| By
Dean Kattari
(As appeared in Gig magazine)
Talk
about going off the deep end, the new B-52 ACT-18
is a nuclear bass bomb designed to make your P.A.
go boom! The ACT-18 ($1,099) is a powered 18”
subwoofer designed to be placed in-line with your
existing system. You just send the Left and Right
outputs from your mixer via standard XLR cables
to the ACT-18’s inputs and them connect another
pair of XLR cables from the Hi-Pass out to your
existing power amp or powered speakers and you
are ready to shake, rattle and roll. By way of
its internal crossover, everything under 120 Hertz
goes to the ACT-18 and everything above 120 Hertz
gets sent to your regular speakers. This way your
existing speakers are running more efficiently
because they don’t have to exert the extra
energy to produce all of the deep and low frequencies
that are being projected by the subwoofers. You
can adjust the bass balance with the internal
level control on the ACT-18 to balance the overall
tone.
As
if this wasn’t enough, B-52 has also constructed
a partner-in-crime known as the ACT-18S, which
is the unpowered sibling of the ACT-18. You run
signal to it from the ACT-18 via a Neutrik (Speakon)
cable. By using these two cabinets in tandem,
you get a double whammy: the digital power amp
on the ACT-18 delivers 1200 watts RMS on the 4-ohm
load (rather than 800 watts on its own at 8-ohms)
and you get a “coupling effect” from
the two speakers which adds an additional 3db’s
to its output.
Construction
The ACT-18 is a real warhorse. All of the components
appear to be road-worthy and able to handle the
kind of abuse we musicians are prone to dish out.
These cabinets are visually impressive an imposing:
black carpeted, Baltic birch construction with
black 16 gauge steel grill and big enough to replace
a stone in the great pyramids of Egypt. They are
designed with a pole receptacle built into the
top of the cabinet allowing you to attach a smaller
full-range speaker cabinet to a 20” aluminum
mounting pole (included!). At first look, they
are a bit intimidating; how are you supposed to
get these muthas into a club? They are supposed
to be portable, but weigh 110lbs! Well, thanks
to the 3” heavy-duty detachable casters and
the thoughtfully provided built-in handles, you
can roll the ACT-18/ACT-18S fairly effortlessly
across any surface. I rolled them down an incline
onto a gravel road then single-handedly lifted
them into the back of my Subaru without breaking
a sweat. However, they are bulky and you will
need a fair amount of extra space in your van
for these to travel with the rest of your gear.
Ins
and Outs
The control panel on the back is thoughtfully
recessed to minimize damage to the components.
To get your signals to and from this box you get
a pair of XLR Inputs, a pair of XLR Hi-Pass Outputs
(over 120 hertz) and a pair of XLR full-range
outputs (to send to other subs or an additional
crossover for a more elaborate system). Additional
controls include a power switch next to the standard
IEC power cable, a separate switch for the remote
subwoofer output, 180-degree phase switch and
an overall level control.
Power
The heart of the ACT-18 is the digital power
amp, which, surprisingly, weighs in at only 6
lbs.! Despite it’s diminutive heft this amp
puts out 800 watts at 8 ohms (for the ACT-18 by
itself) and when connected to the ACT-18S the
amp pushes a mighty 1200 watts at 4 ohms, more
than enough to get that chest-pounding kick drum
sound you been lusting after. And yet, it only
draws only 20 watts when it is in idle (between
sets) so it won't raise the power bill much. The
fact that you don’t need to get an additional
power amp, limiter and crossover to add this subwoofer
to your existing system make this a very economical
way to get serious bottom-end out of your P.A.
rig.
In
Service
I rolled them over to the Stork Club in Oakland,
CA and patched it into their 3-way system. Hooking
it up was a breeze; I patched the ACT-18 and ACT-18S
in from the Left/Right outputs from the mixing
board and, using the full-range outputs, I sent
the signal along to the house system. The first
thing I noticed as I was ringing out the system
was that all of a sudden the low end of my graphic
EQ was actually doing something! I was able to
tune the low frequencies in the room more accurately.
Sounds
In true rock-n-roll fashion that night we
did not do a sound check, we just launched into
the first band’s set. I had placed microphones
on the drums (kick, snare and toms), bass guitar,
electric guitar and, of course, vocals. By the
end of the first song, I pretty much had it all
dialed in. The effect of the ACTs was immediately
noticeable in the tighter definition of the kick
drum in the mix. I didn’t need to use the
full power of the ACTs and had the level set about
two thirds of the way up. With all of the extra
headroom the tone was clear and powerful, you
could feel the bass rather than just hearing it.
I experimented by flipping the phase switch on
the back and noticed that even though the bass
was still clear it wasn’t as punchy or focused
so I ended up leaving it in phase. Most of the
bands had played in this club before and they
all noticed that the sound was better (the drummers
loved the way their tom’s and kick’s
thundered into the room). I was able to EQ more
growl into the guitars than I could before. Even
the vocals had a thicker sound due to the expanded
range of the system using these subwoofers. The
overall effect was a fuller mix with much more
control over the lows. The soundman was walking
around the club smiling and saying, “I could
get used to this!”
Conclusion
For any band needing extra bass in their live
sound, I would recommend the ACT-18 powered subwoofer
along with the satellite ACT-18S as an excellent
addition to your P.A. These behemoths are a must
for any sound reinforcement system that plays
dance, hip-hop or any electronic music that would
sound anemic with out thick, punchy bass. It has
the right combination of portability, flexibility,
and righteous, earth-trembling, booty-shakin’
tone to make for a sound investment.
CONTACT
INFO
B-52 Pro-Audio / E.T.I. Sound Systems, INC.
Telephone: 323-277-4100 or 1-800-344-4ETI
www.B-52PRO.com
Soundcheck:
B-52 ACT-18 and B-52 ACT-18S
Key Features:
Level Control
180-degree phase shift
Thermal and Short Circuit protection
XLR inputs
Specs:
Digital Power amp:
1200 Watt RMS at 4 ohms
800 Watt RMS at 8ohms
Peak power 1600/2400 watts
Peak SPL 132db
Sensitivity: 102db
30-120hz Frequency Range
Total Harmonic Distortion: 0.075% @ rated power
over full bandwidth
Crossover:
Crossover point: 120 hertz
Crossover slope 24 db/octave (high pass and low
pass)
THD: 0.075% @ Rated Power Over Full Bandwidth
Connections/Controls:
XLR balanced inputs
XLR balanced outputs full range or High Pass (over
120hz)
Neutrik (Speakon) subwoofer out to satellite
The Speaker:
B-52 18-200S
1000 Watt RMS 18” polyamide Transducer cast-aluminum
frame with a 4” voice coil and a 200 oz magnet.
8-Ohm Impedance
Frequency response of 20-160hzDimensions:
ACT-18
24”x33”x22” WxHxD
110 lbs.
ACT-18S
24”x33”x22” WxHxD
102 lbs.
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Pros
Powerful clean sound, fairly portable, easy
and flexible patching
Cons
They’re bulky and relatively costly |
