Recording bass guitar is done by either mic’ing up the bass amp cabinet, or by taking a split of the signal directly after the guitar using a DI box. It’s also becoming increasingly popular to use a mixture of both, as it gives you more options and control over the bass tone in the mix. We will look at this in more detail when it comes to the mixing stage.
One good thing about using a microphone is that the bass amp provides a lot of colour and defines the actual tone of the bass. It’s arguable that the amp is actually vital to recording bass, because you only ever hear bass played live through one. The amplifier will probably have some eq and maybe compression built into it, and the speaker and the cabinet will add their own characteristic sound too. Without a mic, you are likely to have to work harder to get a nice full sounding bass. However, if you’re trying to isolate the bass from a kick drum or any other spill or room noise, then using a DI box can be a good solution as it will give you a very clean and dry sound.
Using A Mic
I have seen bass amps recorded with all kinds of microphones; dynamic, condenser and ribbon mics all have their merits and all sound different. Dynamic mics with a decent sized diaphragm like the RE20 and D112 will give you a good amount of low end, as well as some of that natural dynamic-mic compression, which is always useful for basses. On top of that, they are fairly robust which means you can get them in really close and not have to worry so much about damaging the diaphragm. SM57’s and SM58’s will give you even more dynamic compression, but won’t have the bottom end of an RE20, especially if they aren’t rigged very close.
Large diaphragm condenser mics like an AKG 414, or a U87 are definitely worth a try on bass amps, because they have really nice mid tones and a much crisper transient response to the dynamic mics. If they have switchable directivity patterns, then try them out (as they will sound different!) and experiment with distance from the amp too. For a really thick and punchy sound, go for the built-in compression of a dynamic mic up close, and if you want a nice clean and crisp tone then try out a condenser a little further away.
Some people swear by ribbon mics on basses because of their mid to high response, but a word of warning; if you want to try one out on an amp then start with it too far away, listen to it, then move it closer until it sounds right. That way you will avoid rigging it too close, overloading and damaging the ribbon and sending the mic away for a visit in the workshop.
Using A DI Box
If the amp you are using is not quite beefy enough, or your microphone isn’t giving you enough low end, you might try adding in a bit of the DI signal. A DI box will give you an absolutely clean feed from the guitar, free from spill and will deliver the full frequency range of the instrument which makes them very useful for live sound mixing. As the signal hasn’t been through a bass amp, it will sound very bright and clean with a lot more high-mid and top end than you would expect from an amp, so you will have to eq a bit more in the mix to compensate. There are plenty of other tricks you can use to get a really beefy sound out of a DI’ed bass, like using an amp modelling plugin for example, which we will cover in the mixing guide.
Most amps will have a dedicated line output for recording or driving other speakers, which you can use to capture the tone of the amplifier (but not the speaker) without using a mic. It’s not used as often as you may expect, but if your amp has one then it’s a decent compromise between a DI and a mic, especially if you are recording at home and are aiming to keep the budget down.
[image via martinhoward]