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+4 dBu / -10 dBV = $&%*#@!

Discussion in 'Recording' started by Dethwretch, Jul 3, 2004.

  1. Dethwretch

    Dethwretch Active Member

    Can someone please explain these terms to me? From what I understand, these are simply the LEVELs that a particular piece of gear is optimized to perform at (+4 dBu being at a much louder signal level than -10 dBV <- Is this correct?) . The only thing is, I always see something like "+4 dBu is used for PROFESSIONAL gear and -10 dBV is used for CONSUMER gear." I would like to assume that I have professional equipment ($$), but how does one KNOW this.

    Also, there is sometimes a switch that will allow you to go between these settings. Lets say the switch is set at -10dBVs. Does that mean that this switch modifies the INPUT level AS WELL as the OUTPUT level for -10dBVs, or does this switch just controll the OUTPUT level of the signal.

    Though I'm not sure if this applies to the above, but I've also heard of putting a pure sinewave (say 1 KHz) into an input to get an optimum level. Any info on this as well would be much appreciative.
  2. ErichS

    ErichS Active Member

    I can't say I understand it completely, but below is a link to an article that may help


  3. Dethwretch

    Dethwretch Active Member

    Thanx Erich! :) I'll check it out.
  4. MrGrooves666

    MrGrooves666 Guest

    Consumer/professional are just tags really. Those are different scales too and you should be aware of that, +4 is a little higher level, but not much. Remember db scale is all about reference. In +4 dbu gear the optimal operating level corresponds to 1.x volts or so (sorry I don't remember exactly), while in -10dbV, the optimal level is less. Very old gear used to be all -10dbV, but then +4dbu emerged as a standard. It doesn't really have to do much with being pro or con really. Good +4dbu gear sometimes has more headroom though, but that is also related to its design. Also, +4dbu gear has balanced connections, while -10dbV gear has unbalanced, though this is not a rule per se.
    When you set your interface or whatever to -10dbV, you're just "optimizing" it for operation with other -10dbV gear. That is all.

    The sine thing is just about callibration. As all things audio, a system needs to be calibrated (or referenced to some standard) for optimal operation. Optimal operation meaning getting the best out of a system, taking in consideration the noise floor of the system, and also the hottest signal it can handle (aka dynamic range). So this means for ex, if you're using a digital system, you have to reference 0 VU to something, for ex, -18 dbfs, -20 dbfs, or so.
    Hope this helps.

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