Filter Filters GMC Remove All Filters Price $100-$500 (147) $500 and above (9) Condition New (156) Brand Harmony Audio (156) Model Sierra (139) Sonoma (8) Envoy (7) Canyon (2) Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony F124 Dual 12"... $425.99 1999-2006 GMC Sierra Ext Cab Truck Harmony R104 Single 10" Sub Box & CXA400.1 $291.99 Compatible with 2007-2013 GMC Sierra Crew Cab Truck Harmony F124 Dual 12" Sub... $534.99 Compatible with 1999-2006 GMC Sierra Extended Cab Truck Harmony F104 Single... $264.99 Compatible with 2007-2013 GMC Sierra Ext Cab Truck Harmony A122 Dual 12" Sub... $481.99 Compatible with 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony R104 Dual 10"... $310.99 Compatible with 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony A122 Dual 12"... $405.99 2007-2013 GMC Sierra Ext Cab Truck Harmony R124 Dual 12" Sub Box & CXA400.1 Amp $362.99 Compatible with 2007-2013 GMC Sierra Crew Cab Truck Harmony A102 Dual 10" Sub... $424.99 Compatible with 1999-2006 GMC Sierra Ext Cab Truck Harmony A122 Dual 12" Sub... $516.99 Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony R124 Dual 12"... $312.99 Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony A122 Single... $401.99 Compatible with 2007-2013 GMC Sierra Crew Cab Truck Harmony F104 Dual 10" Sub... $479.99 Compatible with 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony F104 Dual 10"... $489.99 2001-2006 GMC Sierra HD Crew Truck Harmony R124 Dual 12" Sub Box & CXA400.1 Amp $377.99 Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony R104 Single... $236.99 Compatible with 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony F124 Dual 12"... $435.99 1988-1998 GMC Sierra Ext Cab Truck Harmony F104 Single 10" Sub Box & CXA400.1 $294.99 Compatible with 1982-2004 GMC Sonoma Extended Cab Truck Harmony R124 Dual 12"... $331.99 Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony R104 Dual 10"... $299.99 Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony R124 Dual 12"... $357.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony R124 Dual 12" Sub Box & CXA400.1 $371.99 Compatible with 2004-2014 GMC Canyon Crew Cab Truck Harmony F104 Dual 10" Sub... $405.99 2007-2013 GMC Sierra Extended Cab Truck Harmony F104 Single 10 Sub Box &... $294.99 1234567