(Ebook) Sound Engineering Tutorials From Sound On Sound -- Technique - Recording Bass Guitar.pdf - PDF - greki

RECORDING BASS GUITAR

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RECORDING BASS GUITAR

Although most modern synths come with good bass guitar patches, there's still

nothing quite like the real thing played well -- provided you know how to record it.

Paul White examines a few alternative approaches.

There used to be a common joke among musicians aimed

at bass guitar players, which ran "What's the similarity

between playing a really good bass line and wetting

yourself? You get a nice warm feeling, but no-one really

notices!". These days, however, bass plays a prominent

role in many musical genres. Dub reggae wouldn't get far

without bass, and nor would many rhythm-heavy styles

such as those found in Latin and South American music.

But even outside these styles, bass can be crucial to the

sound and 'feel' of a track. A well-played and well-recorded

bass is vital to any rhythm section, and it's worth making

the effort to achieve the right sound.

A good bass guitar sound starts with a reasonable-quality

instrument played well. Given that starting point, you then

have to decide whether to mike up a bass guitar amp or to

adopt one of the possible DI methods -- or you could

combine both, as do many professional engineers.

The simplest recording method is to DI the bass, but unless the instrument has active

pickups (if it needs a battery, it probably has), you can't just plug it into a mixer input and

expect good results as there will be an impedance mismatch. The right way to do it is to

use a DI box with an input impedance of at least 500k(omega) and preferably higher than

1M(omega). Virtually all active DI boxes that feature an instrument input fulfil this

requirement, and a number of passive transformer-based models are also suitable.

With the right instrument and good playing technique, this simple approach can produce

good results, but in my experience, the sound tends to lose power when the other

instruments are added to the mix unless the arrangement is very sparse. What's more, the

tone you get isn't the same as if you used an amp, as guitar/bass amps don't have a flat

frequency response. The EQ on most simple consoles isn't able to emulate a guitar

amplifier very accurately, so an outboard processor is a better bet. Placing a good quality

graphic or parametric equaliser after the DI box (usually via the mixer channel insert point)

can improve things greatly. Most musicians know that adding an 80Hz boost will fatten up

the low bass, but if you listen to the bass sound on records, you'll probably find there's also

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RECORDING BASS GUITAR

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quite a lot going on in the mid and lower mid ranges -- most domestic hi-fi speakers can't

reproduce deep bass anyway. The key is to experiment with the EQ in the 120 to 350Hz

region as this is where the real character of the sound is defined. Though bass guitars do

generate high-frequency harmonics, most of these would naturally be lost when the

instrument was played through an amp and speaker cabinet as guitar speakers have a

fairly limited frequency response. You can leave them in if you like the result, but often

you'll find that finger and string noise becomes irritating and that you can roll off quite a lot

of high end without significantly affecting the main

body of the sound. This usually makes the bass sound

tighter and cleaner.

"...if you can save the

EQ until you mix,

you'll keep your

options open."

Another useful technique involves combining the

equaliser with a speaker simulator such as my

personal favourite, the all-passive Palmer Junction

Box. Speaker simulators are designed to duplicate the high-frequency rolloff of real

speakers, so you can still use your outboard EQ to shape the low and mid sounds, then

allow the speaker simulator to take care of the top end. A well-designed speaker simulator

will take away all the grittiness from the sound without killing the transient attack, and will

often sound more natural than using EQ on its own.

Compression

Most engineers use a degree of compression with bass guitar, which is a good idea for a

number of reasons. If the player uses a slapping or pulling technique, the note attacks can

be very loud, so if you don't compress or limit, you either run the risk of overloading the

recorder or you have to set the record level so low that the main body of the bass sound is

too quiet. This type of playing is best dealt with using a compressor that has a separate

limiter, as the traditional way of making a compressed sound retain its attack characteristics

is to set the compressor attack time to several tens of milliseconds in order to allow the

initial transient to get through uncompressed. The release time is generally set to around a

quarter of a second, but this will vary from model to model, so always experiment. Auto-

attack and release settings (where available) also produce good results on bass guitar as

they can adapt to the changing dynamics of different playing styles within the same song.

Allowing the transients to sneak past the compressor might produce a great sound, but it's

those same transients that cause recorder overload problems, so having an independent

limiter section following the compressor is very desirable. The limiter threshold should be

set just below the overload level of the recorder so that limiting takes place only on very

loud peaks.

Even if the bass is played in a more traditional way, compression is still beneficial as it

evens up the levels of different notes and, equally importantly, it increases the average

energy level of the sound -- making it seem louder for the same peak level. You can still

back off the compressor attack a little to accentuate the start of the note, but keep an eye

on those recording levels. A useful tip if you don't have a compressor with a separate limiter

section is to use a dual-channel compressor and feed channel one's output into channel

two's input. Set channel one up to compress as normal, but set channel two to limit by

using the highest ratio possible combined with a fast attack time and as fast a release time

as you can get away with. Adjust the threshold of channel two so that gain reduction only

occurs when the level is within a few dBs of hitting the overload region on the recorder's

meters. Of course those still using analogue tape can afford to be that bit more casual

about levels -- indeed, a little tape saturation can do wonders for a bass sound. Which

leads nicely into...

