ACME sound 112 "Flat Wound" System User manual

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
1
Series III FW and FR Manual.pub
Low B Series II
I Systems
F
ro
m
Acme Sound
Owner’s Guide
Rev
05/2011
Acme Sound Ltd USA
www.acmebass.com
112 “Flat Wound”
System
112 Full Range
System

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
2
Series III FW and FR Manual.pub
Acme Low B Series III 12” Systems Owner’s Guide
Rev 7/9/2012
Table Of Contents
Table of Contents .
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1
Paper Owners Manual vs. Website
.
.
.
.
.
.
.
2
Quickstart
-
Guidelines for Use
IMPORTA
NT TO READ BEFORE YOUR FIRST USE!
.
.
.
.
2
On Amplifier Level Controls
.
.
.
.
.
.
.
2
Quickstart:
Impedance and Amplificati
on
.
.
.
.
.
2
Placement Low B
-
112
.
.
.
.
.
.
.
3
What are the Acme Series III Neo Systems?
.
.
.
.
.
.
4
Why were they crea
ted?
.
.
.
.
.
.
.
.
4
Further Notes on
Impedance and Amplification
.
.
.
.
.
5
Reiteration On Power Amplifiers and Their Level
Controls.
.
.
.
.
5
Cables
.
.
.
.
.
.
.
.
.
.
.
5
On the Subject of Handles
–
Pet Peeve
.
.
.
.
.
.
.
6
Troubleshooting
Gene
ral
.
.
.
.
.
.
.
.
.
6
Distortion
.
.
.
.
.
.
.
.
.
6
Warranty
.
.
.
.
.
.
.
.
.
.
8
Warranty and Service Notes
.
.
.
.
.
.
.
.
8
Service and Component Replacement
.
.
.
.
.
.
.
9
Specifications
.
.
.
.
.
.
.
.
.
.
9
Contact Information
.
.
.
.
.
.
.
.
.
9
Performance Data Low B
-
112 “Flat Wound”System
.
.
.
.
.
10
Performance Data Low B
-
112 Full Range System
.
.
.
.
11

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
3
Series III FW and FR Manual.pub
P
aper Owners Manual vs. Website:
Believe it or not, much of the content in the earlier owner’s manuals was written in the early nineties, before the inte
r-
net made information so easy to get. In updating the manuals for the Series III models, it has become clear that they
could be m
ore useful if focused squarely on practical suggestions, and less on history, philosophy, background and
theoretical considerations. All of that fluff can easily be made available on the web, and has, so this manual will a
t-
tempt to focus on taking the cabinet to the gig, and sounding good when you get there.
Rest assured that you can find all the
bloviating and painful details you want, if you visit the website as www.
acmebass.com. The earlier manuals are available there in the “Support” section, and do contain a wealth of inform
a-
tion, make no mistake. But this document will be about using the speaker.
So, let’s get to work.
Quickstart
-
Guidelines for Use
:
IMPORTANT TO READ BEFORE YOUR FIRST USE!
A little bit of information about the level controls on power amps:
I’ve had unfor
tunate conversations with an alarming number of people who have made the same mistake:
A great many people, I’ve learned, belie
ve that a 1000 watt amplifier becomes a 500 watt amplifer once the level
controls are set to “halfway up,” “12 o’clock,” or “onl
y at 5,” if you catch my meaning.
I would prefer not to have this conversation any more, because it usually is with some well
-
i
ntentioned kid whose
woofers are in tatters, and who can’t understand what he did wrong.
So, read this twice if you have to: L
owering the setting of the Level, or Volume control on your power amplifier does
not limit it’s ability to produce its full powe
r! If a 1000 watt amplifier is only turned halfway up, it does not become a
500 watt amplifer! It is still able to produce it’s
full 1000 watts if it gets a “hot” enough input signal.
Read it again.
Thank you
.
Quickstart:
Impedance and Amplification:
These speakers have a reputation for being power hungry, handling large amounts of power, and being very loud
for their size.
A
l
l of these things are true.
The Low B
-
112
models are
rated at
350
watts RMS continuous.
We recommend 400
-
500 watts.
Grown
-
up
s can be trusted to use more power than that, and those who choose to do so will be rewarded with a very
loud and very clean sou
nd. Just be careful, and listen for distortion, which will be an indicator that your reaching
some limits somewhere. More on thi
s later.

