Speakers - Aiken Amplification Invader MKII User Manual

Speakers

Changing speakers is like getting a whole new amp. Every model sounds completely different,
some sounding quite good and some amazingly bad. The amplifier is particularly suited for use
with Celestion loudspeakers, which give the characteristic "British" sound this amplifier is
designed to create.
Celestion Greenbacks have less volume and a dip in the mids, which makes them nice and
smooth. They are rated at 25W, so they make a nice match for the Invader 18, but are a bit
under-rated for the Invader 30 in a 1x12 configuration. Celestion Alnico Blues are by far the
loudest, with a nice chimey top end (but not extremely cutting highs) and full bottom end, but their
rather pronounced midrange and very low power rating (18W) may make them undesirable for
some users. If you do use this speaker, you may want to set the attenuator to the -3dB position
when playing fully distorted. Jensen P12B "bell" alnico's are far brighter than the Celestion Alnico
Blue, but don't have as good a low-end response. They are, however, rated at 50W and sound
very nice when paired with the Alnico Blue in a 2x12 configuration. Celestion Vintage 30's have a
very pronounced midrange, which may be a bit too harsh in an open-back configuration, which
naturally enhances the midrange frequencies, and can sound a bit "boxy" with the wrong speaker.
They do sound good for some blues styles, and can easily handle the power of the Invader 18 or
30 in a 1x12 configuration. Celestion G12H30's are like a cross between the Greenback and the
Vintage 30, with more low end than the Vintage 30 and not quite as pronounced a midrange, so
they tend to sound subjectively "better" in an open-back cabinet. The G12H30 is preferred in a
1x12 configuration by many customers, as is the Greenback. Your mileage may vary.
Closed-back cabinets have better and tighter bass, without the pronounced midrange hump of the
open-backs, but they don't disperse on stage as well, and tend to be "beamy", sounding very loud
out front, but if you stand above and to the front or back, you can't hear yourself as well. Still,
there is nothing quite like the tone of a cranked up 4x12 cabinet loaded with Greenbacks! For a
more portable closed back, a 2x12 loaded with either of those Celestions will do the trick nicely.
Putting a 2x12 on each side of the stage fills up the tone very well, and provides an almost
stereo-like sound field because of the cancellations that occur when standing in different places
on stage. The Greenbacks are the recommended speaker for 2x12 and 4x12 cabinets for the
"classic vintage" tone.
When changing speakers, always insure that the output impedance selector is set to match the
impedance of the speakers connected to the output jacks. The Invader has two paralleled output
jacks, and can easily drive two 4x12 cabinets to extremely loud volume levels, despite the 18W
rating.
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