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RECORDING BASS GUITAR

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Distortion

Some of the best bass guitar sounds come from valve amplifiers, and as all guitarists and

bass players know, valve amps distort rather musically when you drive them hard. A

number of modern studio processors either include valve stages or offer 'tube emulation'

with varying degrees of success. You can even get valve DI boxes, such as the Ridge Farm

Gas Cooker, and using any one of these can help beef up a bass sound without making it

sound obviously distorted. Of course, if you want the Stranglers' bass sound, a suitably-set

overdrive pedal might well do the trick. Where you place the valve device or valve emulator

in the signal chain is really down to where it sounds best, but if you want to be purist about

it, it should come before the speaker simulator if you use one. That's because in a real

amp, any distortion created within the amplifier circuitry is

filtered by the limited high end response of the speakers,

and if there's a lot of distortion, it is important to remove the

high end to prevent grittiness.

If you like an easy life, some preamps designed specifically

for recording guitar also work well with bass. Last month I

reviewed (and subsequently bought) the Line 6 Pod

physical modelling digital guitar preamp, and initially

wondered why they didn't make a bass version. However,

after a little experimentation, I found that by using a Fender Bassman amp model combined

with a 4 x 12 speaker cab and no effects other than compression and a little amp drive, I

could get a very convincing miked bass amp sound. One practical advantage of a digital

product of this kind is that you can be quite certain of the maximum output level as you can

never get louder than 'all bits on'. If you deliberately overload the input by plugging in a hot

synth so the clip LED comes on, whatever comes out is your maximum level! You can

safely set your record levels with reference to this level. Then all you need do is plug in

your guitar, make sure the input clip LED isn't coming on, and you can play in the

knowledge that your recorder will never clip, no matter how you adjust the preamp drive or

tone controls.

Miking The Bass

Of course, there are those purists who say they'd rather eat their own ear wax than DI a

bass! Miking a good bass amp isn't a problem providing you're working in an environment

where you can play the thing loud enough, and of course you need a decent mic. Though

you could use a general-purpose dynamic vocal mic to capture the bass guitar, you'll find

that most of these have a deliberate low-frequency rolloff to compensate for the proximity

effect when used up close. Because of this, unless these are placed right up against the

speaker grille, you could find the bottom end tends to

lose power. A better bet is to use either a non-vocal

dynamic mic that has a reasonably flat low-end

response or to try one of the dedicated bass/kick drum

mics, placing it around six to 12 inches in front of the

best-sounding speaker in the cab. If you look at the

frequency plot of a kick drum mic, you'll find the

frequency response looks like the back leg of a

donkey that's just been hit by a truck, but the results

are often flattering and powerful, which is far more

important than any misplaced notions about accuracy!

If you're using a valve amp, you may find you don't

need to add further compression, or at least not much,

but if the amp is solid-state and doesn't have a

"A well-designed

speaker simulator will

take away all the

grittiness from the

sound without killing

the transient attack,

and will often sound

more natural than

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RECORDING BASS GUITAR

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compressor of its own, then it's probably a good idea

to at least try adding compression to see what can be

achieved. The safest approach here is to leave the

compression until you mix unless the levels are so erratic that clipping might be a problem.

using EQ on its own."

Tonal changes can be made by moving the microphone -- the brightest sound is found by

pointing the mic at the centre of the speaker, while moving it to one side will produce a

warmer, less in-your-face result. It's also worth varying the distance to see what result that

has. Try adjusting the mic position for the best results before adding any EQ at all, and if

you can save the EQ until you mix, you'll keep your options open. After all, what may sound

great in isolation may not sound so right when the rest of the mix is up and running.

Best Of Both Worlds

If you really want to go to town on the bass sound, try combining a miked amp with one of

the DI techniques described earlier. Often you can get away with a smaller amp than if you

rely on the amp sound alone, as the DI will provide all the bottom end you need. This

combined approach is taken by many professionals. The relative phase of the miked and

DI'd sound has a profound effect on the final result, so you may need to phase-reverse one

of the sources to get the best result. Also, experiment with the EQ of the individual sources

as well as their balance, as the EQ controls may not have the same effect as they do when

the sources are heard in isolation. Similarly, changing the mic-to-speaker distance will also

affect the phase of the combined sounds, so this can be useful in fine-tuning the result.

As you can see, there are several ways of recording the bass guitar, but if you like to keep

your options open until the final mix, there's nothing wrong with DI'ing the bass flat via a DI

box, perhaps in combination with a limiter to catch any excessive peaks, then applying one

of the techniques outlined here at the mixing stage. Or if you have enough spare tracks,

you can record the processed and the clean version of the sound on different tracks. I'd

certainly try to do this if I was miking the amp -- all that's needed is a DI box between the

instrument and the amp (most have an audio thru connector) with the DI out connected to a

spare recorder input. Computer users also have several options open to them when it

comes to treating sounds after the event: in addition to the usual compression and EQ,

there are now numerous software amp simulators that can produce very convincing results.

The beauty of the home studio is that you don't have the same time pressures as a

commercial facility, so you can afford to experiment and see what method works best for

you.

Europe's No1 Hi-Tech Music Recording Magazine

Sound On Sound

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Telephone: +44 (0)1954 789888 Fax: +44 (0)1954 789895

Email: info@sospubs.co.uk Website: www.sospubs.co.uk

and reproduction in whole or part, whether mechanical or electronic, is expressly forbidden without the prior

written consent of the Publishers. Great care has been taken to ensure accuracy in the preparation of this

article but neither Sound On Sound Limited nor the Editor can be held responsible for its contents. The

views expressed are those of the contributors and not necessarily those of the Publishers or Editor.

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(Ebook) Sound Engineering Tutorials From Sound On Sound -- Technique - Recording Bass Guitar.pdf

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