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
4
Series III FW and FR Manual.pub
Placement Low B
-
112
The 112 System has rubber feet on the bottom, which implies a way to stand it up.
The handle is on top.
W
hen ever possible
, place your amp or other heavy object on top to help anchor
your system to the floor. As the speaker cones mov
e in and out, they will have a
tendency to cause the enclosure to vibrate in opposition to the movement of the
cones. (Newton’s
second law of motion.) This effect is present in competing
designs as well, and this is good advice when using any speaker, not
just these
Acme models. It is to your advantage to minimize this effect by using as much
weight as is available on top of the sp
eaker
.
This is more important with a lightweight neo loudspeaker than a traditional,
hea
v
ier, ferrite model.
An unfortunate side effect of a lightweight speaker is the
loss of inertia associated with a heavy, back bre
aking magnet.
I hope you enjoy the diagram I made in 1993 on an Apple IIGS for the original B
-
2.
E
xperience has taught me that musicians “in the field” will often adjust their positioning and placement to their ci
r-
cu
m
stances. Depending on room characteristics, band volume, and balancing between stage and room volume, some
will stack a pair of
speakers column
-
style, some will stack them placed horizontally, and some prefer a side
-
by
-
side,
orientation. Don’t be afraid to
experiment, and don’t be afraid to be flexible.
END QUICKSTART GUIDE

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
5
Series III FW and FR Manual.pub
W
hat are the Acme Series III Neo Systems?
The Acme Low B
-
112 "Flat Wound” and Full Range Systems are compact, lightweight, high
performance loudspeakers
which, like the classic Acme Low B systems using 10” drivers, achieve superior low
-
end output, extension, and tra
n-
sient response by manipulating the Thiele
-
Small parameters in order to optimize for these qualities at the expense of
efficiency
.
The Acme Low B 112 "Flat Wound” and Full Ranges Systems use a special, propriety twelve inch woofer. They repr
e-
sent a synergistic marriage of classic design principles, and cutting edge materials and techniques, executed with
great precisi
on, attention to detail, and craftsmanship.
The Acme Low B
-
112 “Flat Wound” System is a one
-
way system, with no tweeter, and no
crossover. Its surprisingly
extended top end, for a twelve inch bass driver, makes it an excellent solution for a great many ba
ss players, those
in particular, who don’t need an extended studio
-
monitor type of high end, as in our full
-
range models.
It
is simplicity itself. No whistles, no bells. It is as near a perfect distillation to the essence of what a classic Helmholtz
Resonator can do. And it weighs 37 lbs.
It is a stand
-
alone witness to the ability of a modern neodymium woofer to fill a big
room with a big sound, with a
small, lightweight loudspeaker.
The Acme Low B
-
112 Full Range System is similar to the “Flat Wou
nd” System, but with a smoothed midrange, and an
added high
-
output, high accuracy shallow horn tweeter. It is similar to the “Fl
at Wound” unit, but with high end which
extends to the limits of audibility. The Full Range System is a relatively low
-
coloratio
n, high accuracy speaker, much in
the tradition of the classic Acme models, but with lighter weight made possible by the availab
ility of lighter high
-
performance neodymium magnets.
The Full Range System comes in a little heavier, at 38 lbs.
Why were th
ey created?
If I might rephrase that question, what, if anything, is lacking in the traditional Acme Low B systems, which might
be
addressed in these new models?
In a word, weight. The Acme Low B
-
2 system, based on the ten
-
inch woofers, is the same size
as these 112 models. It
is loud, clear, uncolored, has a massive bottom end, and is as relevant today as it was when it was intr
oduced in
1993. It is probably the second most imitated loudspeaker in the industry, after the ubiquitous Ampeg SVT. It was
named one of the “Ten Most Important Products of the Decade” by Bass Player Magazine, has a fanatical following
around the worl
d, and is not in need of substantive improvement. So why bother?
Neodymium magnets were not available in 1993. They are now. My
back is older. So is yours. How much heavy stuff
do you need to carry around in order to make music? As little as possible, tha
t’s how much.
The first choice would have been to introduce the traditional models using a ten
-
inch neo woofer which would be
a
direct replacement for my classic woofer. But no such woofer is available yet. It may be later. I haven’t given up. The
tradit
ional Acme systems will continue to be available, more
-
or
-
less unchanged, and when and if such a woofer is
available, I’ll let y
ou know.
In the meantime, Eminence has a template for a truly great twelve
-
inch neo woofer, and the willingness to modify it to
my specifications. The resulting bass driver is unique in the world, and for people who are willing to use more power
to drive
a less efficient loudspeaker, provides an opportunity to fill a room with loud, extended bass using a system
of unprecedented co
mpactness and light weight.
Most companies in this business introduce a great many new models, year in and year out. We don’t.
We’ve never
had a compelling reason to do so before. Neodymium magnets provide one.
The “Flat Wound“ System was the first model
to use this new woofer. The pleasing nature of the woofer’s high end
was discovered, almost by accident, en route to a standard
, Acme
-
style full range
-
system. But when we heard how
good the simple one
-
way cab sounded, we knew right away that it worthy of
introduction as a stand
-
alone model.
The Full Range System realizes the full potential of the Acme twelve
-
inch woofer.

