Room Noise

[Doug Young]

Originally Posted by 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.

Got it. You know, this noise isn't terrible for a home environment. If you EQ the low end and trim the head and tail, most people probably won't notice. But there are some interesting things about the noise. Your noise floor on the right channel is -62db, pretty good! The left side is -47db. Not so good, and a whopping 15db louder. Most of that is extreme low end, below 60-70 Hz. There's a nice drop off below 70 on the right channel. So what's up with that? No idea, but it's worth exploring. Bad mic, bad mic cord, noisy channel on the duet? Mic without a shock mount? Here's a spectrum of just a noise sample:



For what it's worth, this doesn't sound like Lake Michigan to me :-) Sounds like air conditioning or a furnace, so you may be onto something with the boiler. Or it could be your computer. I often shut things off, even the refrigerator, when recording something I want clean. I just throw all the breakers that don't affect my room, and hope no one else is the house cares, or is around!

But the fact that the noise is so much louder, and has a different frequency characteristics, on one channel is a clue that this may not be all environmental noise.

In any case, here's what iZotope RX can do with your track. I just took a few seconds, including a few seconds of silence. The 1st 7-8 seconds here are your original, then it repeats, but this time processed with iZotope's noise reduction. This is a training system - you give it a sample of the noise, it learns it, then removes it from the whole track. only really works with constant noise, which you pretty much have here.

http://www.dougyoungguitar.com/mp3/J...Test_short.mp3

[alohachris]

Aloha Ukejon,

Please describe your current Room Treatment.

I live at 1,900' on the side of a mountain rainforest & never close my windows. There is a fair amount of steady trade winds flowing through the house.

By strategically placing Fran Guidry's homemade OC 703 & 705 gobo panels around & above my tracking area, I can create "rooms & booths" within my recording space. This eliminates unwanted room, wind, rain, refrigerator, jet or bird song sounds, etc. & is cost-effective. They allow me to control the frequencies of the music AND the environment - without changing the house permanently.

I've made 22 of these free-standing, DIY, storable & portable broadband absorbers. You don't really need that many. I may have shared these links previously with you (sorry if I have). These gobos really work & may help your situation with a non-electronic solution, beyond switching to hypercardioids, adding another plug-in or going to the studio:

http://www.homebrewedmusic.com/2011/...adband-panels/

http://www.homebrewedmusic.com/2009/...-on-the-cheap/

Additionally, you should probably go around the room & disconnect & reconnect every electrical connection in the room just to be sure the noise source is not from something obvious.

Of course, you could always use the natural sound of the waves (if that's the noise source) to your advantage, say, the way Donovan did on his lovely Scottish folk song album, "For Little Ones" a million years ago.

Good Luck, Ukejon!

alohachris

[rick-slo]

Sounds like in the room noise, computer, etc, one mike pointed more directly at it. A little closer mic'ing with less amp gain may held as well as a high pass filter post recording.

[ukejon]

Great info, Doug. The Izotope did clean things up nicely. As for the left channel, well that is the Blue mic which is in its shock mount. When not playing the instrument, I can hear that the mic takes in much more of a boomy or mid heavy sound from the room. Nice piece of equipment but definitely needs some EQ cut to bring down those unwanted sounds, which then brings it into balance a bit more I presume. Here is another thing to consider: I've heard that while it is a very low noise mic, the Baby Bottle has bad rear rejection. So even though it is inside of an Voxguard Primacoustic screen, that deficiency still may be a part of my problem. Certainly I can just record with the Shure KSM 137 or maybe I would benefit from a different second mic (the Beta 57 presumably is not a good option?). Do you put a lot of stock in getting higher end mic chords, such as Mogami? Mine are nothing special.

Chris, greeting and thanks as well. If I combine two 6ft tall wood frame with painted canvas screens (Chinese) folding panels one behind the other behind the Primacoustic, do you think that will handle reflections adequately? Not ideal to be sure, but just curious. By the way, I gotta learn me some of that slack key playing....that is sweet!

[Doug Young]

Originally Posted by ukejon

Do you put a lot of stock in getting higher end mic chords, such as Mogami? Mine are nothing special.

Unless there's an actual problem with the mic cord, I doubt you'll hear any difference. The mic probably explains the difference in noise. Interestly, the only mics I've every had that were so noisy I couldn't use them were Blue mics. I haven't tried a bottle, tho,and I know they have a good reputation.

Using similar mics often creates a nicer stereo image (tho anything is fair game)

I don't really hear any issue with respect to room acoustics, for what it's worth. Your sound seems very nice, just need to get rid of the noise, and low end EQ will handle most of it. You can always improve room acoustics, and every little thing helps, but right now the main thing to address is the noise.

[ukejon]

Have you ever incorporated a Beta 57 into your mix or is that just not up to grade in terms of its clarity or neutrality? By the way, I'll get the Izotope. Used to use their mastering suite (Ozone 3) but found I didn't really need all that they offered. Made it a touch too complicated. Great idea, however.

[Doug Young]

Originally Posted by ukejon

Have you ever incorporated a Beta 57 into your mix or is that just not up to grade in terms of its clarity or neutrality? .

I haven't used a dynamic mic in ages, but you never know. It might sound great on a uke! Give it a try.

