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Aggressor Pro 880 Hertz SPL Kit


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There are many more speakers, amplifiers, and kits to choose from than what you see here.

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Ultimate performance in a stealthy, well engineered kit (single mount only).

Load up to four 8" Hertz pro audio woofers in your bags. This kit delivers more acoustic power than any other Harley speaker kit available. Four 8" woofers adds up to more square inches of cone surface area than any other speaker arrangement available for a Harley application. This is the absolute pinnacle of music reproduction for your bagger.

100% American Made, Built to Exceed the Highest of Expectations. 

Aggressor Pro 880

CNC machined from high density polyethylene, this kit is designed to greatly increase the rigidity of your saddle bags. The trick to getting the most output from speakers mounted in a saddlebag is to increase the rigidity of the bag. With this design we take advantage of the large flat surfaces present in the bags. The kit adds a generous amount of clamping force through the use of quality american made stainless steel fasteners.

  • Machined from High Density Polyethylene
  • American Made Stainless Steel Hardware
  • Powder Coated Steel Grills
  • Designed Specifically for Hertz SV 200.1 Woofers
  • Router Jigs Included for Making Perfect Grill Openings
  • Specialized Router Bit Included 


  • 1998 - 2017 Harley Davidson Hard Bags
  • Will Not Fit Soft or Switchback Bags
  • Works with Aftermarket Bags including Stretched Bags
  • Works with Plastic or Fiberglass Bags

Works with all speaker lid arrangements that we have tested including double 6x9 lids.  

Stealth Installation

Possibly the most amazing part of this kit is that it is completely concealed within the bag and is not at all visible with the lids closed. This makes it a perfect addition to a fairing bike, or a bone crushing loud Road King. 


This kit is made specifically for the Hertz SPL Show 8" woofers. These speakers are nothing like conventional car audio type speakers. They are a pro audio design that have a number of distinct advantages in this application.

  • Light Weight Cone Allows for Very High Output
  • Voice Coil Designed for High Frequency Performance (Up to 7 Khz!)
  • Progressive Surround Allows Much Higher Output with Superior Cone Control
  • Very Powerful Motor Structure
  • Extreme High Thermal Limitations

Hertz ST25 Bullet Horn Tweeters

Hertz ST25 HornsExtreme high output in a very compact size. These tweeter horns are the perfect compliment to the Aggressor Pro 880 speaker system. Efficient compression loading horn and a very powerful neodymium motor make these pro level tweeters spectacular performers. Beautiful, bold, and brilliant, the ST25 horns are amazingly accurate and capable of unreal levels of output without distortion. These horns are quite effective when mounted next to the 8" woofers in the bag pointing in at the wheel. They can also be mounted in the top of the lids or in the fairing. Multiple sets can be added. Sold in pairs. 

Everything You Need Is in the Kit

We pride ourselves on the completeness of our kits. You won't have to worry about sourcing additional parts or doing excessive fabrication. Complete with quality router templates and even a specialized router bit. This kit ensures a top notch end product every time.  

Router Templates

Check out the full installation guide here.