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
6
Series III FW and FR Manual.pub
Further Notes on
Impedance and Amplification
:
As with earlier Acme models, greater than average power is required.
A 200 watt
amplifier, which is more than adequate to power a JBL, can seem gutless when used with these speakers,
the 8 ohm models in part
icular. Low power can obviously be a source of trouble. Even with higher
-
power amps, a
slightly different approach to using your
equipment can be helpful. See the section on “Distortion.”
These systems are aligned using Thiele
-
Small technology to minimize
distortion in the lowest half
-
octave (down to the
"Low B") but this alignment increases amplifier current requirements at these
frequencies. As a general rule, when
distortion is heard from these speakers, it will be eliminated by increasing amplifier pow
er. This is the unfortunate
price we pay for low distortion, extended bass from a compact enclosure.
On paper, h
igh damping fact
or solid state
amps are recommended for greatest cone control, but if you have a tube amp,
live it up
.
Let us know how it works
out.
In fact, please let us know if a particular amp really pleases you, or not...
C
ables
:
As a design goal, internal system resistance has been kept to a minimum. To maintain the same level of electrical
integrity, short, heavy gauge cables are best. Don't run out and spend a fortune however, unless you're certain that
what you h
ave is inadequate. I recommend a cable of under .3 Ohms, and the larger the cable the better.
I’m very conservative in the area of cables, and I believe the benefits of expensive cables are sometimes exagge
r-
ated by those who offer them. See “James Clerk Maxwell.”
R
eiteration On Power Amplifiers and Their Level Controls:
We recommend that you use your power amplifier with the level control
set to their, highest setting, or “full blast,” if
you will. There are common sense reasons for this, that are even more important when using a lower
-
efficiency lou
d-
speaker.
In short, when you “max” the levels on your power amp, you are less likely to overload any of the earlier stages in
your signal chain, which would cause distortion.
I’ve had unfortunate conversations with an alarming number of people who have
made the same mistake:
A great many people, I’ve learned, believe that a 1000 watt amplifier becomes a 500 watt amplifer once
the level
controls are set to “halfway up,” “12 o’clock,” or “only at 5,” if you catch my meaning.
I would prefer not to have t
his conversation any more, because it usually is with some well
-
intentioned kid whose
woofers are in tatters, and who can’t unde
rstand what he did wrong.
So, read this twice if you have to: Lowering the setting of the Level, or Volume control on your pow
er amplifier does
not limit it’s ability to produce it’s full power! If a 1000 watt amplifier is only turned halfway up, it does
not become a
500 watt amplifer! It is still able to produce it’s full 1000 watts if it gets a “hot” enough input signal.

