at these frequencies
is
much reduced com-
pared to sealed or open-backed enclosures,
directly reducing harmonic distortion.
Often,
in
bass guitar systems, a perfectly flat
response
is
not as important as a controlled
response. Typical sound-reinforcement sys-
tems are "tuned,"so the enclosu
re
provides the
flattest possible response. Generally, bass-
guitar system performance
is
improved if the
enclosure is vented or tuned for roughly the
lowest notes that will be played through
it.
For
standard tuning four-string bass, a 44-Hz tun-
ing is recommended. The low "E"
on
a bass
guitar actually vibrates at 41.2 Hz, but a 44-Hz
tuning will provide a reasonable amountof vent
contribution oradditional output at
41
.2 Hz.
If
a
four-string bass with a "dropped
0"
is
used, the
recommended tuning frequency
is
40 Hz. For
any ofthe above examples, the recommended
enclosure internal volume
is
approximately 1.2
cubic feet per speaker. The larger the volume,
the less equalization will be required.
INSTALLATION
The 10BX may be front- or rear-mounted, al-
though front mounting
is
preferred because of
convenience. For simple front mounting, the
convenient SMH-1 mounting accessory
is
rec-
ommended. Complete mounting instructions
for standard front mounting are given below. It
is
importantthat recommended baffleopenings
and mounting hole locations be followed.
Front
Mounting
Front mounting requires a 229-mm (9.0-in.)
diameter cutout and a 244-mm (9.62-in.) bolt
circle. Mark the baffle opening and screw loca-
tions
on
the blank panel first. Drill the screw
holes before cutting the large baffle opening.
If
1/4-20
screws are used, four screws are
sufficient for secure mounting of the speaker.
T-nuts are recommended for simple, secure
mounting.
If
T-nuts are used, the holes should
be
7.1-mm (0.281-in.) diameter (letter "L" drill).
Apply glue to the flanges of
1/4-20
long shank
T-nuts before driving into the rear of the holes.
Sealing ofthe front-mounted speaker
is
accom-
plished with the adhesive-backed foam gasket
segmentsthatareincluded withyournew 10BX.
Strip off the protective paper and apply the
gasket to the rear mounting surface of the
speaker
rim,
makingcertain thatthe holes
in
the
gasket line up with the mounting holes
in
the
speaker frame.
Length of the
1/4-20
screws should be 1/2-inch
plus the panel thickness when using T-nuts.
The screws mustbe tiIIisterhead orinternal hex
drive machine screws to seat down
in
the
recess of the speaker frame gasket (see
Figure
3).
Screws should be tightened evenly
and securely. Maximum torque possible with a
proper size screwdriver should be sufficient.
IMPORTANTI When
front
mounting,
the
screw
head
must
fit
down
Into
the
front
gasket
cutout
(see Figure 3).
Rear
Mounting
Rear mounting requires the same diameter
cutoutandscrewcircleas front mounting.Other
comments regarding the use of T-nuts applyto
rear mounting as well.
Screw length should be 3/4-inch plus panel
thickness if using T-nuts-4onger for standard
hex nuts. If hex nuts are used, a second nut
should be tightened against the first nut to
prevent loosening during operation. A lock
washer and flat washer are recommended be-
tweenthe screwheadand frame (see Figure
4).
Screws should be tightened evenly, but not
excessively. Maximum torque possible with a
propersize screwdrivershould besufficient.
Do
not use adhesive-back gasket segments for
rear mounting.
Custom
Enclosures
If
a cabinet
is
to be constructed from scratch,
3/4-inch
solid and jointed or marine plywood
is
recommended. After construction, be certain
interior
is
completely free ofmetal filings, wood
chips, etc.
Electrical
Connections
Use no. 18 or larger stranded wire to connect
the two terminals
on
the loudspeaker
to
the
amplifier output.
FREQUENCY RESPONSE
Frequency response
waS
measured with the
10BX in a 1.2-cubic-foot vented enclosure,
tuned
to
40Hz, placed
in
an
anechoic(echoless)
environment at 1 meter
on
axis with a 1-watt
sweptsine-wave input. The frequency-response
curve
is
shown
in
Figure
1.
POWER-HANDLING
In
musical-instrument systems, unlike sound-
reinforcement systems, it is advisable to use
speakers that are rated for at least as much
power as your amplifier output rating.
To our knowledge, Electro-Voice was the first
U.
S.
manufacturer to develop and publish a
powertestclosely related to real-life conditions.
Specifically, the 1
OBX
is
designed to withstand
the power test described in EIA RS-426-A
1980.The EIA test spectrum
is
applied for eight
hours. This shaped signal
is
sent to a power
amplifier with the continuous power set at 150
watts into the 6ohm EIA equivalent impedance
(30 volts true rms). Amplifier clipping sets in-
stantaneous peaks at 6 dB above the continu-
ous power, or 600 watts peak (60 volts peak).
This procedure provides a rigorous test of both
thermal and mechanical failure modes.
UNIFORM LIMITED WARRANTY
Electro-Voice products are guaranteed against
malfunction due to defects in materialsorwork-
manship for a specified period, as noted
in
the
individualproduct-linestatement(s) below, orin
the individual product data sheet or owner's
manual, beginning with the date of original
purchase.Ifsuch malfunction occurs during the
specified period,the product will be repaired or
replaced (at our option) without charge. The
product will be returned to the customer pre-
paid. Exclusions and Limitations: The Limited
Warrantydoes notapplyto: (a) exteriorfinish or
appearance;(b) certain specificitemsdescribed
in the individual product-line statement(s) be-
low, or in the individual product data sheet or
owner's manual; (c) malfunction resulting from
use or operation of the product other than as
specified
in
the product data sheet or owner's
manual; (d) malfunction resulting from misuse
or abuse of the product; or (e) malfunction
occurring at any time after repairs have been
made to the product by anyone other than
Electro-Voice or any of its authorized service
representatives.
Obtaining
WarrantyService:
To obtain warranty service, a customer must
deliverthe product, prepaid,to Electro-Voiceor
any of its authorized service representatives
togetherwith proofofpurchase ofthe productin
the form of a bill of sale or receipted invoice. A
list of authorized service representatives
is
availablefrom Electro-Voiceat600Cecil Street,
Buchanan,
MI
49107 (616/695-6831 or
8001
234-6831).
Incidental
and
Consequential
Damages
Excluded:
Productrepairorreplace-
ment and retu
rn
to the customer are the only
remedies provided to the customer. Electro-
Voice shall not be liable for any incidental or
consequential damages including, without limi-
tation, injury to persons
or
property or loss of
use. Some states do not allow the exclusion or
limitation of incidental
or
consequential dam-
ages
so
the above limitation
or
exclusion may
not apply to you.
Other
Rights:
This warranty
gives you specific legal rights, and you may
also have other rights which vary from state to
state.
Electro-Voice
Speakers
and
Speaker Sys-
tems
are guaranteed against malfunction due
to defects in materials or workmanship for a
period of five
(5)
years from the date of original
purchase. TheLimitedWarrantydoesnotapply
to burned voice coils or malfunctions such as
cone andlorcoil damage resulting from improp-
erly designed enclosures. Electro-Voice active
electronics associated with the speaker sys-
tems are guaranteed for three
(3)
years from
the date oforiginal purchase.Additional details
are included in the Uniform Limited Warranty
statement.
Service and repair address for this product:
Electro-Voice, Inc
.,
600Cecil Street,Buchanan,
Michigan 49107 (616/695-6831
or
8001234-
6831).
Specif
ications subject to change without
notice.
