RECORDING STRINGED INSTRUMENTS

RECORDING STRINGED INSTRUMENTS

So what is similar about all stringed instruments? Basically, all stringed instruments work on the same principle of a tightened string between two points thus:

If you check out a guitar and a piano they are both the same. Both have a tunable string stretched between two points. In the guitar the sound board is the flat front of the guitar where the bridge is mounted, in a piano there is a sound board below the strings serving the same purpose. The sound actually varies depending at which point you place the microphone, so that the sound near the bridge end is different from the sound in the middle of the string:

These three different mike positions all present a different aspect of the sound.

• The microphone over the bridge is harder sounding and has more of the mid frequencies than the low frequencies.
• The microphone over the middle of the string has a full version of the sound and when placed near the striking method area has the transient sound of the string and the strike.
• The microphone near the soundboard has no string impact sound but has all the body of the sound.

The way the string is vibrated or striking method - also determines how it will sound.

• You can strum it as in a guitar.
• You can hit it as in a piano.
• You can bow it as in a violin.
• You can pluck it as in a harp.

Either way, the three positions of miking it will always apply.

Select the different pages from the index list above and
see how this principle applies to each instrument.

RECORDING ACOUSTIC GUITARS

The acoustic guitars is the classic stretched string instrument as it has all the positions where the sound varies. These are the main positions that can be used to record an acoustic guitar.

Lets look at the different positions.

• Position A

This is the standard crossed pair stereo miking position. This gives an overall sound of a guitar, it is not a tight presence sound like position B but has the combination of the striking sound, the bridge sound and the body sound. The stereo effect is not very wide but if you want the ambience of the room (like in a full strum rhythm track) it can be appropriate. This can also be a position for a single mike.

• Position B

Position B is the most popular mike position and the one I recommend for normal acoustic guitar recording. The mike is placed about 15cm(6') from the guitar pointing at the end of the finger board but not directly at the sound hole. The pick sound is emphasised in this position giving a nice clean attack to the guitar. This position also has the mike pointing away from the fretboard so finger noise is reduced.

• Position C

This mike is aimed directly at the bridge and is close around 10cm(4'). The sound here is harder sounding as it has less low frequencies and the mid range sounds are emphasised. If I wish to record a stereo guitar I usually use positions B and C and pan one mike left and the other right. In these positions the stereo spread is emphasised because

1. The mikes are about a 30cm(1 foot) apart therefore increasing the difference thus the spread.
2. The sounds are very different because each mike is recording a different aspect of the guitar sound.

• Position D

Position D can be used as an alternative to position C for a warmer stereo sound as it doesn't have the hardness of the bridge sound yet emphasises the warmer body sound. You must note that the mike position at the rear of the guitar causes the mike to be 180 degrees out of phase to the mikes in the other positions therefore a phase reversal must be used.

• All Positions!

Why not use all positions? If you are about to record acoustic guitar tracks why not set up mikes in all positions and play with the balance of each mike to gain the benefits of each. You might have a great stereo spread between positions B and C yet adding some of position A will add fullness and body, or adding position D panned centre to do the same. Play around, don't just limit yourself to one position only.

Tracking Techniques.

How we wish the guitar to sound in the track determines how we track it to tape and how many tracks we use. Lets look at the various ways acoustic guitars are used.

Solo guitar as in folk singer.

Here you can either use position B and have the track in mono or you can create a stereo track using position B and C. The thing about folk singers is that they sing and play at the same time!! so the guitar mikes are going to pickup the vocal as well therefore any EQ, Reverb etc. that you put on the guitar will also affect the vocal. To get the minimum spill of the vocal into the guitar mike I recommend you use position B and raise the mike so it points down at the guitar at about a 45 degree angle but still in the B position. This tends to put the vocalist off mike to the acoustic guitar mike. (You can also do the same with the vocal mike by having it pointing up at the singer and away from the guitar.) Another method I've seen is to place a soft covered sheet of cardboard or timber horizontally above the guitar that divides the spaces between the guitar and the vocal, but your guitarist must be able to play without seeing their hands!! but it does work.

If the singer is going to overdub the vocal later then you can afford to make more of the guitar sound by recording it in stereo but the singer must play the guitar track without singing.

Strummed Rhythm Guitar.

