User manual BLAUPUNKT VPW 380

[. . . ] De We provide a manufacturer guarantee for our products bought within the European Union. You can view the guarantee conditions at www. De or ask for them directly at: Blaupunkt GmbH Hotline Robert Bosch Str. [. . . ] No single design is superior because each has its own compromise in performance, power handling and design complexity. A) designs simply use the trunk of the car for its acoustical enclosure and the rear deck to isolate the front and rear sound paths. Because of the "air spring" provided by the box the advantages include simple box construction, higher power handling, excellent transient response, and smooth low frequency rolloff. Disadvantages include only moderate efficiencies at low frequencies and the need for large box volumes. C) extend the low frequency response below that of the sealed box by using a port tube. Advan-tages include extended low frequency response, lower distortion due to smaller cone movements in its passband, good efficiency, good transient response, moderate size boxes and higher power capacity. Disadvantages include increased complexity in box design and possible woofer damage due to over-excursion of the woofer cone below the cut-off frequency of the vented box. D) are relatively new (about 5 years in the car) but offer some advantages of both the sealed and vented designs. Advantages include reasonable efficiency, small box volumes, good transient response, extended low frequency performance and can be used with very high power amplifiers. Disadvantages include slightly lower efficiency compared to a vented box and increased complexity in box design and construction. E) vent the sound from the front and back of the woofer through individually tuned enclosure on the front and rear of the woofer. The advantage of this design is its high efficiency over a narrow frequency band. Disadvantages include complex design and construction, large box volumes, poor transient response and susceptibilities to cone over-excursions (damage) for sound outside its primary frequency band. ISOBARIC WOOFER CONFIGURATIONS Increasing in popularity in recent years is the compound woofer design, more commonly known as the "Isobaric" design. Isobaric actually means "constant pressure" which is the case having two woofers moving an encapsulated pocket of air between them in the same direction. This arrangement acts like a single speaker which effectively reduces the required box volumes for a subwoofer system by 50% which is substantial if you are space-limited. Unfortunately, the trade-off for space is the 3 dB loss in efficiency but this is usually recovered with increased amplifier power. Care must be taken to avoid air leaks between the two woofers and final speaker wiring and impedance loads must be carefully watched. [. . . ] The final box should be rock solid and air tight but should also remain serviceable should a woofer be damaged for any reason. When possible, use 10 to 15 cm diameter port tubes to avoid wind noise from smaller diameter sizes. PVC plumbing pipe in various diameters is available at most hardware stores with , , elbow" pipes allowing you to bend the tubes inside the box. [. . . ]