Staggering a spaced pair

[TBman]

Since I upped the input gain to where it should be to record I haven't really cared for the way my Avalon was recording. It was sounding too muddy for lack of a better description. I had the mics set back 10" from the neck/body joint and the bridge.

I thought I would experiment with mic placement instead of trying to fix the recordings in post (I didn't think I knew how either). I kept the left mic at the neck/body joint and moved the right mic back another foot or so and I got a much better sound I think. I tried to set the gain as evenly as possible, but I had to boost the right by 3db in post. I didn't do a lot of eq'ing, just a hi pass, stereo adjustment and then reverb. I think I managed to get a lot of the "mud" out. Other than the need for room treatment I think I'm in a better place overall.

[Doug Young]

I'd try adding about 1ms of delay to the mic you moved back to compensate for the phase difference. (Sound travels about 1ms per foot)

Did you try maybe just moving both mics back a few inches (split the difference?). Every room and guitar are different, so sometimes you have to experiment with the right placement. But in general, with spaced pairs I'd keep them relatively close to the same distance from the guitar. Doesn't have to be exact, but a foot different seems extreme, and definitely will introduce phase differences that you may not want.

[rick-slo]

More distance will reduce mike proximity effect and just plain air mass movement that would hit a mike somewhat in line with the guitar soundhole.
You can certainly play around with staggered mike distances. Post record tweak as your ears tell you.

[TBman]

Ok thanks Doug and Derek. I'll have to teach myself a bit about using delay and phase issues. I don't know if I would recognize a phase issue as being a phase issue. What sort of plug in could detect it? What should my ears be telling me about phase issues?

[Doug Young]

Originally Posted by TBman

Ok thanks Doug and Derek. I'll have to teach myself a bit about using delay and phase issues. I don't know if I would recognize a phase issue as being a phase issue. What sort of plug in could detect it? What should my ears be telling me about phase issues?

Your DAW should have a phase correlation meter. If not, there are plenty out there, likely free. You can sum to mono and listen. Phase cancellation will cause a tonal change. With spaced pairs, this will definitely happen, but it can be better or worse depending on mic placement. You can also simply do math in this case - sound travels 1000ft/sec, or 1ms a foot. So if your mic is 1ft further back, you have a delay of roughly 1ms between the two mics. Phase is frequency dependent, so this will result in different phase shifts at different frequencies.

All's fair in recording if it sounds good, but for "normal" stereo micing techniques, I'd avoid this kind of placement. If I find myself having to do something unusual to get a better sound, I'd generally step back and re-evaluate. My guess is your core challenge is room acoustics. Fix that, and you'll probably find that everything just gets easier.

[TBman]

Originally Posted by Doug Young

Your DAW should have a phase correlation meter. If not, there are plenty out there, likely free. You can sum to mono and listen. Phase cancellation will cause a tonal change. With spaced pairs, this will definitely happen, but it can be better or worse depending on mic placement. You can also simply do math in this case - sound travels 1000ft/sec, or 1ms a foot. So if your mic is 1ft further back, you have a delay of roughly 1ms between the two mics. Phase is frequency dependent, so this will result in different phase shifts at different frequencies.

All's fair in recording if it sounds good, but for "normal" stereo micing techniques, I'd avoid this kind of placement. If I find myself having to do something unusual to get a better sound, I'd generally step back and re-evaluate. My guess is your core challenge is room acoustics. Fix that, and you'll probably find that everything just gets easier.

Ok thanks Doug. So I would have to delay the closer mic to make the mics seem as though they are the same distance from the guitar?

[Doug Young]

Originally Posted by TBman

Ok thanks Doug. So I would have to delay the closer mic to make the mics seem as though they are the same distance from the guitar?

Right. This is actually something Rick has described before - you can add a little delay to a side, which will alter the sound, possibly the tone. If you're looking at a phase meter, you can try to minimize phase differences. There's also at least one plugin (Auto-Align) that will automatically compute the distance between two mics and correct it.

As I said, anything goes with recording, but to me, when you do something that's not entirely natural, my brain says something's not right as I listen. My one ear shouldn't be a foot further back from the other one, for example. I have the same issue with some of the alternative micing techniques, like over-the-shoulder, vertical XY, and so on. My ears just get uncomfortable without me being clear why. Most of the standard stereo micing techniques were designed to sound "right" (whatever that means). But that's just me, and there's no harm in experimenting. If you find a setup that sounds good to you, that's the bottom line.

