Bass Amp Simulator
A free bass amp simulator that runs in your browser: plug your bass into an audio interface and play through a compressor, an octave down effect, a bass amp with four-band EQ and a cabinet.
Your guitar signal is processed on this device and is never recorded or sent. Use wired headphones.
Put on wired headphones first
With speakers, the microphone hears the amp and the sound can build into a loud squeal (feedback). Plug in wired headphones and turn your device volume down before you start.
Latency: press Start or Play demo riff to see what your browser reports.
Keyboard: Space starts and stops the input, D plays the demo riff.
How to use the bass amp simulator
This bass amp simulator is a practice rig for headphones. Press Start bass input, confirm that you wear wired headphones and allow the input. Set Input gain so the Input meter moves well without turning red, then raise Volume slowly; it starts low and a limiter catches sudden peaks. To hear the amp without a bass, press Play demo riff, which plays a short synthesized bass line through the same chain.
The chain runs Noise gate, Compressor, Octave down, Bass amp, Cabinet. On the amp, choose a Voice (Clean, Growl or Overdrive) and set Gain, Blend, Low, Low mid, High mid, Treble and Master. Everything is kept for your next visit, and Copy link to these settings makes a link to this exact sound. On a computer, Space starts and stops the input and D plays the demo riff.
What the controls do
| Control | What it changes |
|---|---|
| Voice | Clean keeps the low end round and clear. Growl adds grit with a mid push. Overdrive clips harder for a driven rock tone. |
| Gain | How hard the bass drives the clipping stage of the voice. |
| Blend | Mixes the clean bass with the driven sound (Growl and Overdrive). Lower it to keep a solid, clean low end under the grit. |
| Low, Low mid, High mid, Treble | Four-band EQ: around 80 Hz, 250 Hz, 1.2 kHz and the top end. 5 is flat. |
| Compressor | Evens out loud and soft notes, so every note sits at a similar level. |
| Octave down | Adds a note one octave below what you play. Octave sets its level, Dry the level of your own note. |
| Cabinet | 1x15, 4x10 or 8x10: filter curves from deeper and darker to brighter and punchier. |
The voices, the octave effect and the cabinets are our own designs made from filters, clipping curves and an octave divider. They are not copies of any brand of amp, and no speaker recording is downloaded.
How the octave down effect works
Wikipedia's article on effects units describes an octave effect as one that raises or lowers each note by a set interval. This one works like a simple analog octave divider: it watches the low part of your signal, flips a square wave each time the wave crosses zero going up, which halves the frequency, and follows your playing dynamics. That makes it fast and tight on single notes, especially on the lower strings. Chords and double stops confuse it and it glitches, the same as an analog divider. Some browsers cannot run it; the card says so if yours cannot.
How to connect your bass
Basses with passive pickups want a high impedance input. On a USB audio interface that is the socket or switch marked Inst or Hi-Z; Focusrite says its instrument inputs switch to a high impedance mode built to take hot pickups without clipping. A microphone socket is the wrong match: the Wikipedia article on DI boxes explains that instruments are typically high impedance and microphone inputs low impedance, which is exactly the job a DI box solves on stage.
Set it up in this order: cable into the instrument input, wired headphones into the interface, interface gain up while you play your loudest open E until the light shows signal but never red. Then press Start bass input, choose the interface in the Input list and pick channel 1 or 2 if the bass only sounds on one side. Active basses are louder, so start with the interface gain lower.
Latency and headphones
Bass players feel delay fast because the groove sits on the drums. The Android developer guide on audio latency adds input latency, processing time and output latency together as round-trip latency, and says musicians generally want about 10 ms. Under the volume slider this page shows the figures your browser reports for its own processing and output stages. MDN calls output latency an estimate, and most browsers leave out the input side, so the delay you hear is longer than the total shown.
- Works best: a computer, a USB audio interface and wired headphones.
- Too slow: Bluetooth headphones or speakers. Wikipedia's Bluetooth article gives 100 to 200 ms for classic Bluetooth audio.
- Avoid: laptop speakers next to a microphone, which feed back, and phone microphones, which hear the room instead of the pickups.
Practice with the bass amp
Tune first with the bass tuner. Lock in with the metronome, or record a groove in the online looper (choose Bass amp as the sound) and play over it. Learn the shapes with bass scales and bass chords. Your bass signal is processed on this device and is never recorded or sent.
More for bass: Bass Tuner · Bass Chords · Bass Scales · Fretboard Notes · Guitar Tab Maker · Online Looper
Questions
Is the bass amp simulator free?
Yes. The amp, compressor, octave down, cabinets and share links are free, with no download and no sign-up.
Can I use the online bass amp with headphones only?
Yes, that is how it is meant to be used. Plug wired headphones into your audio interface or computer. Bluetooth headphones add too much delay to play along.
Why does the octave down glitch on chords?
It divides the frequency of one note at a time, like an analog octave pedal. Play single notes for a clean octave.
Does it record my playing?
No. Your signal is processed on this device and is never recorded or sent. To record, use the online looper, which keeps recordings in the tab only.