Logitech Squeezebox Instrctions

[Page 1] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 1 Logitech Squeezebox Boom Audio Design Caleb Crome Sr. Hardware Engineer Logitech, Inc. Introduction Ever since I bought my first Squeezebox from Slim Devices several years ago, I want...

[Page 2] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 2 Although we believe Squeezebox Boom sounds great today, because of the extremely flexible and upgradeable nature of the Squeezebox architecture, we can roll in new features on an ongoing basis to...

[Page 3] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 3 are going to use. Power Amplifiers High-performance class-D amplifiers power the woofers and tweeters and can easily deliver full power to the speaker drivers with minimal distortion. We chose h...

[Page 4] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 4 Figure 3: Grills and front panel removed. Figure 4: Main board removed, exposing the rear of the main board and acoustical chamber. Figure 5: Acoustic housing disassembled. The woofers ...

[Page 5] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 5 !"#$#%&'() *+! ,)- ./01&,233 4/5"#$ (675/!#$3 8#9"&!7#2:#$ ;/01"&!7#2:#$ !"#$#%&'() *+! ,)- ./01&,233 4/5"#$ (675/!#$3 8#9"&...

[Page 6] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 6 In order to perform DSP effectively, the DSP processing must have significantly more precision than the signal being operated on. Of course, a 16-bit processor can perform 32-bit, 48-bit, or high...

[Page 7] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 7 Figure 9: Click-less volume changes in Squeezebox Boom. This volume ramping profile shows how the volume gently changes from one volume to another. This shows a switch from 0 to 100% volume, but...

[Page 8] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 8 proven track record. The extreme flexibility of the networked music player plus a completely software controlled audio architecture allows us to continue to improve the product over time and make...

[Page 9] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 9 Figure 11: Frequency response of Squeezebox Boom, with theoretical low frequency compensation filter. Red: Measured response; Blue: theoretical model; Green: compensating filter; yellow: Theoret...

[Page 10] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 10 Figure 12: Family of low-frequency equalization curves (blue) and simulated low-frequency system response (green). The curves show cutoff frequencies ranging from 20Hz to 137Hz in 1/3-octave st...

[Page 11] Logitech Squeezebox Radio

©2008 Logitech Squeezebox Boom Audio Design 11 The difference between with and without bass-extension was surprising to me. At low listening levels, with significant extension, the listener can easily be fooled into thinking a subwoofer is a...