Effect 15 of 15 · Pedals
Cabinet simulation: an approximation, and labelled as one
Five filters in a row, shaped roughly like a guitar speaker. It was not measured from any speaker and does not model one.
Play it alone
Signal into the board
Use headphones. With speakers, a microphone hears the board’s own output and sends it round again: that loop is feedback, and it howls. Turn the output volume down before you press Start.
The test signals are synthesized by this page, sample by sample. Your instrument is asked for only when you press Start with “Your instrument” chosen, with the browser’s echo cancellation, noise suppression and automatic gain control switched off.
Clipping: the output reached full scale. Turn a level down.
- Sample rate
- not started
- Processing latency
- not started
- Output latency
- not started
- Input latency
- not started
- Reported total
- not started
Browser audio has latency: you hear each note a little after you play it. These are the browser’s own figures and they leave things out.
The cabinet, alone
In, this one pedal, out. Drag a knob sideways, or focus it and use the arrow keys or the wheel. The whole board has the rest.
Cabinet
Body+4.0 dBTop4.5 kHzLevel0 dB
The signal
What it does to the signal
A guitar amplifier’s speaker is part of its sound. Wikipedia’s article on guitar speakers gives the range such drivers typically produce as approximately 75 Hz to 5 kHz: A drive pedal heard without a speaker is heard with all of the upper harmonics that a speaker of that kind would not have reproduced.
This pedal is a filter curve with that general shape. A high-pass at 80 Hz removes the bottom. A peak at 110 Hz, whose height is the Body knob, stands in for the resonance of a speaker in its box. A fixed 3 dB lift at 2.4 kHz adds presence. Two identical low-pass filters, one after the other, cut the top at 24 dB per octave from the frequency the Top knob sets.
It is an approximation, drawn by hand. A measured impulse response of a real speaker, microphone and room would be more detailed, and would be a recording of somebody’s equipment. This page loads no recordings.
There is no amplifier on this board either. If you came looking for an online guitar amp, the nearest thing here is the overdrive, the EQ and this cabinet, in that order: gain and clipping, tone controls, and a speaker-shaped filter. It is a chain of three effects, not a model of an amplifier.
General definition: Wikipedia, “Guitar speaker” (revision 1323080466, read 2026-09-28). Everything on this page about how this pedal works describes this page’s own code. It is built from standard Web Audio nodes.
The graph
The graph, drawn.
audiocontrol: moves a setting, is never heard
Six nodes in a row: five filters and a gain.
The knobs
Every knob, in real units.
| Knob | Range | Starts at | What it changes |
|---|---|---|---|
| Body | 0.0 dB to +9.0 dB | +4.0 dB | Gain of a peak at 110 Hz, standing in for the resonance of a speaker in its box. |
| Top | 2.5 kHz to 7 kHz | 4.5 kHz | The corner of two cascaded low-pass filters (24 dB per octave together). |
| Level | −40 dB to +12 dB | 0 dB | Output gain. |
Measured
What the test measured
Rendered offline, then measured
- Switched off and rendered over 48,000 samples of the plucked-string signal, the output was identical to the input in every sample, and the pedal was not in the graph. [as described]
- Body +4 dB, Top 4.5 kHz. Relative to 1 kHz the response was −17.4 dB at 30 Hz, and below 400 Hz it peaked at 116 Hz (3.1 dB). [as described]
- It was 3.5 dB at 2.4 kHz, −1.8 dB at 4.5 kHz, −27.0 dB at 9 kHz and −72.8 dB at 18 kHz: between 9 kHz and 18 kHz, one octave, it fell 45.7 dB. [as described]
- With Top at 2.5 kHz the response at 5 kHz was −24.7 dB relative to 1 kHz. [as described]
Rendered in an OfflineAudioContext at 48,000 Hz in Chrome/154.0.8037.58, 2026-09-29 01:07 UTC. The test is work the page’s builder ran, not something your browser does when you open this page.
Limits
- It is a smooth curve. A real speaker’s response is full of narrow peaks and dips, and changes with the microphone and where it is put. None of that is here.
- It has no loudness-dependent behaviour at all: it is the same filter for a whisper and for a full-scale signal.
Where it goes in the chain
Last. A speaker is the last thing in a guitar’s signal path, and everything before it, reverb included, is heard through it. Switch it off if the board is feeding a real guitar amplifier, which has a speaker of its own. The whole order, and the reasons, are on the signal chain page.
Method
What is computed, and what is read.
Computed here, nothing fetched
Every sound on these pages is computed in your browser by the Web Audio API: 9 of the 15 pedals are graphs of the engine’s standard nodes, 5 are AudioWorklet processors, the wah is both, and the 3 test signals are synthesized sample by sample. No recording is loaded and no data feed is read. The one request the board’s own scripts make is for their AudioWorklet module, a file on labs.llc; the pitch detector is the one the Tuner uses.
Every effect was rendered offline with a known signal and measured: 73 of 73 checks came out as described. Nothing was tested on a real instrument or audio interface, only one browser was used, and nobody listened: the tests measure numbers, not tone. The method, the table of checks and what the latency figures mean are on the about page.
Sources
The W3C Web Audio API 1.1 and Media Capture and Streams specifications (W3C Document License); RFC 9110 and RFC 3986 for the share link’s fragment; GuitarPlayer’s guide to pedal order, quoted briefly; Wikibooks, “Guitar/Effects Pedals”; and each effect’s English Wikipedia article at a named revision (CC BY-SA). All read 2026-09-28; none is fetched by the page.
What happens to what you play
Audio from your input goes into the audio graph and out to your output device, and nowhere else: it is not recorded, stored or sent. Presets and the board as you left it stay in this browser’s local storage. A share link carries the board after the #, which browsers do not send to servers.