Two-Microphone A/B Comparison: Compare Mics Side by Side
Overview
Two-Microphone A/B Comparison. The Two-Microphone A/B Comparison records the same phrase with two different microphones, then plays the results back blind — alternating and unlabeled — so your judgment isn't biased by knowing which one you're hearing. It's the only reliable way to actually choose between two mics. Use the online android mic check whenever you want a fast, repeatable way to confirm this.
Two microphones can look worlds apart on a spec sheet and sound almost identical on a real voice, and the only way to find out is to hear them under the same conditions. This two-microphone A/B comparison lets you compare microphones side by side in your browser: connect both, record the same sentence once, and get matched level, noise and tone readings for each mic so you can pick the better one for streaming, calls or your home studio. It's free, with no registration and nothing to install.
How to Run a Two-Microphone A/B Comparison
Everything runs in the browser through the Web Audio API, so there's no software to download first. Connect both microphones before you open the page. Two USB mics work, and so does a USB mic against your laptop's internal mic, or a headset against a webcam mic, as long as your operating system lists each one as a separate input device. The tool is free to use as often as you like, so run as many rounds as the decision needs. The condenser microphone sensitivity and gain test runs entirely in your browser via the Web Audio API — nothing is uploaded anywhere.
- Click Start and grant microphone permission when the browser asks.
- Pick a mic for each card from its dropdown (see below).
- Press Live on each card and talk normally; watch both meters respond.
- Press Record on each card, read the same passage once, then stop.
- Play the recordings back one after the other and note what changes.
- Click Compare Both Mics for the scored summary, then download any take you want to keep.
Select Mic A and Mic B From the Device Selector
Each card has its own device selector. Put the mic you already own on the A card and the one you're considering on the B card, so "A" always means your current baseline. An XLR mic only shows up through an audio interface; if your interface has a single input, pair it with a USB mic rather than a second XLR model. If a mic is missing from the list, unplug it, plug it back in and reload the page so the browser scans its devices again.
Record Both Mics at the Same Distance
An A/B result is only as fair as the setup behind it. Mount the two capsules next to each other at the same distance from your mouth (15 cm is a sensible speaking distance), angle both toward you, and keep a consistent distance for the whole take. Leaning 5 cm closer to one of them adds level and low frequencies that have nothing to do with the hardware.
Capturing at the same time matters just as much. If you record Mic A first and Mic B second, you're comparing two performances, not two microphones. With simultaneous recording and playback, each clip holds the identical sentence, so any difference you hear in the recordings belongs to the mics. Listen on closed headphones rather than speakers so the room doesn't colour the judgement. Monitoring latency doesn't affect the recorded clips, so ignore any delay you hear while monitoring live.
What the Microphone Comparison Tool Measures
Every reading appears once per mic in a side-by-side comparison layout, so you never have to remember a number from an earlier take. Like any good mic comparison tool, it also lists each device's sample rate and channel count, which helps when one mic sounds dull simply because the system is running it at 16 kHz. The xlr microphone and audio interface test takes under a minute and needs nothing but your browser.
Live Waveform and Volume Level
The live waveform draws each mic's amplitude in real time, and the meter beneath it shows the average volume level as an RMS reading in dBFS (decibels relative to digital full scale, where 0 is the loudest possible sample). Normal speech should sit roughly between −24 and −12 dBFS. If a waveform hits the top of its box and flattens, that mic is clipping: the input is too hot, and the flat tops are audible distortion, not character.
Frequency Spectrum and Peak Frequency
The frequency spectrum overlays the two mics on one chart, built from a fast Fourier transform (FFT) of each input. Read it in three bands: low-end energy below 250 Hz (body and rumble), the mid-range from 250 Hz to 4 kHz where most of the words live, and high-frequency detail above 4 kHz (air and sibilance). The peak frequency readout names the single strongest frequency in each signal at that moment. Unlike a lab spectrum analyzer, this view reflects your voice in your room, which is exactly what you'll be recording with.
