Two-mic technique

[Sasquatchian]

Originally Posted by b1j

I was thinking about that, too: the boom is pretty audible, so I expect it might show up well above 80 Hz. My gear is considerably less sophisticated than some, but Studio One’s graphic EQ clearly pinpoints the trouble frequencies and gives fully discrete control over adjustments in central frequency, dB cut or gain, and Q — with several bands available across the spectrum.

In the past I have hastened to EQ every track before I have the right balance! I’m committed to stop doing that. For this song, I have been waiting to put the EQ on it until I have the balancing done. Nearly there.

Fab Filters EQ's have some very cool features to help you identify areas in different tracks that might be competing with one another and will even highlight them in red. It's amazing how cutting a bit here while boosting a bit there can totally free up the mix.

[runamuck]

I put a low cut filter on most tracks to eliminate what doesn't need to be heard. I solo the track with the filter engaged, raise the cut off to the point I can hear it and then back it off some.

[Doug Young]

Originally Posted by b1j

I was thinking about that, too: the boom is pretty audible, so I expect it might show up well above 80 Hz. My gear is considerably less sophisticated than some, but Studio One’s graphic EQ clearly pinpoints the trouble frequencies and gives fully discrete control over adjustments in central frequency, dB cut or gain, and Q — with several bands available across the spectrum..

Boominess can be from a lot of things, but one common culprit is room acoustics. Rooms have resonant frequencies just like guitars, and a typical bedroom ends up being around the lower notes on a guitar. Find an online mode calculator and enter your room dimensions to find your resonant frequencies. Mic placement can also be a factor, close micing can be boomy due to proximity effect. But in poor room acoustics, you're stuck between a rock and a hard place.

Where are you placing your mics? XY can be tricky, since the usual recommended spot typically ends up with a mic aimed into the soundhole, and "boom"...

You may be able to reduce boominess with a Dynamic EQ, which can be set to cut a specific note only when the boom occurs, so you you reduce the problem without cutting the overall bass of the track.

[b1j]

Originally Posted by runamuck

I put a low cut filter on most tracks to eliminate what doesn't need to be heard. I solo the track with the filter engaged, raise the cut off to the point I can hear it and then back it off some.

Yes, I’m looking forward to getting into the EQ next. Thanks!

[b1j]

Originally Posted by Doug Young

Boominess can be from a lot of things, but one common culprit is room acoustics. Rooms have resonant frequencies just like guitars, and a typical bedroom ends up being around the lower notes on a guitar. Find an online mode calculator and enter your room dimensions to find your resonant frequencies. Mic placement can also be a factor, close micing can be boomy due to proximity effect. But in poor room acoustics, you're stuck between a rock and a hard place.

Where are you placing your mics? XY can be tricky, since the usual recommended spot typically ends up with a mic aimed into the soundhole, and "boom"...

You may be able to reduce boominess with a Dynamic EQ, which can be set to cut a specific note only when the boom occurs, so you you reduce the problem without cutting the overall bass of the track.

This conversation keeps getting more interesting.

I did a quick lookup for mode calculators. It seems a bit over my head at the moment. I’ve stopped using my 12 x 13 spare bedroom for recording (poor results) and moved to our kitchen/DR/LR for tracking. The room’s dimensions are complex. If there were nothing in it, it would be about 20 x 35 feet, but there are partial walls and other baffle-like structures. There’s soft furniture and stone countertops. It’s not clear to me how I would use an app to calculate modes or harmonics or whatever matters.

I situate myself about 8 feet from two walls, in one far corner of the space, aiming diagonally into the long end of room. First reflections are projected out in front of me several feet beyond the mics.

My XY setup places the fronts of the mics, of course, at 90° to each other, and 9 or 10 inches in front of the soundhole. They point to the 12th fret and the bridge, but I know they’re not pinpoint directional mics, they’re cardioid. They only drop a couple of dB at 45°, so I can see how I could get a proximity effect. Entirely possible. Makes you wonder how engineers deal with proximity effect with XY, and makes me think about trying a spaced pair to get away from the soundhole.

I’ll see by how much I can tame the low boom. I’m encouraged that there is no clipping.

You’ve given me one more skill set to investigate in dynamic EQ. I have not seen this. But as you describe it, it might not be for these tracks. The part is a rolling repetition, almost a steady drone, so where there’s sound, there’s boom. No, for now I’m going to see what can be done with old-fashioned subtractive EQ.

In the future, with different songs and different playing dynamics, I’ll have different lessons to learn. I’m glad I have a simple arrangement to work with right now.

I am greatly enjoying the informed comments and recommendations here. Thank you all. I hope to post a SoundCloud clip of the song here once it’s all done with the vocals.

[Doug Young]

Originally Posted by b1j

This conversation keeps getting more interesting.

I did a quick lookup for more calculators. It seem a bit over my head at the moment. I’ve sworn off my 12 x 13 spare bedroom for recording and moved to out kitchen/DR/LR for tracking. My recording room’s dimensions are complex. If there were nothing in it, it would be about 20 x 35 feet, but there are partial walls and other baffle-like structures. There’s soft furniture and stone countertops. It’s not clear to me how I would use an app to calculate modes of harmonics or whatever matters.

There are also ways to measure it. Look up Room EQ Wizard, free app.

[b1j]

Originally Posted by Doug Young

There are also ways to measure it. Look up Room EQ Wizard, free app.

Thanks for that. Lots to learn.

[RodB]

Originally Posted by b1j

..........My XY setup places the fronts of the mics, of course, at 90° to each other, and 9 or 10 inches in front of the soundhole. They point to the 12th fret and the bridge, but I know they’re not pinpoint directional mics, they’re cardioid. They only drop a couple of dB at 45°, so I can see how I could get a proximity effect. Entirely possible. Makes you wonder how engineers deal with proximity effect with XY, and makes me think about trying a spaced pair to get away from the soundhole.

........

Bear in mind that mic placement is a continuum with plenty of option between XY at 90deg and spaced pairs. You could avoid the soundhole a bit more by just separating the the mics a bit in a near coincident arrangement without radically changing things.

Even just opening out the XY from 90 deg slightly could help avoid the soundhole.

[b1j]

Originally Posted by RodB

Bear in mind that mic placement is a continuum with plenty of option between XY at 90deg and spaced pairs. You could avoid the soundhole a bit more by just separating the the mics a bit in a near coincident arrangement without radically changing things.

Right. Lots to explore.

[min7b5]

I’ve been tending to high pass around 50hz to target unwanted stomach rumbles, foot stomps, etc. And then as far as lowering the boom I like to use Fabfilter's dynamic eq (essentially a multi-band compressor) feature, usually in the 150-200hz neighborhood with the q at something like 3.5, and do a cut that only kicks in at certain threshold. I’ve actually started to turn off ProQ3's spectrum analyzer and/or close my eyes completely for the final tweaks -as I’m starting to think mixing with my eyes is like painting with my ears

[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.

[Glennwillow]

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.

Interesting...

I have been using a multi-band compressor in this way recently, with the low crossover point at 125 Hz. This approach has been helpful, though I had thought I had come up with this idea on my own. I should have known it was out there floating around on the ether somewhere.

- Glenn

[rick-slo]

Originally Posted by b1j

My XY setup places the fronts of the mics, of course, at 90° to each other, and 9 or 10 inches in front of the soundhole.

Yikes. That setup is bound to result in lower frequency boom if not thunder.

[DupleMeter]

Originally Posted by Glennwillow

Interesting...

I have been using a multi-band compressor in this way recently, with the low crossover point at 125 Hz. This approach has been helpful, though I had thought I had come up with this idea on my own. I should have known it was out there floating around on the ether somewhere.

- Glenn

It's a trick I learned from some very well respected engineers (sitting with them in the studio NOT just on YouTube). I first ran into it doing a session at Avatar/Power Station. Held on to it.


I also learned from a bunch of dialogue editors that do blockbuster movies about using a multiband on vocals with the crossovers set at 300Hz & 4kHz. So much of the voice's energy is in that middle band...it allows for smoother/less obvious compression. While meant for dialogue, I started using it for vocals.

[b1j]

Originally Posted by rick-slo

Yikes. That setup is bound to result in lower frequency boom if not thunder.

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