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audio interface preamp is very, very quiet?

Discussion in 'Preamps & Processing' started by lunchwithmike, Feb 4, 2009.

  1. ever since i purchased my mbox 2 mini i have had a problem getting decent volume from my mics through the low-z xlr input. both of the 1/4" line inputs work fine when plugged into a guitar amp. the mbox 2 mini is supposed to have a preamp on the xlr input but i have to crank the gain up to 10 to hear anything from both of my mics. (when the gain is on 10 the noise floor is quite high too) i own two different dynamic mics: Shure SM57 & Nady Starpower cheap thing.

    what should i due to get some more gain?

    should an external mic preamp do the trick, even though the xlr input has a built in preamp? (there is no way around the internal preamp on that channel)

    should i use an external micpreamp into a line level input instead?

    any other ideas?

    thanks in advance!
    let me know if i left out any useful information in solving this problem.
  2. Boswell

    Boswell Distinguished Moderator Resource Member

    Apr 19, 2006
    Home Page:
    The Mbox 2 mini has got half-decent gain, so you should be able to get acceptable levels from your SM57. Are you sure you don't have the 20dB pad switched in?
  3. yes im positive on that.
    the cheap little Nady mic is actually a bit louder than the 57.
    this thing is weird and its driving me nuts!
  4. Codemonkey

    Codemonkey Distinguished Member

    Dec 11, 2007
    Scotland, UK
    Are your inputs on the DAW software turned down?
    Remember, there's more to it than a gain knob.
  5. well i get the same results whether i am using Pro Tools, Logic, or Garageband.

    even when i just listen to the output on some headphones straight from the mbox itself its very quiet.
  6. RemyRAD

    RemyRAD Guest

    Sep 26, 2005
    I beg to ask, or you recording rock or orchestral soft instruments? While the microphone preamp in your unit doesn't offer extreme gain. It's more than sufficient for rock-and-roll. This definitely sounds like some kind of operator error. No way you should be hurting for that much gain. What are you trying to record? Your stomach growling? A baby breathing? Worms burrowing into the ground? I think not?

    Now if you are recording at 24-bit, your record levels should reflect at least 15 to 20 DB of headroom. It's not supposed to be peaking into the red. And you don't need to do that.

    You should be able to mix a good mix, regardless whether you feel you're recording levels are low or not.

    Another problem could be, with your microphone, that you are using a XLR to 1/4"? And then yeah you ain't gunna' get enough level. You need to use a XLR on both ends of your microphone cable. And that would explain your lack of level.

    I've never had problem with microphone level
    Ms. Remy Ann David
  7. hueseph

    hueseph Distinguished Member

    Oct 31, 2005
    Vancouver, BC, Canada
    Have you tried recording anything yet? I'm going to guess that you haven't tried playing with the mix knob at all. The one that controls the monitoring from the input to the DAW mix. Fully counter clockwise will allow you to hear what you've already recorded. Fully clockwise will allow you to hear the input.

    If you have to, an external preamp is fine. I use an external with my Mbox. It's a bit fidgety since the line in doesn't fully bypass the preamps.The pres are just attenuated afaik.

    Lovin' ProTools 8 Though. It's a hog but the new set of plug ins is really nice. Watch that D-Verb! it's a resource hog compared to the old one.
  8. i have been using the mbox for quite some time for recording an acoustic guitar, a guitar amp and vocals. all of the line ins work fine its just the mics. i thought that my cheap nady mic was the problem but the 57 is actually a little quieter. i do record in 24-bit but the problem seems to be within the mbox itself. in order to monitor the xlr input i have to max the gain and the output volume. i know what the mix knob is heuseph! haha im not really much of a beginner to this anymore i am more or less using the mbox just because im poor.

    i got pro tools 8 and it ran way to slow on my 2.16 ghz core 2 duo macbook so right now im back to 7.4

    ill save 8 for the future macbook pro. :D
  9. FlyBass

    FlyBass Active Member

    Oct 31, 2007
    Central Indiana, USA
    You say it's the mics, but have you tried a different XRL cable?

    How does the audio file look? Does it seem to record too low or is it just the playback that's too soft?
  10. i actually only have one cable
    i don't think that that should make much of a difference in volume?

    and the file couldn't change anything because i can monitor the result before it goes into the computer.
  11. hueseph

    hueseph Distinguished Member

    Oct 31, 2005
    Vancouver, BC, Canada
    I just plugged a 57 in and it recorded fine. I was able to crank the input to distortion(it sounded kinda cool actually). Not digital distortion but the preamp was definitely clipping.

