What does Reference Level Mean?

Discussion in 'Archived Threads 2001-2004' started by Tommy T., Jan 13, 2002.

  1. Tommy T.

    Tommy T. Extra

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    I'm new here & I've read several times about reference output levels being at 105db. What does reference level

    mean? I was guessing maybe it's the std. volume for Dolby Digital, but that seems too loud to me.

    Thanks for any responses...

    Tom T.
     
  2. John Welch

    John Welch Stunt Coordinator

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  3. Tommy T.

    Tommy T. Extra

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    Thanks for the link John... Now I understand but I'll tell you 105db will blow you away so I'm still a little confused why that is called reference level.

    Tom
     
  4. Patrick Sun

    Patrick Sun Studio Mogul

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    Peaks of 105dB at the seats is part of the Dolby spec, normal is 85dB at the seats. Why? Because some folks at Dolby labs decided that this was what was needed to impart the full theater sound experience at the home theater level.
     
  5. Tim Kline

    Tim Kline Stunt Coordinator

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    How can people actually listen to it that loud though?
    I mean.. my receiver shows volume by db.. I usually do -35, but sometimes that's too loud and I go to -40.. I cranked it up to -25 once and it was ears-wanna-bleed loud. I can't imagine having to keep it at reference level or even -10.
    Is it my equipment making it be louder than it should be? Or is reference level type stuff more for really big rooms where the sound spreads out more? my HT area is a 12x15 room [​IMG]
     
  6. nolesrule

    nolesrule Producer

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    The volume level on your receiver doesn't have to be at 0 to be at reference level. In my room, reference level is when my master volume is set to -17. I usually listen between -20 and -25.

    Where the master volume has to be depends on the size of your room and where your listening position is. You need an SPL meter to figure it out.
     
  7. Vince Maskeeper

    Vince Maskeeper Producer

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    Tommy,

    To answer your question of "WHY" is the issue of dialog levels.

    Someone determined where dialog volumke should be in terms of ouptut level. This level would be the median level of sound. Someone then figured out how much dynamics the system should allow BEYOND the level of dialog.

    So, the systems is setup so that it allows good dynamic range- specifically 25-30db of headroom ABOVE the level of dialog. The wanted dialog at aprox 70-75db of SPL- and thus- the max level is 105db spl from any one speaker.

    As was said above- the volume on your receiver means NOTHING, Ref level measures output- and the volume knob on your receiver is not directly connected to output level (obviously your receiver set to 0 with you sitting 5 feet away would cause you to perceive one OUTPUT level while sitting 100 yards away would provide a different level-- although the volume knob would stay the same.).

    Ref level is loud- but it is the level of commercial theaters (or at least properly calibrated ones). I'll be honest that ref sounds better with good amps/speakers- because the harshness of soundtracks are made worse by straining components. Moseso, a large room without tons of reflection will make ref level more digestible. I have a room about the size of yours and I'm usually -5 or -10 from Ref

    You should get a SPL meter and a calibration disc and determine where ref level is for your room (and this will also balance your speaker levels, which is the most important setting in you HT). You might find that ref level on your unit, in your room with your speakers is equal to -25 on the volume knob... again it is a measure of output which can only be achieved with a tool to measure output (SPL meter) and tones set to a specific level (like those found on calibration discs like Avia, Video Essentials or the upcoming Digital Video Essentials).

    But no one says you have to listen at ref, even after you determine where it is. It's good, usually, to know how far you are from it- just as a point of ref when asking questions or seeking to upgrade equipment. To be able to say "i'm looking for a sub- but I usually listen at -20 from ref in my 10x12 room-- will help people make suggestions on what type of sub you need to push good coverage at that volume).

    -Vince
     

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