Now that we have revealed five of our most important “Lessons Learned”, we can now apply these lessons to your Hybrid Audio installation. The first important matter is the physical installation of your Hybrid Audio midbass and/or midrange, and more specifically with respect to improving the Hybrid Audio midbass’ or midrange’s mounting baffles. Most vehicles’ factory mounting locations for speakers are less than ideal. In most cases, the OEM speaker mounting flanges are likely nothing more than flimsy extruded plastic and provide no sonic benefit to your Hybrid Audio installation. Hybrid Audio drivers are long-throw midbass, and high-performance midrange, and the plastic mounting baffles that come from the factory in virtually every vehicle will lead to buzzes, rattles, vibrations, and resonances, all of which negatively affect your Hybrid Audio installation. In other vehicles, you may have attached the Hybrid Audio midbass’ or midrange’s direct to the door metal (hopefully with a layer or two of self-adhesive sound damping in between), but this is still not entirely ideal. In whatever scenario you have installed your Hybrid Audio midbass and/or midrange, there are certain “tricks” and techniques that may be applied to get the most out of your Hybrid Audio component set, specifically the midbass and midrange installation, as follows:
Mounting the baffle, sound damping, and “decoupling”
The mounting baffle or mounting location should either be secured extremely well to the vehicle’s body or completely isolated from the vehicle’s chassis. The reasoning is that the speaker’s baffle panel will vibrate and will radiate sound. Even small vibrations can result in the baffle itself radiating more sound than the actual speaker at certain frequencies. The mounting baffle or mounting location should be damped with a layer of typical sound damping to reduce the Q of the baffle and lower its vibration resonance frequency below the range of the driver’s frequency response. In many cases, using thicker baffle panels in concert with self-adhesive sound damping can also be advantageous, provided the rearward wave of the speaker has no obstructions created by the baffle itself. Finally, if possible, the speaker should be mechanically decoupled from the baffle. This can be something as simple as a layer of self-adhesive foam tape, to more exotic examples of decoupling, including rubberized rings or multiple-layer septum shielding.
Building solid mounting baffles
In many cases, it is advisable to mount your Hybrid Audio midbass’ and/or midrange’s in high-stiffness wood or high-density fiberglass (or wood treated with fiberglass resin). Hybrid Audio Technologies recommends the use of solid hardwood, such as birch or oak, namely because these woods are stiff and help to dissipate resonance, and screws can be inserted and removed multiple times without stripping. Avoid Medium Density Fiberboard (MDF), particularly in wet environments like the door, as the MDF will act like a sponge with humidity and moisture, and not only that, the MDF is a dense, but not the stiff type of wood, and the results may not be particularly noticeable if you use MDF. Once your baffle is built, it must be covered in one or two layers of a good-quality, brand name self-adhesive damping product; a solid wood mounting baffle with sound damping treatment will augment the Hybrid Audio installation by eliminating resonances.
Mounting baffle dimensions
While building baffles is important, it is notable that mounting baffle size is equally important. All mounting baffles should be kept as small as possible with respect to the size of the speaker. The purpose of using a small baffle is to avoid the potential for low amplitude diffracted sound waves becoming summed with the incidental waves. A narrower baffle also becomes increasingly important as frequencies range into the Hybrid Audio midbass’ and/or midrange’s upper bandwidth, where the power response is more uniform and incident and reflected waves are indistinguishable. In practical terms, keep baffle dimensions small with respect to the size of the Hybrid Audio midbass and/or midrange, chamfer or round sharp edges (including, in particular, the mounting hole’s rear inner edge), flush-mount the speaker whenever possible, and use shallow, surface-mounted hardware. Also, remove all unnecessary protrusions from the baffle surface.
Hybrid Audio Technologies Specifications and Parameters Spreadsheet (Google Sheets) — Advanced System Installation — Lesson One: Off-Axis Response — Lesson Two: Equalization of Pathlength Differences — Lesson Three: The Effect of HRTF, ITD, and IID — Lesson Four: Point-Sourcing — Lesson Five: Reference — Mounting Baffle Considerations — Crossovers — Time Correction — Acoustic Treatment — Acoustic Treatment — Conclusion