Use the direct box in GarageBand on Mac
A direct box (also known as a D.I. box) is a device used in recording studios to connect the output of an electric instrument directly to a mixing console, without using an amplifier. The Direct Box in Bass Amp Designer is modeled on a well-regarded American device. See Bass Amp Designer signal flow in GarageBand on Mac.
Show the direct box
Direct Box button: View the Direct Box interface and controls. Click the Amp button to show the Bass Amp interface and controls.
Adjust the direct box controls
Boost knob: Set the input gain of the Direct Box.
HF Cut button: Turn on a highpass filter. This is used to reduce noise.
Tone knob: Set the tonal color of the Direct Box. Each number represents a preset EQ curve.
1: An EQ curve with a -6 dB scoop from 100 Hz to 10 kHz, most pronounced around 800 Hz. Suitable for acoustic and string instruments, electric bass, and keyboards.
2: An EQ curve with a very pronounced -24 dB v-shaped notch from 100 Hz to 10 kHz, centered around 800 Hz. Suitable for electric bass guitar.
3: An EQ curve with a -3 dB scoop from 100 Hz to 10 kHz, most pronounced around 800 to 1200 Hz. Suitable for acoustics, strings, electric and bass guitar, and keyboards.
4: An EQ curve with a -3 dB scoop from 1 kHz to 10 kHz, most pronounced around 8 kHz. Frequencies between 60 Hz and 1 kHz have a slight boost of 1 or 2 dB above unity. Frequencies above 10 kHz have a +3 dB boost. Suitable for acoustics, strings, electric and bass guitars, and keyboards.
5: A sloped EQ curve that ramps up from -24 dB at 10 Hz to + 3 dB at around 900 Hz. Suitable for acoustic and electric guitar.
6: A sloped EQ curve that ramps up from -24 dB at 10 Hz to +3 dB at around 900 Hz. The signal rolls off by approximately 6 dB between 10 and 20 kHz. Suitable for electric and bass guitar.
Tone On/Off button: Turn the tone control on or off.
Blend slider: Drag to hear the Direct Box alone or in parallel with the amplifier.
Amp button: View the Bass Amp interface and controls. Click the Direct Box button to view the Direct Box interface and controls.
Use the direct box only (no amp)
Drag the Blend slider all the way to the right.
Use the amp only (no direct box)
Drag the Blend slider all the way to the left.
Use the direct box and the amp in parallel
Drag the Blend slider to any central position between the left and right edges.