Tracking bass instruments ranks among the hardest tasks to get right in a home setting for several reasons. None the less, it’s perfectly possible to get great results.
TRUSTING WHAT YOU HEAR
Before talking about the sound you are recording, it’s really important to be able to hear the bass recording accurately on playback so you can reasonably assess the part you have just recorded.
In other words, think about the accuracy of your current studio monitoring with respect to low frequencies.
Correct placement of monitors in the room is a big deal here, and my post on studio monitoring covers a lot of the salient information.
If you have a subwoofer, make sure you can trust the low end in your room with it switched on. They do much more harm than good when improperly configured for the room and the monitors they are paired with.
I would advise using nearfield monitors that have 8″ woofers for dance music to approximate a club in a smaller room and maybe 5″ will get you by for softer, lighter music or folk or singer/songwriter, where there is little deep bass content required most of the time.
A recording of a voice (or massed voices) with an acoustic guitarist has nothing below 80-100Hz of any great significance, for instance, and an HPF filter set accordingly will usually be applied to voices and acoustic guitars alike to discard all those lower frequencies.
Many singer/songwriters make whole albums of material exactly like this and nobody minds the absence of the extreme lows. We don’t tend to listen to this sort of music on massive sound systems or in night clubs, where the sub-bass is an essential ingredient.
If you do use a subwoofer, or even two (gasp!), then make sure you check your work against commercial mixes regularly, using songs that you already know sound great in clubs and on your best, biggest monitor speakers.
After you’ve heard the differences between your bass sound and theirs, you can apply filters, and adjust EQ and levels accordingly to better standardize your results, making your mix ‘portable’, which simply means it sounds good on as many playback systems as possible, whatever their size.
STRINGED BASS INSTRUMENTS DOUBLED WITH MIDI
For the purposes of this post, I will simply mention in passing the bass synthesizers, Hammond B3 and left-hand piano parts that keyboard players and/or MIDI can bring to a song. Reason, Omnisphere, Massive, and the many Moog and Prophet V sims spring to mind for MIDI bass options. Explore away!
Although majestic bass sounds can be found in the land of MIDI and/or keyboard instruments in general, we won’t look at them in this post, other than to mention that they can work really well for doubling real acoustic basses or electric bass guitars if you maintain good phase relationships.
If you do this, keep them mixed below the stringed instruments to prevent them revealing themselves too easily, but loud enough to provide solid support and added girth in the lows. Check your intended mix collapses to mono successfully, without losing the bass.
I’ll visit those keyboard-related bass sounds properly when I deal with mixing in a series of posts coming shortly, and there is plenty of valuable information already posted here at wiggly toes music on getting great bass synth sounds in my MIDI-related posts. I’ll also deal with the classic puzzle of how to lock the bass and kick together tightly in a mix, as I will be writing a post specifically on that one topic in a week or two.
Today I’m really looking at stringed bass instruments, including electric bass guitar, acoustic bass guitar and acoustic upright (double) bass.
The biggest factor is easily the player, and secondly the instrument, and then the room. I’ll take it for granted that the bass part is great and compliments the rest of the parts playing in the song, and has prosody with the lyric and feel of the song (supporting rather than conflicting with the sentiment, as it were).
It’s essential to be in tune, so keep checking tuning as you work, without breaking the flow unnecessarily. Pitch is very important with bass, and due to our hearing mechanism we can easily have trouble detecting low pitches accurately. Use a tuner. A lot.
Nothing undermines a mix more than being unable to pin down the fundamentals of the tones used due to out-of-tune bass notes, and being forced to use Auto-Tune or Melodyne or another pitch-correction algorithm, setting them up to deal specifically with bass.
It’s hard to create a rich, complex, well-supported harmonic series in a mix when there’s a bass and low mids problem, and the trouble immediately spreads to the kick drum, hurting the groove as a whole, since the bass instrument is a key piece of the interlocking puzzle of low-end groove in a mix and the kick drum needs to be complimentary in tone, filling frequency spaces the bass avoids, and vice versa.
Playing style and technique is far and away the biggest factor in getting good results, so if you are hoping for a very high quality real bass sound, choose the player carefully for best results. Better players usually use better instruments, which also helps a great deal.
If you are playing and you only have a cheap bass, consider renting a higher quality instrument for a day from a music retail outlet or instrument hire company. The sound quality and the intonation and playability are noticeably better. It’s only a few dollars a day, and the bass that ends up on your song will be there forever to plague you or please you.
