Will I get phase issues...

TelePaul

...if I 'stereo' mic an acoustic at the bridge and 12th fret with two SDCs and then back a LDC off a few feet for some ambience?

ogy

you can just make sure theyre phase aligned by recording a little and then zoomng in on the waveforms and checking. set up one mic where you want it, then phase align the other two by doing this. the one a few feet back will obviously get the waveform later, but just make sure the peaks and troughs line up, not neccesarily the first peak with the first peak etc but just so that the ups and downs are aligned. if you want to you can move the track afterwards so that they do line up perfectly but there are arguments for and against this.

trackmixstudio

Get somebody to play the guitar while you move the distant mic back and forth with phase reverse switched in. When the signal is most out of phase flip the phase back and you should be ok. It is easier (for me) to check out of phase than in phase so reversing one of the mics makes it fairly easy.

teamdresch

With all due respect, you are better off moving mics with reference to your ears than a waveform on a computer screen.

TelePaul

trackmixstudio wrote: »

Get somebody to play the guitar while you move the distant mic back and forth with phase reverse switched in. When the signal is most out of phase flip the phase back and you should be ok. It is easier (for me) to check out of phase than in phase so reversing one of the mics makes it fairly easy.

Hi. Thanks for this but I don't have a phase reverse button on the mic or channel strip.

Dravokivich

if you have a spare lead or some small peice of cabling/ spare connections you can just have the polarity reversed at 1 end. that should do the same thing.

ogy

so lets talk about phase!

heres my understanding of things:

1 - its important to get all mics your using phase coherent (obviously)
2 - you should be able to hear when stuff is out of phase, but to make sure you can record little bits and check by zooming in on the waveform. if mics are at different distances, obviously the peaks and troughs your lining up aren't gonna be the same ones, you just aim for the least phase cancellation possible. is this really accurate, can cubase/protools be trusted?:) are there any other methods to check phase?
3 - you shouldn't line up waveforms after the event because your only lining up certain frequencies, not others, as they all have different times of arrival etc. so you could be causing more phase issues than your solving. however a lot of people (on the interwebs:)) seem to disagree with this.

discuss!:)

fitz

Might be slightly off topic, but why the need for so much micing?
I've been in a position where a lot of time was put into stereo micing my acoustic, with 4 mics recording at a given time, the primary pair of which were AKG 414s, but the pres being used weren't great at all.

I've since recorded the same guitar with a single Neumann TLM103 into a UA Solo610, and got fantastic results that outstrip the complicated techniques I was exposed to before. I suppose what I'm getting at is this: are you using multiple mics to try and get a quality of sound you're not getting from a single mic because of the mic/pre/guitar being used? If that's the case, you might be wasting your time and energy.

I'm not being gear snobby here...if you are having issues, it could simply be a matter of changing what strings/gauge are being used, or trying to record in a different room...

madtheory

+1 on on changing the strings/ guitar/ room/ guitarist

TelePaul wrote: »

Hi. Thanks for this but I don't have a phase reverse button on the mic or channel strip.

It's a very clever way to get the mics in phase, or to at least get the phasing to sound nice, which is probably better . Don't you have polarity inversion (correct term!) available in your DAW?

I agree that there's probably too many mics. Unless it's a really fabulous sounding room and/ or a guitar soloist, it's never useful to mic the room for an acoustic guitar. So to contradict myself, the room should be miked in stereo... or faked into stereo with a delay or WHY.

Personally, I prefer an XY pair on acoustic guitar rather than a single mic, about a foot away. It's far easier to catch the guitars sweet spot in stereo than with one mic. It's much easier to get a stereo guitar to sit well in the mix than a mono one, IMO. The ear likes space.

Although I do like the mock stereo of multi tracked mono acoustic rhythm guitars with different chord inversions, and Nashville tuning thrown in too

Seziertisch

I would say 3 mics is asking for trouble, unless you have an extraordinary space to record in. That said you could maybe try m/s instead of just a straight stereo pair and see what it does for you. If time is an issue and there is other stuff that needs to be recorded the same day then just go with one mic.

TelePaul

Hello all, thanks for the replies. Perhaps I should offer up some more info.

AFAIK, Cubase SE3 allows for phase reversing, but not in real time or as a real-time plug-in; you can process a track after it's been recorded but not on the way in.

As for the mics, I'm using a matched pair of Naiant MSH2s about 6 inches out, one aimed at 12th fret, one aimed at the bridge but find myself running the pre-amps quite hot to peak at -18dbs.

When I play back the recorded sound unprocessed it does sound quite weak...seems most of the body is missing from the guitar, that big resonant sound (Martin D15, Mahogany, solid top/back/sides). New strings, .50mm pick...

It's just a few open chords, very strummy. Any thoughts?

fitz

I don't like SDCs on acoustic, or at least, I don't like the ones I've heard used on my acoustic. Each guitar will want a different mic to bring out the best results, it's all about finding the best tool you have available to you for the job.

Record the guitar using just one of each mic you have, play the same thing, just a short snippet, maybe 30 seconds worth. Then compare. Keeping it short means all the recording conditions are going to be as close to identical as you can get them....you're not gonna wear out strings in 30 seconds. Comparing those tracks will give you a much better sense of what each mic will do for the overall recorded tone of the guitar. Whichever one sounds best mono, phase and other recording logistics aside, is likely to sound good recorded in stereo.

Once you've gotten that done, try recording doubletracked mono, same thing, 30 seconds with each mic. See what mic works best that way. See if you can combine tracks using different mics to see if you get any interesting combinations.

Then try a simple stereo setup.
I think mono acoustic can get overlooked when there's a matched pair of mics lying around. Maybe you've tried all this already, and if so, sorry if I'm suggesting something too obvious!

Personally, I think you can sometimes get much more interesting results using double tracked mono recordings of an acoustic than with a stereo recording. The variations in performance and the interaction between the two tracks can lend a texture to things that you don't get from a single stereo take.

This is all just imo of course.

progsound

fitz wrote: »

The variations in performance and the interaction between the two tracks can lend a texture to things that you don't get from a single stereo take.

+1 but it depends on what vibe you want.

Double tracked will sound bigger due to the subtle variations in the performance but the song might not require a bigger sound maybe it needs a more sparce sound to fit the vibe thats the producers (i.e you) call though

fitz

Exactly. What I was trying too get at was that if this micing scheme was being chosen to try and fix a weakness in what was being tracked, as opposed to being selected to achieve a specific sound. I think from what TelePaul said, it's the former.

teamdresch

ogy wrote: »

so lets talk about phase!

heres my understanding of things:

1 - its important to get all mics your using phase coherent (obviously)
2 - you should be able to hear when stuff is out of phase, but to make sure you can record little bits and check by zooming in on the waveform. if mics are at different distances, obviously the peaks and troughs your lining up aren't gonna be the same ones, you just aim for the least phase cancellation possible. is this really accurate, can cubase/protools be trusted?:) are there any other methods to check phase?
3 - you shouldn't line up waveforms after the event because your only lining up certain frequencies, not others, as they all have different times of arrival etc. so you could be causing more phase issues than your solving. however a lot of people (on the interwebs:)) seem to disagree with this.

discuss!:)

Stop LOOKING at music.

Seziertisch

TelePaul wrote: »

Hello all, thanks for the replies. Perhaps I should offer up some more info.

AFAIK, Cubase SE3 allows for phase reversing, but not in real time or as a real-time plug-in; you can process a track after it's been recorded but not on the way in.

As for the mics, I'm using a matched pair of Naiant MSH2s about 6 inches out, one aimed at 12th fret, one aimed at the bridge but find myself running the pre-amps quite hot to peak at -18dbs.

When I play back the recorded sound unprocessed it does sound quite weak...seems most of the body is missing from the guitar, that big resonant sound (Martin D15, Mahogany, solid top/back/sides). New strings, .50mm pick...

It's just a few open chords, very strummy. Any thoughts?

The problem with phasing is that its not necessarily the case that the mics are completely out of phase with one another, in which case reversing the phase makes little or no difference in terms of improving things.

You could try something like the Little Labs IBP or Radial Phazer. I know UA also make a plug-in version of the Little Labs. I think that there are some other companies making similar plug-ins.

That said, you really should try and avoid resorting to tools like this (ignoring the expense) if it is only a couple of mics you are using. It might take some work, but shouldn't be impossible to get them in phase.

Also do you notice an improvement in the sound when you solo one of the tracks? If the body is back when soloing it is a phasing thing, if not, it could be that the sound you are looking for requires different tools.

madtheory

I get the impression that not many of us are reading all the posts- lots of repeated directions going on...

So, OK, seems like the real problem is mic positioning technique.

First, listen to the instrument being played. Then you've got to put on good headphones, and move the mic til it sounds right. Acoustic instruments always have a spot where the sound the nicest. With acoustic guitars, you'll often get a bump no matter where you put the mic, around 200Hz or so. I believe this is due to a combination of the body resonance and proximity effect.

Those Naiants are omnis I think, so there will be no proximity effect.

Go look up stereo mic techniques on the dpa microphone site, read up on spaced omni as a stereo technique.

If you're recording yourself, then do various test recordings with the mic in different places, like fitz said.

studiorat

madtheory wrote: »

First, listen to the instrument being played. Then you've got to put on good headphones, and move the mic til it sounds right. Acoustic instruments always have a spot where the sound the nicest.

^^^
heap much good sense.
Personally I've never been big on stereo acoustic guitars. Two mics maybe and maybe not even a pair but never panned hard left and right. Three is just making things difficult for yourself IMO. I'd spend the time getting one mic in the right place.

Don't worry about phase unless it's making things sound worse. Cancellation can be a good thing too!!:D

iamnothim

best sound i've ever gotten from an acoustic guitar was last week. A takamine EN10c, with 1 week old strings, two mics - an AKG C12vr at about 6 inches from the 12th fret and a neumann USM69 stereo mic about 6 feet away to pick up some ambience. the room was fairly dead so the amount the neumann was used in the mix was minimal, a good stereo reverb would have been good enough to replace this. the sound of the C12 was nearly perfect on it's own. great mic that!

i can post a short sample of the sound