User manual BLAUPUNKT VXW 250

[. . . ] New strontium ceramic ferrite magnets yield smaller magnet sizes without reduced magnet strength but retain their magnet power far beyond the expected life of the woofer. Four layers of high-temperature wire on DuPont Kapton Polyamide voice coil bobbins allow for voice coil temperatures exceeding nearly 225 degrees Celsius without damage. Rear vented T-yokes allow fresh air to move in from behind the woofer to cool the voice coil. Safety precautions Before starting to mount your speakers, please read carefully the instructions on installation and connection. [. . . ] No single design is superior because each has its own compromise in performance, power handling and design complexity. DUAL VOICE COIL ADVANTAGES The dual voice coil woofer is actually quite old in the home audio industry but still relatively new to the car audio world. the largest advantage of the DVC woofer is in the flexibility in installation. In order to raise the sound pressure level (loudness) in a car, you can either add more speakers or add more amplifier power to drive a single speaker. Many cars cannot fit two subwoofers and their necessary enclosure volumes but can easily fit large power amplifiers and a single woofer. Simply speaking, the DVC woofer allows you to make up for speaker deficiencies with additional amplifier power. 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. [. . . ] The application of self-adhesive damping mats to the inside walls also helps to eliminate wall resonances. - The cables running from the amplifier to the subwoofer should be as short as possible with a cable cross section of at least 4 mm2. - 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. [. . . ]