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Presonus Firebox on the way

Discussion in 'Recording' started by Guitarfreak, Mar 2, 2009.

  1. Guitarfreak

    Guitarfreak Well-Known Member

    I'm so excited and can't wait to try it out. It is an ADC right? Will this mean that I will be able to drive a hotter signal without clipping? I ask this because sometimes currently with DI the sound audibly clips while the level stays comfortably within the yellow.
     
  2. Jeremy

    Jeremy Active Member

    You made the correct choice to start with a Firebox. Best bang for the buck IMO. I started with a Firepod the box's older brother. When you are ready to upgrade, the Mackie Onyx as of this day and time is a logical jump. Who knows maybe that studiolive will knock the socks off the Mackie's, only time will tell.
     
  3. Codemonkey

    Codemonkey Well-Known Member

    "It is an ADC right?"
    You mean you bought it without knowing what it was?

    Here, buy this. Features:
    - easy interaction,
    - simple to learn,
    - instant feedback on actions,
    - clean, ergonomic design
    I'm not telling you what it is or does though.

    "Will this mean that I will be able to drive a hotter signal without clipping?"
    Maybe. This is irrelevant though.

    Search for "gain structure" and work on it. There's no need to record the hottest signal you can.
     
  4. Guitarfreak

    Guitarfreak Well-Known Member

    Lol, no I just thought it was a good way to ease into the question. I will look up gain structure. Thank you
     
  5. Codemonkey

    Codemonkey Well-Known Member

    Ah. My bad.

    Gain structure (quick overview, I suggest you still dig for additional info) basically, keep your inputs -6dB at max volume. Once you get out of the realm of soundblasters the signal-noise ratios are generous so noise isn't really a worry.

    Just keep your signal from clipping (unless that is your bizarre intent) and then a little bit more headroom on top of that.
     
  6. Guitarfreak

    Guitarfreak Well-Known Member

    When looking up gain structure, I read where boosting a signal via preamp too much adds noise, is this because we are talking about a digital preamp? I remember hearing something with analog equipment, maybe tube or tape related, but the more you boost the signal the LOWER the noise floor gets.

    I can see this with the tape deck in my car, the tape deck being a basic ADC. I have my iPod plugged into my tape player and using the built in iPod volume as a sort of "preamp" I can see the results. Below 50% volume, the signal is weak and dull sounding and there is a lot of static noise. The noise floor drops steadily until around 75-80% then the signal gets so hot that it starts to clip and the speakers start to rumble.

    I just realized that I have no idea what I am talking about and am just rambling...oh well. Maybe someone can make sense of this.
     
  7. Codemonkey

    Codemonkey Well-Known Member

    Preamps are analog!

    Err... the only thing I can think of that would lower the noise floor is if you engage the pad - then it drops by 20dB (and RemyRAD, among others) think it provides a more open sound. They have their reasons, I don't have quality gear to hear it.

    Anyway - your preamp should be set so that the output signal from that is about -10dB allowing for headroom etc. - if you're likely to get carried away with the music then make it -15dB for regular volume - this gives you plenty of headroom.
    All additional gear (if you have any) should receieve an input of about the same - (most analog gear can handle greater input volumes, however it's not necessary to feed them hotter) - and your ADC (which is the end of the analog chain) should recieve the same again.
     
  8. Greener

    Greener Guest

    "Err... the only thing I can think of that would lower the noise floor is if you engage the pad - then it drops by 20dB (and RemyRAD, among others) think it provides a more open sound. They have their reasons, I don't have quality gear to hear it. "

    I think it raises the noise floor.
     
  9. Codemonkey

    Codemonkey Well-Known Member

    No, no, it'll decrease the noise floor on the output.
    It'll also decrease the usable signal as well, which may give you headroom, or put you below unity, and if you increase the gain to compensate, THAT will add to the noise floor.
     
  10. Greener

    Greener Guest

    Ahh, indeed.
    (Dead Link Removed)
    I forgot the "with gain" part of the equation.
     
  11. Guitarfreak

    Guitarfreak Well-Known Member

    I just realized that in my last post I may have been hung up on some terminology. When I said the noise floor, I probably meant S/N ratio.

    Can someone comment on this for me? So far (and I know I need to just play around with it to get a feel for it, bear with me it's not here yet and I'm antsy :D) But it seems that when setting a preamp level you must set it high enough to get a good S/N, but not so high that the device starts to add noise (Noise floor).

    Also, the firebox has a clip LED. In my head I think what I'm going to do is boost it until I find the spot where the LED clips, and then from there back it off 5-10dB. Does this sound like a good starting method?
     
  12. Codemonkey

    Codemonkey Well-Known Member

    The preamp in itself is designed to be as low noise as possible.

    I think you mean,
    You should set the preamp so that subsequent parts of the signal chain receive a hot enough input so to minimise the need for further gain and thus adding noise, but not so hot that the signal clips.
    Allow for headroom to taste.
     
  13. Jeremy

    Jeremy Active Member

    Ohh you rascal monkey. Good post.
     

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