Page 1
SOUNDROOM
MXR
M87 Bass
Compressor
BY ED FRIEDLAND
COMPRESSION IS A FUNNY THING. FOR
an effect that’s supposed to be transparent,
it can really screw things up; user competence makes a big difference, but less-thanfull-featured stompboxes certainly don’t
help. And although great studio compressors like the venerable dbx 1066 offer several ways to tweak compression’s critical
parameters—input and output levels, attack,
release, and ratio—it’s rare that something
as small as MXR’s new M87 Bass Compressor pedal offers such fl exibility and control.
GOOD THINGS IN SMALL
PACKAGES
The M87 manages to squeeze controls for
input and output levels, compression ratio,
release, and attack on the faceplate of a box
the size of the classic MXR Phase 90 pedal.
But in a stroke of genius, they also added an
LED meter along the top of the unit. Com-
pression is a subtle but potentially dangerous
effect, and having visual feedback helps you
dial in the perfect amount of gain reduction,
and accurately gauge response time, too.
The
INPUT control sets the relative com-
pression threshold—the point at which the
compression kicks in, and how much actual
gain reduction occurs. Clockwise adjustments increase the amount of compression.
Most people get into trouble by using too
much gain reduction; if you can hear compression working, you’re using too much.
But with calibrations at -1, -3, -5, -7, -10,
and -20dB, the
see how much gain reduction you’re using.
Keeping the meter between -3 and - 7dB (in
conjunction with other parameters) will
help prevent heavy signal squash.
The
which the compression responds to the signal.
The M87’s attack control ranges from a relatively slow 20 microseconds (fully counter clockwise) to 800 microseconds. Slower
speeds preserve the attack of percussive techniques like slap and pickstyle, while faster settings create a tighter-sounding compression
that can round off the front end of your note.
Release time is a critical factor for effective
use—slower release times can aid with sustain
on long notes, but a faster release maintains
the note attack for rapid passages. The MXR’s
release time ranges from 1.1 seconds to 50
milliseconds when fully clockwise.
LED meter makes it easy to
ATTACK knob determines the speed at
MXR M 87 Bass Compressor
Street $189
Pros Capable of studio-quality tone,
highly adjustable
Cons None
TECH SPECS
Input impedance 1MΩ
Output impedance 600Ω
Max input level +14dBV
Max output level +8.5dBV
Frequency response 20Hz–20kHz
Gain +31dB
Compression ratio 4:1, 8:1, 12:1, 20:1
Attack time 20ms–800ms
Release time 50ms—1.1s
Bypass True hardwire
Dimensions 43" x 23" x 1
Weight 8.4oz
Made in USA
Warranty One year
Contact jimdunlop.com
9
/32"
60 | JANUARY 2012 BASSPLAYER.COM
Page 2
SOUNDROOM
ratios: 4:1, 8:1, 12:1, and 20:1. 4:1 means
that once the input level reaches 4dB over
the point where the compression kicks in
(threshold), the output signal will be 1dB
over that threshold level—a gain reduction
of -3dB. The 4:1 compression ratio is a standard for recording bass; it interferes the
least with the natural dynamic range of the
instrument. The 8:1 setting hits the signal
harder, but can be very useful for evening
out your two-handed tapping technique. The
12:1 and 20:1 ratios puts the MXR in limiter
mode. Limiting, which is essentially compression with a high ratio and fast attack,
prevents any signal from going beyond the
threshold; it can be very useful for protecting underrated speakers at high volumes,
or maintaining a consistent level for broadcast purposes. 12:1 is considered soft limiting, which is more performance-friendly,
while 20:1 is known as “brick wall” limiting—the name says it all.
the M87’s signal path, and the MXR offers
a whopping +31dB of gain to make up for
any reduction taken at the front end. Why
use gain reduction, only to add it back, you
ask? The point of compression is to shape
and compact the signal, which naturally
causes gain reduction. In order to use this
newly shaped signal, especially in a live
setting, you’ll need to bump the level back
up. The MXR’s output level can easily compensate for even the most dramatic gain
reduction, allowing you to maintain your
position in the mix while enjoying the benefi ts of the effect.
room Technology (CHT), which produces
18 volts of headroom from a single 9-volt
battery using voltage step-up techniques.
MXR states that CHT will consistently produce 18 volts even when your battery drains
down as far as 4.5 volts, or with increased
voltages up to 30 volts. CHT also protects
against incorrect reverse polarity and AC
voltages. The M87’s true bypass keeps your
sound uncolored when not in the loop, but
the overall frequency response of the unit
is very transparent—with more subtle settings, it can be hard to tell if it’s on without looking at the meter. The M8 7 runs on
a single 9-volt battery or a Dunlop ECB003
AC adapter.
PUTTIN’ THE SQUEEZE ON
I’ve never been a fan of compression pedals,
as most of them tend to be too heavy-handed
for live work and not fl exible enough for
62 | JANUARY 2012 BASSPLAYER.COM
The MXR offers four preset compression
The
OUTPUT control is the fi nal step in
The M87 features MXR’s Constant Head-
studio use. So it was with a certain amount of
skepticism that I took the M87 out on a gig.
On a rootsy country gig, I dialed in a
4:1 ratio with a slow attack speed, medium
release time, with gain reduction set between
-3 and -5dB. It transformed my usually woolly
P-Bass into a slick, processed Nashville session tone machine. The M87 made the bass
sit in the live mix like it would on a recording. Then I experimented with squashing the
signal a bit more with an 8:1 ratio, but still
keeping the attack speed slow to maintain
the front end of my note. I used a slightly
slower release time to increase sustain, and
kept the gain reduction below -7dB. Pushing the output a little hotter kept the overall volume intact, resulting in a well-formed
tone that responded to a very light touch,
but still left room for right-hand dynamics.
It was neat to hear the grindy top end of my
broken-in roundwounds suddenly push its
way to the forefront.
Under normal circumstances, I’d never
use a 12:1 ratio for live work. Using a conservative amount of gain reduction, a medium
attack time, and more gain at the output,
however, I was able to keep my place in the
rhythm section while using a super-light
right-hand approach. I tried my luck with
a 20:1 ratio, and was surprised that I could
dial in something that worked live—the key
was moderate gain reduction, a slow attack
time, and a healthy dose of output gain. I
achieved a perfectly useful tone that spoke
clear and strong, and it a touch so light that
looking at the strings was almost enough.
Digging in produced absolutely no change
in the dynamic level: The M87 had taken
complete control of my sound. It’s not something I would use often, but it could be a
real boon to the two-hand tapping crowd.
Slapping with the M87 was a treat. This
stompbox allows the highs to shine through
unmolested, and I dialed in a variety of
sounds with the various controls. Using mild
gain reduction and a slow attack speed, I
was able to subtly round out the pops without messing with the thump, but you could
easily achieve a chopped and formed tone
that emphasizes the effect. I also tried the
M87 in front of several other effects with
great results. It enhanced the response of
the already excellent MXR Bass Octave
Deluxe pedal, for example, and made harmonics pop with MXR’s Analog Chorus unit.
Overall, the MXR M87 is a big winner.
It has all the fl exibility and sonic purity of a
high-grade rack unit, and if you understand
how to implement it correctly, it can turn
your everyday gig tone into studio gold.
BP
Loading...