Noise Floor and Self-Noise
Stay silent for five seconds and the tool measures the noise floor: the level each mic records when nobody is talking. That figure combines the mic's own electronic self-noise, heard as a faint hiss, with whatever your room adds. For voice recording, a floor below −60 dBFS is clean, while anything above about −45 dBFS will be audible between sentences. Lower is better, but only once each mic is judged at the same speech level, as the next section shows.
Quality Score and Comparison Report
The compare button scores each mic out of 100 across four equal parts: average level, voice clarity (the share of energy in the speech band), noise and frequency breadth. Treat the quality score as a quick summary, not a verdict. A gap of under about 8 points usually vanishes after EQ and compression, so weigh it against fit, polar pattern and price.
Free, Private and No Upload
All analysis happens on your device. Nothing is uploaded, the recordings stay in browser memory until you download them, and closing the tab clears them. That privacy matters when your test sentence is a client script or an unreleased track.
Why a Microphone Shootout Must Be Level Matched
The biggest trap in any A/B test is loudness. Listeners reliably prefer whichever mic is slightly louder, hearing it as fuller and clearer even when the gap is only about 1 dB. Professional comparison libraries remove that bias on purpose: they play one recorded vocal performance through a speaker in an anechoic chamber into every mic, match the levels, and let you audition without labels so you can trust your ears. It's the try before you buy idea for studio and live sound gear, and the same rule applies to a home shootout: match levels first, then listen.
Do the same here. After recording, turn the louder mic down by the level difference so both clips are level matched, then run a double-blind listening test. Have someone else shuffle the clips so neither of you knows which is A, and score each one before the labels come off. The same offset applies when you compare mics for music production rather than speech. Three numbers make the comparison fair:
$$\text{SNR} = L_{\text{speech}} - L_{\text{noise}}$$ $$\Delta L = L_A - L_B \qquad \text{amplitude ratio} = 10^{\Delta L / 20}$$Here each L is an average level in dBFS. SNR, the signal-to-noise ratio, tells you how far your voice stands above the mic's own noise; ΔL is the level offset you remove before judging tone.
Worked Example: Signal-to-Noise Ratio for Each Mic
Say you're choosing between a USB condenser (Mic A) and a dynamic broadcast mic (Mic B) for a spare room that doubles as a podcast studio. You record the same 20-second read on each and the tool reports:
| Reading | Mic A (condenser) | Mic B (broadcast) |
|---|---|---|
| Average speech level | −21.4 dBFS | −27.9 dBFS |
| Noise floor (silence) | −63.8 dBFS | −71.2 dBFS |
| Speech minus noise | 42.4 decibels | 43.3 decibels |
| Strongest frequency | 1.6 kHz | 210 Hz |
| Low / mid / high energy share | 24% / 52% / 24% | 31% / 58% / 11% |
Mic A's margin is −21.4 − (−63.8) = 42.4 decibels; Mic B's is −27.9 − (−71.2) = 43.3 decibels. Mic A is \(\Delta L = -21.4 - (-27.9) = 6.5\) dB louder, an amplitude ratio of \(10^{6.5/20} \approx 2.11\). Its raw noise reading looks 7.4 decibels worse, which would make Mic B the obvious winner. Subtract the offset, though, and Mic A's floor drops to −70.3 dBFS at matched level, only 0.9 decibels behind Mic B.
So the real difference between these two microphones isn't noise at all; it's tone. Mic B's energy peaks at 210 Hz and 31% of it sits in the low band, which points to proximity effect from close use, while Mic A carries more than twice Mic B's share above 4 kHz. That trade-off between a fuller voice and a more detailed one is the real decision this microphone comparison hands you.
