How to eliminate background noise while recording

stanfan · #1 10-23-2009, 03:53 AM

Hello everyone,

Here's my situation......I have a Boss BR1200 set up in an unused bedroom of my house. I tried recording last night and though the recording quality of the guitar was ok (still have to experiment with mic placment), but when played back, I could hear background noise. Is there any cheap/practical ways of trying to soundproof the area. I'm using Apex 2021 mics to record with.

Thanks,

Rob

Bob Womack · #2 10-23-2009, 05:39 AM

Not having heard your recording, I can only guess. Here are some of the main sources of BG noise:

1. A/C heat. Shut it down when recording if need be.
2. Incorrectly set signal chain. This causes self noise that sounds like white noise. Read your recorder's manual and learn how to set the preamps for lowest noise.
3. Setting your mics to far from your source. The closer the mic, the less room noise. This is a trade-off with the sound you are attempting to get.
4. Home noise. Record at quiet times at your house.

There are other things you can do to reduce high and mid frequency external noise from bleeding in. Low freq bleed is an expensive proposition. The first to try are pulling in your mics closer to the instruments and turning off the A/C.

Have fun,

Bob

Michael Watts · #3 10-23-2009, 06:23 AM

What mic/s are you using, are they omni or directional? How far from the guitar are they? What's the noise you're picking up? Is your room treated at all?

We'll get to the bottom of this!

stanfan · #4 10-24-2009, 05:36 AM

Thanks for the replies....

I'm using an Audio Technica AT2020 Cardioid condenser for vocals and blending between the AT2020 and an AT2021 small diaphragm for instruments.

I'm recording in a spare bedroom, carpeted floors, gyproced walls, approx
10 X10, mics are in center of the room.

Thanks again,

Rob

Bob1131 · #5 10-24-2009, 07:29 AM

Rob, that is good advice from Bob Womack, and based on your equipment description, I suspect the noise you are getting is due to your recording chain settings. I use a BR864 which I think operates the same as the BR1200. If so, there are dozens of input settings and you can adjust input gain for mics, line-in and guitar input. Some of the input settings will include compression that also provides a sound threshold gate. Find one of those settings and adjust the input gain downward until your level bars drop off completely when you are not playing or singing. This will push room and house noise well below the level of your instruments and vocals. In other words, the "gate" effectively turns off your mike until there is a sound loud enough to be recorded. You may have to raise the master volume on the unit to compensate for the lower gain on the input, but the result is clear, quiet recordings.

The BR864 doesn't have phantom power, so I use a separate mixer with good preamps and phantom power before the Boss recorder. Consequently, I use the "line" inputs on the recorder and often make use of a setting that is titled "Tight EQ." That setting provides a fairly high threshold gate, compression and a limiter (which prevents over-driving the track). I use this setting mostly for background vocals because it allows no noise and assures a constant volume on the vocals which then makes them easier to mix/blend.

I hope this helps!

ljguitar · #6 10-25-2009, 03:01 PM

Quote:

Originally Posted by stanfan

...I have a Boss BR1200 set up in an unused bedroom of my house. I tried recording last night and though the recording quality of the guitar was ok (still have to experiment with mic placment), but when played back, I could hear background noise. Is there any cheap/practical ways of trying to soundproof the area. I'm using Apex 2021 mics to record with.

Hi Rob...
Make sure you are turning the gain up to an appropriate level while recording (not so far you overdrive channels, but a good solid signal), or you will magnify the room noise while turning the recordings up to useful listening levels.

Fran Guidry · #7 10-25-2009, 06:50 PM

Quote:

Originally Posted by ljguitar

Hi Rob...
Make sure you are turning the gain up to an appropriate level while recording (not so far you overdrive channels, but a good solid signal), or you will magnify the room noise while turning the recordings up to useful listening levels.

Larry, are you suggesting that raising the preamp gain will raise signal without raising background noise?

Let's remember, gain is gain, and sensitivity is more of the same. To the mic and preamp and converters and hard disk bits the sound of the guitar is exactly the same as the sound of the refrigerator, the passing motorcycle, and the squeak of our chair. Using a more sensitive mic, or turning up the preamp, or turning up the playback gain will raise both the signal and the noise equally.

And the background noise in most home recording environments is a _LOT_ louder than the hiss from most preamps, even when the preamp is being abused. In my experience it's very common to mistake the amplified ambient noise (room tone, some call it) for preamp hiss when we crank the gain.

This is why home recording is hard. Mic pattern and position are about the only tools we have for improving the signal to noise ratio, and changing either of these changes the recorded sound. We're searching for that perfect position that optimizes both as well as possible.

Fran

Doug Young · #8 10-25-2009, 07:12 PM

Quote:

Originally Posted by Fran Guidry

Let's remember, gain is gain, and sensitivity is more of the same.

Yeah, my experience is the same as Fran's. if you have a noisy component somewhere, it may be different, but most electronics these days are pretty quiet. I've had people recommend "proper gain staging" as a way to reduce noise, and I've yet to figure out any setting of my various gain controls that makes the slightest difference, and I've done a lot of measuring. My noise is coming #1 from my environment, and to a lesser degree, self-noise from mics, so any gain I use anywhere in the path is going to amplify those. The only only way to reduce it is to shut off any household things that are making noise, and mic closer, or play louder.

