The woofers use a cone material made of black, woven fiberglass. Its design is said to offer a reasonably low-resonance frequency (Fs) of 64Hz to help reduce door resonance for a snappier midbass sound. At the cone's outer edge, SEAS uses a thin, pliable low-loss rubber surround, while a plastic phase plug fixed atop the motor's pole-piece to help smooth the frequency response sits in its center. A large 1.5" aluminum voice coil former sits around the outside of the phase plug with barely a millimeter or two separating them. The voice coil former is anodized black to dissipate heat better and improve the power handling of the two-layer voice coil.
Out back, the magnet structure uses a bumped back plate making room for extreme cone excursions. SEAS added a rubber cup around the magnet system for protection and (what may be one of the best marketing lines I've heard) "to reduce enclosure reflections."
SEAS uses a slightly larger than average tweeter set with the PS165/1. Using an "optimally" shaped 27mm diaphragm, the design gives them a well-controlled behavior throughout their entire high-frequency bandwidth. The diaphragm is produced from a proprietary material called Sonotex that was developed and manufactured by and for SEAS only. The Sonotex process pre-coats the fabric four times with a damping/sealing material that SEAS claims results in excellent acoustic performance and consistency. The tweeter Fs was tuned to 800Hz, largely a product of the rear chamber which helps control and eliminate unwanted chamber resonances and reflections. This rear chamber and the addition of magnetic fluid around the voice coil improves heat transfer and power handling of the tweeter.
Last of the main components are the crossovers. The 2-way passive has just about the largest copper traces that I've ever seen on a PC board! This provides a low-resistant, low-loss path throughout the crossover. SEAS selected high-quality MKT polypropylene capacitors, precision high-tolerance resistors and extended laminated core inductors. All of these parts come together in a true -12dB high- and low-pass crossover. To give the installer some tuning flexibility the tweeter has a three-step adjustment level.
Manual
The owner's manual is adequate and details that the PS165/1's are rated for 200 watts maximum power/90 watts nominal power handing, with a frequency response of 60Hz to 25kHz. The installation template for cutting the correct size of mounting holes is just a sheet of white paper. I recommend mounting it to something thicker or you'll need to be very careful with it until you're done. I always like to see the whole size templates on a cardboard or at least a heavy card stock rather than a sheet of copier paper.
Installation
These SEAS require just a normal and straightforward installation. All of the components are beautifully engineered and constructed. The midwoofer uses what is now becoming the standard mounting size for 6.5" drivers of 5.75" in diameter. This is larger than many factory cutouts, so some cutting will be needed. The 3" overall mounting depth of these drivers is really pretty standard. The one oddity of the midwoofer is the holes where the mounting screws hold the midwoofer into the door. As has become common practice with Quart, Genesis, Focal and other European manufacturers of speakers, the outside diameter of the SEAS midwoofer has eight notches around its circumference. When the speaker is being installed within the supplied grille ring, these notches are made into holes that will keep the midwoofer from slipping out of the notch while installing. If you aren't going to install the midwoofer into the supplied grille ring, you have to be very careful that the midwoofer doesn't slip out of position until you get at least three screws in place around it.