Tuning Tips for Velocity RZ69H 6x9 Harley Speakers
The Velocity RZ69H speakers should be crossed over with a high pass filter at 100hz with a Minimum 12db slope. A 24db slope should be used if it is available to you. The included 12db per octave passive crossover should be used in parallel between the tweeter horn and the woofer to facilitate a smooth transition between the woofer and the horn tweeter.
In general, all pro-audio-type speakers should have an equalizer (DSP) in the system. The RZ69H speakers kind of break that rule due to their exceptionally great frequency response. These speakers can be used without equalization, but the following is a list of tuning tips if you do have an equalizer in your system. Correct DSP adjustments will always improve the performance of any speaker in a Harley application.
At 630hz there is a sizable rise in output due to the woofers high efficiency design that should be padded down with the equalizer for a smother response. To do this, bring 630hz down by 10 to 12db with a standard Q (band width) of 4.32. All 1/3rd octave equalizers have a Q (band width of each adjustment) of 4.32. So no adjustment needs to be made to the Q here.
Add 8db of boost at 4khz and no Q adjustment. This will help compensate for the speakers facing up at the sky instead of at your face like the front speakers do.
At 6.3khz bring the level down by about 6db to compensate for the tweeter horns over efficiency in this range. If your equalizer is a parametric (has band width adjustment), lower the Q to 2.7. If you do not have a parametric equalizer, you will need to bring down the surrounding bands (5k and 8k) slightly as well.
Do not add any bass boost (any boost below 250hz), as it will only lead to over taxing the speakers. Every 3db of equalization boost doubles the heat generated at the voice coil.
Below is a screenshot of typical adjustments for RZ69H speakers in the lids of a 2019 Road Glide(radio flashed).