[ukejon]

Will do. I think the Baby Bottle may be a trade in......

Appreciate the help from all of you.

[alohachris]

Aloha Ukejon,

I agree with Doug that taming the electronic noise issue is the first order of business here. If it is environmental, the absorbers WILL help tame that, but not electronic noise.

I also like the way Doug & others have been inventory-ing possible causes for the noise, including the obvious such as using matched mic's.

I'm big on that one, Uke. Although many recordings are made mixing/matching mic types & brands these days, for home recordists, I still think that using a matched pair is the way to go. It eliminates many problems. It's all about control & phasing issues, & things like the very different levels I hear on your fine recording of classical music using the Blue & Shure LDC's together.

In fact, I'd even try recording with one of those mic's alone, Uke. Perhaps the noise issue will make itself clearer doing that. I only use matched pairs of mic's on acoustic instruments - usually one SDC pair, but sometimes I add an LDC pair a bit farther out in a spaced pair for some room.

Although I suffer from inconsistent performance & tracking, I don't have the kinds of problems I think you are experiencing by using those two different mics. Again, the level on that lovely piece you shared is much stronger on the right channel - an example of the issue I suspect.

AND DON'T RECORD W/THE BETA 57 DYNAMIC! The ukulele's small box has enough difficulty translating its subtle overtones & complexities to recording. Why use a less sensitive dynamic? I'd try using the 137 alone on the uke, first.

RE: Treatment? In less than ideal recording spaces, I think you need to surround your tracking area with something like the gobos I mentioned & also above where you play. I don't think it's enough to treat just the area in front of the mic. The reflective walls & area behind the player is just as important.

For my basic setup using those gobos, I place two on each side of me (not always in parallel), 2-4 in front & 2-4 behind me. I also add two more from above hanging from the open ceiling rafters. That controls the reflections around my tracking space. The SPL meter readings bear that out.

BTW, tha's a vert nice Koa uke, Uke. Who made it?

RE: Cables. Jake swears by his $300 Analysis Plus cable. And I did hear a subtle difference on a vocal mic using that cable once. However, if you stick with good affordable cables, like Planet Waves or better such as Canare/Neutrik & Mogami, you'll at least take that question of quality out of your thinking, right?

Yeah, Uncle Fran really plays that real nice nahe' nahe' slack key well, doesn't he?

Here's another:

http://www.youtube.com/watch?v=9eppkvikTIc

Good Luck, Ukejon

alohachris

[RustyAxe]

Originally Posted by Doug Young

A lot of people who live in noisy environments just have to accept that they can't record there.

That's my world. I live in a small city, on a rather busy street. Traffic noise is incessant. I do just as you say, demos and working out ideas, but am at a loss for the final recording. I hadn't thought of renting a country house ... or perhaps one of my wealthier friends might let me use theirs for a few days. Worth a shot.

[ukejon]

Thanks for the advice, Chris. I'll keep it simple and learn to love a single KSM 137. As for the uke, it is a custom KoaWorks tenor made by Rich Godfrey in Kane'oe, HI. I own two....his ukes are unreal. This one has the darkest koa you've ever seen, which give it a really rich, darker sound.

Sean has one for sale: http://web.me.com/syacavone/Site/Koa...%EF%BC%89.html

[ukejon]

RE: Treatment? In less than ideal recording spaces, I think you need to surround your tracking area with something like the gobos I mentioned & also above where you play. I don't think it's enough to treat just the area in front of the mic. The reflective walls & area behind the player is just as important.

For my basic setup using those gobos, I place two on each side of me (not always in parallel), 2-4 in front & 2-4 behind me. I also add two more from above hanging from the open ceiling rafters. That controls the reflections around my tracking space. The SPL meter readings bear that out.

Chris, at Home Depot I can buy $7 packs of EPS foam boards 4' x 3/4" x 18". They come six to a pack and when still shrink-wrapped they form nice, freestanding panels. I realize these may not be ideal but having four or six of these to play with in addition to my Primacoustic Voxguard may really help. Question: if I cover these with fabric can I leave the shrink-wrap on underneath? Holds them all together nicely and also may reduce some offgassing. I'm also going to take my nice 4' x 8' oriental carpet off of the wooden floor underneath my chair and maybe hang it on the wall behind me.

[moon]

I don't think rugs or polystyrene foam will help much. High-density mineral wool is what you really need, such as something from Knauf or Owens corning. Even then, they won't absorb low frequencies well unless they're incorporated into some kind of bass trap design, which can be as simple as an air gap behind the panel.

Here's a test you can try to get an idea what your room is like.

[Doug Young]

Here's a chart that shows how different materials absorb sound at different frequencies (1.00 would be no sound coming back). They don't have any foam boards like you're talking about, but I think you'd find the values for it are very low, and essentially 0 at lower frequencies, which tend to matter the most. A quick scan of this table will show you why everyone recommends fiberglass:

http://www.sae.edu/reference_materia...nt%20Chart.htm

[Brent Hutto]

Thank you for posting that test, Moon. I'm looking forward to running it in my music room, although I already know it's bad. Real bad, probably. Especially the main mode it has around 120-125Hz that is just brutal. But those tests will give me an idea of the more subtle things going on.