Also, make sure that the strings are played in enough to sound good and remain stable in tuning, but not so used that they are approaching the dull and lifeless stage.
Very new strings tend to be squeaky and may drop in tuning during a take when played hard, and fret noise can be a real problem with fretted stringed instruments in general.
Bass is very susceptible to phase issues, and you really don’t want your bass disappearing when the song is played on a mono system, of which there are many. Most restaurants and stores and malls play music in mono, for example, so that the listener’s location relative to different speakers is not problematic.
The easiest method is to use an electric bass guitar and take a DI from it. It’s much harder to get a good sound from an amp, and most of us are unlikely to have a big enough room in a house to record it really well.
If it is impossible for you to use an amp where you are, you can get a really rather good bass sound with a DI box or interface Instrument Input, and run it through a plug-in or two later to simulate an amp miked in a room. Most of the time this will work very well.
There are serious constraints imposed by the laws of physics which affect your ability to capture bass well. You also have to remember noise levels, since bass is an irritant to many neighbours, being disturbingly muffled and yet still loud at a distance through walls. Most bass players want to hear a fair bit of volume when they are recording their instrument, so that they can “lock in” with the kick drum and groove.
It’s also more or less impossible to effectively isolate a bass amp, so you can’t really prevent a loud bass amp from getting into other mics that are in use on other sources at the same time in the same space.
You might choose to record a DI track, and re-amp the bass at a convenient time, nailing the sound at your leisure as an overdub.
See my post on tracking electric guitars for reamping details.
YOU CAN’T CHANGE THE LAWS OF PHYSICS, JIM
Consider that the length of the lowest note’s waveforms can be over fifty feet long, meaning that even a single wave cycle (from peak to trough to next peak) of a bottom E note on a bass cannot physically occur within most rooms in most ordinary houses.
In comparison, a fairly high note may be only a few millimetres long for a single wave cycle, making due care and thought about microphone positioning of great importance, especially on bright-sounding instruments.
Bass instruments can produce long waveforms on the order of tens of feet, and therefore, when you record a bass with a microphone, you should do so in the biggest room in your house that you can.
A single wave cycle, regardless of pitch, travels from zero degrees to 180 degrees and on to complete at 360 degrees, which of course will be seen as zero degrees for the next cycle to begin.
Having a signal be in phase with another signal, as I’ve mentioned in previous posts, is a matter of aligning peaks with peaks, not peaks with troughs, and doing so as accurately as possible at as many frequencies as possible.
In practice, we can only do so much, but the phase inversion switch is very handy if you don’t have a phase inversion plug-in and there will almost always be an audible improvement with a phase inversion setting made on one of the channels, whether it be ON or OFF, when two signals are combined, because you are statistically likely to be getting nearer to either zero or 180 degrees, one of which will be an improvement relative to the other signal in the overall combined sound.
Using the best equipment possible is a big help with getting great bass sounds. A good DI box, a good preamp, a good instrument, all these things help a lot.
Some DI boxes sound a lot better on bass than others, so audition some at a store and read online reviews in Sound On Sound or Mix magazines, or at the web forum Harmony Central. There are loads of great threads on recording bass. Explore and see what else you find.
ELECTRIC BASS GUITAR
Most of the time, in most contemporary genres, an electric bass guitar will be used.
Working at home, the most popular way to record bass guitar is to use a DI box, or an Instrument Direct Input, either on your interface or on a standalone preamp or console with the appropriate input type.
This method will allow you to work with headphones or speakers for your monitoring as you prefer, and will not annoy neighbours or wake the baby. The same cannot always be said of an Ampeg bass amp with a 4 x 12 cabinet, for example, but you will find the DI a satisfactory method for many styles of bass.
A DI is clean and functional, with a full frequency response. The missing ingredient is the sense of moving air that a bass amp and loudspeaker provide for you when miked up, and the room sound factors of the space you are playing in.
You can DI a bass, or you can mike it up by playing through an amp and speaker and miking the speaker. A lot of the time, you may do both, provided you can cope with a bass amp being miked up in your space.
DI boxes can be tube or solid-state, and for bass the tube version often wins due to warmth, character and flattering harmonic distortion in the sound. However, the solid-state sound is also useful since it is exceptionally clean and on the sterile side, which often can be exactly what you need from a bass guitar part.
