Specifications
M&K Sales Training Outline
page 9
May 98
http://www.mksound.com
M&K’s innovative Push-Pull Dual Driver configuration delivers a
major improvement in subwoofer detail and clarity by virtually elimi-
nating even-order harmonic distortion, which produces a boomy and
poorly defined bass sound.
In these subwoofers, one driver is mounted conventionally on the
cabinet’s front baffle. The second driver, however, is mounted
inverted
.
The front of its cone faces the inside of the cabinet, with the back side
of the cone, magnet, and frame facing the outside.
Although both drivers fire into the room in pressure phase (one with
the front side of its cone and the other with the back side), they oper-
ate mechanically out of phase relative to each other’s magnetic struc-
ture. (They are driven electrically out of phase). Therefore, regard-
less of position, each cone is always in the exact opposite position
from the other in its travel, relative to its own magnet.
The even-order (second, fourth, etc.) harmonic distortion prod-
ucts of each driver cancel acoustically because the even-order
harmonics of each driver are both virtually equal and exactly opposite
in time phase to each other. Even-order harmonic distortion is caused
by different non-linearities in the cone’s motion when the voice coil is
moving deep into its magnet compared with when it is moving away
from its magnet.
As important as the distortion cancellation, push-pull also doubles
efficiency in comparison to a single 12" driver subwoofer (the same
as doubling the amplifier power), as well as allowing twice the ampli-
fier power to be used because of the power dissipation of two drivers.
The total output improvement is four times! (6 dB).
M&K Push-Pull Dual Driver designs deliver deep bass with very low
musical distortion and tremendous articulation to produce a very natural
and powerful bass reproduction.
Push-pull dual driver
configuration
Push Pull Dual Driver Deep Bass Subwoofers
The M&K Deep Bass concept
Since 1974, M&K has invited listeners to "Discover Deep Bass."
Deep Bass specifically refers to a subwoofer's ability to produce us-
able steady-state and transient output below 20 Hz. M&K's Deep
Bass design produces significant deep bass output in some
models down to frequencies below 10 Hz. This output makes a
major difference in subwoofer performance, producing what some have
described as the "startle factor," or "awesome" bass.
Most conventional subwoofer designs (especially units with passive
radiators and vented cabinets) have an extremely sharp rolloff
(24 dB/octave) below the lower limit of their "flat" response. But M&K
subwoofers have a much shallower rolloff below their -3 dB anechoic
response frequency. By reproducing bass frequencies well below 20
Hz, M&K subwoofers have a lifelike power and authority that other
subwoofers cannot match.