Equalization can really make or break, a bass sound
(and any sound, for that matter).
It's important to remember no two instruments sound exactly alike, so in addition to trying the suggested EQ settings, you should get to know how your bass responds at specific frequencies. This will help you recognize the problem areas and find sweet spots. As usual, experimentation is the key.
Tweak the EQ controls and let your ears be your guide, there are no rules in EQ-land.
And remember that like basses, not all EQs have the same sonic character. This is one area where subtle differences in tone, can really influence the overall sound.
Strings As Tone Control
Strings are the most basic form of EQ.
New roundwounds have more highs, old strings sound more dull, or mellow, depending on your taste, and many also have tuning inconsistencies.
Flatwounds have less highs and produce fewer squeks. Also, playing fingerstyle generally produces less highs and than using a pick. To make sure our new strings stay in tune while recording, after tuning a string to pitch, pull hard on it to take up any slack on the tuning machine. Retune, pull again, and repeat until the pitch stays constant.
Shelving EQ, is similar to the type found on a typical home stereo. It can boost or cut either the treble or the bass. Common corner frequencies are 100Hz for bass, and 10kHz for treble.
A 3-band EQ system, adds a midrange control, which typically boosts or cuts 12-18dB, sometimes at a selectable frequency. A stepped switch or variable control selects the center frequency, and a knob dials in the amount of boost or cut.
Graphic EQ, splits the audio spectrum into a number of bands and lets you boost or cut each band with a slider. The more bands a graphic EQ offers, the more precise the adjustments you can make. Top-of-the-line graphics provide a band every third of an octave. Graphic EQs work best for subtle sound-shaping over a wide range, or significant boosts or suts within just one or two bands.
A Parametric EQ, is a more flexible device that spaces several full- function, active filters throughout the audio spectrum. Controls for each filter includes boost/cut, center frequency, and bandwidth ( also called "Q", or "resonance" ). Some mixing consoles have what's called "semi- parametric EQ". This resembles a parametric, but without the bandwidth control.
Finding EQ Hot Spots
Here's how to find any instrument's EQ hot spots. It works best on a full parametric EQ, but can modify the procedure to work with other EQ types.
Step 1. Start with a fairly low monitoring level, as you will be adding a lot of boost. Set the boost/cut controls to zero and the bandwidth controls to a relatively narrow Q value (such as 1/4-octave).
Step 2. While you're playing, have someone boost the low frequencies by 6-8dB. Sweep the frequency control, rapidly at first to get an overview, and then more slowly to zero in on specific areas.
Step 3. You will encounter certain settings that sound good and strong, while others will sound bad (muddy, noisy, etc.). After finding a good spot, set the boost/cut to flat, turn up to a normal
monitoring level, and then boost or cut as needed. You may also need to narrow or widen the Q setting, go back and forth between the Q and boost/cut controls, until you get the sound you want.
Follow the same procedure with all of the EQ's frequency ranges. If you hear a response "bump" (peak) you want to remove, find the frequency where the bump is most obnoxious, and cut that frequency until the sound is more balanced. With parametric EQ, if the bump is not too wide, a small Q may be all you need.
Typical EQ Hot Spots
Here are some important frequency ranges for bass :
Most home stereo's can't reproduce this range, so there's little point in boosting here. If you do boost in this area and don't hear any change, return to zero boost, otherwise you'll use up the headroom on frequencies you'll never hear, and you may even damage your (and other's) monitors woofers.
While miking your amp, if you hear "room rumble" from a ventilation system or outside traffic, try cutting in this range, using shelving EQ if available.
Boosting here brings out the fundamentals (lowest notes) of your bass notes.
A little 200Hz boost may help the bass sound rounder, but if you add only at 200Hz, lower frequencies may seem less prominent, thinning out your tone. If you like what your hear when boosting at 200Hz, use a parametric EQ with a wide Q (two or more octaves) so the boost extends down to 100Hz. If using a wide Q reaches up into the 300-400Hz range and the sound becomes too "puffy", narrow the Q.
Boosting in this area tends to cloud up the sound, making neither the notes nor their attacks stronger. You may even want to cut a bit in this region, but be careful, there's still lots of bass energy here.
To emphasize the higher harmonics, try boosting here. A little more 800Hz usually does the trick. If the bass is in a thick mix and isn't very audible, boosting here will allow the bass to "speak" more, and you won't have to increase the overall level (which can clutter the mix further).
1kHz helps define notes but does not increase brightness. 1,5 - 3kHz emphasizes upper harmonics as well as the sound of the strings hitting the frets. In general, boosting here adds snap and definition.
Adding a little boost around 4kHz can open up the sound slightly, but finger noise might get overpowering, especially if you're using compression. If you want to boost in this range, listen to the bass part all the way through first.
Boosting this region doesn't add much (other than finger and string noise) unless you're going for a bright slap sound. But remember, there are no rules, so if this works for you, great.
Basically the same as the previous range, boosting at 10kHz can add a little air to the sound. If the string noise is not too bad and boosting here sounds good, go for it.
A Typical EQ Application
Consider what kind of bass sound will be appropriate for the song, not just what sounds good by itself. You will almost surely re-tweak EQ during mixdown so the bass sits well with the other tracks, but get as close as possible whil tracking, as the bass tone will also influence the other parts as well as the way you play.
Let's assume the song calls for a fairly standard bass sound and you're playing with your fingers. First, experiment with the low-frequency settings. A typical adjustment isto boost a bit at 100 or 150Hz. Play a groove that uses all the strings but favors the low ones. Boost 100Hz by 2-3dB and listen. If this adds a "friendly" bottom without increasing the amplitude too much, fine. If the sound gets kind of muddy (the notes lose definition) but you like the lows, try adding 2-5dB at 800Hz with the midrange control. This brings up the harmonics, which helps define pitches. Go back and forth between 100Hz and 800Hz and find a good balance.
Second, you may want more upper harmonics for brightness and snap. If so, try adding a few dB at 1,5-3kHz.
Third, check for noise problems, possibl y due to an active direct box or active onboard electronics. If you're recording to an analog tape recorder and the bass has it's own track, wait to roll off any high-frequency hiss until the mixing stage, so you can reduce the tape hiss until as well.
Hiss can be reduced by rolling off the highest frequency your console allows (usually 10kHz or above, sometimes a high-cut switch will do this). Note that even though the bass does not put out much energy above 10kHz, rolling off these frequencies may start to remove some air from your tone.
Playing with a pick typically produces less bottom and a brighter top. If you want a more finger-style-like sound, cut a few dB around 2kHz, that's the frequency region of the pick's bright attack.
Also consider boosting at 100 - 200Hz, since the pick does not get as much natural low end as fingers. With a pick, boosting at 800Hz may not be necessary, as the pick usually provides plenty of high-frequency definition.
Thumb-style playing usually sounds best with a scooped tone, where the lows (250Hz and below), are boosted while the mids are cut. This "smiley face" EQ curve is best achieved with a graphic equalizer.
EQ: Pre- or Post-Compressor ?
Should EQ come before or after compression ?
That depends on the application. For example, if the EQ first evens out the signal by reducing a peak at a certain frequency, the compressor will do its job more efficiently. Post-compressor EQ adds peaks or dips at various frequencies, which kind of defeats the purpose of compressing.
Some may argue this concept (get used to people arguing any concept, when it comes to recording), for example, if you specially want to boost a frequency range, it makes more sence to put the compressor first, because post-EQ compression will minimize the boost.
Which works best in a particular situation ?
Experiment and listen, but remember that the usual approach is to place the EQ before the compressor.