Normal recording levels: Presonus MP20, AT4050, the spok

Discussion in 'Microphones (live or studio)' started by Fozz, Sep 17, 2003.

  1. Fozz

    Fozz Active Member

    Jun 4, 2001
    Williamsville, NY
    Home Page:
    This is my first venture into recording. It is for fun, not profit. I did not want to buy specialized equipment like shot gun mics for people talking and then condenser mics for people singing.

    Project one: record people in their living rooms or sitting around their dining room tables talking about their lives. People could be sitting 6" to a foot away from the mic or as far away as two feet.

    Project two: be able to record people singing or playing instruments.

    I'll save space here and leave out the rationale for why I ended up with the following particular pieces of gear:
    • <font size="2" face="Verdana, Helvetica, sans-serif">a pair of Audio Technica AT4050s
    • <font size="2" face="Verdana, Helvetica, sans-serif">Presonus MP20
    • <font size="2" face="Verdana, Helvetica, sans-serif">recording to a borrowed Sony PCM-2600 DAT
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    Because of my inexperience I don't know if the results of the following tests are normal, or not:

    Test #1:

    I'm not a soft spoken person, nor do I always talk loudly. When I speak
    • <font size="2" face="Verdana, Helvetica, sans-serif">at what I think is a normal level
    • <font size="2" face="Verdana, Helvetica, sans-serif">about 4" to 6" from the AT4050
    • <font size="2" face="Verdana, Helvetica, sans-serif">the mp20's gain starts at 10 dB and goes up to 60 dB. I have it set about half way at 12 o'clock (about 35 dB)
    • <font size="2" face="Verdana, Helvetica, sans-serif">this results in the meter on the mp20 peaking at abour -2 or 0
    • <font size="2" face="Verdana, Helvetica, sans-serif">the DAT's recording level was set at 7, its meter measures about -8 dB
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    I think everything sounds fine and, to reiterate, I am just talking, not singing.

    Question: I understand that all mics and preamps and people are different. Is it normal to have to turn the gain half way up for someone who is just talking 6" from the mic in order to get the preamp meter to peak at about 0?

    Test #2:

    Similar to the above, I didn't change any levels, but I stood five feet away and talked at the same normal volume.

    • <font size="2" face="Verdana, Helvetica, sans-serif">the MP20 meter only measured -24 dB
    • <font size="2" face="Verdana, Helvetica, sans-serif">the DAT also measure about -24 dB
    <font size="2" face="Verdana, Helvetica, sans-serif">
    It sounds fine, I guess, like I am standing five feet away from the mic.

    Question: without changing any levels from the 6" case to this five foot case, is it normal that the meters will just barely register anything, i.e. just one led lights up on the MP20?

    Test #3:

    In this test I wanted to see what I had to do to get the MP20 to peak at 0 while standing five feet from the AT4050 and just talking in a normal voice.

    I had to turn the MP20 gain almost all the way up, to the 18th tic mark. The last mark on the gain is the 19th representing 60 dB. I certainly don't want to do this because I definitely hear hiss, self noise, whatever it is called, in the background.

    Question: I'm guessing that the sound pressure level from a human voice at five feet is kind of low, so is it normal to have to turn the gain almost all of the way up to get peaks at 0?

    Test #4:

    In the last test I started to hear noise, hiss, white noise(?). What I did was make sure that everything in the house was off. No computer noise, no refrigerator, no A/C, not water running through pipes. I live on a quiet street. I slowly turned up the gain until I thought I heard the noise. It became barely audible at about 1:30, which is tic mark 13 out of 19, about 43 dB, if the gain is linear from 10 up to 60.

    Question: is it normal to start hearing that self noise which is either coming from the mic and or the preamp, when the gain is turned up to about 70% of its max?
  2. RecorderMan

    RecorderMan Distinguished Member

    Mar 28, 2001
    In a word. Yes to everything you asked.

    The human ear is a remarkable instrument, and can listen to a very wide range of levels. The range is so great in fact that a linear scale wouldn't be able to fit it so we calculate in with a logarithmic scale.

    If you plan on doing this frequently you should buy just one more piece of equipment: A RNC or really nice compressor. I believe you can get one for less than $200. You will patch it after your microphone pre-amp and before your dat recorder. It will make your louder-signals softer and your softer signals louder, thereby squeezing the dynamic range of the audio. Then you can send a louder average signal into the DAT. This will make your recordings much less noisy and prevent any distortion. Very important, especially if your recording anything that is spontaneous.

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