DI boxes (and preamps) built by Sonic Farm, Aguilar, and Radial are all quite exceptional at recording bass guitars, but these will cost you a lot of money. With a DI or preamp, you usually get what you pay for, and with bass it shows more than in most areas. See my recent blogpost on DIs, preamps and line conditioners for more.
You should be able to get really good results from a DI input on your interface, in most modern interfaces, but you will find it harder to achieve the “moving air” sound of an amp without miking an amp in your space.
The amp sims in your DAW should provide bass amp and speaker combos in digital form that you can try to your heart’s content after the recording is made with a DI input or a standalone DI Box or preamp.
You will find some great sounds in the DAW for use on bass, such as the Sans Amp PSA-1 plug-in, which has great presets for bass guitar.
It’s a great idea to add a hair of distortion to the frequencies at the first couple of harmonics in the series of overtones produced by the low notes on the bass. For example, boosting low mids somewhere appropriate between 200 Hz and 300 Hz can make it much easier to make out the notes in the bass line on a very small speaker. More on this when I blog about mixing techniques in a couple of weeks time.
Most people agree that the ideal bass guitar sound in contemporary pop music genres is to combine a clean or tube DI with a miked-up 4 x 12 speaker cabinet driven by the best bass amp you can find.
Doing this requires two tracks, one a DI and one the mic in front of the amp’s speaker(s). The two tracks really, really do need to be in phase with each other or you will have a weak and possibly unusable result when you come to mix, so you will probably want to shift one track relative to the other on your DAW’s timeline by a few milliseconds after recording to ensure the very best phase compatibility. This is due to the inherent time difference between the two recording input chains.
USING BASS AMPS
There are many great bass amp and speaker makers, too many to list, but Ampeg stand out for me as virtually synonymous with great bass sounds in a studio. Over most of the history of pop music, the Ampeg has been amongst the front runners for bass rigs.
The Ampeg SV range is very well regarded for studio and live work. The much older Ampeg B15 ‘Portaflex’ was always a very popular amp, also called the piggyback or the fliptop. This is another great type of bass amp for recording, and although the original models are hard to find and could be costly to maintain, there are plug-in emulations that model the B15.
The B15 was often called a fliptop or piggyback because the amp was mounted on a piece of wood which doubled as the top of the speaker cabinet, so at the end of your gig, you could unclip the top part of the speaker cabinet (the amp and its tubes) and reverse the piece of wood, so as to contain the amp on the inside of the speaker cabinet for transportation purposes. Neat!
Sometimes it’s good to have the player sit on the floor and play their electric bass through the amp, since the vibrations in the floor add to the feel for the player. Low end is enhanced this way, but you can also decouple the amp from the floor to lose some of the lowest rumble from the sound in the room. Stand it on a chunk of rubber or an Auralex GRAMMA pad or similar product.
Mic the amp from at least one foot away, maybe 18 inches. This will let the long waves develop somewhat before hitting the mic. If there is more than one speaker, pick one only. Miking between them can cause phase anomalies. Aim off centre to the cone.
You can put gobos around an amp, but they won’t contain the longest waves. They do help with upper bass and low mids though.
It’s a good idea to throw away the rumble from the amp recording later with an HPF set carefully to suit the mix requirements of the song, which you can’t be sure of until you finish the tracking phase. You probably will choose a cut-off frequency for the high pass filter of 30 to 60 Hz, with as steep a filter slope setting as you can get away with without impacting remaining lows.
Placing the mics similarly to electric guitars works well. I like to leave at least a foot, since these are long waves. I choose mics with good low-end response, which means large diaphragms.
If you point straight on at the cone not too near the edge or the centre, you will get more brightness, more high end, than if you point off to the sides of the speaker cabinet further out where richer lows are swirling but with less definition.
In folk, bluegrass, jazz and classical music, typically a double bass is used (also called an upright bass, or an acoustic bass). Almost any genre will be suitable to use the acoustic bass, so there are no real barriers in trying different bass sounds than you are used to.
There are also acoustic electric bass guitars, which are audible without using any amplification, like the upright bass, but which are shaped like a guitar and have 4 or sometimes 5 strings.
An upright bass played with a bow is usually reserved for classical music, but there are some jazz and folk songs where this will be a pleasant choice for the bass part, and some adventurous pop records.
Upright bass loves to bounce off nearby wood, so have a sheet of plywood handy to throw on the floor below the instrument if you are working in a carpeted room. Transmitting the vibration through the floor connection is helpful, and the early reflections add a great dealt to not only the sound you record, but also the sound the player hears and feels as he plays.
