Magneplanar!
DWM Bass Panel!
Instruction Manual
!
Table of Contents
1. Introduction/General Description 2
2. Carton Contents 2
3. Packaging 2
4. Installation and Hookup 2
5. Placement 3
6. Phasing 4
7. Bass Attenuation 6
8. Midbass Attenuation 6
9. Better bass for full-range Maggies 6
10. Service and Shipping 8
11. Specications 8
Page of 1 8
Revision-- 10-3-12
1. Introduction/General Description
e Magneplanar DWM Bass Panel is a dipole, thin-lm planar/magnetic
woofer which is a derivative of the MG 20.7 DiPlanar bass panel technology.
e DWM Bass panel has one diaphragm which is driven by two separate
ampliers (typically the front le and right channels). When two Bass Panels
are used, one of the voice-grids is not used. A built-in crossover provides a
high-pass output for use with “small” Magneplanars.
2. Carton Contents
1 - DWM Bass Panel with base
1 - Magnepan “Shaped” Pink Noise CD Test Disk
2 - 2 ohm, 25 watt resistors
1 - Hex Wrench
1 - Speaker Logo
1 - Owner's Manual
2 - 1/4-20 x 1" Truss Head Machine Screws
Packaging Instruction Sheet
3. Packaging
Save all packaging. e DWM Bass Panel can be shipped safely only in the
original packaging. Should you discard it, packaging is available from
Magnepan.
4. Installation and Hookup
Remove the 1/4-20" screws from the bottom of the Bass Panel. Discard screws.
Install the base with the 2 screws in the Literature Kit. It may be necessary to
realign the dowel nut in the speaker before installing the base and screws.
Connect the speaker wire from the amplier to the amplier input on the
DWM, observing polarity. Connect the “small” Magneplanar to the output of
the DWM, observing polarity. (Note- ere are no le or right inputs or
outputs on the DWM Bass Panel.)
If 2 Bass Panels are used for a 2-channel setup, one set of connections is used
for each Bass Panel.
Page of 2 8
Revision-- 10-3-12
5. Placement
As a general rule, dipole speakers produce the deepest and most linear bass
and midbass when positioned approximately 4-6 feet from the front wall or 1/3
of the way into a room. is rule may conict with the necessity to have
correct time alignment with the “small” Maggies. Since rooms vary greatly,
these setup instructions are principles of operation and specic and detailed
instructions are not possible. Magnepan and our dealers can provide advice on
the specics of your room.
It is generally understood that placement of subwoofers is very exible. While
subwoofers do offer more latitude in placement due to the long wavelengths at
low frequencies, technically, there is an ideal place in a given room for
optimum subwoofer performance. e DWM is a woofer, not a subwoofer.
And the superior performance of the DWM, as compared to a subwoofer, is
due in part, to extremely wide bandwidth (at to 5 kHz). e DWM can
seamlessly cross over at a higher frequency to any of the limited bandwidth
“Maggie” models. However, the higher crossover points require proper time
alignment to achieve the most seamless blend between the DWM Bass Panel
and the limited bandwidth Magneplanar. erefore, the DWM should be equidistance from the listener to the limited bandwidth Magneplanar. Minor
adjustments from that position are oen necessary for “ne tuning” as
described under “Phasing” below.
e DWM should be oriented so it is perpendicular to the side wall and
playing down the length of the room as shown in Fig. 1 below.
e DWM Bass Panel will give the lowest frequency response if a boundary is
used to reduce dipole cancellation of bass frequencies. A placement along a
wall or next to a cabinet or piece of furniture will reduce dipole cancellation.
If two DMWs are used, the midbass response may be improved and smoothed
by placing the bass panels at different distances relative to the listener.
!
!
Page of 3 8
Revision-- 10-3-12
FIG. 1!
6. Phasing
e Magnepan Pink Noise CD Test Disk included with your DWM can be
used to determine if the DWM is in ACOUSTICAL phase with your limited
bandwidth Magneplanar. e test CD has a 9 db peak at 80-100 Hz that draws
attention to the frequencies which will be depressed in an out-of-phase
condition. Place the DWM next to your limited bandwidth Magneplanar and
change the phase. (It is much easier to detect an out-of-phase condition when
the “small” speaker is physically next to the woofer.) Since the DWM is a
dipole woofer, the easiest way to determine if the DWM is in-phase is by
simply turning the woofer around (180 degrees). e speakers are in-phase
when the peak is the loudest.
e high output of the DWM is in positive polarity with respect to the bass. In
this particular case, do not think that the plus output of the DWM must go to
the plus terminal of the “small” speaker. Depending upon the “small” speaker
to be used with the DWM, it may be necessary to operate the “small” speaker
with the phase reversed for smooth frequency response through the crossover
region. If you are uncertain if the acoustical phase is correct, a technique
which can help is by leaning over and positioning your head between the
Page of 4 8
Revision-- 10-3-12
Magneplanar Bass Panel and the “small” Magneplanar as shown in Fig. 2
below. e le and right ears are equi-distance to the respective speakers. High
frequencies will appear to be up and low frequencies will appear to be down.
Midbass frequencies, if in phase, will appear to be in the middle (and louder).
