Electric guitar speakers are intended to be loud, yet most of them
share an incongruous common trait: you can’t hear them. To be more exact,
you can’t hear the mids and highs unless you’re directly in front of them-
and sitting on the floor.
That's because guitar cabs have very narrow dispersion in the mid and
high frequencies. To compound matters they’re usually placed on the floor
just a few feet in back of the player, so those directional frequencies pass
around knee level. Even worse,
to ‘look right’ beneath an amplifier that’s 20 to 24 inches
wide, dual driver cabs place their drivers horizontally. This narrows
the horizontal dispersion angle even more, and causes comb filtering in the highs.
In an audio engineering course on how not to build a
speaker the typical electric guitar cabinet would be around the top of the list.
The simple solution is to vertically array the drivers, which would
widen horizontal dispersion, eliminate combing and put the source closer
to the player’s ear level, but the resulting tall, thin cabinet
would ‘look funny’ with the amplifier overhanging both sides. Guitar players
themselves have never had a problem with looking funny, but they do draw
the line when it comes to how their gear looks. Enter Plan ‘B’:
the cross-firing XF guitar speaker.

The XF is available as the XF210 for two tens, the XF212 for two
twelves, and the four driver XF410 and XF412. The ten inch cabs are 24 inches
wide, the twelve inch cabs are 28 inches wide.
While many guitar cabs are angled back a few degrees, the XF210 and XF212
have a rear tilt of 15 degrees, while the taller XF410 and XF412 have an 8 degree
rear tilt. With that much tilt-back you can actually hear what you're
playing, even when you're only a few feet away from the cab.
The drivers also cross-fire inward, at a 20 degree angle, shown in the
cutaway cab view below.

This minimizes the center to center spacing of the drivers for reduced combing,
and widens high frequency horizontal dispersion by up to 40 degrees compared
to a flat baffle.
Guitar cabs tend to two varieties, sealed and
open back, with most players having a preference to one or the other.
To appeal to both camps the XF can be built with a removable rear panel
that allows it to be either sealed or open with the flick of a latch.
Construction Degree of Difficulty: 4
Performance Quotient: 9
Equivalent Retail Value: 210 $899, 212 $999, 410 $1299, 412 $1499
Plans are $19.95, delivered within 24 hours as email attachment in MS Word
format. 13 pages, 8 photos, 28 diagrams. PDF version available on request.
The comprehensive plans show you not only what tools to use but
also how to use them.
The XF 210, 212, 410 and 412 are four different projects. Be sure to indicate
when ordering which plan you want.
Can’t build your own? Contact the nearest authorized Builder for a quote.