It’s a cheap and simple way to repurpose your space for recording and easy to remove afterwards. Make sure you don’t get splinters!
Naturally, the bow is suited to either fast songs (bouncing off the strings for dramatic rhythmic effects, or for an enhanced sense of attack to the notes) or to slow songs, as in the long, sonorous sustained notes on dreamy ballads, and various other techniques of playing.
Mos of the time, the players will be using fingers to play the strings while standing, and you will either take an output from them in the form of a 1/4″ jack socket at instrument level or you will put a big condenser mic in front of them near the floor. The player is almost certainly going to like the microphone sound much more than the pick up, but the pickup can save you in case of a problem with the mic, including the problem of too much drums or saxophone getting into that mic. The mic will sound great, and if you can do this as an overdub, all the better.
Large ribbon mics like the AEA R84 are great too, and anything with ‘large’ in its description should be good to go. Putting a mic into figure-8 pattern (bidirectional) is a great idea if you have a nice sound in the room where it is being played. Just remember to turn off any forced air vents, fridge, freezer, furnace, doorbell, whatever, since bidirectional or omni will be more of a problem with ambient noises!
Omnidirectional is a nice sound with a jazzy acoustic bass, being natural and free from the proximity bass boost effect that plagues cardioid patterns, but you will want to consider leakage from other sources into the mic.
TRY AN SM57 – ARE YOU KIDDING?
An upright bass is not especially loud at the best of times, but it does have a rather large dynamic range.
You can wedge a small-diaphragm condenser or even a dynamic into one of the two f-holes on the instrument. Wrap it’s body in foam to minimize the possibility of scratching the instrument or the microphone or both, but leave a good gap between the foam and the capsule so it doesn’t affect sound entering the capsule. Protect the body of the instrument. You can even Blu-Tack a Lavalier-style clip-on mic to the body (with permission), also called a lapel mic. Protect the body of the instrument, once again.
You will, at a pinch, on a low budget, be able to get a workable bass sound using a Shure SM57, which is a low-cost small-diaphragm dynamic microphone that is very robust.
The Shure SM57 does capture frequencies as low as 40 Hz and as high as 15 kHz, so it goes lower than you might have expected and exhibits a nice low pass roll-off that suits bass instruments well, since they don’t have extreme highs either in most cases.
A Sennheiser E602 is another good microphone choice for a fair price.
The downside is that it simply does not capture the lowest frequencies.
Accordingly, what you end up with is a good recording of the upper bass and low mids, that allows the first and second harmonics of the notes to be clearly audible in smaller speakers. What you don’t get is the deep, ‘feel it in your chest’ bass that you would want when listening on a very big or loud playback system that has subwoofers and can reproduce frequencies down to 35 Hz or even lower.
It’s a fine result if you have a deep, low kick drum, since when they play together they will lock very well, neither interfering with the other and never encroaching on each other’s space in the mix. It’s a wonderful thing for your sonic quality when you can avoid using an EQ on the bass sounds, since they are extremely phase-sensitive and need to sound solid.
Taping mics to an instrument requires permission of the owner, so if it’s someone else’s, ask them first before you do anything to their lovely bass that might upset them.
It can be tough to isolate the bass mic from other sounds that are being played at the same time in the same room.
The acoustic basses may offer a mounted pick-up with a high-impedance instrument level 1/4″ jack output, just like an electric bass guitar, or you may want to use your own microphone(s), or you may like to record both ways at the same time to two tracks or more.
If there is no mounted pick-up, and you are using a microphone, you will usually find that a large-diaphragm microphone is the best choice. A dynamic is very good, such as an AKG D112 or an EV RE-20, and can cope with the large dynamic range of a bass. On the other hand, for detailed, airy bass sounds with plummy lows, the large diaphragm condenser mics are the first choice. The bidirectional ribbon mics are excellent too.
In a big commercial studio, you would usually see a Neumann U47 tube mic out in front of the upright bass, near to the floor where the lows are somewhat enhanced and there are naturally-occurring early reflections to reinforce the sound entering the mic. Failing the U47, you could well see a Neumann U87 solid-state mic. These are both large-diaphragm condensers, well-suited to longer wavefronts.
These mics are simply too expensive for all but a few home users, but fortunately there are countless suitable condensers on the market that will get you a nice sound for a much more reasonable price.