Reading Your Mic Comparison Results
Most outcomes fall into a handful of patterns, and two quick visual checks come first. If one waveform shows constant fuzz between words while the other stays flat, that mic is picking up handling noise, desk thumps or fan noise. Move it onto a shock mount and aim it away from the source; better isolation often closes the gap on its own. If the matched playback sounds clearly different, you're hearing coloration: each design shapes the voice in its own way, and neither is wrong. Judge it on overall audio quality for your use, not on one meter.
One Mic Is Louder: Sensitivity and Gain
A large level gap at equal distance means the mics have different sensitivity, quoted in mV/Pa or dBV/Pa. A more sensitive mic needs less preamp gain to reach a healthy level, which helps with quiet sources such as soft speech in a home studio or an acoustic guitar. A less sensitive one tolerates loud sources such as a shouted vocal or a guitar amp without distorting. Louder isn't better by itself; it only tells you how hard your interface will have to work.
Different Frequency Response: Warm or Bright
If the spectrum shows one mic heavier below 250 Hz and the other stronger up top, their frequency response curves differ. A presence boost in the upper midrange makes speech more intelligible and helps a voice cut through game audio or background music. Extra bass makes a voice sound warm and full, but much of it is proximity effect and room rumble, and a high-pass filter around 80 Hz cleans it up. For podcasting, a warm tone is usually easier on the ear over an hour; if the bright mic makes sibilance bite, trim a little treble rather than switching mics.
Built-In Mic Versus a USB Microphone
A built-in mic is tuned for video calls. Heavy noise reduction and compression keep a webinar intelligible, but they also smear consonants and pump background noise up and down between words. Against almost any external mic it scores low, and that gap is the clearest case for spending a little on better recording quality.
A/B Testing Both Microphones Before a Two-Host Kitchen Podcast
The question is simple: my co-host sits 60 cm across a kitchen table, and I have two mics to hand out. One is my cardioid condenser (Mic A), the other a borrowed supercardioid broadcast mic (Mic B). So I run the pair through the A/B comparison together, and whichever handles the fridge hum and the other voice better goes to my co-host. Result: Mic B wins by about 4 decibels at matched level, but the real culprit turned out to be the fridge.
I mount both on arms 12 cm from my mouth, read the same 30-second intro, then stay silent for ten seconds while my co-host says a few lines from their seat. The readings:
| Reading | Mic A | Mic B |
|---|---|---|
| My voice | −19.6 dBFS | −26.2 dBFS |
| Silence (fridge running) | −58.3 dBFS | −68.9 dBFS |
| Co-host bleed | −31.5 dBFS | −40.8 dBFS |
Margins first: −19.6 − (−58.3) = 38.7 decibels for A, and 42.7 for B. A is 6.6 decibels hotter, so I subtract that from its silence reading: −64.9 against B's −68.9, a real 4.0-decibel gap rather than a loudness illusion. Separation from my co-host's voice tells the same story, 11.9 decibels on A against 14.6 on B. I checked the arithmetic by hand against the meter, and it matched to the tenth.
Loudness normalisation before publishing lifts voice and noise by the same amount, so this 4-decibel gap from the comparison survives into the finished episode.
Then the rerun that changes the conclusion: fridge unplugged, same take. A's silence drops to −66.2 dBFS and its margin jumps to 46.6 decibels, now ahead of B. Mic A wasn't noisy; it was hearing the kitchen. That's the trap with any A/B result recorded in a live room: a mic that hears more of the room loses on the meter for reasons a quieter room would fix.
My call: B goes to my co-host, because I can't unplug the fridge for a 90-minute session, and its tighter pattern also cuts the bleed between our seats. If we ever move to a quieter room, I'd rerun this comparison before buying anything.
Microphone Test Tips for a Fair Side-by-Side Comparison
An online mic comparison is only as good as the room it runs in. Every rerun is free, so repeat the test whenever you change something. These habits keep each microphone test honest:
- Cut background noise first. Switch off fans and air conditioning; ambient noise raises both floors and hides real differences.
- Tame reflections. Hard walls add echo, and poor room acoustics favour the more directional mic. A rug, curtains or a duvet behind you levels the field.
