TOPIC
Question 1:
What are the total harmonic distortions from input to output?
DISCUSSION Note: Complete information on these topics is available in the PowerBook 190 and 5300 developer notes. Question 1: What are the total harmonic distortions from input to output? Answer: Total harmonic distortion and noise is less than 0.05 percent with a 1-V rms sine wave input. The signal-to-noise ratio (SNR) is 85 dB, with no audible discrete tones. Question 2: What is the frequency response of the sound? Answer: 20hz to approximately half the selected sampling rate which would be 22Khz, 11Khz, or 5.5Khz. Question 3: What are the sampling rates? Answer: Sample rates supported are 44.1, 22.05, or 11.025 kHz, at a sample size of 8 or 16 bits. Question 4: Can I use both sound inputs at the same time? Answer: The PowerBook 5300 is capable of recording sound from either the internal microphone or from the sound input jack. Only one input can be used at a time. Question 5: Does the internal microphone capture monophonic or stereo sound? Answer: The internal microphone allows the user to record monophonic sounds. This microphone also allows the user to implement Apple's Plaintalk speech recognition software. Question 6: Can I capture stereo sound from an external source through the sound input jack? Answer: The Sound input jack can record stereophonic sounds from any device that outputs a line level signal. Line level signals are common from CD players, tape decks, VCRs and most other consumer electronic devices. To use an external microphone with the sound input port, the external microphone's signal would first have to be amplified up to a line level signal level. It can be done by using a microphone preamp or by running the microphone signal through a mixer that has a built-in microphone preamp. Question 7: What sound capability does the PCMCIA slot have, if any? Answer: PCMCIA cards can generate sound back through PowerBook 5300 and PowerBook 190 systems. This is useful for modem cards to generate connection status or for any PC Card to play system beeps. Question 8: I need some information about all the other sound specifications for Macintosh PowerBook 190 and 5300 series computers. Answer: Output Impedance The output impedance, nominal is 32 ohms. Frequency Response Of Speakers The frequency response of the speakers will be 20 Hz to 20,000 Hz. Line Level Input Line Level is a standard in the audio field and now in the computer industry. Line level is defined as 1 volt peak to peak. Line Level provides an industry standard so that all audio and other electronic equipment can operate properly together. Most VCRs, including both home and professional audio equipment use Line Level as a standard. Audio Input The audio input of the 190 and 5300 series PowerBook is specified to operate at 5.6V Peak to Peak. Line In Impedance Line In Impedance: 6.8K ohms Max Input Max Input before clipping, Singer (sound chip) gain = 0 dB is 2 Vrms, nominal 5.6 Vpp Max Output Max Output into 10 k ohm load 1.4 Vrms, nominal 2 V Peak to Peak. The output level will of course drop with a low impedance load like headphones; the 2 Vpp, 32 ohm Thevenin equivalent is well suited to drive headphones. 16-bit stereo CD-quality, 16-bit stereo sound capable of driving headphones or other stereo equipment. Analog/Digital Conversion Digital-to-analog and analog-to-digital conversion sampled at 11.035, 22.050, or 44.100 kHz. This article was published in the Information Alley on 12 June 1996. |
| Document Information | |
| Product Area: | Computers |
| Category: | PowerBook |
| Sub Category: | PowerBook 190 Series; PowerBook 5300 Series |
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