In this situation you may wish to have a single stereo/mono guitar track or you may wish to multitrack the acoustic. I often double track an acoustic rhythm guitar with one panned left and one right. Another good method is to get the guitarist to play one part through then to put on a capo and play the same chords but in a different position on the guitar. This expands the guitar sound and sounds really good. Some people call it 'adding a high strung' You play the first part in say the standard C position and then play the part capoed up to the third fret but play it in the A position. You can go even further , as I have often, and record two tracks in the C position and then do two tracks in the higher capoed position. The effect is a wall of acoustic guitars. You can pan the two high strungs left and right and pan the low strungs half left and right.

RECORDING ELECTRIC GUITARS
AND BASS GUITARS

Electric guitars lend themselves to multiple recording techniques. You can put a mike on and amp and leave it at that or you can try all sorts of things. The following options are available:

1. Direct feed from the guitar.
2. Close mike on the amp
3. Ambience mike on the amp.
4. Direct feed from the effects units
5. Room Ambience mike.
6. Second Guitar amp.

Direct Feed.

If you are fortunate enough to have a real-time analyser you will find it interesting to plug your guitar straight into it and look at the frequency response a guitar puts out. The standard Fender Strat peaks at around 7kHz and rolls steeply off from there up whereas the old classic Les Paul peaks at around 4kHz and falls off quickly from there. It's worth noting that factor when listening to the direct sound from a guitar. If you are going to plug the guitar directly into the console you will need a direct box.

This is a box that matches the impedance of the console and the guitar. A guitar is designed to plug into an amplifier that has a high impedance input whereas a console mike input is designed for low impedance inputs thus the direct box. The impedance matching circuit can be either a transformer - passive - or a circuit - active. If your unit is an active one it will require power which can be supplied either by an internal battery or by Phantom Power fed from the console mike input. Once plugged into the console have a listen to the sound. You will find immediately that the sound is dull and has no real bite in the top end like we are used to in a guitar so quite a large amount of high end EQ is required to brighten up the sound. You can put the direct feed through some effects units and compress it and it will probably sound better but it won't sound like an electric guitar as we know it . On the other hand a small amount of the equalised/compressed direct signal added to the amp sound can add a soft presence to the sound that is nice in certain circumstances like a soft chorus guitar playing chords etc. To get the full grunt of a guitar you will need an amplifier.

Miking an amplifier.

The thing about guitar amplifiers is that they have a huge amount of upper-mid and high end equalisation in the first stage, which is called the pre-amp, to compensate for the lack of high end in the original signal. Guitar amps also have addition equalisation on the front panel as an option. This equalised signal is then fed to the power amp and the speakers. Some amplifiers allow you access to the signal after the preamp and before the power amp. It is then possible to take a split of the signal after the preamp , with all the additional EQ, and feed it into a direct box and then straight to the console.

The standard mike technique for recording an amp is to place a mike 10cm(4') from the speaker at an angle.

You will note the mike at the rear of the cabinet. This mike has a boxier sound than the front mike and is 180 degrees out of phase to the front mike so a phase reveral is required. Remember when setting the sound of an amplifier to put your head where the microphone is. The front of a standard amp is directional and if you stand above the amp you won't get the true sound coming from the speaker. The microphone used must be capable of handling high sound pressure levels.

Adding an ambience mike.

An ambience mike will add another dimension to the sound. It can be another cardiod mike or you can us a U87 in a figure 8 pattern. (Very popular) This puts the direct sound off axis to the ambience mike and it also picks up the room ambience. This extra mike can be mixed with the other mike onto one track or it can be tracked to another track allowing you to adjust the balance at the mixing stage. It can also be panned differently than the close mike which gives the guitar sound a stereo sound with more breadth and makes the guitar sound bigger. Alternatively you can use a MS Stereo setup.

Using effect boxes.

Most guitarists these days have a bank of effect units setup between the guitar and the amp. You can intercept them by plugging them into the direct box before the amp or you can use your own effects. You must remember that the sound coming out of the DI box will not be the same as the one coming out of the amp because the amp adds all its EQ etc. but a feed from the units can contribute to the sound. Some of the effect units such as the multipedal floor units also operate in stereo and can give you a stereo feed of the signal with stereo effects.

