Noisy Mic Preamp

[DanLuedke]

I'm having trouble making quality acoustic guitar recordings. Here is an example:

https://soundcloud.com/dansguitarstudio ... li/s-nLk3B

Too much noise in the background. I believe I have isolated the problem to the mic preamp on my M Audio Fast Track Pro because the noise is there whether a mic is plugged into the input or not and the noise rises and falls when I adjust the gain. All the advice I find online says I am recording with the gain too high. This advice doesn't make sense to me because if I turn the gain down my guitar gets turned down too so that I need to turn the track up after recording and then the noise is there again (ie. the noise is still just as loud relative to my signal level).

I decided to compare the noise level of my interface to those of my friends with cheap interfaces. Their interfaces were just as loud, which makes me think I am doing something wrong while tracking. I use general purpose dynamic mics such as SM57 and SM58. It's tough to get a good signal level without sticking them right up to my soundhole and nearly ripping the strings off as I play. Do I need to be using a different kind of mic? A lot of what I record is more delicate fingerstyle guitar.

Thanks for reading. All advice is appreciated!

[teleblaster]

First of all, great playing. I love the interpretation and execution of this piece. I would think this would be a shoe-in for the classical guitar listing right now.

I do hear the noise you're talking about. How much compression do you have on the track, parallel busses or the master buss? Remove them and see what you wind up with. I have some compressors that work better with acoustic guitar than others -- you might want to try using different ones. Maybe try using a limiter instead of a comp. Limiters shouldn't raise the noise floor like a comp does.

Nylon string guitar is a really delicate instrument to track and produce. It all starts with getting the cleanest signal your gear can produce. I recommend turning off all compression/limiting and play with the gain stage of your pre-amp until you get the cleanest signal to disc. Also, make sure there's no ambient noise in the environment, PC fans, AC/heat etc. Unlike a typical pop/rock mix these tracks decay down to the noise floor frequently and you're gonna hear everything; especially with a compressor in the mix. Once you've done that, then use comp/limiting and EQ gingerly to taste.

You might also want to consider getting a condensor mic at some point. I used the Gauge ECM-87 for this piece : http://www.reverbnation.com/aerichgrube ... ensitivity. I think they capture the ACgit really well.

HTH,

[Len911]

It does make sense to turn the gain down on the preamp for less noise. Your dilemma is that you have a dynamic mic, not as much output as a condensor, though more than a passive ribbon mic. The cheapest solution imo seems to be something like the ~$150 Cloudlifter http://www.soundonsound.com/sos/nov11/a ... lifter.htm

Tubes might give you the gain, but they are usually noisy, so I'd steer clear of tube preamps and tube mics in general.

You could also shop for a clean preamp, good condensor mic, the uber clean solution is probably the Neumann D mics, they have an onboard a/d converter that don't use a preamp but interface by an aes or s/pdif digital connection. The TLM 103D is nearly $1700 I believe, but that is about par with buying a good preamp and microphone.

[DanLuedke]

Teleblaster, thanks for the compliments. I enjoyed listening to several tracks on your page. The ECM-87 sounds great! So does your playing! My track and several others of mine have been returned for sounding 'too live'. The screeners seemed to indicate they would otherwise be forwards for Solo Classical Guitar listings. I would have loved to submit to the most recent one but I need to solve this noise problem before I waste any more time tracking sub-par recordings.

Len, thanks so much for directing me to the Cloudlifter. After doing some research it seems like the perfect solution. I'm going to get the CL2 next time I see a sale at GC or other dealer. Eventually, I would love to have a Neumann D or a similar high quality set up but that will have to wait until my budget can afford it.

[teleblaster]

I highly recommend the Gauge if you do a lot of acoustic guitar. I'm not aware of an LDC mic in that price range that matches it, let alone betters it for that application. I use it alone, about 12" from the center of the guitar, or about 12" from the lower bout in tandem with a Sure SM-81 pointing at the 12th fret and blend and pan them to taste.

You're in a good place when you have great performances and need to work on your recording quality. That's an easier fix than the other way around. Best of luck to you.

[DanLuedke]

Thanks again, Teleblaster! I have officially put the ECM-87 on my wishlist as my first condenser mic.

[andygabrys]

Thanks again, Teleblaster! I have officially put the ECM-87 on my wishlist as my first condenser mic.

can't go wrong. I also have an ECM-87 and its pretty decent and relatively noiseless. And they sell it for a discount at the Rally if you are going to be there anyways.

I agree that if you had the "magic bullet" mic and needed more gain, the Cloudlifter would be awesome. Maybe if you had an old ribbon that had just a sweet sweet sound. I think in your case, you could use a little extra detail in the midrange and top as well without having to eq it in (which exacerbates noise as well). So a condenser would be a nice addition. If you have some sound absorbing panels, you can place them on the back side of the mix as well when recording to try and cut down on some of the "room" sound if that's an issue, or have a fridge or computer fan working away in the background too.

also if you are doing a lot of classical recording and you find noise is a problem, blending some of this in can help: http://www.lrbaggs.com/lyric-classical - depending on your guitar it will be more or less boxy sounding, but its a nice compliment to an external mic, and has little to none of any of the "clank" that you find with a piezo pickup as this is a mic, not a pickup in the usual sense. In addition a little subtractive eq can sweeten it up quite a bit.

If you already have a piezo in your guitar re-fitting this one is an easy deal, if not, you have to DRILLLLLLLLLL. anyways. I have one and enjoy it.

If you have a bunch of recordings done, you might also send them to somebody who has Waves X-noise or the similar plugins that are available from other companies - plugins that take a noise print. I have had good results using stuff like that mixing acoustic music with a lot of noise (i.e. brooklyn apartment adjacent to the BQE) in ambient / distant / room mics.

Nice playing too! (and you too Erich - checked out your page).

[DanLuedke]

Golden advice as usual, Andy.

I didn't know the ECM-87 is discounted at the Rally. I will consider picking one up when I'm there this year. Great tip with the absorbing panels. Currently, my room noise is inaudible compared to the mic preamp hiss so I'm addressing the hiss problem first. Yesterday, I sold an inexpensive 12-string to raise funds for a Cloudlifter which is in the mail. Maybe I will post a comparison track when it arrives.

The lyric classical mic is an intriguing product. I have never seen anything like it before. First I need a guitar that I am willing to drill into but is also worth recording. My guitars are all one or the other right now. That Omar Torrez guy blew my mind though.

If anybody wants to try using a noise reduction plugin on my track, let me know! It could make a fun third comparison.