Blaupunkt PCA2120 SYSTEM CONFIGURATION #1, SYSTEM CONFIGURATION #2, Channel Dual Subwoofer Mode

4Ω (main)

SYSTEM CONFIGURATION #1

Full-Range		For higher output, you can connect a subwoofer
	Full-Range
		to two output channels. Look for the + and – to
		indicate the correct connections.

Subwoofer

Full-Range Full-Range

1 Channel Bridged Subwoofer Mode

By electrically connecting a subwoofer speaker in the way shown above, you are able to greatly increase the output power delivered from the amplifier to the speaker. Such a circuit increases the voltage “swing” across the speaker which increase the power seen by a factor of 2 to 4 times that in stereo mode.

This is a very logical set-up for systems that are space limited to allow for only one subwoofer in a vehicle. The number and box

volumes are compensated by simply more amplifier power pushing a single speaker.

Such a configuration is also a surprisingly good performer. These increases in power are always welcome but you must take care to avoid low impedances (below 4 ohms) since most amplifiers will overheat and shut down if over-driven into such a configuration. You must also take care that you are not exceeding the thermal, or excursion, power limiting values for the woofer. Surprisingly high power levels can be achieved with such a system without realizing it thus quickly damaging the woofer.

SYSTEM CONFIGURATION #2

Full-Range Full-Range

Subwoofer

Full-Range Full-Range

2 Channel Dual Subwoofer Mode

The largest improvement in sound quality always comes when adding some kind of subwoofer via a dedicated subwoofer amplifier and electronics crossover. The electronic crossover

ensures minimal overlap of the bass response with the mid and high frequencies from the other speakers resulting in a more accurate performance compared to conventional coaxials with additional power.

By installing this amplifier in the stereo mode, you are able to drive two subwoofer speakers and in to low impedance loads (e.g., 2 ohms) without over heating the amplifiers. Also, such an installation more easily supports a standard 2 speaker woofer box that may already be constructed. Since two woofers can play 6 decibels louder than one at a given power (due to acoustical laws of “mutual-coupling”), the resulting sound pressure level is substantial. This is probably the most common use for a conventional two channel amplifier there is.

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