But what about my own effects I hear you say - why should I use that cheap $150 delay stomp box when I've got a $2000 delay unit. This question is a matter of choice - the guitarist might like the cheap effect unit , is used to it and has created a sound around it - on the other hand you may be able to produce a much more diverse delay effect. Remember the guitarist's effects are going through the amp whereas yours aren't. This is where you and the guitarist must play around and try different things. If both of you are into getting the best sound you will get it but if you are both into maintaining your respective egos all hell could break loose.

For more info regarding using effects units go to the pages on Using Effect Units.

Adding a room ambience mike.

You can go one step further than the close ambience mike and add a room mike (or two). This can give that large grunge guitar an extra beef and for extra effect can be gated so it stops short when the guitar stops. It can be a mike like a U87 with a figure 8 setting or you can use a shotgun mike and aim it at the amp. Considering that sound travels at around 30cm(1ft) per millisecond a mike at 15ft is going to be delayed by 15ms. This could be great or it could be awful - experiment!!

Adding a second amplifier.

You can also add another amp and split the guitar feed into each. If you have a stereo effect system you can split it left and right, mike each amp and put a stereo ambience mike between both amps. You can set each amp up differently, or use two different amps. If miked separately you can achieve a perfect double track as each amp will sound different but have the same signal.

Playing in the Control Room.

Most guitarists like to play in the control room even though their amp is in the studio. This allows them to hear the guitar as it would in the track on your speakers and with any effects that you've added. To enable this you must run a long guitar lead through to the amp. It is worth considering having a plug in the wall that they can plug into that can be picked up on the other side of the wall and plugged into the amp. Alternatively you can run a long lead via the doors - unfortunately guitar leads don't like being long as they loose high frequencies when travelling long distances. One way to stop the loss is to use two passive transformer based direct boxes. You plug the guitarist into one in the control room and then take the low impedance feed out and run that into the studio. In the studio you plug in the other DI box and come out of the guitar input and plug it into the amp. What we are doing here is using low impedance to travel the distance and bring it back up to high impedance to plug into the amp.

You will need a sex change plug from male to female XLR to get back into the second DI.

Additional Factors.

There are a few additional factors that must be considered here. I'm sorry but a great engineer can't make a bad guitarist sound great!! There are a few things that can seriously effect the sound a guitarist makes. Firstly, is the guitar setup correctly? Apart from the pickups, model etc. which are set, the variables are - correct alignment of the neck so that the strings are not too low. If they are too low you will experience string distortion caused by the string hitting the adjacent fret, which tends to muddy the sound as the string is not free to vibrate evenly. Secondly the strings used can be too light. A guitar strung with light gauge strings will not sound fat and grungey. A very good guitarist friend of mine says that most people can't play his guitar because it is strung so high and the strings are heavy gauge, but believe me his sound is great. From a musical point of view the guitar might not have the harmonics in tune so that when the guitarist plays up high on the frets the guitar is flat or sharp. All these factors affect a guitar sound but you can't beat the truism that if you want a great guitar sound get a good guitarist.

There are many ways of approaching recording the electric guitar. The main thing I believe is to give yourself as many options as you can. Experimentation is the call here, as with the acoustic guitars take the time to put up all the mikes and experiment with the different combinations. I can remember when I was recording an OZ band called Mondo Rock and we wanted a close sounding power chord in a song called 'Come said the Boy'. The sound we wanted was a Marshall wound up to 11 but recorded close. We tried every mike we had but they all distorted when put so close to the amp, even an SM57 fell over. That day a rep from Neuman came to the studio to try to flog us the new TLM mike. I was reading the specs and it said that it would handle up to 139spl so we asked him if he could leave the mike with us and we'd assess it. When he'd gone we quickly stuck it on the amp and bingo! it worked. The song went on to sit at number two on the charts for about eleven weeks constantly stopped from going number 1 by John Lennon's Imagine. Them the breaks!!

BASS GUITAR

The electric bass guitar differs from the electric guitar in that the direct signal from the instrument does not need special EQ so direct feed via direct box is the normal way of recording a bass guitar. Typically most bass amps offer an extensive EQ section and some offer a valve preamp but the bass amplifier is just a dirty big power amp which is required to move the cones of the large heavy speakers. Often a bass amp setup will have two boxes, one with a set of 10' speakers and another with a heavier 12' or 15' speaker. In this setup you can mike each box individually

The bass guitar also lends itself to bi-amping where a crossover circuit divides the signal into two or three frequency bands and uses a separate amplifier and speaker for each band.

