Skip to main content

Sound Test

SolvedVerified By Sound TestVerified By Sound Test

spectrum analyzer shows flat line nothing moving

Ask By Ryan C.861 views

opened the spectrum analyzer and its just a flat line. allowed the mic i think? music is playing next to me

Brand
Acer
Model
Aspire 5
Connection
Built-in Speakers
System
Windows 10/11
Browser
Firefox 131
Sample Rate
48 kHz
Output Channels
2 channels
Using Sound Tester ToolsWindows PC
Tool used in this discussionSpectrum AnalyzerSee any sound split into its frequencies live
Open Free Tool
Short Answer

A flat spectrum means the browser is not receiving audio. Allow microphone access for the site, pick the right input in the browser and check the Mic Test moves.

Verified By Sound TestVerified By Sound Test
Harvey Finch
Harvey FinchAudio Team
Spectrum Analyzer Lead · 9+ years experience · Answered Oct 16, 2026

A flat line means no audio is reaching the page, so the issue sits between the microphone and the browser. The analyzer itself only draws what the Web Audio API gives it.

The quickest check is the Mic Test. If its meter moves, the analyzer will move too once access is granted.

Step By Step Fix
  1. Click the padlock beside the address bar and set Microphone to Allow, then reload
  2. Choose the correct microphone in the browser prompt or the site settings
  3. Check that Windows allows apps to use the microphone under Privacy
  4. Close other apps that might be using the mic exclusively
  5. Hold your phone speaker close to the mic and play a tone to see a clear peak
Sources
  1. W3C Web Audio API
  2. Microsoft Support

Checked by Rishabh Sharma on . How we verify answers

Did this fix your problem?
Was this answer helpful?
Share this discussion

Community Replies 4

  • Madison ReedCommunity Member

    allow mic access in the browser, mine stayed flat till i hit allow

  • Brandon HayesCommunity Member

    check the right input is selected. mine was on a webcam mic that was muted

  • Ryan CooperCommunity Member

    browser had blocked the mic, fixed it

  • Kunal JoshiCommunity Member

    On Firefox I had to allow the mic in the address bar. After that the analyzer moved straight away.

Add Your Reply

Add screenshots, a short recording or filesDrag here, paste a screenshot, or tap to choose. Up to 2 files, 8 MB each. JPG, JPEG, PNG, WEBP, GIF, TXT, LOG, PDF, MP3, WAV, OGG, M4A, MP4, WEBM

Similar Discussions Other Listeners Started

Tools Mentioned In The Answer

Hearing & AnalysisMic TestCheck your microphone input with a live level meter
Open Free Tool
Harvey Finch
Written and tested by

Harvey Finch

Spectrum Analyzer Lead at Sound Test

Harvey Finch is the Spectrum Analyzer Lead on the Sound Tester Audio Team. Audits real-time fast Fourier transform (FFT) spectrum mapping and audio visualizer rendering accuracy. Contributes open-source digital signal processing tips on GitHub. On Sound Tester he answers Spectrum Analyzer questions, including flat displays, permissions and reading peaks, and reviews how each result is drawn.

FFT analysisspectrum accuracyaudio visualizers
  • 10 answers on Sound Test
  • 9+ years experience
  • Reviewed by Rishabh Sharma
View full profile

The Audio Team Behind These Answers

All 38 specialists
Brandon VanceBrandon VanceAudio & Acoustic Performance LeadXavier CruzXavier CruzFrequency Sweep SpecialistDiana ChenDiana ChenHearing Test ArchitectAlistair CrossAlistair CrossHeadphone Benchmark LeadImogen BlakeImogen BlakeBinaural Beats EngineerCallum SterlingCallum SterlingSurround Sound AuditorGemma GallagherGemma GallagherTone Generator ValidatorRishabh SharmaRishabh SharmaAudio DSP Engineer

Each answer is written by the specialist closest to the topic and checked by a second team member. How we verify answers

Answers are free general guidance from the Sound Tester Audio Team and community. They are not medical advice. For hearing loss, ringing or ear pain, see a doctor or audiologist. Opening a device can void its warranty, so check the maker's support first for hardware faults.

Free Sound Testers

Every tool runs in your browser. No sign up, no download, nothing uploaded.

All tools

Read Next On The Sound Tester Blog

All articles

Community Discussions

The newest replies from listeners and the Audio Team.

All discussions