Rob, if you posted a sample of the sound you're getting, people could probably make more focused suggestions.

ljguitar · #9 10-25-2009, 08:01 PM

Quote:

Originally Posted by Fran Guidry

Larry, are you suggesting that raising the preamp gain will raise signal without raising background noise?

Hi Fran...
I think I was thinking that it might be equipment noise being boosted, not room, furnace, house or street noise...

I was thinking that if I don't get the input setting ''hot'' enough when I record, when I raise the level of the recording for decent output levels, the noise from the equipment itself (no equipment is totally quiet) combined with any self-noise of the mic(s) will go up to quite audible levels...

I just know recordings made where I don't set the preamp levels hot enough are slightly noisier than when I do. If it were not the case, then we'd just record at half volume and boost everything later to be sure we didn't overdrive recordings wouldn't we?

Bob1131 · #10 10-26-2009, 03:36 PM

Larry,

If the OP is plugging directly into the Boss BR1200, then he is not using a preamp. The input gain of the BR works in concert with a multitude of presets, so a lower setting on the input gate will be needed to assure a low gate threshold. If the setting is too high, then the gate will stay open allowing room noise to enter the recording chain when there is no other sound. Set properly with an appropriate preset model, the gate will not allow sound to enter the recording chain until a certain dB is exceeded. This doesn't eliminate room noise, but prevents it from being recorded in pauses in the music, thus yielding a quieter sounding recording. There are other controls on the unit to adjust the recording level, so the "input gain" on a BR1200 does not function the same as the gain on a preamp or mixer.

ljguitar · #11 10-26-2009, 04:44 PM

Quote:

Originally Posted by Bob1131

Larry,

If the OP is plugging directly into the Boss BR1200, then he is not using a preamp. The input gain of the BR works in concert with a multitude of presets, so a lower setting on the input gate will be needed to assure a low gate threshold. If the setting is too high, then the gate will stay open allowing room noise to enter the recording chain when there is no other sound. Set properly with an appropriate preset model, the gate will not allow sound to enter the recording chain until a certain dB is exceeded. This doesn't eliminate room noise, but prevents it from being recorded in pauses in the music, thus yielding a quieter sounding recording. There are other controls on the unit to adjust the recording level, so the "input gain" on a BR1200 does not function the same as the gain on a preamp or mixer.

Hi Bob...
So the inputs on the BR1200 don't have preamps connected to them internally?

Actually, I thought we are just brain storming possible sources of background noise and I'd still like to hear the original recording...without it it's hard to tell if it's equipment, room, or or a combination of sources.

Steev · #12 10-26-2009, 09:13 PM

Hi stanfan

The close micing that everyone is referring to is probably the easiest way to improve your sound in a domestic room.
The Inverse Square Law comes into play, which means that for every halving of the distance between the mic and the sound source, the gain is doubled.
For example; If you were recording at 2 feet away from your guitar and moved to one foot away...
The guitar will now be twice as loud as before but the room tone (ambient noise) will be the same, so therefore proportionately softer.
You may get to a point where the guitar is too loud and now have to reduce the input gain which means you're reducing the room tone even more!
It's not the same as recording in a great acoustic space but you can add reverb to your mix later.

Bob1131 · #13 10-27-2009, 12:54 PM

Quote:

Originally Posted by ljguitar

Hi Bob...
So the inputs on the BR1200 don't have preamps connected to them internally?

Actually, I thought we are just brain storming possible sources of background noise and I'd still like to hear the original recording...without it it's hard to tell if it's equipment, room, or or a combination of sources.

Larry, I suppose it must have some sort of preamp, but it is integrated with the presets, so the input control doesn't function as you would expect for just a preamp.

Yep, just brain-storming...didn't mean to offend...I was just trying to explain how the BR1200 functions. If the OP sets the input gain high on that unit, he will pick up an ant's breath on the other side of his house, depending on his mic and the preset he chooses! That's just the way that unit works. That's why I suspect the noise he is getting has a lot to do with his set up. Of course, I too would like to hear the recording to know for sure.

ljguitar · #14 10-27-2009, 02:58 PM

Quote:

Originally Posted by Bob1131

......didn't mean to offend...
...Of course, I too would like to hear the recording to know for sure.

Hi Bob...
You surely didn't offend me.

I think we were (are) just tossing out ideas for the original poster to consider, and discard or apply to see if he can get the pesky background noise under control.

sharkydude50 · #15 10-29-2009, 01:44 PM

Off the top of me old head you can:

-Put a towel under the door to cut down on hallway/house noise, cover/fill gaps around the door
-Get some of those foam acoustical panels to put up on the walls
-Tack/nail up a large beach towel over your windows/ check windows for rattles and seal. Deaden any window/glass pane vibration
-Record during more "quiet" times of the day/night (less outdoor activity & noise)
-Don't use florescent lighting

When I used to record my guitar using a camcorder and it's mounted mic I would wrap the whole unit in a towel during recordings. I was really suprised how much less camera/tape noise I got by doing that, maybe 30-50% less noise!

Best of luck recording