Behringer BVT4500H, BVT5500H 4. About speaker impedance, About speaker impedance, SEND, LEVEL, RETURN, RETURN, RETURN, PRE/POST, PRE/POST, TUNER OUT, EFFECTS SEND, PREAMP OUTPUT

ULTRABASS BVT4500H/BVT5500H

++ 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 rating 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 RETURN (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 {6}.

4. About speaker impedance

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 another BVT speaker jack, the speakers are connected in parallel. To calculate the resulting total impedance of the speakers, use the following formula—

—where Z1, Z2 etc. are each the impedance of a single speaker and Ztotal is the resulting impedance of all speakers.

For two speakers (Z1 and Z2), the formula reads as:

Ztotal =	Z1 ⋅ Z2
	Z1	+ Z2

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.