Check your music instrument retailer’s biggest local branch – bigger stores in bigger cities will have the best selection of microphones.
EQs on BASS
Analog equalizers cause audible ‘smearing’ of some frequencies when they are used. It’s an inevitable product of the laws of physics. However, there are also ‘linear-phase’ equalizers.
The linear-phase equalizers are not magic bullets however, and do have their own drawbacks. Still, they don’t exhibit smearing, so they are another option readily available in plug-in format for your DAW.
For energetic music, there is less attack in an acoustic bass than an electric one, since the transients are rather more rounded and softened.
If you use EQ before dynamics, you will impact the action of the compressor or limiter. Place it afterwards for easier use, otherwise wherever you boost a frequency will get over-compressed relative to other frequencies.
This usually leads to over-compressed lows, which sucks the life out of the track. If you must EQ lows on the bass sound before sending it into a compressor, try raising the threshold to get less compression, or dropping the ratio slightly, or changing to a softer knee setting.
I like to EQ after compression to avoid this issue. In fact, I prefer to avoid any unnecessary EQ and compression altogether until I have already recorded the part, unless it is inspirational to the player to hear that particular sound as they play, in which case, sail full steam ahead and man the lifeboats!
Jazz bass can generate some excessive thumps when the player is really into it and playing with fingers, digging in to the groove, so the issue arises of preserving natural dynamics and sound whilst guarding against transient overshoots with compression and/or limiting.
Picks are often used on electric bass for their punchy attacks, but virtually never on acoustic bass, which is played with the fingers (and, as mentioned above, occasionally with a bow) but this is a musical decision for the arranger of the music. That’s probably you, so it’s good to consider the various types of bass you might try on a song in light of the prosody achieved and keep your mind open to alternatives in the bass instrumentation.
Good bass adds a great deal to the experience of listening to music, and grounds things nicely. There are many ways to get there. Multiband processing or frequency-conscious compression (sidechaining) is very helpful, but you should refer to my various posts on dynamics processing for more details.
Does the bass sound compliment the song, or is it somehow lacking the right atmosphere? Only you can decide. Perhaps synths would be better? Perhaps doubling the bass part with a synth to really pin it down and stabilize the level and feel? These are all valid choices, but phase relationships between the basses are critical to maintain if you take this route.
A good start for compression settings is to start at about 8:1 or even 12:1 and use a 10 ms attack with a 20 ms release. Opt for the hard knee setting where you have the choice. Set the threshold so that the bass is evenly compressed and not lifeless, retaining dynamics in the part as appropriate but not clipping the recorder input or disappearing on certain notes.
Poor intonation on a stringed instrument can cause uneven frequency response such that some of the notes in the bass part disappear or are much quieter than other notes. Some notes may boom unnaturally loudly, and strings may buzz or rattle. other things in the room may also rattle in sympathy with certain notes, so listen in the room where the player is playing, and check that the room is not joining in! Compression increases the level of these unwanted side effects relative to the notes being played, and that’s bad.
A truly great player may not even require compression, but if you have one of those you probably don’t need to read this post! These guys are very rare. The rest of us will need dynamics control of some sort, even if applied after the fact in the mix.
If this is an electric slap-bass style, then you may need a minimum of 12dB compression, and possibly limiting ratios of 20:1 or more if they are going wild! You must not overload the input to a DAW track since digital distortion is appalling and unbearable. You don’t want it.
The rest of us will want compression applied, but these days it is possible to record to a DAW without it and add it later to taste, keeping the very loudest peaks at least -6dBFS, meaning you should aim to stay at least six DB below the Zero mark on your DAW input meter on the very loudest bits. This does require t
he player to be comfortable with the uneven nature of the different note levels when compression is not used, since what a player hears while recording is of extreme importance to getting a great take.
Compression also can make fret noise louder, and remove the life from a performance. Be on the lookout for these symptoms when you use compressors. It’s all too easy to overlook them and regret it later.
If you prefer, you could record the bass with a few dB of compression on the peaks, with a limiter following set to prevent any sudden overshoots from clipping the digital input of the recorder or DAW. This way, the signal has been smoothed out a little before you apply more severe compression later as required.
DAW automation also helps enormously, and there are plug-ins that can automate the automation! Waves Audio make Bass Rider and Vocal Rider, for instance, which do this sort of thing.
Well, that’s it for bass instruments and I hope you can join me for my next blog post, on tracking brass players. One little letter ‘r’ different from bass players, but totally different when recording them!