Bass amplifiers come in different forms: combo amps and separate power amp “heads.” For large venues, high-powered heads paired with single or double cabinet amplifiers provide powerful bass tone.
Many bass amps feature a gain (sometimes known as drive) control to modify signal intensity. Reduce it for cleaner sound or push harder for added grunge.
Volume
Most bass amplifiers offer a master volume control that allows players to adjust the overall decibel level. This control is important as it helps a bassist maintain an acceptable volume level when performing on stage without overpowering their speaker system. A bassist may also utilize an external volume pedal in conjunction with their amp to help regulate gain and distortion when turning up their volume knob higher.
Guitar and bass amplifiers may incorporate various tone-shaping electric circuit stages, including a preamplifier that boosts audio signal voltage to drive the power amp which, in turn, drives loudspeakers that produce sound. Tone controls may include bass/treble/presence controls similar to those found on home stereo systems with equalizers as well as presence control for higher frequencies. More expensive amplifiers may feature graphic or parametric equalizers that utilize vertical faders to adjust multiple frequency bands simultaneously.
Bassists who specialize in quieter genres and gigs often opt for smaller combo amplifiers that combine preamplifier, tone controls and power amps in one unit – this makes transport and setup much simpler than using separate heads and speaker cabinets; however, bassists who perform louder genres may prefer larger amp heads with greater wattages that produce sound more efficiently at higher volumes.
Most bass amps feature a Tone section, more commonly referred to as an Equalizer or EQ, where players can manipulate the controls of the amplifier to produce their signature sound. Most amps will also feature a gain control known as drive or distortion; when this knob is turned up, amp breakup occurs, creating a gritty tone which is ideal when looking to achieve specific sounds for various parts of a song.
As both gain and volume control the intensity of a signal, their differences can be difficult for new bassists to grasp. But there’s one crucial difference: Gain is used as the initial control in a chain; its purpose is to set input level while volume determines output level.
Bass and Treble Equalizers
Bass and treble equalizers provide one final round of equalization before your signal leaves your amp and goes somewhere else, such as a mixer if performing or an audio interface if recording. Many guitar amplifiers feature integrated equalizers; preamp pedals may include one as well. An equalizer allows you to customize the sound by cutting or adding frequencies; when starting to use one it’s best to begin at lower frequency ranges then work your way upward. Doing this ensures your ear can hear any changes you are making as they won’t get lost among other sounds or noises.
Most bass amplifiers feature various controls to tailor the tone, such as gain, bass, mid, and treble controls. Gain acts similar to volume controls but changes intensity instead. An increase in gain will cause more distortion while decreasing it will provide you with cleaner foundation sound.
Your bass amplifier’s EQ settings may depend on the genre of music you’re performing; guitarists may choose to increase the low-mid and mid frequencies to add depth and sustain to their sound; doing this may bring out finger style playing more clearly while providing midrange clarity.
Enhancing certain frequencies can be great, but too much of it may make the bass harsh and dull. So it is advisable to experiment with your EQ settings but keep in mind that less is usually more.
Most bass amps provide a bass control ranging from 60Hz to 4kHz, where most pitches you hear will reside; this area includes sub bass and your body sound. As you increase this frequency spectrum, so too will become higher-pitched and brighter your sound; the further away from 60Hz you move along it the brighter and higher pitched it becomes. Treble gives guitar its distinctive sparkle between 5kHz-20kHz; when turned up loud enough harmonics may also become audible.
Safety
Though it may appear simple enough to plug your bass into an amp designed for guitar, doing so could result in irreparable damage to both speaker and amplifier components. The reason is straightforward: bass frequency range is one octave lower than guitar’s; therefore most electric guitar amplifiers weren’t specifically made to accommodate this, potentially damaging speakers or the amp’s components.
Just a few simple steps can help prevent this from occurring, including playing at low volumes to decrease speaker movement and refraining from using effects.
Another step you should take before unplugging an amplifier is ensuring it has been switched off completely. The terminals for standby and power switches can become dangerously hot if touched while running, so keep a drain probe handy so you can quickly empty out filter capacitors that hold large amounts of current when working on your amp.
If you must use a guitar amp for bass, be cautious in positioning the cabinet. Bass frequencies are omni-directional; that is, they bounce around until they hit a surface and either absorb or reflect them back towards their source (in this case your bass amp). If these waves collide they could cancel each other out completely and change your prized tone into nothing more than noise.
To avoid this scenario, place your bass cabinet in an environment specifically tuned for bass response or choose a specific ported or sealed speaker combination to increase sound quality. Also ensure it is contained within an enclosed enclosure to avoid air leakage that could cause vibration and damage internal components of the amp. Furthermore, bass guitar frequencies require more power than regular guitar amps do; look for models within 200- to 400-watt power range as 100 watt amps may provide plenty of output but might be insufficient when performing gigs or rehearsal studio sessions.
Noise
Bass amps typically possess more speakers than guitar amps in order to handle the lower frequencies produced by a bass guitar, as well as having higher power output as bass frequencies require additional power in order to be heard. Due to this increased pressure being placed upon its components, it is critical that any amp can handle these lower frequencies without becoming damaged from overexposure.
When an amplifier cannot produce an even, balanced sound, its low end can become muffled or the sound may distort. You can improve its performance using preamp EQ to adjust frequency response; additionally, using high-quality pickups (such as those found on bass guitars known as humbuckers that cancel noise by producing two signals that cancel each other out) is essential; otherwise it may result in muted tones or unbalanced signals which lead to amps sounding muddy or producing an audible hum.
As amplifiers are turned on, some noise may be produced; this noise should not be loud enough to damage either the amplifier or other components inside its cabinet. To reduce noise pollution and play more quietly with your amplifier, lower its volume until its noise production subsides sufficiently.
Although some amps come equipped with built-in noise filters, you can also purchase additional ones and attach them directly to the front of your amplifier. When using pedalboards in conjunction with amplifiers it’s essential that their power cables don’t touch one another as this may create unwanted ground loops which could introduce unwanted hum.
Some bass amplifiers utilize a crossover circuit to separate lower frequencies from higher ones, giving bassists access to fuller sound with increased depth and clarity. For instance, the Bassman amplifier first introduced in 1952 used this design, popular among funk bassist Larry Graham of Led Zeppelin fame and John Paul Jones of Led Zeppelin among many others.