The split from each frequency band is sometimes available as a console feed from the rear of the amp so you can take two/three direct feeds into your console. This allows you to compress and EQ each band separately and assign them to different recording tracks for full control later in the mix. The crossover frequency is selectable in most amps with the crossover frequency usually at around 100 - 150Hz with the 10' speakers handling the high section and the larger 12'/15' speakers handling the powerful lows.

I often feed the bass straight into a DI box and have the player in the control room which helps separation. The bass guitar lends itself to compression. The low frequencies it produces contain a lot of energy and containment with compression is recommended.

RECORDING PIANOS & ORGANS

The Grand Piano

The piano is really just a guitar (or more accurately a harp) lying on its side. It has strings stretched between two bridges, a striking area where it is hit with a soft hammer, and a sound board below.

The drawing above shows the main areas of concern when recording a piano. The mikes can be placed in any of the position A - D as well as underneath. The sound holes give you access to the sound board below the strings. So lets look at each position.

Position A

Position A is the most typical mike position used in studio music recording. It's a stereo pair that is about 150cm(6') apart, placed over the hammers with one pointing to the lower strings and the other directed toward the high strings. They should be about 150cm(6') above the strings. They are placed just behind the music stand. If there is no music involved the music stand can be removed giving a cleaner access to the strings. If these two mikes are placed correctly you can achieve a really good stereo image where the low strings appear from the left and the notes follow to the high notes on the left. Because the mikes are over the hammers the notes are bright and have a nice attack.

Position B

Position B utilises the hardness of the bridge and can be used to emphasise the low strings. I often add a small amount of it to the left of the image to accentuate the bass strings. Great if you have a 7 or 9 foot grand!!

Position D

Position D is the traditional Classical way of recording a grand piano and is still used today when recording grand pianos with an orchestra. It can also be used to add body and warm to a position A setup.

Position C

Position C is a position that accesses the sound board. The level coming off the sound board is quite high so it is a good position if you are caught having to record a grand piano in a studio with other instruments and you want separation from the other instruments. Two mikes places in the sound hole s allow you to lower the piano lid to the lower stand and with a couple of blankets or sleeping bags thrown over the lot you will get good separation yet a clean sound that will sound even better with a bit of high shelving added. Another way of accessing the sound board is to place a mike under the piano pointing straight up. This is often used in TV where they don't want the mikes to show.

PZM Mikes

There is one more way of recording a grand and that is to use 2 x PZM mikes fixed to the lid and then the lid closed. This produces a beautiful clean sound and is also great if you have spill problems, hence there use on stage shows. Give me two good Neumans or AKGs and I'll go with them anyday though. The AKG 451 is my favourite.

The Upright Piano

Unfortunately most home studio owners don't have a grand piano but lots of you have an upright. So what's the best here - well - treat it like a grand. It has all the same spots.

Here we have a typical upright piano with the typical three positions. To access some of these positions you may have to pull the piano apart. The front panel above the keys can easily be removed as can the panel below the keys. The easiest and simplest is to simply drop two mikes on boom arms through the top and set them up as a stereo pair as in the grand piano over the hammers and about 15cm(6') apart and pointing left right. This placement is easier if you can remove the front panel.

Position A

This is the standard position as described above and can be supplemented with either a rear soundboard mike (out of phase) or a lower mike in a sound hole under the keys. In this case the lower front panel must be removed. Try and avoid getting the lower mike too close to the pedals as their sound will become annoying.

Position B

Position B is the one used on the old TV shows where they didn't want you to see the mike but it also has a lot of body and warm in the sound so when incorporated with position A it can be helpful.

Position B

Position C is a variation of position B except that it can also incorporate the harder bridge sound.

Personally I would go for position A every time and would only use the other positions to supplement the sound or because I can't get into the piano and can't take off the front panel.

PZM Mikes

Once again two PZM mikes strapped to the front panel at the height of the hammers will work very nicely indeed.

The Organ

The Hammond Organ is another beast altogether and although it's not a stringed instrument I'll include it here. The Leslie box consists of a divided cabinet. In the top section is a rotating horn covering the high frequencies from around 800Hz up while below is a woofer cabinet covering the lows. The woofer also has a wooden horn shape that rotates. This is how I like to mike a Hammond Leslie Box.