[rick-slo]

Various different mike positions can give good sounding recordings (or a bad sound recording for that matter) of an acoustic guitar.
The thing about mic'ing a larger sound source like an acoustic guitar (as opposed to something like a voice or even say a small wind
instrument) is that the guitar is out of phase with itself at every point around it (where the mike is, where your ears are, etc.). That
contributes to the sound of the instrument as we decode it.

When listening with your ears to a live guitar or to a stereo recording of one the phase and volume differences are interpreted in part
as that of a real world representation of the instrument's location rather than just nastiness. It gets complicated as to what degree of
R and L out of phase of various frequencies will give the sound you like the best. Think of all the phase, timing and volume differences
reverb adds, yet at least some reverb usually enhances a recording's sound to some degree or another.

[Wrighty]

Hi Barry, I have had better results with varying the height and angle of the mics rather than the distances they are from the guitar. Pushing a little further back and having the right side mic higher and angled down and in slightly gave me more clarity in the bass and lower mids - although it is still an issue I have not completely resolved despite a fair amount of room treatment.

The Auto align plug in Doug mentioned did not help me - the mics did not sound better completely phase aligned.

[RRuskin]

Not that anyone asked, an easy way to avoid proximity effect, the prime cause of muddiness, is to place your mics at least as far away from your guitar as its body length.

[TBman]

Originally Posted by RRuskin

Not that anyone asked, an easy way to avoid proximity effect, the prime cause of muddiness, is to place your mics at least as far away from your guitar as its body length.

Thanks. I'm going to push the left mic back as well to see how it sounds. I don't have a treated room so I'll see how that works out. I'm going to try the angle approach suggested by Wrighty as well. The best solution could be a combination of the two because of my room.

[Doug Young]

Originally Posted by Wrighty

Hi Barry, I have had better results with varying the height and angle of the mics rather than the distances they are from the guitar. Pushing a little further back and having the right side mic higher and angled down and in slightly gave me more clarity in the bass and lower mids - although it is still an issue I have not completely resolved despite a fair amount of room treatment.

Good advice. You have 3 degrees of freedom when placing mics - har near/far, where they are on the vertical plane - up/down, and rotation. If a guitar is boomy, moving the mics higher often works well. I often aim for being about aligned with the top of the waist.

The Auto align plug in Doug mentioned did not help me - the mics did not sound better completely phase aligned.

I wouldn't suggest this plugin for normal stereo micing. It was designed for drum sets, where you have tons of mics, all with bleed, where you need to minimize the phase issues with the bleed. I find it useful when using 3 or more mic for helping to align between sets of mics (not between mics in a stereo pair), and mostly use it as a way to measure the effective distance between, say a space pair and a third center mic.

[Doug Young]

Originally Posted by RRuskin

Not that anyone asked, an easy way to avoid proximity effect, the prime cause of muddiness, is to place your mics at least as far away from your guitar as its body length.

Barry's challenge is that he's recording in an untreated garage. So being out 2-3 feet will likely have too much bad room sound. Works great in a good-sounding room.

[TBman]

Originally Posted by Doug Young

Barry's challenge is that he's recording in an untreated garage. So being out 2-3 feet will likely have too much bad room sound. Works great in a good-sounding room.

Its actually a spare bedroom, but it is on the small side. I was thinking the same thing though, if I push the mics out too much I might get too much room. I'll play around with the mics positions and angles and see if I can get rid of all of the "muddiness."

[Doug Young]

Originally Posted by TBman

Its actually a spare bedroom, but it is on the small side. I was thinking the same thing though, if I push the mics out too much I might get too much room. I'll play around with the mics positions and angles and see if I can get rid of all of the "muddiness."

Oh, I thought you'd moved into the garage. In many cases, there's no way around room acoustics, but it all depends. Further back, you're going to get more room sound, more environmental noise, less guitar. Moving up or down may help. Going wider can also reduce bass - you're adding more spaciousness, and getting further from the soundhole. High pass filters, either on the mic, or when you mix may help make up for excess proximity if you have no other choice.

A lot of this is jumping thru hoops tho. Get room acoustics under control, and suddenly mic placement becomes easy - things will sound "good" anywhere, and then it's just a matter of the stereo image and tone you want. No one wants to do it - everyone wants to buy a new guitar or new mics. But if your room is the problem, then room treatment will make the biggest difference, and it can be a very big difference.