How to prevent booming sound when recording loud strumming

[gfsark]

When I was being recorded for a class exercise the prof rushed in and said, do not strum so loud, it overdrives the mics (or something like that). Since then I've wondered how to get a good dynamic range when recording something like flamenco guitar. Or anytime when finger picking is alternated with banging on the strings. The prof suggested I turn away from the mic when I get to the loud strumming.

Here's an example of what I consider to be an example of a bad recording as regards managing a large dynamic range on the guitar: About 1:30 in, it hurts my ears. https://www.youtube.com/watch?v=p2A6fM406k4

I'm wondering if adding hardware compression after the mic and before the DAW would help? I'm thinking before the signal gets to the DAW?

[Doug Young]

Complicated topic, and maybe some of the pro recording engineers will have some advice. But mine would be

1) make sure you leave enough headroom for the loud parts so you don't overdrive the recording. You also need mics that can handle the volume without being overdriven (rarely an issue with acoustic guitar)

2) try to play with more controlled dynamics. Strumming doesn't have to be dramatically louder than fingerpicking. Somewhat louder, sure, but dynamic control is something you usually need to do differently when recording than playing live.

3) You can adjust volumes of different parts in the recording software manually, that's part of mixing.

4) compression can limit loud parts, basically turning them down automatically. There are hardware compressors or software. Unfortunately, compression often sounds bad on solo guitar. It may work in a mix with a rhythm guitar or something, but with solo guitar, it usually becomes pretty obvious and won't sound natural, unless it's used very lightly - too lightly to solve the issue you're asking about. Compression is often used in mastering solo guitar recordings, just to make the overall sound a little bigger and fatter, but it's not so great for dramatically reducing the dynamic range.

[Doug Young]

I'd add that sometimes you want dynamics. Guitar actually has a pretty limited dynamic range compared to most instruments, or a full orchestra. If you listen to the Beatles' original recording of that song, there's quite a big dynamic range in that piece, if I recall. So I think the guitar player in the video is just trying to give a sense of that. I don't find his dynamic range to be a problem, listening over my monitors.

[jim1960]

Controlling the dynamic range of an acoustic guitar being alternately strummed and picked is no easy task. A "boomy" sound can be from a couple of things. Yes, you can be overdriving the mics and getting boom along with some distortion, but it can also result from a room with bad acoustics. So how to deal with each becomes the question.

For the overdriven mic, you simply have to back off. Yes, that will mean the softer picked parts will be even softer, so you'll get better results with low noise mics and preamps. Compression certainly can help. I'd likely opt for an opto-type compressor like the LA2A. "Before the DAW" doesn't make much sense to me unless you have an outboard preamp. The compressor will have to come at some point after the preamp. If you have a outboard preamp, I'd go mic-preamp-compressor-DAW. If you don't have an outboard preamp, the compressor will help control the dynamic range but won't do as much for the boominess that you've already captured.

Another way to do it is to set up four microphones. Adjust two for the loudest parts and two for the softer parts, then automate the faders in your DAW to bring each pair in and out as needed in the mix.

For boominess from a poor acoustic environment, it becomes harder to control. The first thing to consider is where in the room you're playing. You don't want to be dead center nor do you want to be too close to a wall. About a third of the way in is a good starting point.

You'll also want to avoid mic techniques that capture a lot of the room. Spaced pairs, or a single well positioned mic would probably work best. XY or Blumlein may also work as long as you're not putting the mics too far away. I'd avoid mid-side and ORTF. Mic positioning in a bad room is critical. You may have to try a lot of positions to find something that works.

I've never recorded Flamenco guitar. I suspect the percussive right hand has to be taken into account in some way but never having done it, all I could do is guess and I'd rather not put bad info out there.

[Doug Young]

Originally Posted by jim1960

A "boomy" sound can be from a couple of things.

Good advice. I didn't take the OPs term "boomy" literally, since I don't hear a boomy sound on the reference video he posted, just a section that was louder. So I was just talking about the dynamics range aspect. But I agree getting a truly "boomy" sound is mostly a matter of room acoustics and mic placement.

I don't know much about flamenco either, but I once had the opportunity to record Andy McKee, who does lots of body percussion as well as 2 handed tapping, harmonics, etc. What impressed me both in person and on the recording, was that I had to do - nothing! He had such control over his dynamics that the loud stuff (percussion) wasn't that loud, and the soft stuff (tapping, harmonics) was as loud as regular notes. Some things can be best fixed by how you play instead of doing anything artificial in the recording process. But I assume flamenco is meant to be quite dynamic, so you may very well want that to come across on the recording.

[SprintBob]

I have to agree with Doug. I enjoyed the recording and did not find the strumming parts were boomy in the way the OP suggests.

[rick-slo]

Originally Posted by gfsark

When I was being recorded for a class exercise the prof rushed in and said, do not strum so loud, it overdrives the mics (or something like that). Since then I've wondered how to get a good dynamic range when recording something like flamenco guitar. Or anytime when finger picking is alternated with banging on the strings. The prof suggested I turn away from the mic when I get to the loud strumming.

Here's an example of what I consider to be an example of a bad recording as regards managing a large dynamic range on the guitar: About 1:30 in, it hurts my ears. https://www.youtube.com/watch?v=p2A6fM406k4

I'm wondering if adding hardware compression after the mic and before the DAW would help? I'm thinking before the signal gets to the DAW?

I agree.

Pretty bad mike placement in the video (too close to the guitar and aimed right at the soundhole of the guitar). Mike further out.

For recording with one mike the classic starter mike position is to aim the mike pointing at the guitar neck body joint.

Reasonable advice here:

[KevWind]

Originally Posted by gfsark

When I was being recorded for a class exercise the prof rushed in and said, do not strum so loud, it overdrives the mics (or something like that). Since then I've wondered how to get a good dynamic range when recording something like flamenco guitar. Or anytime when finger picking is alternated with banging on the strings. The prof suggested I turn away from the mic when I get to the loud strumming.

Here's an example of what I consider to be an example of a bad recording as regards managing a large dynamic range on the guitar: About 1:30 in, it hurts my ears. https://www.youtube.com/watch?v=p2A6fM406k4

I'm wondering if adding hardware compression after the mic and before the DAW would help? I'm thinking before the signal gets to the DAW?

As noted a fairly complicated subject. Acoustics are somewhat difficult in general and especially when played aggressively. Particularly with the percussive "bang the heck" out of the strings or body technique which has come in vogue in the last decade especially. Which unless done in a very restrained and intermittent manner , IMO always sounds bad. And overly aggressive close mic'ed strumming can be a problem also. So as the prof suggested stop doing that. And stop "banging on the strings" until you can at least get good strumming sound. Percussive embellishment can come later.

Flamenco can be difficult , often because aggressive strumming and for some reason classical/nylon string guitars often have significant boom in the low end.

The best recordings of flamenco I have heard had one SDC mic pointed at neck joint and one at the top of guitar just back from the waist curve. both about 2 or more ft. away.

And in that video the room may be the biggest issue, concrete floors are very problematic . As suggested the mic's could be backed off another foot or two

Since you did not give details of the class recording situation IN general

#1 The biggest and most often occuring mistake is having a mic close and pointed directly at the sound hole. Live or recording people seem to assume since it is the "sound hole" it is the spot for mic, but that is almost never the case.
And not understanding that placing mis in front of a guitar creates an un-natural sound and dynamics situation as compared to listening un-mic'ed in the room. So technique (especially aggressive techniques)need to be adjusted accordingly for the mic'ed sound

#2 in order to eliminate proximity boom backing the mics off helps. BUT the more one does that the more the room becomes an issue.

#3 moving the mic position is the first , best EQ type method to address .

#4 Personally I think acoustic guitar should usually be recorded raw no FX compression or EQ . Those should be handled in the mixing stage and always low end subtractive EQ first.. before any compression

[gfsark]

My recording-class session was in a decent recording studio, but it has been a while so I can’t remember mic or mic placement details. Totally get that recording in a concrete echoey room is less than optimal.

Is overdriving the mic even possible (newbie question here)? One of my mics is a Rode M3 which has a max SPL of 143 dB. Which I think is about as loud as a jet engine up close, the threshold of pain. So somewhere else in the signal chain the overdriving is taking place. Trim levels on the pre are set too high, for the low level signals, and then the pre get overdriven on the loud parts. Does that sound right?

[rick-slo]

Originally Posted by gfsark

My recording-class session was in a decent recording studio, but it has been a while so I can’t remember mic or mic placement details. Totally get that recording in a concrete echoey room is less than optimal.

Is overdriving the mic even possible (newbie question here)? One of my mics is a Rode M3 which has a max SPL of 143 dB. Which I think is about as loud as a jet engine up close, the threshold of pain. So somewhere else in the signal chain the overdriving is taking place. Trim levels on the pre are set too high, for the low level signals, and then the pre get overdriven on the loud parts. Does that sound right?

Overdriven preamp more likely though I doubt either is the case (and not in the video you posted).

[RRuskin]

Originally Posted by gfsark

When I was being recorded for a class exercise the prof rushed in and said, do not strum so loud, it overdrives the mics (or something like that). Since then I've wondered how to get a good dynamic range when recording something like flamenco guitar. Or anytime when finger picking is alternated with banging on the strings. The prof suggested I turn away from the mic when I get to the loud strumming.

Here's an example of what I consider to be an example of a bad recording as regards managing a large dynamic range on the guitar: About 1:30 in, it hurts my ears. https://www.youtube.com/watch?v=p2A6fM406k4

I'm wondering if adding hardware compression after the mic and before the DAW would help? I'm thinking before the signal gets to the DAW?

Simple ways to avoid excessive low end: Using omni mics or backing off from directional mics. I'll keep cardiods about the same distance from a guitar as the instrument's body length. Any closer than that and proximity effect comes into play. There is also no reason not to shave any objectionable boom via eq as you record. Personally, I avoid compression when I record for the mere fact that unlike eq, it can't be corrected/undone after the fact.

For the record, I can't say I like the sound of the guitar being played in that video but it isn't due to anything being boomy or distorted.

[Doug Young]

Certainly some confusion about what the question is. I hear no "boom" in the posted recording. Mediocre sound in a poor room, but I don't hear "boom". I hear some pretty loud playing in the section being questioned. The tune has a large dynamic range, which is deliberate.

So, OP, what's the question: "getting rid of boomyness (excessive bass)" or "dealing with a large dynamic range"? They're really 2 different issues, you can have one without the other (or you can have both). You can even have a boomy sound on a very quiet passage.

[keith.rogers]

"Boom" is something I associate with having the mic placement incorrect, often too much of the soundhole. Very few mics could be overdriven by an acoustic guitar if they are placed correctly. I agree with the suggestion it was most likely an improper gain setting at the preamp/interface if there was any clipping being introduced. And, the mic could simply have been too close, causing both problems. If it was a studio, and, admittedly without hearing the player, I'd guess that just backing the mic off another 8-12" might give you a fine track.

[gfsark]

Thanks for clarifying the difference between boom and distortion caused by too much gain. Based on this, and to answer your question Doug, it seems that the challenge is recording a large dynamic range, not boominess per se.

[jim1960]

A good end product can also be accomplished by creating a composite track. Do a few passes for the louder parts, then adjust the gain and do a few passes for the softer parts. Playing to a click track would make it very easy to line it all up afterwards.