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Decibel Levels????

Discussion in 'AV Receivers & Amplifiers' started by pobrien31, Sep 22, 2003.

  1. pobrien31

    pobrien31
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    Hi, funny someone else posting on this topic as I have been scouring the 'net for info on decibels.

    Man, it's another complete world to delve into.

    My reason for enquiring is that on my Pioneer receiver the optimum level for listening seems to around 40db.

    I thinks it's 40 anyway, although it could be -40, as the display looks as though it has a field for 3 digits???

    But checking the internet, 40db seems to be just above a whipser!?!?!?!?

    When I turn the volume up, the decibel reading gets lower and when I turn the volume down, the decibel reading gets higher.

    Any and all help would be gratefully appreciated. I have read about the reference level at 0db etc, but am still unsure.

    Thanx in advance.

    Regards,

    Patrick.
     
  2. pwiles1968

    pwiles1968
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    Reference level at 0dB on your display will be in the region of 75dBC at your seating position using the amplifiers internal test tones (this is assuming they are output at –30dB below reference on the Pioneer)

    When you turn the volume down the dB or dBC level will reduce i.e. –40dBC on your volume level will give 35dBC at your seat with your test tones and up to 65dBC with other media, such as CD, notice I said per speaker earlier if you double the speakers you double the SPL or add 3dB, therefore in stereo from a CD assuming you have the speakers set up to reference you have up to 68dBC. A bit more than a whisper. I listen about -30 to -20dB. depending on the source.

    (dBC an SPL value {sound pressure level} if you have a meter)

    Hope this does not confuse you further.
    :D :confused: :D
     
  3. GaryB

    GaryB
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    You're comparing two different things here. In electronics, Decibels are a way of expressing a ratio between two voltage, current or power levels. That is the dB scale on your amplifier which shows attenuation relative to its maximum power. This is why the reading decreases as the level increases. There is also dBm which is an absolute level referenced to 1 milliwatt (0 dBm=1mW).

    Decibels in acoustic terms (also known as dB/A) are an absolute measure of a sound level. This is probably where you have seen the various figures - 100dB for a jet plane (or my stereo), 120db for threshold of pain, etc.

    Try a Google search on dB, dB/A, etc. and all will be explained.
     
  4. ewin

    ewin
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    Just a quick note .What pioneer do u have as i have a vsx-510d a/v amp and my Db level in dts is about 45-50 and in dolby about 40-35 Db.
    If there`s one thing i know is that some dvd`s are at different sound levels. Some are louder than others.
    p.s Does your pioneer lack bass in dd as i have to put the loudness on and sounds better ,dts is the same untill i switch on the midnight mode on. totally crazy.anyway getting a yamaha soon.
     
  5. Reiner

    Reiner
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    40dB on your volume knob is the attenuation of the amplifier circuitry, not the volume or rather sound pressure level (SPL).

    That is correct. Unfortunately there is no standard for the levels to be recorded AFAIK.
     

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