Ground Support Subwoofer Product Specification Sheets
 GP218-sw
WideLine™ Ground-Support Subwoofer
The  GP218-sw  is  a  premium,  high-
performance, rectangular dual 18" subwoofer 
designed  for  ground  stacked  use  in  the 
most demanding touring or installed concert 
applications. With an impressive combination 
of  punch,  low-frequency  extension  and 
musical accuracy, the  GP218-sw  is  an  ideal 
companion for the acclaimed QSC WideLine 
series  as  well  as  other  professional  sound 
reinforcement systems. 
For suspension  in  permanent  installations 
each GP218-sw subwoofer comes with a 
total  of  sixteen  (16)  threaded  M10  inserts 
(four per side). 
For  ground-supported  applications,  the 
subwoofers may be stacked horizontally using 
their interlocking  feet and  recess features 
machined into the enclosure’s top panel. 
The 18" woofers incorporate a double layer 
spider  and  triple  roll  surround  for  extended 
and  controlled  excursion  at  extreme  power. 
The  4"  voice  coil  is  wound  on  a  fiberglass 
former  to  prevent  deformation  at  high 
operating  temperatures  and  is extensively 
vented to reduce  power compression.  An 
aluminum demodulating ring is employed 
for low distortion. 
The  extremely  musical  yet  powerful 
performance of the subwoofer is the result of 
carefully  balancing  the  transducer  selection, 
cabinet volume and port tuning. The resulting 
system  offers  plenty  of  “punch”  while 
maintaining ample extension so the musically 
important and satisfying fundamentals are 
solidly and accurately reproduced. 
The enclosure of the GP218-sw is constructed 
of  premium  quality  birch  plywood  finished 
in  an  environmentally  friendly,  waterborne, 
polymer  finish  that  stands  up  to  life  on 
the  road while  also  being  field repairable. 
Extensive  internal bracing  is  employed to 
eliminate  acoustic  losses  due  to  panel 
resonance.  Further  contributions  to  cabinet 
rigidity come from vent walls constructed of 
the same plywood as the enclosure. Woofers 
are protected  by a  heavy-duty,  14 gauge, 
powder coated  steel grille and housed  in 
separate chambers to prevent failure of one 
driver from causing damage to the other.
Despite  the  extremely  large  amount  of  air 
moving  in  the  ports,  careful  attention  to 
detail  has  resulted  in  a  system  that  is  free 
of port distortion “chuffing”. Ample port area 
allows massive amounts of air to move freely 
with  minimal  turbulence  and  the  ports  are 
arranged so  as to  eliminate asymmetrical 
loading  of  the  woofers,  which  can  result  in 
distortion and voice coil failure related to 
rocking-modes. 
Like its “flyable” brother, the WL218-sw, the 
GP218-sw  subwoofer’s sonic performance 
and output capacity  are second to none. 
But for those who only need the exceptional 
sonic  performance,  without  the  need  for 
expensive  rigging  and  flying  capability  – 
the  GP218-sw  gives  the  exact  same  sonic 
impact, but for a more economical price tag.
QSControl.net™/ BASIS™  DSP  files  are 
available  for  download.  They  have  been 
fine  tuned  for  use  with  the  GP218-sw 
and  the  WL218-sw  to  provide  optimized 
performance right out of the box.
Features
•  Very high acoustic output capability – 140.5 dB SPL  
  (1m) peak
•  Tight musical “punch” combined with low-frequency    
  extension down to 27.4 Hz 
•   Elegant transport and handling features including 
an optional transport dolly plus soft cover and four 
thoughtfully placed handles
•   Premium-grade, long-excursion, high-power woofers  
with 4", fiberglass voice coils, double layer spiders and 
triple-roll surrounds
•   18 mm Birch ply enclosure with independent, dual 
chambers and extensive internal bracing for rigidity  
and solid, accurate reproduction


