Cerwin-Vega stroker Pro 15 - Manual (Page 2)

Since 1954,
Cerwin Vega, one of the
oldest speaker companies around,
has had a major reputation for building speakers
that allowed everyone to be “loud and proud.”
Therefore, it’s no surprise that Cerwin-Vega has
introduced one of the most outrageous car sub-
woofers I have reviewed to date, the Stroker Pro
15. At 68.3 lbs., they have the “Where’s the Beef?”
award in the bag. Even more impressive than its
physical size is this product’s technology.
The Stroker Pro cast aluminum frame acts as
both a giant heatsink (an old but good trick) and a
highly effective Faraday
shield or shorting ring (a new
patent-pending trick). The cut-
away drawing (Fig. 1) shows that this woofer not
only has two separate magnets (actually, the lower
magnet is two magnets stacked together, so tech-
nically three magnets), but also two gaps, a tech-
nology known as Multiple Magnet Air Gap (MMAG).
Because of the physical layout of the MMAG motor
format, CV could mount the lower magnet system
to the back of the frame, like a normal woofer, but
turn the frame’s inside diameter upward to form a
shorting ring.
In addition to attenuating nasty eddy currents
produced by the woofer motor and lowering distor-
tion, a large shorting ring also reduces motor tem-
perature by decreasing inductive heating. Figure 2
reveals what an outstanding thermal pathway this
frame makes with the upturned section directly
adjacent to the naked voice coil. The Stroker has
four other thermal pathways: two in the spider-
mounting area and two at the rear of the motor.
There are two sets of vents integrated into the
lower-spider mounting shelf (this woofer has two
mounting shelves for three spiders). A 1/8” gap
goes around nearly the entire perimeter of the
CERWIN-VEGA
STROKER
PRO 15
TEXT: VANCE DICKASON &
ERIC HOLDAWAY
PHOTOS: COURTESY OF MANUFACTURER
MORE
THAN A ONE
NOTE WONDER —
A FRONT-RUNNER FOR
SOUND QUALITY AND SPL