rated in XX dBu (please consult to manufacture whether the
maximum output corresponds to 0 dBFS or other. For example: RME Fireface UFX monitor output is spec’d as follow:
Output level at 0dBFS @ 24dBu: +24dBu
This means at 0dBFS of the digital fader, using 24dBu mode, the maximum output is 24dBu. The nominal input of
the amplifier is -3.8dBu (≈ -4dBu), therefore the digital fader should not exceed -4 – 24 = -28 dBFS.
Another example is M-audio Audiophile 192 sound card which has a max output (balanced) of +14dBu (3.9VRMS).
To avoid clipping the master output fader should not exceed -4 – 14 = -18dBFS.
It is wise to start with a low output (-40dBFS or lower) and slowly raising the fader. If distortion starts to get noticeable
(although very little), the output is probably already 3dB or more too hot!
S
URFACE
C
LEANING
Exterior box surface of may be cleaned using a lint-free cloth lightly damped with water. Please make sure to
disconnect the power cable from the amplifier. Do not use alcohol-based cleaners.
Driver surfaces (diaphragms and surrounds) may be cleaned using dry soft bristle brushes. The diaphragms are fragile
and easily damaged, please proceed with great care. Gently brush dust away from the surface.