广达(DELL)扬声器标准

附件一 广达(DELL) Speaker Acoustic Requirements 3.2 Acoustical Requirements The following items define the audio requirements for acoustic outputs (internal speakers). These requirements are not associated with general noises generated by the system, e.g. fan, HDD, or ODD noise. Detail measuring methods, stimulus levels and test setup are defined in Appendix C.

Four requirement categories are defined in Table 2: Performance, Mainstream, Value and Basic (in descending performance order). The platform Marketing Requirements Document (MRD) will indicate which of the performance requirement tiers to be implemented. If the RFQ package or MRD do not specify which performance tier is required, use Basic.

3.2.1 Internal Speaker Acoustic Requirements – In-System Response Table 2 below defines the internal speaker performance requirements. The response requirements are based on the system performance in full plastics with all equalization and/or compensation enabled. Also, note that EQ will not be used to provide gain at the low end roll off of more than 6dB.

Performance Mainstream Value Basic Freq Response (-3dB) 250Hz – 12.5kHz 400Hz – 12.5kHz 630Hz – 10kHz 800Hz – 8kHz

Freq Response (-10dB) 160Hz – 20kHz 250Hz – 20kHz 400Hz – 16kHz 500Hz – 12.5kHz Loudness/SPL at 0.5m (dBSPL) 80 dBSPL 77 dBSPL 77 dBSPL 74 dBSPL THD+N vs. Frequency <5% (315Hz-15kHz) <5% (750Hz-15kHz) <5% (800Hz-15kHz) <5% (1000Hz-10kHz) Power (Peak/avg): Main speaker 2 x 8Wp/5Wavg Or 2 x 3Wp/2Wavg mains 2 x 2.5W/2Wavg 2 x 2.5W/2Wavg 2 x 1.5Wp/1Wavg Or 1 x 2.5Wp/2Wavg

Power (Peak/avg): Subwoofer 10Wp/6Wavg sub n/a n/a n/a Transducer size (W x L x D mm) Mains: 20 x 40 x 10.4 18 x 18 x 8.2 Sub: 28 dia x 10 18 x 18 x 8.2 14 x 25 x 5 18 x 18 x 5 14 x 25 4.6 10 x 25 x 5.6

Enclosure Volume 40cc each Or 15cc main + 40cc sub 15cc 8cc 4cc Table 2: In-System Speaker Performance Requirements Note: The “Main Speaker Power” section in Table 2 provides a guidance on speaker selection, speaker amplifier power rating and amplifier gain level. It is possible for speaker vendors to have more efficient designs that can achieve the same total sound pressure level with a lower power rating. The “Total Sound Pressure Level” requirement takes precedence and must be satisfied.

The “Enclosure Volume” and Transducer size sections in Table 2 provides guidance on initial speaker enclosure target sizes. This is the total external enclosure size that needs to be designed into the NB system. It includes the enclosure wall thickness, internal acoustic volume and the bass reflex port. However, the actual enclosure volume might vary depending on the actual speaker design implemented.

3.2.1.1 Frequency Response Frequency response is the measure of the speaker’s spectrum response at the output to a signal of varying frequency (but constant amplitude) at its input. The frequency response requirements are defined at the -10dB points referenced to the average sound pressure level of the speaker system. These roll-off points are measured at 1/3 octaves within the specified -10dB bands in the Table 2. This is the response of transducers inside an enclosure located inside the system chassis with equalization enabled. The average sound pressure level should be calculated from the frequencies listed in Table 3.

Performance Mainstream Value Basic 160 Hz 200 Hz 250 Hz 315 Hz 400 Hz 500 Hz 630 Hz 800 Hz 1000 Hz 1250 Hz 1600 Hz 2000 Hz 2500 Hz 3150 Hz 4000 Hz 5000 Hz 6300 Hz 8000 Hz 10000 Hz 12500 Hz 16000 Hz 250 Hz 315 Hz 400 Hz 500 Hz 630 Hz 800 Hz 1000 Hz 1250 Hz 1600 Hz 2000 Hz 2500 Hz 3150 Hz 4000 Hz 5000 Hz 6300 Hz 8000 Hz 10000 Hz 12500 Hz 400 Hz 500 Hz 630 Hz 800 Hz 1000 Hz 1250 Hz 1600 Hz 2000 Hz 2500 Hz 3150 Hz 4000 Hz 5000 Hz 6300 Hz 8000 Hz 10000 Hz 500 Hz 630 Hz 800 Hz 1000 Hz 1250 Hz 1600 Hz 2000 Hz 2500 Hz 3150 Hz 4000 Hz 5000 Hz 6300 Hz 8000 Hz 10000 Hz

Table 3 Frequencies for average sound pressure calculation 3.2.1.2 Loudness/SPL (Sound Pressure Level) This defines the minimum sound pressure level when the system is: a) configured at maximum electrical output level capability (maximum volume) and b) playing the Burosch Professional Audio Test CD, track 06, pink noise in correlation, -10 dB.

The playback volume sliders in both the application and the master volume mixer should be set to maximum levels. (Also, see Appendix C, Section 4.) The measurement unit is dBSPL and the measurement frequency range is full bandwidth 20 Hz to 20 kHz. The measurement is not A-weighted.