    Cables can make a huge difference. I just eliminated a bugger of a noise problem with a $30 investment in two three foot patch cables.
  12. alright so i decided to test out the xlr cable i unscrewed and check the soldered connection and they look fine, and then i realized it would smarter to just plug it in to the DI on my guitar amp. ha. and that worked fine. i got a lot of power through it, so the cable must be fine. it must just be the mbox itself i guess? i have only had it for a little over a year now. would digidesign fix/replace it if its already been a year now? i didn't even register it or anything!
  13. GeckoMusic

    GeckoMusic Guest

    If the cable is mis-wired say hot to ground and ground to hot, then the cable will pad the signal 6dB (half volume). At least a couple cables that I bought have been mis-wired. Same if a signal conductor is missing or broken. The DI will give you plenty of volume because they just do. When I use a DI on a guitar vs a dynamic the gain is normally 6 to 10 dB lower for the DI.

    Maybe it's microphone placement? For rock and roll, 3 to 6" and sing your heart out. ... The last recording I did was about that far, but now that I think about it most of the time I have my nose on the wind screen of the microphone... For micing a cab get it as close as you can without it rattling on the speaker cloth.
  14. i looked up some stuff on miswired xlr cables and it seems that that can only effect the the phase rather than the volume.
  15. RemyRAD

    RemyRAD Guest

    Sep 26, 2005
    You have all the answers don't you? So why are you even here?

    There is nothing wrong with your M-Box. But I can tell you you don't have a clue as to what you are doing.

    God help you if you ever have to sit behind a real console. Miswired microphone cables can absolutely have an effect on level. Have you even completed high school yet? I think not. It's sad when folks like yourself cannot even comprehend their instruction manual. Sorry to sound so harsh but this is beyond stupid. 99.44% of the time it's operator error. Or, haven't you learned that either? Oh? You already know that? Then you know it's operator error.

    You are pushing my buttons the wrong way
    Ms. Remy Ann David
  16. GeckoMusic

    GeckoMusic Guest

    A differential amplifier like the one you have in your M-Box works by inverting the cold signal and adding it to the hot. So if you have some signal "A" the hot will have +A, the cold will have -A. With a correctly wired cable the amplifier will produce -(-A) + (A) = 2A.
    If the hot an cold are reversed you will get -(A) + (-A) = -2A. The phase inverted case you mentioned.
    If the hot and ground are swapped, the +A term will be zero, so you get -(-A) + (0) = A. This is half of the proper value, or 6dB down.

    A little bit of friendly advice:

    Making statements on things you know little about is a sure fire way to get burned and look like a jack ass. Instead, ask a question in a way that shows some understanding of the material.

    For example you could have said "I understand how a mis-wire can cause a phase reversal, but how can it make a difference in volume?"

  17. wow
    i tend to look things up and try to get more information on something before i go out to the garage and look for the soldiering iron to fix a cable. and yes i have completed high school, i should still be in it, but i graduated early. yeah im not stating my life on the miswired xlr cable thing i just could not seem to find anything else on the net about misfired xlr cables decreasing the volume. the mbox itself seems to be quite obvious to operate in upon its intended function. im pretty sure i have a grip on how to use it, i am not any audio engineer/video engineer/producer. i enjoy music, so i am interested in recording it.
  18. BRH

    BRH Active Member

    Aug 16, 2006
    LA, CA
    Is your mic cable XLR on the mic end and TRS 1/4 on the "D.I." side?
  19. nope its xlr on both ends
  20. GeckoMusic

    GeckoMusic Guest

    Seriously, I'm just trying to help you out.

    Your statement is wrong because you made some AssUMe-tions. You generally can't arrive at "only" from "looking some stuff up".

    If you just looked some stuff up, you don't have a good understanding of it. It takes more than a little reading and thinking to understand something.

    I wouldn't suggest getting a soldering iorn out unless you know what you are going to solder. I did suggest checking for a mis wire in your cable.

    Good for you on graduating high school early. Most of the knowledgeable people on this board graduated decades ago, and have a 4 year collage degree in something, and have at least a decade of experience in recording.

    Did you check for a mis-wire?
    What distance are you recording from?
    What is the source?

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