Room Noise

[ukejon]

For those of us who record at home, are there setup, recording, or mixing tricks to keeping ambient room noise out of the final mix? Among other things, I notice that if I aggressively pull down the EQ in the 100 hz range, some of the room noise goes away. What about other EQ techniques, limiting, mic isolation (Shure KSM 137 and Blue Baby Bottle), techniques of setting recording levels either high or low? All help here will be most appreciated.

[moon]

That's pretty low. What's the source of the noise?

[ukejon]

Possibly the rumble of the waves from Lake Michigan.

[Dr.Agave]

Originally Posted by ukejon

For those of us who record at home, are there setup, recording, or mixing tricks to keeping ambient room noise out of the final mix? Among other things, I notice that if I aggressively pull down the EQ in the 100 hz range, some of the room noise goes away. What about other EQ techniques, limiting, mic isolation (Shure KSM 137 and Blue Baby Bottle), techniques of setting recording levels either high or low? All help here will be most appreciated.

As you've discovered by aggressive use of equalization, you were able to reduce low frequency noise but at the expense of full bandwidth recording.

Your Shure microphone incorporates a high pass filter, engage it to reduce low frequency noise. Your Blue Baby Bottle does not have a high pass, but if your mixer or mic preamp includes a high pass filter you will achieve the same result.

The only other improvement you can make, short of remediation of the noise source or isolating your room from the noise, is to maximize the acoustical signal level by moving your microphone closer to your instrument.

This will improve the signal to noise ratio at the microphone. You will sacrifice some flexibility, and the positive benefits of using the room ambiance to enhance the sound, such is the trade off of recoding in non-idealized spaces.

[moon]

If wave noise is the source the sound should disappear in perfectly calm weather.

More likely to be a ground loop, I think: more info.

[Doug Young]

Noise is a tough problem. Adjusting recording levels won't help, and if it's the lake waves, it'll be hard to build enough sound isolation to help much. Not that it couldn't be done, but it would likely be pretty expensive. Floating floors, isolated walls, that kind of thing. But less drastic measures could cut out some of the higher frequency noise. There are many books on room acoustics for small studios. Just search on google or amazon.

But I'd start by working to identify your noise sources. You may think it's Lake Michigan, but it might actually be your refrigerator, or computer, or... Until you know exactly what the noise is, it's hard to know what to do about it.

The simplest thing you can do is improve your signal-to-noise ratio, the volume of your guitar relative to the noise. Try close micing, and also make sure you're playing as loud as makes sense. Hypercardiod mics have a tighter pattern which may help. Experiment with different rooms, different spots in the room, different orientations, to see if you can find a quieter setup. Just record the ambient noise and measure the level. The differences are likely to be subtle, but you may come up with something.

Cutting the frequencies below around 80 Hz (the general cut-off of your guitar in standard tuning) can help cut out rumble. For higher frequencies, there is noise reduction software. That's not an ideal solution, but some of them work very well, and can gain you some headroom. Compression, limiting, etc aren't going to help. If anything, they'll make the problem worse by raising softer sounds or reducing the loud sound (your guitar)

[ukejon]

Thanks to you both. I'll look into that ground noise issue. For now, I'm running the two mics into an Apogee Duet 2, which in turn goes into my MacBook, which is plugged into the wall. So would my mic cables possible be a problem?

Also, played around a bit with AU Hi Pass Filter in GarageBand. Pretty good trick. Since I record a lot of solo uke instrumentals, that seems like a very useful tool.

But I will say that the Lake rarely is quiet and that is a lot of water and waves to make noise....like a train going by in the distance.

[Doug Young]

Originally Posted by ukejon

But I will say that the Lake rarely is quiet and that is a lot of water and waves to make noise....like a train going by in the distance.

A lot of people who live in noisy environments just have to accept that they can't record there. You can't convince the lake to move or stop making waves. You can record demos and work on material at your place, ignoring the noise. Then find a friend or relative who lives in a quiet area who will let you visit for a weekend for serious recording. Or rent a weekend house out in the country. Or go to a pro studio when you want a serious track.

[Dr.Agave]

Originally Posted by moon

If wave noise is the source the sound should disappear in perfectly calm weather.

More likely to be a ground loop, I think: more info.

How do you get to "ground loops" as cause when the OP identifies acoustical noise as the issue?

Second clue is that he is recording with microphones as opposed to direct, thus no ground loop path.

[moon]

I thought Ukejon wasn't sure what the source of the noise is. Personally, I'd be surprised if wave noise would create a low frequency rumble, unless you had big waves of several tons in weight crashing on the shore in a storm. I could be wrong - ukejon said it sounds like a train and of course he knows best.

If you can rule out all acoustic sources all that's left is the electronics, although you're right it is a simple Duet & laptop setup, as we learned later.

[ukejon]

Doug, I've toyed around with SoundSoap. Can't really make sense of the software and if you go too far the track gets quacky sounding. My Blue is definitely more boomy and mid-rangy than the Shure, so when not playing there is more deep breathing in the ambient room noise (if that makes any sense). The Shure with the Hi Pass on cuts that out. I also have a Shure Beta 57A, which is super cardioid. Can that be of any use. If you visit my website, that is the type of home recording solo instrumental that I'm doing (just a middle aged guy with an uke...although a lovely Zimnicki piccolo guitar is on the way).

[Doug Young]

Originally Posted by ukejon

Doug, I've toyed around with SoundSoap. Can't really make sense of the software and if you go too far the track gets quacky sounding.

I never had much luck with SoundSoap, you probably need something a little more serious. If you post a track segment (or send it to me), I can try to do some noise reduction on it, and people may also be able to make more on-target suggestions. Ideally, leave some quiet space on the record without any music, so we can hear just the noise.

[ukejon]

Doug, just sent a small mp3 file to the email address on your website. Thanks for taking a listen to this. I'm no pro, but anything that will help emphasize the instruments and de-emphasize the other crap is desirable.

[redavide]

I just listened to your Theme from Love Story on Youtube (BTW, very nice) -- and cranking it up at very high volume, I can't hear trains, waves, hums or anything else in the background . . . Sounds very clean and quiet.

At least on Youtube . . . Do you publish it anywhere else?

[ukejon]

Thanks. That recording is much quieter. I'm beginning to wonder if the sound from the large gas flame boilers (furnaces) in the basement travel up to the 2nd floor. They can be pretty loud. This is an old house with radiator heat and I presume sound can travel in all sorts of weird ways. There is another similar building nearby and I just went over and could hear the low rumble of the boilers on the 1st and 2nd floors. Maybe as a rule they should be turned off.

And let me also add that this continues to be just a fantastic site. Where else can one go to get such specific and well considered advice so quickly? I really appreciate this place.

....and I also will say as a bit of a plug here that the Apogee Duet 2 is stunningly well designed. Easy to use, indeed completely intuitive, and the sound quality is much more sensitive and interesting than my old M Audio Fast Track Pro.