Acceptable noise levels

Discussion in 'Microphones (live or studio)' started by xian, Oct 29, 2005.

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  1. xian

    xian Guest

    Hi all,

    I am doing some recording on my computer and I am getting a bit of ambient background noise while recording through a mic. Sonar records it at around -50.5 dB.

    Here is what I'm using:

    Desktop PC with Sonar 3 PE
    Behringer B2 Pro Condenser Mic
    2 ch phantom power box
    Stock soundcard that came with my computer (SoundMAX digital audio)

    The mic is plugged into the phantom power box which goes into my soundcard on my computer. I know it's not a lot to work with, but it's all I got right now.

    I was wondering if anyone had any suggestions on how to reduce this white noise or any recommended (hopefully free) plugins that may help filtering the noise out.

    I was also wondering what an exceptable level is for white noise. I know it's very subjective and I am talking about a small home studios here (around $5k)
  2. xian

    xian Guest

    Even with the mic unplugged, it's coming in at -52.0 dB
  3. David French

    David French Well-Known Member

    Jun 19, 2002
    My best guess is that the soundcard is the offender. Get an M-Audio Audiophile or similar for $100 if you can. Also, is this phantom power box also a preamp? I hope you're not trying to make up gain in the computer somehow.
  4. Mr-Nice

    Mr-Nice Guest

    I bolded what is the culprit is. I would say its 85% of the problem too. The rest of the noise can be from the rest of your hardware. Get a card that is for recording audio. Make sure it is full duplex. Also try to get one with a breakout box as then tend to be a bit quieter.

    Does this help?
  5. John Stafford

    John Stafford Well-Known Member

    Oct 1, 2004
    If you get a better soundcard, and the improvement isn't quite as big as you expect, you will probably want to dump the Behringer mic as well. These mics can be very noisy. Ignore the published specifications.

    Good luck
    John Stafford
  6. David French

    David French Well-Known Member

    Jun 19, 2002
    Is there an echo in here? ;)

    More like early reflections. :lol:
  7. Mr-Nice

    Mr-Nice Guest

    Is there and echo in here? :wink:

    More like early reflections. :D
  8. David French

    David French Well-Known Member

    Jun 19, 2002
  9. TeddyG

    TeddyG Well-Known Member

    Jan 20, 2005
    If you have a way of measuring noise with your recording software(A built-in analyzer, maybe?), you might also note "where" the noise is at. Is it, for instance, almost all "AC line noise", at around 50 or 60 hertz, depending on where you live? If so, you might try engaging a "rolloff" filter - at as high as 120 hertz(To cover first harmonics which can be strong) on ALL material i/o! Then see how much "overall" noise you have left... A UPS(Uninterruptible Power Supply) may help with this, too? Sad fact is that, for many of us, knocking the "all noise included" down to about -60 or -70 db may be the best we can do without spending some serious money - though this can be quite acceptable as with the mentioned filters the rest of the spectrum may be pretty clean. To get down to the -100 db noise level all the way through the chain, considering the recording environment and all equipment, is pretty tough...

    Other than that, even a slightly better sound card may help, for the moment, but you will soon want everything "balanced", etc., and again, it begins to get "pricey" fast...

    UPS(A nice one should help with many kinds of "noise")
    Good connections(Good cables don't have to cost much)
    A "real" sound card(Not built-in on the MB) - think $100+ US(Mine was $500 and I'm soon going $1000 - it never ends)
    Use 50/60 cycle filters on everything(Get used to it). Frankly, most MB sound devices and "consumer-type" sound cards "show" - 45 to 50 db because it's plenty good enough for most people, just like a 150 horsepower car is good enough(Or even too much) for most people.
    If you can, try to "go balanced", from sound card to pre's to speakers - everything. No RCA's and few TS cables, 1/4" minimum, XLR best.

  10. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    If you are going from your microphone, into a phantom power supply and then directly into a cheap soundcard input, go to RadioShaft and get yourself a cheap microphone transformer. XLR, female to quarter inch male and then an additional adapter, if necessary to 1/8". The transformer offers a winding ratio of 1: 10 which gives you approximately 10 DB of free gain! A passive preamp so to speak. You might also try to get away with running that into the cards line input, instead of the microphone input, gain permitting. Cheap audio cards microphone inputs are simply dreadful!
  11. xian

    xian Guest

    Wow, thanks everyone for the responses!

    Ya, I'm gonna have to say that the soundcard theory definitely checks out. I was checking noise levels and I found with nothing plugged into the sound card at all, I was getting up to -45dB of white noise depending on the gain settings on the soundcard software (ie, I'd boost the mic input levels and the noise would skyrocket).

    Also, I am connecting to the mic input on my soundcard, not the line input. Does this mean I am making up gain on the soundcard? Because that is the only way it seems to work. I guess then the phantom power box isn't a pre-amp? (I don't think it is).

    Thanks, I'll try these suggestions. For the uninterruptable power supply, you are talking about the PC's power supply, right? When you are shopping for a power supply, is UPS a spec that you can ask for or do I have to know something else? Also, I'm looking at going to a laptop soon, can I get a laptop with a UPS?

    This is probably a topic for another discussion, but what would you suggest for around $350?

    Thanks for all the input guys, I appreciate it. I'm looking at getting a Firewire I/O (the Onyx 400F is my top candidate right now). That should take care of the soundcard end of it, correct? I am still interested in knowing more about UPS' and laptops, if anyone has any info.

    I also have another totally newbie question. My acoustic guitar has an active pickup in it. So does that mean there is a pre-amp in the pickup? I assume that it does, so how would be the best way to record the guitar using this pickup? Line-in on the soundcard, or do I need like a Hi-Z input or whatever? Right now I've been plugging into the Mic input on the soundcard and the white noise hasn't been too bad (relatively speaking). Also, I'm not sure if anyone will know this, but my soundcard software has this "microphone boost" checkbox. Does anyone know what's happening here if I check that box. It gets louder, that's all I know (I wanna find out why).

    Thanks for you knowledge and patience,

    Forever confused :wink:

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