Depending upon the location of the DWM with respect to the limited
bandwidth Magneplanar, the DWM might be 90 degrees out of phase with the
“small” Magneplanar and changing the phase does not make a noticeable
difference in the loudness of the pink noise peak. It may be necessary to move
the DWM with respect to the Magneplanar to achieve a better acoustical inphase condition.
FIG. 2!
Page of 5 8
Revision-- 10-3-12
7. Bass Attenuation
If it is necessary to reduce the output of the DWM, remove the Bass Attenuator
jumper and insert a 25 watt (or higher wattage) resistor. Typically, 1-4 ohms is
sufficient for most installations where bass reduction is needed. If a large
amplier and/or high power bass levels are used, four 2 ohm, 25 watt resistors
can be used in a series/parallel combination that will provide a 100 watt rating
at 2 ohms. Caution--Depending upon how loud the system is played, the
resistor could become hot and cause a painful burn.
8. Midbass Attenuation
In the event there is too much lower midrange/upper midbass from the DWM
Bass Panel, a 1.4 mh iron-core inductor may be installed in the Attenuator
terminals for a faster roll-off rate. Use an inductor with low resistance to
maintain maximum output of the lowest frequencies.
9. Better bass for full-range Maggies
Put a big speaker in a small room, too much bass. Put a small speaker in big
room, too little bass. Everyone knows that. In general, it is true. ere is no
one-size-ts-all.
Most of the area of any full-range Maggie is devoted to bass reproduction. (In
the case of the 20.7, 76% of the total radiating area is devoted to bass.) e
Magneplanar Bass Panel offers you the exibility to add bass diaphragm area
to t the needs of your room. Due to standing waves, dips and peaks in the
bass and midbass are a fact of life. Each room has its sonic signature
depending upon the size, shape and construction. Some sound rooms are
“hostile” to dipoles and it is difficult to generate bass or midbass. From the
$600 pair MMG to the 20.7, the Maggie Bass Panel can get the bass/midbass
“just right.”
e DWM should be equi-distance from the listener (but, 12 inches closer to
the listener) for oor-standing models to achieve proper phase. Imagine
stretching a string from your listening seat to your full-range Maggies (but, 12
inches shorter), drawing an arch on the oor would be the possible positions
Page of 6 8
Revision-- 10-3-12
for the Bass Panel. Each position of the Bass Panel in the room will give a
different frequency response characteristic. is response characteristic
becomes one of your means of contouring the overall response of your system.
Placing the DWM against a side wall or cabinet will increase the coupling and
result in both lower bass response and different midbass response. e same
effect can be achieved by placing the DWM next to the oor-standing model
for mutual bass coupling. Angling the Bass Panel slightly away from the
listener will increase the roll-off of higher frequencies, if desired.
If two Bass Panels are used and there is a midbass peak, the peak can be
reduced by placing the two Bass Panels at different distances relative to the
listener. For example, one Bass Panel 12 inches ahead of the le/right speakers
and the other 12 inches further than the le/right speakers.
Amplier connection-- If your amplier doubles in power from 8 ohms to 4
ohmns (or nearly doubles), it is a high-current design. Most ampliers of this
design can be safely connected in parallel with the DWM--especially if a
resistor is used on the DWM for bass attenuation. If the amplier used on the
oor-standing models is not a high-current design, a separate amplier can be
used to drive the DWM.
Level and crossover slope-- If you have a room that is decient in bass/
midbass, or has a midbass hole in the response, you may nd that the full
output of the DWM is desired. However, the addition of bass and midbass is
analogous to adding seasoning to food. Just a little too much seasoning can
ruin the meal. If would be a typical scenario if you nd it necessary to
attenuate the output of the DWM aer extended listening.
If the Bass Panel is adding too much output in the lower midrange or upper
bass, a 1.4 mh inductor (with low DCR) can be installed in the Attenuation
terminals for a faster roll-off rate. Inductors are available from Magnepan.
Since a power resistor will mostly be needed to attenuate the DWM output,
large gauge speaker wire for the DWM is not needed or recommended. Save
Page of 7 8
Revision-- 10-3-12
your money, because there is no sonic advantage to large gauge speaker wire in
this application.
10. Service and Shipping
In the unlikely event you should need service for your DWM Woofer, we
recommend you return it through your dealer. He is experienced in providing
service and can assist you if the speaker must be returned to the factory. If you
determine you need to return it directly to Magnepan, ship the speaker freight
prepaid to:
Magnepan, Incorporated
1645 Ninth St.
White Bear Lake, MN 55110
1-800-474-1646
Include a note describing the nature of the problem. Please include your name,
address, and a daytime telephone number.
11. Specications
System Description: Planar-magnetic dipole bass panel.
Frequency Response: 40-200 Hz*
Recommended Power: See F.A.Q. on web site www.magnepan.com
Sensitivity: 86 dB @2.83V/1 Meter/50 Hz
Impedance: 4 Ohms
Dimensions: 19.25H x 22.5W x 1.25D (inches)
Warranty: Limited 3-year to original owner
Weight: 19 lbs.
*Bass response will vary depending upon placement near walls, cabinet or furniture.
Page of 8 8
Revision-- 10-3-12
Loading...