This kit is designed specifically for use with Hertz SV165.1 6.5” speakers and Hertz ST25 compression horn tweeters. Use with other speakers may result in the woofer cone striking the back of the tweeter magnet.

The kit consists of four main parts

  1. Stamped Steel Grill
  2. Tweeter Mounting Bracket
  3. Tweeter Spacer Ring
  4. 5.25” to 6.5” Speaker Adapter

Remove the factory speaker and grill. Install the horn tweeter into the tweeter bracket with the pocketed side of the bracket facing the woofer (not towards the grill). Then place the spacer ring over the tweeter and then the speaker grill over the entire assembly. Lastly screw on the tweeter locking ring and bezel.

Note: both the locking ring and the bezel go on the outside of the speaker grill.

Now place your 5.25” to 6.5” speaker adapter over the rear of the assembly. Route your tweeter speaker wires from the terminals on the tweeter through the slot in the tweeter bracket. Be sure to position the tweeter so that the terminals are parallel to the two screw holes that are opposite of each other on the horn mount bracket. This will ensure that the woofer cone does not come into contact with the tweeter terminals at high volume levels. It is recommended that you use gasket material (foam tape) between the tweeter bracket and the speaker adapter.

Because the tweeter bracket and grill add about 1⁄4” of thickness to the speaker
assembly, the supplied speaker screws are extra long. Be careful that you do not run the lower position screw through the front side of your fairing. CHECK TWICE!

Add your capacitor in line with the positive side of the tweeter speaker wire outside of the speaker assembly. Do not try to locate the capacitor within the speaker bracket/adapter.


WARNING! Read this before you install your new Hertz ST25 or ST35 horns.

Damage do to overdriving these horns is not covered under warranty. It is not a manufacturing failure or a material defect when the voice coil is melted or the diaphragm is torn to pieces. These horns are serviceable. In the event you find that you have blown one of your horns, a replacement diagram can be purchased to repair your horn.

The three allen screws on the back of the horns are what attaches the magnet to the horn body. These three screws are only snug and can be prone to backing themselves out in high vibration situations. It is recommended that you remove these screws one at a time and add a small amount of blue (medium) threadlocker to each screw. Caution! ​These screws are not super tight for a reason. If you over tighten these screws you run the risk of changing the way that the tweeter sounds. Just snug them up like they where.

Never use pliers or a wrench of any kind to tighten the wire terminals​. If over tightened, you run the risk of breaking the terminal away from the voice coil inside the horn. 

Do not throw away the two rubber terminal boots​. These must be put back in place in order to keep the terminal from coming loose.

Always use the included yellow capacitor in line with the positive terminal as shown in the Hertz documentation.​ An exception to this rule is if you are running the horns on their own dedicated amplifier channels (Active), with an electronic crossover. The crossover must be set to a high pass frequency of 3,000 hz with a slope of 24 db per octave. Warning! When running horns active you assume the responsibility of making sure that the crossover is properly set. A crossover that is not set correctly will quickly damage the speaker. A blown horn due to an improperly set crossover is not a manufacturer defect. It is user error.