- Test from the side too. Speak from 45° to each mic for a few seconds. The one whose level drops more rejects off-axis sound better, which matters in a noisy home.
- Repeat the take. Run three takes at different times of day; extra rounds are free, and one session can hide an intermittent buzz.
- Start both from the same input setting. Set each mic's system input level to the same position before recording, so the level offset you remove reflects the mics, not two different sliders.
Weight the readings by job: for meetings and content creation, the noise and voice clarity readings matter most; for music, the spectrum and the sound quality of the two recordings decide it.
Fixing a Mic Test When One Microphone Is Missing
If one card stays flat or a mic never appears in the list, work through these in order:
- Browser access blocked: click the lock icon in the address bar and allow the microphone for this site.
- Another app holds the mic: quit Zoom, Discord or Teams, since some apps claim exclusive access.
- Disabled in system settings: on Windows open the Microphone page in Settings and switch app access on; on macOS tick your browser in the Microphone list in System Settings.
- Driver or connection fault: try another USB port or cable, and update the driver in Device Manager.
- Identical device names: two units of the same model can show the same label; unplug one to see which entry disappears.
- Still silent: try the mic on another computer to rule out a hardware failure.
Mic Specs That Explain Your Comparison Report
When the numbers disagree with your ears, the spec sheet usually explains why. These are the specs that most often decide a mic comparison:
- Capsule type: a condenser, including large-diaphragm studio models, needs phantom power or USB power and captures fine detail; a dynamic mic is rugged, handles loud sources and hears less of the room; a ribbon sounds smooth but is fragile.
- Polar pattern: cardioid rejects the rear; supercardioid narrows the front for noisy rooms; omnidirectional hears everywhere; figure-8 takes front and back, which suits two-person interviews.
- Frequency response: a flat response across 20Hz-20kHz is neutral, while voice mics often tilt toward presence.
- Maximum SPL: the loudest sound pressure level the mic takes before distorting. It matters for drums and amps, rarely for speech.
- Impedance and connection: low-impedance balanced mics run long cables cleanly, while a long unbalanced run can add hum that shows up as a higher silence reading for that mic; USB mics include their own converter.
- Bit depth and sample rate: 24-bit at 48 kHz is plenty for voice; the bit depth matters more than a higher rate.
- Accessories: a pop filter tames plosives on P and B sounds, which otherwise thump harder on the more sensitive mic.
Frequently Asked Questions
- Is the two-microphone A/B comparison free?
- Yes. Every reading, the quality score and the comparison are free to use as often as you like, with no account and no registration.
- Can I compare two different microphones at the same time?
- Yes, as long as your computer lists both as separate input devices. Connect both before you open the page, pick one for each card and record them together, so both capture the identical take. Safari may not allow two microphones at once, so use Chrome, Edge or Firefox for the comparison.
- What kinds of microphones can I compare?
- Any two inputs your operating system recognises: USB condenser or dynamic mics, XLR mics through an audio interface, headset mics, webcam mics and the built-in laptop mic.
- How is the quality score worked out?
- Each mic gets up to 40 points for average level, 25 for frequency range (from its peak frequency), 20 for a low noise floor and 15 for clarity when the peak sits in the 200 Hz to 4 kHz speech range. Treat it as a quick summary; a gap of a few points rarely survives EQ and compression.
- Why does the louder mic often seem better?
- Listeners tend to prefer whichever take is slightly louder. That is why the tool also reports the level-matched noise gap: it turns the louder mic down by the level difference before comparing noise, so you judge the mics rather than their volume.
- What does the noise floor tell me?
- It is the level each mic records in silence, combining the mic's own self-noise with your room. Lower is better; below about -60 dBFS is clean for voice, while above about -45 dBFS the hiss becomes audible between sentences.
- Is my audio uploaded anywhere?
- No. Capture and analysis run in your browser, recordings stay in memory until you download them, and closing the tab clears them.