Sweep: Speaker Tuning

Carl Sieber

About this app

See how your speakers really sound.

Sweep plays a log sweep through your speaker and plots its frequency response — measured from your listening position. No laptop, no audio interface, no mic stand. Just your phone, a calibrated mic, and a clear picture of what you're hearing.

The untethered scout between full bench sessions — the fast check from your chair you'll actually run. A minute, not an afternoon.

SWEEP. CAPTURE. COMPARE.
• Sweep — tap once and a 20 Hz–20 kHz log sweep plays through your speaker (the Farina ESS method the bench tools use) — wired, over a USB-C audio adapter, or to a Bluetooth speaker.
• Capture — a calibrated USB measurement mic (Dayton iMM-6C, miniDSP UMIK-1/UMIK-2/EARS, or any REW-style .cal file) or your phone's built-in mic records it; on-device math extracts the impulse response and plots the curve.
• Compare — overlay runs, each its own color, to see exactly what a change did. Measure, adjust, measure again.

TWO WAYS IN
No audiophile experience required. Tune My Receiver runs a guided measurement, then hands back actual settings — "Bass +5, Treble +8" — instead of a chart to interpret. A plain-language results tour walks through what it found, and Balance Speakers checks your channels match before you start. Measure Again starts a new before-and-after round without losing the first. Prefer the full picture? Everything above is one tap away, from the same library.

ALSO IN THE APP
• Scrub any frequency — drag the cursor; it snaps to peaks and troughs and reads frequency · dB right where you need it. Pinch to zoom into any band; hold near the edge to pan.
• Target curves — overlay Harman Room, B&K, a tilt, or Room Gain as a dashed reference so you know what "good" looks like, not just what you measured.
• Aim at what you listen to — pick a listening style (Bass-forward, Warm, Bright, and more) and Tune My Receiver's recommendation steers toward it, not just flat.
• Average or Difference — power-average two or more captures (walk the room, average the seats) or compute A − B to see exactly what a change did, both as new measurements you can keep comparing.
• Real smoothing, applied after the fact — every capture keeps its full resolution; change 1/24 to 1/3-octave anytime and every trace redraws, no re-measuring.
• Set levels with confidence — a built-in test tone and live meter get your output where it should be before you measure. Each mic keeps its own calibration trim.
• Share your capture — export the chart as a labeled image card (from Tune My Receiver, it carries your verdict and knob settings too), or the measurement as a file: text, CSV, impulse WAV, or a Sweep file that Sweep for Mac and iPhone open directly. Sweep files from them open here too.
• Tablets — the chart takes the whole screen, your measurements in a side column.
• Undo delete — swipe away a measurement by mistake? Undo is right there for a few seconds.

HONEST BY DESIGN
Sweep shows relative frequency response — the shape you need to tune speaker DSP and EQ. A time-gate isolates the direct sound; down low, the room is part of every measurement, so what you see there is speaker plus room, not the speaker alone. Phone microphones vary and some phones process the mic signal; every phone-mic and wireless measurement is labeled, and a calibrated USB mic gives you the real numbers. Not an SPL meter, not a full bench replacement — it names its limits up front, so you can trust its strengths.

PRIVATE BY DEFAULT
Everything runs on your phone. No account, no signup, no cloud, no tracking, no analytics SDK — Sweep doesn't even request internet access. Your measurements go only where you send them.

Free. No in-app purchases, no ads, no account.

Sweep is part of a family of focused instruments alongside Pull, Grip, Lean, and Level.

What’s new

First release of Sweep for Android: measure your speakers’ frequency response with your phone or a USB measurement mic, tune your receiver step by step, and share the results.