What's an "average" db for mic line noise?

[kaelinsanity]

I'm just setting up to record and I'm annoyed by noise on my mic lines. Even in a silent (not soundproof) room, my software reports -60db anytime I activate a mic line. Is this normal?

My gains are at 0... both software and hardware, and I'm using a fairly inexpensive at2020 mic----though even with a totally cheap radio shack mic, I get the same levels of noise. I have a SoundBlaster X-Fi sound card.

So again, am I complaining about nothing or should I be getting less noise? What might I do to lower these levels if they are too high?

Thanks

 

[Tifstorey]

Could be quite a number of things, but i'd say your best bet is to use a different cable? If it's damaged, it would create a lot of noise.

 

[mixsit]

It could be mostly the ambient noise level but it would depend on how mic sensitivity, amp gain and a/d sensitivity stack up. Some pres have min gain of 10-15, my RME a/d has three input gain choices for example. (What is the spl of a "quiet" ie not sound proof room?) Also, consider where -60 is relative to what you'd record where those gain settings get you a nominal record level.
Try it with the mic boxed up completely muffled (maybe with w/o the low cut) and w/o the mic plugged in -just eclectrical and a/d noise.

 

[TimN]

I was going to say get another sound card, but -60 db? That's actually
pretty good for home recording. Unless you're recording some very quiet
vocals a capella, try not to worry about it--you'll never hear any noise
with everything else going on, even if the "everything else" is just an acoustic
guitar. By using wave editing (that is, precise elimination of the waveform you don't need), noise can be effectively dealt with.
You still might want to get another sound card, though. The X-fi is more suited for movies and gaming. Also, try isolating
yourself and the mic from the computer, which can get very noisy.

 

[Farview]

Soundblasters are not recording cards. They are gaming cards. While you aren't getting that much noise, the noise you are getting is coming from that card.

Any of the m-audio cards that are the same price (or cheaper) will give you at least 10 or 12db better noise figures. Once you get down to -70db noise, you will have to do a significant upgrade to get much better.


BTW the AT 2020 is one of the cheapest condenser mics out there. It can be had for cheaper than the list price of an SM57.

 

[kaelinsanity]

Thanks for all your responses. I was able to get the line noise down to -80db avg for all three mic inputs (actually using an X-Fi I/O upgrade box but didn't think to mention it). It seems that I needed to throw in Hi Z transformers on the mic lines. The ASIO drivers from creative(SoundBlaster) list the two of the inputs as Mic/line and a the third as Hi-Z/line, so I assumed that the mic inputs were low Z. We all know what happens when you assume. In this case, line noise. So, now I get the importance of impedance matching. Any other comments/advice are welcome and appreciated, though for now I'm satisfied with the amount of line noise vs. the input signal strength, everything seems to be working well.

 

[pandamonk]

I'm just setting up to record and I'm annoyed by noise on my mic lines. Even in a silent (not soundproof) room, my software reports -60db anytime I activate a mic line. Is this normal?

My gains are at 0... both software and hardware, and I'm using a fairly inexpensive at2020 mic----though even with a totally cheap radio shack mic, I get the same levels of noise. I have a SoundBlaster X-Fi sound card.

So again, am I complaining about nothing or should I be getting less noise? What might I do to lower these levels if they are too high?

Thanks

How is everything connected?

Edit: Ohh you got it sorted.