Creating a new speaker is a balancing act that requires compromise at every stage of the design process. Balancing measurements with listening tests, efficiency with power handling, enclosure size with low bass, etc. In fact in the last few years the biggest challenge has become finding a balance between art and engineering. From the perspective of the speaker engineer, this comes down to, "How do I make that drawing of a speaker that marketing just gave me actually sound good."
Inverted dish shape cones are the latest in the current marketing trend in speakers. These cones are becoming popular because they provide a seamless appearance. From the art perspective this is about as good as it gets. Simple, smooth, and lots of room for logos and eye catching color. From the engineer's perspective, this is a nightmare. The shape isn't always as strong as a conventional cone, and in fact to make it work you actually have to attach a small conventional cone to the back side. This means extra weight, manufacturing problems, and potential high frequency and efficiency problems as well.
Still most companies are market driven; that's just the nature of the economic beast. So engineers do their best to find ways to solve these problems and perhaps even to find benefits in the new design. This is what the people at Alpine appear to have done.
The SPR-176A is really beautiful from a marketing perspective and well designed from an engineering perspective. Here are some examples of its balance in terms of art and engineering:
Art: Beautiful dished cone with a vapor deposited aluminum coating.Engineering: Lightweight paper undercone minimizes mass, large diameter, lightweight santoprene edge reduces mass and minimizes "Edge Hole" frequency response errors.
Art: Simple elegant cast frame with a minimum number of spokes.Engineering: Three spokes eliminate basket ringing, basket is designed to center the frontplate for faster production speed, and the spider landing diameter is very large allowing for a high excursion and linear suspension.
Mounting the speakers has also been thought through well. Many cast frame speakers have large flanges that make them very difficult to mount in factory holes. The Alpine woofer has an outside diameter of 6.5" and a mounting diameter of 5.75", making it fit standard holes perfectly. Its depth of 2.75" is a bit much for compact cars, but it should drop in to your SUV just fine.
The silk dome tweeter is simple, easy to install and has the smallest possible size for a 25mm dome (i.e., it doesn't look like an afterthought when mounted in your door). There is a provision for both flush and surface mounting via a unique mounting ring that tightens down to the door panel by threading onto the outside of the plastic housing.
The crossover could be seen as just another variation on the rectangular box theme. However its shape is smooth and elegant; it is made of a dark smoked plastic that is nearly completely opaque, giving it a very high quality (price) appearance. Inside the crossover strikes the same balance. Good quality components (mylar caps and air core inductors), and a simple and functional design (12dB highpass with polyswitch protection, 6dB lowpass).
So now the question is, "Do they perform as well as they look"?
With all of the obvious attention to engineering as well as cosmetics, the answer of course is yes.
The testing was done on a MLSSA system using ACO pacific 100kHz. mics., a class A lab amplifier, and ultra high grade cables. The speakers were mounted in an EIC baffle accurate to 200 Hz. and frequencies below 200 were tested by the near field method and spliced to the 1 meter responses. Parameters were also tested using MLSSA using the fixed Mmd method. All of the response graphs were exported to LEAP to make their graphic output higher quality.