Ich hab jetzt noch mal die Notizen gefunden, die ich mir rausgeschrieben habe dazu:
The woofer on the Boom is a custom part from a vendor in China (GGEC 03904). If someone wanted to replace them as a DIY project, here's the specs for that part: Diameter: 3 inches / 82 mm Impedance: 4 ohms Frequency Response: 72-7KHz Sensitivity: 82db 1W/1m Max power input: 15 watts Resonance frequency: 72 Hz http://eetimes.com/design/audio-design/4015899/White-paper-Logitech-Squeezebox-Boom-audio-design Loudspeaker Drivers The drivers we chose were custom developed by Logitech's audio engineers to produce the best sounding products while maintaining reasonable costs. The woofers are 3" long-throw drivers with woven cloth cone and a rubber surround. They have a flat frequency response of between 100 Hz and 4 kHz. The tweeters are ¾" soft-dome drivers that have a flat response of between 1200 Hz and 20 kHz. There is almost no signal loss all the way to 20 kHz. The woofer-tweeter crossover is set at 2 kHz. The woofers share a rear acoustic chamber. Production units have foam around the wires to prevent buzzing. Each channel uses a woofer and tweeter. Subwoofer/Headphone Output The Squeezebox Boom has a subwoofer/headphone output. A Wolfson WM8501 DAC, the same chip that is use in Squeezebox Receiver, drives this output. It is in a slightly different configuration optimized for headphone and subwoofer output, as opposed to line out. It is capable of driving about 1V RMS into a 16-ohm load, or about 1.7V into a high-impedance load. The WM8501 DAC is driven from the same DSP chip that drives the speaker DACs, and it can be controlled completely independently. This means that in headphone mode, the output will get full stereo output with full frequency response. When the device is configured for a subwoofer, we automatically slide the low frequency cutoff filter for the woofers up to 100 Hz, and create a complementary low-pass filter at 100 Hz for the subwoofer output. Both filters are also 4th-order Linkwitz-Riley filters, which create a very nice crossover between the Squeezebox Boom and the stand-alone subwoofer. The beauty here is that the user only needs to turn the 'frequency' knob of the subwoofer up all the way " no need to fine-tune the frequency knob since the Squeezebox already knows the optimal cutoff frequency and will automatically implement the best possible filter. ------------------------------------------------------------------------ OleHB's Profile: http://forums.slimdevices.com/member.php?userid=35873 View this thread: http://forums.slimdevices.com/showthread.php?t=99889
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