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
7
Series III FW and FR Manual.pub
On the Subject of Handles
–
Pet Peeve:
Loudspeaker handles have been a bane of my existence, and a curse of disproportionate sig
nificance to what I
consider my mission statement, which is to offer a high
-
performance tool for reproduction of sound.
When d
esigning a loudspeaker for optimum performance, the idea of providing a handle, or handles, for easy
transport does not enter in
to the equation. A handle can be detrimental to performance, or at best, can be
performance
-
neutral, and not do any damage.
It
is my experience that any type of handle represents a problem of some type to some people. No matter what the
designer offers,
some people will hate it, and some will like it. This is the curse of the professional loudspeaker
designer.
The recessed hand
les on the older models were used, in part, to provide an internal point to which the port could be
fastened., for structural in
tegrity. Brilliant idea. But in terms of transport, some people hate them. Others don’t. But
customers have been after me for ye
ars to offer a handle which would enable the user to carry the speaker with one
hand.
The Series III models actually incorpor
ate the port tube into the bracing mechanism, which allows the use of a handle
with pure ease
-
of
-
use as the primary consideratio
n. What a great opportunity, I figured to incorporate a handle that
people would love! Little did I know.
At least one person w
as complaining about the new handle before a single 112 model had left Denver, simply based
on a photo, and in fear of a tiny am
p not having tall enough rubber feet to clear the external height of the handle. Is
that about the amp, or the speaker?
The le
sson is that there is no such thing as a handle which everyone will like. If handle considerations are a deal
-
breaker for you, I
would rather you buy a different speaker than complain about the handles.
The single hinged, recessed handle is now located on
the top of the vertically
-
oriented box. It is precisely over the
unit’s center of mass, so it will carry easily. If you don’t l
ike it, I don’t want to hear about it, unless you’ve got a better
idea.
Troubleshooting
:
Genera
l:
A 200 watt amplifier, which is more than adequate to power a JBL, can seem gutless when used with th
ese speakers,
the 8 ohm models in particular. Low power can obviously be a source of trouble. Even with higher
-
power amps, a
slightly different approach to using your equipment can be helpful. See the section on “Distortion.”
Distortion
:
Distortion, wh
en introduced by any part of a sound system, will be heard from the speaker. If, for example, an
amplifier has a weak tube, the
effects of that weakness will be heard as distortion
from the speaker
. Sometimes,
then, to say “the speaker is distorting,” can
present a false picture.
A couple of gents had their Low B speaker disassembled before they realized that their effects process
or had a low
battery. Another fellow sent frantic email asking help in diagnosing his faulty speaker, before realizing the batte
ry in
his bass was nearly spent, and he hadn’t noticed with his old speaker. A new battery fixed his speaker!
The point, then,
is that when you hear distortion, you must isolate the cause of it. If your instrument is at one end of a
chain, and your speake
r is the other end, distortion occurs when any link in the chain is overdriven. To
overdrive
any
component is to expose it to an
input signal of sufficient strength to exceed it’s capabilities.
Sometimes, when faced with a speaker of lower efficiency, su
ch as the Low B systems, a player will, without thinking,
boost the volume control on his/her instrument to compensate. To do th
is though, is to risk overdriving the
preamplifier, by exceeding it’s input capability. Similarly, to turn the volume control to
levels that would try to
squeeze 200 watts from a 100 watt amplifier is to (over)drive the amplifier into distortion. To push 1
000 watts into a
500 watt speaker will obviously overdrive the speaker.

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
8
Series III FW and FR Manual.pub
So, having explained that, if you hear distortion, proceed as follows:
(1)
Increase the volume setting on your power amp, if yo
u have one. Compensate by decreasing the volume on
your preamp.
(2)
If distortion persists, increase the setting on your preamp
’s volume control,
and compensate by decreasing the
setting on your instrument’s volume control.
(3)
If distortion persists, ch
eck all of your batteries, and make sure any
ancillary equipment is
operating properly.
(4)
If distortion persists, and you’re
not playing very loud, you might not have
enough power. If you’re playing
quite loud, you might have too much
power, and could b
e overdriving the speaker (Yes, it
is
possible.) Try with
another amp.
(5)
If distortion persists, call Acme, and we’ll talk
about it.