The rear of the Leslie cabinet will need to be removed, its only a few screws. The microphones are basically two stereo pairs which you pan L/R. If you wish to be really mad you can carefully put one of the high frequency mikes into the cabinet like this:

This really gives a great stereo effect and the Leslie rotates in your head with headphones. The top mikes are totally 180 degrees out of phase but who cares, the effect is great.

Incidentally, if you want that incredible Emerson Lake and Palmer growl from the Leslie, remove one of the large output valves that I've drawn in the picture above. Some people have modified their Leslie cabinets so you can plug a guitar directly into the valve amp so you can get a real Leslie effect on a guitar. If you also remove the output valve you'll get the wildest guitar grunge!!

RECORDING OTHER STRINGED INSTRUMENTS

The Harp

The harp is the ultimate stringed instrument and I sympathise with all the harp players as it is the devil of an instrument to tune. They say mischievously that harp players spend half the time tuning up and the other half playing out of tune! (sorry harp players)

There are basically two ways to record a harp. If it's on its own as an overdub a simple high quality Condensor mike 30 - 60cm(1 -2 ft) from the instrument aimed at the striking point (hands) will cover it fully. You can also use two mikes as a stereo pair similar to the position A in pianos aimed at the top and bottom strings respectively and as close as the player finds comfortable.

I used to often have a harp within a big band/strings situation where it was so quiet relative to the rest of the brass etc. that a mike in this position was 80% spill so I had to find a better way. What I found is the other way of recording a harp using the sound board as the source. Like the holes in the frame of a grand piano the harp has a series of sound holes down the back. If you get a quality mike and wrap it in a cloth you can jam it into the centre hole. The cloth will hold it tight and stop any handling noise and you will get a good level signal that with a little top EQ will work very well and have a lot less spill and you'll be able to mix those beautiful glissandos over the brass. A combination of both mike positions will give a fuller richer sound if used together.

The Banjo and Mandolin

The banjo and mandolin are similar to the acoustic guitar and both have the same points - strike area, bridge and sound board - thus the same mike positions apply. I don't like to get too close to a mandolin or banjo because their sound doesn't fully develop until around a foot or two away.

The Dobro

The Dobro and lap steel both have a recording problem mainly the string noise as the slider moves up and down the strings. If you think of them both as guitars on their backs and place the mike in the acoustic guitar position B where the mike points back towards the striking position you can put the fingerboard off axis to the mike and thus reduce the slide noise. You can also mike the sound board and bridge as per the acoustic guitar.

The Violin Family

The violin, cello viola etc. are all the same except different sizes.

They all have a strike point (bow area), a bridge and a sound hole and soundboard. For the violin and viola the typical miking is to place a quality mike 30 - 60cm(1ft - 2ft) above the instrument pointing down aimed at the strike area. This gives a balance between the bow, bridge and soundboard sounds. One technique I have tried is to mike the violin from underneath as well as overhead with the bottom mike in the opposite position to the overhead mike and phase reversed. By adding a little of the under mike you can add body and warmth to the sound because you are adding more of the soundboard sound. It can also be said that a violin player should be on a reflective floor as opposed to carpet because the sound emanating from the soundboard will reflect back off the floor and add to the fullness of the sound.

The cello is the same with the mike out in front of the instrument pointing at the bow area. Additional close mikes near the bridge and the sound board/hole can be used for effect if required. Again a reflective floor is recommended.

The Acoustic Bass

I have singled out the acoustic bass because it is one of the hardest instruments to record in my opinion. Being a classic stringed instrument it has all the sound areas - bow area, bridge, and soundboard and soundhole. It depends on the style of music as to how you mike it but the hardest is the straight plucked jazz bass. The traditional technique is to use a good mike (preferably with a large capsule like a U87 or U49 and put it about 5 - 10cm(2' - 4') from the bridge. This will emphasise the attack of the fingers with the added hardness that the bridge sound has. Another mike can also be added that is aimed at the sound hole which will emphasise the warmth and lower frequencies. A mix of these two should cover it nicely. Many bass players have an electric pickup on their bass and a combination of direct pickup and mike works well as the pickup adds presence.

Be very careful about the low end of the sound. It may sound silly but quite often to get a good bass sound you have to remove bass from the signal. A low end rolloff from around 80 - 100Hz can stop the bass from sounding muddy or a dip around the low mids at 200 - 300Hz will also work. There is a lot of energy in the low end of an acoustic bass and reasonable compression can help to contain it.