The most important thing is to walk around the instrument as it’s being played. Get your ass out of the chair! Walk fully around it. Use one ear up close and in various positions around the instrument. Every acoustic instrument is different and has its own “sweet spot” – it’s your gig to find it! I’m going to give you the boiler plate of micing these very finicky and subtle things. You will no doubt find different places and positions to mic but this will give you a nice starting point.
I prefer a pencil condenser mic. A large diaphragm condenser will also get it done. A dynamic mic is gonna give you a rough time for recording the important subtlety’s but it can also be a “vibey” sound. A ribbon is cool but generally is used as a supplemental mic, not primary but then again it can be an interesting sound. You can also use a room or ambient mic(s) along with close mics and blend it in to taste when you’re mixing.
Acoustic or Classical guitar:
A mic positioned at the 12th fret 6 inches from the neck and looking down the fret board towards the sound hole is the most standard way of micing. Or try the mic looking directly at the neck at the 12th fret, out about 4 inches from the neck. I also use an additional mic about a foot out directly in front of the sound hole and then flip the phase on this mic. You can also position a ribbon mic at this position or even have it looking down over the shoulder of the player. You could also place a second mic 2 feet in front from the back edge the guitar looking (pointed) at the bridge of the guitar. I’ve also used two pencil condenser mics, one on either side of the sound hole, about a foot off the sound hole and a foot apart. They should be parallel to the instrument and looking in at each other. Now turn each mic towards the guitar about 20 degrees. In this method you’re using phasing as your friend. Small movements of the mic in all these methods make a big difference and can take a sound from awful to bliss and vice versa. If you must, then record the DI if the instrument has it. Sometimes, especially live or in a room with other instruments it’s necessary but usually there’s as much soul and vibe to them as a piece of particle board, sometimes less. If perfect isn’t an option then getting the job done is.
When I mix I usually have the F hole mic down -10 to -15 db from the mic over the finger board. I’ll bus both mics to a mono Bus/Group and compress and EQ from there. I like a moderate to slow attack, a fairly quick release, and at a 4:1 ratio. EQ is generally added around 3K and also at 11K and take away at 100Hz or 200Hz – sometimes I’ll put a low pass filter starting at 50Hz or even at 100Hz and then EQ more out between 100 and 250 Hz with a fairly tight Q.
You can use these ideas for similar instruments such as a Lafta, Lute and other more exotic instruments.
National/dobro guitar:
The doughnut is key. Lots of the instruments tone comes from the resonating doughnut and also the F holes. I’ve used dynamic and condenser mic and combinations of the two. Start with a neck mic, as described above. Now take a dynamic mic and place it straight on and 6 inches to a foot away from the bottom F hole. You might find moving this mic directly center to the doughnut is also cool sounding. Rooty and vibey are what you’re going for – it’s not an acoustic guitar, it’s its very own unique vibe and kinda small and nasally is a goal.
Same thing for EQ and Compression as outlined above for Acoustic Guitar but I might focus and boost more at 1K instead of 3K
Upright Bass:
If I can, I prefer two mics on upright. I listen for a sweet spot around the bridge and F Hole. Once I’ve found a well balanced spot I’ll use a large condenser at that spot – generally at a 45 degree angle from the instrument, a foot out looking towards the spot between the top of the F Hole and bridge. Maximum low end is not the issue – you’ll usually have more than you’ll want. Look more for full and rich rather than boom. I’ll also use a pencil condenser mic on the neck, a half to 3/4 of the way up the neck, a foot off and looking toward the end of the fret board. This will give you definition and attack. You’ll need to flip the phase on one of the two mics. You can also just use one mic. If I’m only using one mic I’d move the bottom mic a little further up to where the instrument is plucked. In live situations I’ve also taken a dynamic mic and wrapped it in foam with only the capsule uncovered. I’ll stick that under the strings past the bridge looking up towards the bridge. This eliminates a ton of bleed from other instruments and will at least get you something usable. Cool if the instrument doesn’t have a DI or the DI sounds like crap, which most do on an upright.
When I mix, I’ll send the two mics (generally with the top mic being louder than the bottom mic) to a mono Bus/Group and Compress and EQ that channel. Compression is just like an electric bass – slow attack, fast release, and 4:1 or 8:1 ration. For EQ I often put on a low pass filter and take away sub low stuff 45Hz and below. I’ll also make sure the two mics balance so that there’s not too much string slap or fret noise. Unless you have huge speakers or a sub you won’t hear just how much of the very low end you have – just presume you have a ton and treat accordingly – it can mess a mix up quick.
Cello:
Upright bass and cello are not that different when it comes to micing. Sometimes I use two mics but usually I just use on large diaphragm condenser mic and try to really be specific where it’s placed according to how that individual instrument sounds. Usually the mic is place 2 to 3 feet away from the instrument at a 45 degree axis from straight on, looking more at the bridge than F Hole and sometimes slightly above the bridge – which will get more of the bow’s sound.
When mixing a cello, I compress slightly to even it out and EQ to give it air and a little more attack – 11K and 2 to 6 K range respectfully. Be careful on the low end – too much take away in the 200 Hz range and you can kill the body of the sound, so try a tighter Q when EQing in this range.
Violin/Viola:
Air! Give it some room. No such thing as close micing on a violin or viola, unless you’re going more for a fiddle sound. Violins are delicate things – the sound is generally small and can get abrasive quickly, especially with a less than proficient player. Viola’s are more robust but can have some trouble in certain frequencies. I usually only go with one mic. You can add a room mic but the primary mic is going to pick up a lot of room anyway. Go high. I use a pencil condenser at least 3 feet above and 4 feet in front, pointed towards the center of the violin/viola. If it’s too ambient for your taste, just move in a foot each way until you like what you hear.
Lots of times I use a violinist/viola to cut multiple parts and quadruple each line played – kind of building up to the equivalent of a chamber orchestra. Important: You must playback the parts the player has just played in their headset when they start to double . It’s important they hear the line before that they have just cut in order to match vibrato and expression. Also if you’re doubling/tripling/quadrupling a line make sure that with each new pass the player moves from the spot they just recorded from, just a foot or so either way. This will make a huge difference and a much fuller richer sound. Think of it like a violin section of the orchestra – they sit in chairs next to each other, not on top of each other – although that would be fun to see. You won’t have a different violin or different player’s hands for each pass but you’ll at least have a slightly different timbre on each pass. It makes a difference.
When I mix a violin/viola part it starts with the compressor at a slow attack and slow release, and moderate ratio – 4:1. But let’s say I have an arrangement that consist of 3 violin lines and 2 viola lines, and with each line being quadrupled. I’ll pan all 20 channels at their individual faders according to where I want them in the stereo image. I usually pan just as if I’m looking at an orchestra: Violin 1’s quadrupled parts are paned in various degrees of fairly hard right, violin 2 less so hard right but still each quadrupled part with a different pan, violin 3 the same but more towards center, and viola’s occupying soft right, center and soft left. No right or wrong to this – it’s according to your taste. After I’ve got my panning together I’ll bus all to a stereo Bus/Group and compress using the same setting as I would with one instrument. Sometimes I’ll bus each line (ex only violins that make up Violin 1, 2, etc) to a and individual stereo Bus/Group and then send all the individual lines to a master string stereo Bus Group. I generally won’t eq or compress the individual Bus/Groups but this will allow you to control levels of a part using only one fader instead of 3 or 4. Instead I’ll compress and EQ on the Master String Bus/Group. Only trouble with this method is that if you’re really increasing a line at a certain time then you are sending more into the master compressor, which means you’re hitting it harder and thus fighting it a little – but most times it’s a cool thing. If this is a problem then just compress and EQ on each parts individual Bus/Group and then send to a master Bus/Group which will be used only for overall level of the entire string section.
A word on EQ. Be careful of taking out too much low end. A lot of body is in the 100 to 300Hz range. I will roll off everything below 75 Hz and then dip a little out between 700Hz and 900 Hz and again cut at between 1K and 3K – all depending on the tone of the instrument you’ve recorded and then I’ll lift, very subtly, above 6K. You don’t want woofy, you don’t want slicing abrasiveness, and you definitely don’t want whinny.
If I can I’ll set up two reverbs – one a large room/Hall/plate with a long decay and another reverb that is smaller with a short decay and then add both to taste to my master string Bus/Group. Lush but not smeared is the goal. As a quick reference I use 3 different recordings as touchstone, The Beatles “Eleanor Rigby” – a quartet in a close space, almost tight and dry, Jeff Buckley’s “Last Goodbye” – a moderate room with a small chamber orchestra, and then anything by the Philadelphia Orchestra pre 1990’s for big and lush. But you’ll find your own references. I recommend listening to them in order to keep them fresh in your head as you begin to mix your own strings.
Mandolin/Ukulele/Banjo:
Each of these instruments are so dependent on the particular instruments tone that there is no hard and fast rule. You must listen to the instrument, know what you want from it, and mic accordingly. With Mando and Uke if you want a starting place it would be a mic at the neck looking back towards the body. Also try the mic looking directly at the neck a few frets from where the neck meets the body. Mando you might find straight on to the top of the F Hold is best. Banjo can be the same neck position but you also might find straight on where the hand picks is the place. My compression setting is very similar to a acoustic guitar but I’ve also really leaned in and smashed them too – depends on what you want. For EQ, get rid of stuff below 75Hz and add some air (above 10K) and attack (1 to 6K). You might also need a little cut around 300Hz.
PIANO:
There are endless ways to mic pianos and endless ways a piano can sound. Grand, baby grand, Upright, Spinet. Know what you want for an end result before micing! I’ve mic’d a baby grand but mic’d and processed to get a more honky tonk sound – depends on what you have and what you need. But here are a few ballpark ways of micing. The first would be an X/Y micing (refer to X/Y micing under Drum Overheads which describes what and how) with the mic’s placed center and over the hammers. Another method is larger diaphragm condensers placed on the side and looking over the edge of the piano, one at the top of the bend looking towards the hammers and the other at the bottom of the bend of the piano. You can also take large diaphragm condensers and have each looking straight down and about a foot off the strings, one placed towards the hammers focusing on the higher strings and then the other mic place midway down the piano and focusing on the lower strings. You can add in room mics (X/Y or wide placement) placed in the preferred position for maximum room but still having clarity. I’ve also used one ribbon mic on a baby grand sitting on top and to the front of the piano and looking down towards the hammers. This is a cool rock sound especially when you’ve compressed the living crap out of it. Piano’s have a large dynamic range so be careful to not give the mic pre too much gain or you’ll peg it on the heavy hits.
To mix it you can either pan hard Left/Right or less so. I’ll send the two mic’s to a stereo Bus/Group and compress and EQ from there. A light touch to maximum warp just depends on what you want. Try a fairly slow attack and fairly quick release with a moderate ratio as a compression starting point. When you EQ try to reduce sub low rumble and give it some air on top. The 2 to 3k range is important – you want attack but you don’t want the audience to feel assaulted – most of the time.