About Speaker Impedance - Behringer Ultrabass BVT4500H User Manual

Your speaker cabinets should have a sufficient power
+
rating (BVT4500H: > 450 W, BVT5500H: > 550 W) and
preferably a total impedance of 4 Ω or higher. Too high
a load impedance will decrease the output power rat-
ing of the power stage. For details, refer to the chapter

"ABOUT SPEAKER IMPEDANCE".

(27) POWER AMP INPUT: To connect an external preamplifier
to the BVT, use this ¼" TS jack.
(28) PREAMP OUTPUT: To connect an external power amplifier
to the BVT, use this ¼" TS jack.
EFFECTS LOOP jacks
To connect the BVT4500H/5500H to an effects processor you can
use one or, alternatively both of these jacks ((29)- (30)). Keep in
mind that the BVT4500H and the BVT5500H do not process effects
in the same way. For details, see "THE SIGNAL PATH".
(29) RETURN jack: To send an audio signal from an effects
processor to the BVT, use this ¼" TS jack.
(30) SEND jack: To send an audio signal from the BVT to an
effects processor, use this ¼" TS jack.
LINE OUTPUT features
To send an audio signal from the BVT to a mixer or a recording
unit, use the LINE OUTPUT features ((31) - (34)), as follows:
(31) LEVEL control: To adjust the level of any LINE OUTPUT,
turn this knob toward min (no level) or, alternatively max.
The value of the max setting depends on what you selected via
the PRE/POST button (33). If you selected:
= PRE: max is ~ 0 dB.
= POST: max is ~ 10 dB.
(32) GND LIFT button: To manage the ground connection be-
tween the BVT and a mixer/recording unit, use this button.
When this button is:
= pushed out, you maintain a ground connection that prevents
electrostatic charges from interfering with an audio signal.
= pushed in, you break the ground connection. Do this only when
ground-loop hum interferes with an audio signal.
(33) PRE/POST button: To select the type of signal you want to
send to a mixer/recording unit, use this button.
When this button is:
pushed out (PRE EQ and effects), the BVT does not apply any
=
preamp features (TONE/EQ/EFFECTS) to the audio signal.
pushed in (POST EQ and effects), the BVT applies all preamp
=
features to the audio signal.
For details, see "THE SIGNAL PATH".
(34) BALANCED OUTPUT: To connect the BVT to the mic input
on a mixer or, alternatively to a recording unit, use this XLR
jack (balanced).
Before you connect the BVT4500H/5500H to mic input
+
on a mixer, turn off the phantom power on the relevant
channel of the mixer.
(35) TUNER OUT jack: To connect the BVT4500H/5500H to an
electronic tuner, use this ¼" TS jack.
To tune while muting the PARALLEL SPEAKER OUTPUTs, do
one of the following. If you work with:
= the BVT4500H, turn the MASTER control to 0 (minimum
setting).
Alternatively, you can use the tuner's mute feature: Connect
EFFECTS SEND (30) to the tuner input and EFFECTS RE-
TURN (29) to the tuner output. When you:
activate the mute feature on the tuner, the tuner does not
=
send the audio signal to the RETURN jack.
deactivate the mute feature on the tuner, the tuner sends
=
the audio signal to the RETURN jack. The audio signal
follows the signal path to the PARALLEL SPEAKER
OUTPUTs.
the BVT5500H, activate the mute feature
=
ULTRABASS BVT4500H/BVT5500H
4.
The total impedance of the speakers that you connect to the
BVT affects the power output of the BVT. The minimum speaker
impedance is 4 Ω. When the total load is 4 Ω, the BVT supplies
the optimal power.
How to calculate the speaker impedance
When using more than one speaker and each connecting to an-
other BVT speaker jack, the speakers are connected in parallel.
To calculate the resulting total impedance of the speakers, use
the following formula—
—where Z
and Z is the resulting impedance of all speakers.
total
For two speakers (Z
Via the formula, you get a 4 Ω load with:
one 4 Ω speaker
=
two 8 Ω speakers
=
one 8 Ω speaker and two 16 Ω speakers
=
As the speaker impedance decreases, the output power
+
of the BVT increases. High output power can damage
your speakers. As the speaker impedance increases,
the output power of the BVT decreases.
{6}.
About speaker impedance
About speaker impedance
, Z etc. are each the impedance of a single speaker
1 2
and Z ), the formula reads as:
1 2
Z ⋅ Z
Z =
1 2
total
Z + Z
1 2
7