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
9
Series III FW and FR Manual.pub
Warranty and Service Notes:
I
t’s most important to get the speaker operating properly, so all the world will know how great it
sounds! But we’re
unable to subsidize destructive behavior by replacing for free anything you can find a way to damage. If, for
example, your amplifier fails, and sends something hideous through the speaker, or you like to pound on your
strings at full vo
lume to massage your back, please, I beg of you, don’t send me back woofers whose cones are in
tatters with the expectation that
they will be replaced for free, because this type of horrible damage cannot be
construed as a “defect” in the product you were
sold.
Forms of abuse not covered:
Blown Speakers
:
A woofer which was shipped to you with a defect of some kind will not show si
gns of physical
destruction when it fails. If, for example, you can see a “creasing” around the circumference of the cone, your
speaker has been overdriven, exposed to a DC component, or been fed a distorted signal by an overdriven amplifier.
This is not a
defective woofer. If your voice coil has been burned to carbon, please don’t bother to make your case
that it was received with
a defect.
Pounding on your strings with your palm.
Yes,
it sounds cool, but that’s not the point. Power handling decreases
drastically
below 31 Hz (B), and string pounding can send near
-
DC through the poor thing. If pounding is an integral
part of you
r playing style, you shouldn’t be using a vented
cabinet, but would be better off with a sealed
-
box
system, such as an SVT.
Bu
rnt voice coil
:
The best way to destroy a voice coil is to continue to play at a higher volume than either the amplifier
or spea
ker will handle. If either is pushed beyond its limits, damage to the speaker could occur. Listen to your system
carefully. Inor
dinate distortion, regardless of the source, is a sign that you’re pushing the envelope, and could
damage your amp, speakers, or
both.
Drop/smash. No explanation necessary.
Please remember if you have any trouble, that
we’re
mostly interested in solvin
g your problem as quickly as
possible, and saving whatever money can be saved by either or both of us!
I hope this information
makes it possible for you to get the most from your speaker. Again, if you have ideas to
make this guide more useful, please le
t me know.
Warranty
Acme Sound Ltd warrants this speaker to be free from defects in materials
and workmanship for a period of two years fro
m date of purchase. This
warranty includes cost of any covered repairs and shipping one way.
Warranty not to cover repairs neces
sary as a result of abuse. Warranty
voided by any attempt to modify, improve, or reverse engineer the
speaker.

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
10
Series III FW and FR Manual.pub
Specifications:
Frequency Response:
“Flat Wound” System:
31 Hz to 4 kHz
Full Range System
31 Hz to 20 kHz
Sensitivity
:
91.1 dB 1 watt/1 meter
Loading Method:
Helmholtz Resonator
Dimensions:
23 x 15.75 x 16.5 (D) inches
58 x 40 x 4
2 (D) cm
Power handling:
350 watts RMS
Recommended amplifier power:
400
-
500 watts
Impedance:
4 or 8 ohms
Weight:
37
lbs “Flat Wound” System
16.8 kg
38 lbs Full Range System
17.3 kg
Connection:
Neutrik NLJ2MD
-
V dual connectors
(2 parallel)
accepts Neutrik Speakon and/or standard USA 1/4” phone plug
Rohs compliance:
Compliant
Contact Information:
Acme Sound L
LC
PO Box 2556
Englewood, CO 80150
Information/Customer Support
(303)783
-
8766
Toll Free
(800)226
-
3583
Fax
(
303)783
-
1060
E
-
mail
[email protected]
Website
www.
acmebass.com
Service and Component Replacement:
The Series II models use faston, or “Quick
-
Connect” connectors to make electrical connection
s to crossovers and drive
units.
Long a devotee of soldered connections, for obvious reasons, I finally caved. I saw connectors
of this type when I was
snooping around inside my favorite studio monitor speakers. If it’s good enough for them, it’s good eno
ugh for me.
I love the easy serviceability and upgrade. You will too. That’s it in a nutshell.
When and if, for whatever reas
on, a driver has to be replaced, it will no longer be necessary to have soldering
equipment, just a Phillips head screwdriver.

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
11
Series III FW and FR Manual.pub
Performance Data Low B
-
112 “Flat Wound”System:

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
12
Series III FW and FR Manual.pub
Performance Data Low B
-
112 Full Range System:

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
13
Series III FW and FR Manual.pub
Performance Data Low B
-
112 Full Range System:

Owners Notes
Low B
-
112 “Flat Wound” and Full Range Systems
14
Series III FW and FR Manual.pub
Performance Data Low B
-
112 Full Range System: