Two-mic technique

[b1j]

Originally Posted by DupleMeter

As a general rule, apply a HPF only when necessary. All filters introduce ringing & distortion to some extent. They also introduce a certain amount of phase shift, unless you use one of the phase coherent models, but the trade off is more ringing in the circuit/algorithm. And, while phase shift tends to be a buzz word & assumed bad, there are times when phase shift is acceptable if not desirable (think Pultec & the low end trick).

It’s probably better to address the issue by zoning in on the problem frequency & use a parametric EQ to tame it. Then just adjust the Q. Or use a proportional Q EQ (like an API style).

A simple approach might also be a multiband compressor. Set the lowest crossover somewhere around 150Hz use that to tame the low end. Just disable the rest of the bands.

Compress only below 150 Hz. Interesting.

[DupleMeter]

Originally Posted by b1j

How would you do 90° XY if you want one mic pointed just behind the bridge and the other at the 12th fret?

Why keep it as an X/Y? That's really better suited for pulling back & capturing the natural sound source in it's environment.

Just move the mics into position where you want them: one at the bridge area & one at the neck/body joint. It will make things easier in the long run.

[rick-slo]

Originally Posted by b1j

How would you do 90° XY if you want one mic pointed just behind the bridge and the other at the 12th fret?

You have proximity effect and billows of air from the soundhole.
Back away the mikes another few inches. Have the mike height above the sound hole somewhat.
Have you any recordings of the sound you have been getting?

FWIW for solo guitar I generally prefer using space pair mikes.

[b1j]

Originally Posted by DupleMeter

Why keep it as an X/Y? That's really better suited for pulling back & capturing the natural sound source in it's environment.

Just move the mics into position where you want them: one at the bridge area & one at the neck/body joint. It will make things easier in the long run.

Thanks. I haven’t seen XY explained as a way to capture room sound as well. But if the XY mics are much more than 9 inches from the guitar, I can see how they would pick up the room.

I don’t want the room sound, because it’s not a studio. So I’m going for close mics to place the guitar many dB above the room. I’ll have to re-read the reference I checked that recommended XY at 9 inches.

[b1j]

Originally Posted by rick-slo

You have proximity effect and billows of air from the soundhole.
Back away the mikes another few inches. Have the mike height above the sound hole somewhat.
Have you any recordings of the sound you have been getting?

FWIW for solo guitar I generally prefer using space pair mikes.

To your question, yes, I have R and L tracks for both guitar parts (see top of the thread). I will get to the EQ step when I return from the next two weeks out of town.

For the future, you, Derek, and DupleMeter are all recommending spaced pair. That makes sense to me. It can still be close mic’d and capture the range of tones from the 12th fret and the bridge, but it would avoid the soundhole problem — even more so if I space them a bit wider and angle them in slightly.

That will be my next setup, especially if that song uses strumming or heavy low end. For the current song I may have lucked out because the low part is a drone confined to a few notes, and the high part is on different tracks, so discrete EQ should be able to tame the low tracks.

[Doug Young]

XY is rather hard to work with on guitar, especially if you follow the usual position you'll read on the internet of putting them at the neck/body joint. That pretty much means one mic is aimed at the neck, getting very little sound, while the other is aimed into the sound hole, getting a lot of boom. So thin, boomy, and unbalanced :-). I never quite understand why that keeps being recommended.

A lot depends on what you're recording. You mention heavy strumming, is this a rhythm track in a mix? If so, you may not even want stereo. A single mic at the neck/body joint can work well for that. If the guitar is featured, and you want stereo, then you have lots of options.

XY was invented to create a stereo sound from a fair distance away, like recording an orchestra - it wasn't intended (originally) for close micing a guitar. It can work, tho. What I do if using XY - and I'm nearly always recording solo instrumental guitar, where the guitar is my "orchestra" - is position the mics centered on the body, but *above* the soundhole. You can control how much bass you get by how far above. I usually start at the top of the waist, but you can move up or down to dial in the tone. You can also get closer or further away. Too close and you get boom from proximity effect, too far and you'll hear too much room sound, especially in an untreated space. It's a balancing act.

Using spaced pairs avoids a lot of the issues, since it keeps both mics away from the sound hole. Then you are only dealing with the room vs proximity issue. However, spaced pairs aren't very mono-compatible, so you want to be sure you really want stereo if you go that route.

If you haven't seen it, here's a demo I made a while back of 5 typical stereo placements, which might give you some ideas. (there are others, but these are a starting point). Your mileage may vary depending on your guitar, mics, room and taste, but maybe these will help get you started.

[rick-slo]

Originally Posted by b1j

To your question, yes, I have R and L tracks for both guitar parts (see top of the thread). I will get to the EQ step when I return from the next two weeks out of town.

For the future, you and DupleMeter are both recommending spaced pair. That makes sense to me. It can still be close mic’d and capture the range of tones from the 12th fret and the bridge, but it would avoid the soundhole problem — even more so if I space them a bit wider and angle them in slightly.

That will be my next setup, especially if that song uses strumming or heavy low end. For the current song I may have lucked out because the low part is a drone confined to a few notes, and the high part is on different tracks, so discrete EQ should be able to tame the low tracks.

Here are a few recordings and pieces of mine so that you can get an idea of what I aim for in recordings:


http://dcoombsguitar.com/Misc/Blusey.mp3

http://dcoombsguitar.com/Guitar%20Music/Rebecca.wav

http://dcoombsguitar.com/Guitar%20Music/Felicity.mp3

http://dcoombsguitar.com/Guitar%20Music/HandInHand.mp3

[b1j]

Originally Posted by Doug Young

XY is rather hard to work with on guitar, especially if you follow the usual position you'll read on the internet of putting them at the neck/body joint. That pretty much means one mic is aimed at the neck, getting very little sound, while the other is aimed into the sound hole, getting a lot of boom. So thin, boomy, and unbalanced :-). I never quite understand why that keeps being recommended.

A lot depends on what you're recording. You mention heavy strumming, is this a rhythm track in a mix? If so, you may not even want stereo. A single mic at the neck/body joint can work well for that. If the guitar is featured, and you want stereo, then you have lots of options.

XY was invented to create a stereo sound from a fair distance away, like recording an orchestra - it wasn't intended (originally) for close micing a guitar. It can work, tho. What I do if using XY - and I'm nearly always recording solo instrumental guitar, where the guitar is my "orchestra" - is position the mics centered on the body, but *above* the soundhole. You can control how much bass you get by how far above. I usually start at the top of the waist, but you can move up or down to dial in the tone. You can also get closer or further away. Too close and you get boom from proximity effect, too far and you'll hear too much room sound, especially in an untreated space. It's a balancing act.

Using spaced pairs avoids a lot of the issues, since it keeps both mics away from the sound hole. Then you are only dealing with the room vs proximity issue. However, spaced pairs aren't very mono-compatible, so you want to be sure you really want stereo if you go that route.

If you haven't seen it, here's a demo I made a while back of 5 typical stereo placements, which might give you some ideas. (there are others, but these are a starting point). Your mileage may vary depending on your guitar, mics, room and taste, but maybe these will help get you started.

Doug, my XY put the condensers right out in front of the soundhole, not in front of the neck joint. Unlike your XY, my mics took the full brunt of the soundhole (albeit at 45°). Therein lies my current problem: too much proximity effect.

Thanks for showing me your video; I hadn’t seen it. I went through it a few times, and I have to say the XY sitting above the soundhole is most like what I hear in my mind as what I want to produce. Most of the others (but not all) had more “room” than I can tolerate. It makes so much sense just to aim away from the direct line of the soundhole. Derek also advised placing the mics above the soundhole.

After hearing your video I’m less interested in either ORTF setup, but I did like the spaced pair, although I thought I heard a little more “room” with it. Still, it’s on my To Try list.

But the revelation was that the Aim High XY might be even better for the sound I want to hear — at least from the part I want in stereo. That will also allow me to to dial in the stereo effect between tightly aimed “mono” (with both neck and lower-bout tones, blended) and hard-panned L and R. If I’m adding an acoustic lead to the main part I’ll want the lead to sit somewhere specific in the field, so I might go with one mic for that.

[b1j]

Originally Posted by rick-slo

Here are a few recordings and pieces of mine so that you can get an idea of what I aim for in recordings:


http://dcoombsguitar.com/Misc/Blusey.mp3

http://dcoombsguitar.com/Guitar%20Music/Rebecca.wav

http://dcoombsguitar.com/Guitar%20Music/Felicity.mp3

http://dcoombsguitar.com/Guitar%20Music/HandInHand.mp3

Derek, these are with spaced pair? They are very pleasing. I listened in my monitoring headphones. I’ll give them a run on my nearfields later. I expect the recordings will bring out a dynamic (active) stereo field in the room.

With this greater separation between the bouts, it’s interesting to hear how different notes seem to dance back and forth from R to L.

Very little room sound — are you in a treated studio?

[rick-slo]

Originally Posted by b1j

Derek, these are with spaced pair? They are very pleasing. I listened in my monitoring headphones. I’ll give them a run on my nearfields later. I expect the recordings will bring out a dynamic (active) stereo field in the room.

With this greater separation between the bouts, it’s interesting to hear how different notes seem to dance back and forth from R to L.

Very little room sound — are you in a treated studio?

Recording computer in closet to the left.

[Doug Young]

Originally Posted by b1j

Thanks for showing me your video; I hadn’t seen it. I went through it a few times, and I have to say the XY sitting above the soundhole is most like what I hear in my mind as what I want to produce. Most of the others (but not all) had more “room” than I can tolerate. .

I'm in a heavily treated space, and the mics are about the same distance, so I don't think what you're hearing is "room". My guess is that you're hearing the sound of spaced pairs which is more "spacious" because there are timing (phase) differences between the mics. As you noted to Rick, spaced pairs also tends to be less stable, with the left and right sides bouncing around a bit, which can be pleasant in many cases.

But that was the point of that video - to hear how each placement approach sounds. There's a continuum between the focused sound of XY and the spacious, more diffuse sound of spaced pairs, with others in between. Spaced pairs, of course is kind of a wide-open category, and you can put the mics anywhere that sound good. People will suggest that you listen for the "sweet spot" on each side of the guitar and place the mic there. So with different guitars, rooms, mics, taste, etc, there can be quite a variety of spaced pair sounds.

Since you seem to go for the more focused side of the spectrum, you might also look into MS, which is very much like XY when properly decoded, but that, if anything, is even more of a focused sound. This requires a figure-8 mic, tho. It can produce a sound that is very stable and centered, even while being ultra-wide stereo. It has a cool benefit on the guitar in that you can place the mid mic of the setup above the soundhole, avoiding the boom, but put the side mic right in front of the soundhole. The null of the figure 8 notches out the soundhole sound, but gives you an in-your-face stereo effect, sort of like sticking your nose in the soundhole while your ears are on each side. Here's a demo and explanation of mid side I did some time back:

[Doug Young]

Originally Posted by b1j

Doug, my XY put the condensers right out in front of the soundhole, not in front of the neck joint. Unlike your XY, my mics took the full brunt of the soundhole (albeit at 45°). Therein lies my current problem: too much proximity effect.

BTW, that would explain your boominess problem. Note that when putting the mics in front of the soundhole the bass isn't "proximity effect". Proximity Effect is a phenomena that produces more bass as a cardioid mic gets closer to the sound source. That would apply regardless of what that source is - you can get proximity effect even if your guitar had no soundhole. It's how radio announcers get that big "radio voice." If you have a mic aimed into the soundhole, you're just picking up the sound that's there - the soundhole is boomy! It would be boomy even if you used omni mics, which have no proximity effect. You just always want to avoid the soundhole when micing.

[b1j]

Originally Posted by Doug Young

I'm in a heavily treated space, and the mics are about the same distance, so I don't think what you're hearing is "room". My guess is that you're hearing the sound of spaced pairs which is more "spacious" because there are timing (phase) differences between the mics. As you noted to Rick, spaced pairs also tends to be less stable, with the left and right sides bouncing around a bit, which can be pleasant in many cases.

But that was the point of that video - to hear how each placement approach sounds. There's a continuum between the focused sound of XY and the spacious, more diffuse sound of spaced pairs, with others in between. Spaced pairs, of course is kind of a wide-open category, and you can put the mics anywhere that sound good. People will suggest that you listen for the "sweet spot" on each side of the guitar and place the mic there. So with different guitars, rooms, mics, taste, etc, there can be quite a variety of spaced pair sounds.

Since you seem to go for the more focused side of the spectrum, you might also look into MS, which is very much like XY when properly decoded, but that, if anything, is even more of a focused sound. This requires a figure-8 mic, tho. It can produce a sound that is very stable and centered, even while being ultra-wide stereo. It has a cool benefit on the guitar in that you can place the mid mic of the setup above the soundhole, avoiding the boom, but put the side mic right in front of the soundhole. The null of the figure 8 notches out the soundhole sound, but gives you an in-your-face stereo effect, sort of like sticking your nose in the soundhole while your ears are on each side. Here's a demo and explanation of mid side I did some time back:

Doug, again, I’m grateful for all this knowledge you are sharing. Mid-side seems a distant, unlikely possibility for me, not the least because I don’t have a figure 8 mic. But seeing the processing that’s required with it, I can’t imagine being ready for something like this for quite some time.

Fortunately there is a lot of growth ahead of me using two cardioid SDCs — or even one SDC and one LDC. You and others here have given me lots to work on.

[Doug Young]

Originally Posted by b1j

But seeing the processing that’s required with it, I can’t imagine being ready for something like this for quite some time.

The process is quite easy - record a stereo track and throw a (free) plugin on it. but it does require the figure-8 mic, which is probably why it's a less-used technique. In any case, there are *lots* of options, as you can see. They can all yield good results.

[b1j]

I’ve had a most enlightening time blowing up my [AGFlaying] ratio with this thread. Thank you all for your insights and advice. I will carry them forward.

I won’t have results until after I return from a trip in mid-July. I’ll see you on the other side!

All the best,
Bob