TITLE
    Macintosh Performa 6400, 6500: Sound FAQ
Article ID:
Created:
Modified:
20213
7/25/96
3/24/98

TOPIC

    This article contains frequently asked questions (FAQ) about the sound capabilities of the Macintosh Performa 6400/180 and 6400/200 computers and the Power Macintosh 6500.

    Questions Answered in this FAQ

      1. Do these computers have 8-bit or 16-bit sound?
      2. What is the purpose of the subwoofer?
      3. What happens when I turn the subwoofer balance control, which is located on the back of the computer?
      4. Why are there two sound output jacks--one in front and one in back?
      5. What is SRS Sound?
      6. I have headphones plugged into my monitor, but I still hear sound coming out of your computer. Why?
      7. I am using the headphones plugged into the front of the computer, but the sound appears distorted. What could be causing this?
      8. Why do I not hear any sound emitting from the computer?
      9. What are the speaker size, frequency range, and power specifications of the subwoofer?
      10. What effect does the subwoofer have on the SRS technology?

    For a general-purpose "frequently asked questions" article regarding Macintosh Performa 6400 series systems, please see the following Tech Info Library article:

    Article 24215: Macintosh Performa 6400 Series: Frequently Asked Questions


DISCUSSION

    1) Question: Do these computers have 8-bit or 16-bit sound?

    Answer: The Macintosh Performa 6400 series has 16-bit stereo sound input and output.


    2) Question: What is the purpose of the subwoofer?

    Answer: The subwoofer, which is built into your computer, functions as a full-range, monophonic speaker. However, when you attach external speakers to the sound output port on your computer (or if your monitor has built-in speakers) the subwoofer functions only as a bass speaker, to augment and complement the stereo sound coming from the speakers.


    3) What happens when I turn the subwoofer balance control, which is located on the back of the computer?

    Answer: If you want to increase or decrease the bass coming from the subwoofer in relation to the sound coming from the external speakers, adjust the subwoofer balance control. The subwoofer balance control only works when external speakers are attached.


    4) Question: Why are there two sound output jacks--one in front and one in back?

    Answer: There are two sound output jacks, one on the front and one on the back. Both output jacks are connected to the sound amplifier. Inserting a plug into either jack disconnects the internal speakers. The jack on the front is intended for headphones, and the jack on the back is intended for external speakers. The rear jack is muted when headphones are plugged in the font jack.


    5) Question: What is SRS Sound?

    Answer: SRS (Sound Retrieval System) is proprietary technology from SRS Labs, which Apple has licensed and implemented on the Power Macintosh 5400/120 computer in order to enhance the sound field of the computer.

    The usability, compatibility, and performance of the computer is not affected if SRS sound is enabled or disabled. However, enabling SRS yields a more spacious stereo sound from the computer. You can try it both ways to determine which you prefer.

    For additional information about SRS, see the following Tech Info Library article:

    Article 19953: Macintosh Computers: What Is SRS Sound?

    6) Question: I have headphones plugged into my monitor, but I still hear sound coming out of the computer. Why?

    Answer: When you plug headphones into the headphone jack on your monitor, you hear the sound through the headphones but the subwoofer sound also continues to come out of the subwoofer in your computer. To avoid this, plug your headphones into the headphone jack on the front of the computer, not the monitor.

    If you want to keep the headphones connected to the monitor, manually turn down the subwoofer. Turn the knob in the subwoofer balance control port all the way to the left to turn off the subwoofer volume. Remember to turn it back up the next time you want to hear the subwoofer.


    7) Question: I am using the headphones plugged into the front of the computer, but the sound appears distorted. What could be causing this?

    Answer: You may have SRS turned on, which does not work through headphones. To turn it off, open the Monitors & Sound control panel, which can be found in the Apple menu, and click the Sound icon. Then click to remove the check mark next to SRS.


    8) Question: Why do I not hear any sound emitting from the computer?

    Answer: Turn up the subwoofer balance control on the back of your computer. It may have been turned down too far.

    The subwoofer balance control affects the subwoofer volume only in relation to external speakers, if you've attached external speakers or if your monitor has built-in speakers. Otherwise, it has no affect on your computer's overall volume. Adjust your computer's overall volume by using the sound controls on the front of the computer or monitor, by using the volume control sliders in the Monitors & Sound control panel, or by using the volume controls in AppleCD Audio Player (if you're listening to a CD).

    9) Question: What is the speaker size and frequency range of the subwoofer?

    Answer:
    The speaker on the subwoofer is called a "74mm square-frame device", which means it is a 3-inch round speaker. The frequency range is approximately 70 Hz to 10 kHz. It is a 4.0 Ohm, 3.0 watt device.

    10) Question: What effect does the subwoofer have on the SRS technology?

    Answer: The subwoofer has no effect on the SRS technology since SRS does not need a subwoofer to perform. Essentially, the subwoofer makes the resulting sound much fuller.

    For additional information about SRS, see the following Tech Info Library article:

    Article 19953: Macintosh Computers: What Is SRS Sound?


Document Information
Product Area: Computers
Category: Power Macintosh
Sub Category: Macintosh Performa 6400; Power Macintosh 6500
Keywords: kfaq

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