MAGNEPLANAR DWM User manual

Magneplanar DWM Woofer Instruction Manual
Table of Contents
1. Introduction/General Description
2. Carton Contents
3. Packaging
4. Installation and Hookup
5. Placement
6. Phasing
7. Bass Attenuation
8. Service and Shipping
9. Specifications
1. Introduction/General Description
The Magneplanar DWM is a dipole, thin-film planar/magnetic woofer which is a derivative of the MG 20.1 DiPlanar
woofer technology. The DWM can be driven simultaneously by 2 separate amplifiers (typically the front left and right
channels). A built-in crossover provides a high-pass output for use with "small" Magneplanars.
2. Carton Contents
1 - DWM Loudspeaker with base
1 - Magnepan "Shaped" Pink Noise CD Test Disk
1 - Hex Wrench
2- 2 ohm, 25 watt resistors
1 - Speaker Logo
1 - Owner's Manual
3. Packaging
Save all packaging. The DWM can be shipped safely only in the original packaging. Should you discard it,
packaging is available from Magnepan.
4. Installation and Hookup
Install the base with the 2 screws. It may be necessary to realign the dowel nut in the speaker before installing the
base and screws.
Connect the speaker wire to the amplifier input on the DWM, obvserving polarity. Connect the "small" Magneplanar
to the output of the DWM, observing polarity.

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. This rule may conflict with the necessity to
have correct time alignment with the "small" Maggies. Since rooms vary greatly, these setup instructions are
principles of operation and specific and detailed instructions are not possible. Magnepan and our dealers can
provide advice on the specifics of your room.
It is generally understood that placement of subwoofers is very flexible. 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. The 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 (flat to 5 kHz). The 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 and the
limited bandwidth Magneplanar. Therefore, the DWM should be equi-distance from the listener to the limited
bandwidth Magneplanar. Minor adjustments from that position are often necessary for "fine tuning" as described
under "Phasing" below.
The 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.
The DWM 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.
Fig. 1

6. Phasing
The 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. The 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). The speakers are in-
phase when the peak is the loudest.
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 Magneplanar Woofer and the "small" Magneplanar as shown in Fig. 2 below. The left 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 in-phase condition.
Fig. 2

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, 2 ohms is sufficient for most installations where bass reduction is needed. If a
large amplifier 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.
In the event of the diaphragm bottoming from extreme bass (such as the LFE in movie tracks), capacitors can be
inserted in lieu of the Bass Attenuator jumper to act as a high-pass function. The capacitor values will depend on
the desired crossover point.
8. 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.
9. Specifications
System Description: Planar-magnetic dipole woofer.
Frequency Response: 40 Hz-5 kHz*
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: 19.25Hx22.5Wx1.25D (inches)
Warranty: Limited 3-year to original owner
Weight: 19 lbs.
*Bass response will vary depending upon placement near walls, cabinet or furniture.