SWR Sound Bass Combo Amplifier - Manual (Page 15)

more during peaks), but since it has a higher impedance (8 ohms) than the internal speaker (4 ohms), it will
receive slightly less than half (200 watts) the total power delivered. Other than this imbalance, there is no
reason why you can’t connect an 8 ohm extension cabinet together with the 4 ohm internal speaker in the
Black Beauty. In any event, make sure your extension speaker cabinet can handle the power.
There is also the situation known as underpowering your speakers. This is caused when the power amp, in
the process of trying to drive one or more speaker cabinets, reaches its limit and goes into clipping. That
“clipped” waveform (or “square wave”) will quickly heat up the voice coils in speakers, and if operating
continually while clipping, eventually will burn the voice coils and cause the speakers to fail. (Remember,
engaging the Limiter will not allow the power amp to clip, so we recommend that you not disengage the
Limiter when running at low total impedances in general.)
Also be aware that when running the amp at 2 ohms, you are operating at the maximum capacity of the
power amplifier. With extreme settings on the Gain and Master controls and the Limiter circuit disengaged,
you may hear audible clipping of the power amp. If so, you have exceeded the maximum capacity of the
power amp. POWER AMP CLIPPING CAN CAUSE DAMAGE BOTH TO ITSELF AND YOUR SPEAKER CABINETS.
Either re-engage the Limiter (by pushing in on the Effects Blend control) to help smooth out the peaks, or
back off on the Gain and Master controls.
Remember, it’s always better to have a little too much power than just barely enough. If you find yourself
constantly wanting more power than the Black Beauty provides, either:
a) Tell your bandmates to turn down
b) Tell the monitor engineer to turn you up
c) (better option) Take the time to investigate getting an external power amp for the additional speaker
cabinets to supplement your rig
d) (best option) Investigate getting a larger rig (perhaps something modular, with a large head and two
speaker cabinets) for those gigs where more power and volume is needed
NOTE: The frequency response of the Black Beauty is far greater than usually found in musical instrument
amplifiers (20 Hz to 40K Hz). This was engineered in order to give the bass player the same punch and
clarity on stage as found in the studio or concert P.A. systems. Therefore, it is doubly important that you
are aware of the impedance and power rating of the extension speakers that you intend to use, and that
they are compatible with the Black Beauty. Speakers that have been overdriven are easy to detect and
generally do not fall under a manufacturer’s warranty.
EXTENSION SPEAKER OUTPUT JACKS
One Speakon Jack and one 1/4" phone jack (both wired in parallel) are provided for connection of an
extension speaker to the Black Beauty. Whenever possible, use of the Speakon jack is recommended.
Speakon jacks and connectors offer the best possible connection and are far superior to banana or 1/4"
phone jacks in that they not only lock in place (preventing accidental disconnection), but also offer a greater
and more
stable connection surface. This solid connection provides a more effective transfer of power to your speaker.
Only SPEAKER CABLE of 18 gauge or heavier (the heavier the cable, the lower the gauge) should be used to
connect an extension speaker to your Black Beauty. Do not use shielded instrument cable in this application,
as this can result in intermittent power loss, cause your amp to oscillate and damage itself and/or your
speakers, and render the cable useless for any purpose.
Recommended SWR Speaker enclosures for use as an extension cabinet with the Black Beauty include:
• Goliath III 4x10
• Goliath Junior III 2x10 (8 ohms)
• Son Of Bertha 1x15
• Big Ben 1x18 Subwoofer
• Bass Monitor 12"
SPEAKER FUSE
The speaker fuse is provided to protect your speakers in the unlikely event of a power amp failure or to
protect your power amplifier from incorrect speaker impedances or hookups. Size and rating of the fuse is
BLACK BEAUTY OWNER’S MANUAL • 13