QRNix, HF DSP noise reduction

Connection guide

Connect the audio path safely.

QRNix belongs between a controlled radio audio source and your speaker or amplifier. Set the source level once, then leave it stable for reliable noise reduction.

Signal path

Radio audio → QRNix → speaker.

Radio line or headphone out QRNix line in QRNix line out Powered speaker or amplifier

Connection steps

Make the path, then establish the input level.

  1. Choose a suitable source. Use the radio's line output when available. A headphone output can work if its level is kept controlled.
  2. Connect source to QRNix line in. Use an appropriate stereo audio cable or adapter for the radio and QRNix jacks.
  3. Connect QRNix line out to the listening system. Use a powered speaker or amplifier input, not a passive speaker directly.
  4. Apply USB power. QRNix starts in its normal boot sequence and the OLED is optional to audio processing.
  5. Start in Bypass with the source level low. Bring the radio audio up until you hear clean, unprocessed audio through the listening system.
  6. Watch for CLIP. If the display inverts its mode line, lower the radio source level. Once CLIP stays clear, keep the source setting fixed before using Spectral capture.

Why level matters

Set it once, then let the DSP compare like with like.

Spectral mode stores its captured noise profile in absolute digital levels. Changing the input level after capture makes the profile stale, which can lead to over- or under-suppression. The CLIP indicator exists to make the initial level setting visible without test equipment.

Line output

Preferred. Set it low first, then raise only until the normal listening level is clean and CLIP stays clear.

Headphone output

Usable with care. Keep the radio volume low at first and use CLIP as the hard limit.

Speaker output

Requires a proper attenuating interface before QRNix. Do not connect it directly to the current line input.

If audio is wrong

Three quick checks.

No audio reaches the speaker

Return to Bypass, check that QRNix is powered, confirm the radio is feeding line in, and verify that the listening system is connected to QRNix line out and powered.

The audio is distorted or the display indicates CLIP

Lower the radio source level. A speaker-level output must not feed the current QRNix line input directly.

Spectral mode changes little

Capture again during a representative noise-only moment. If the band changed after capture, the old profile is no longer representative.