Last updated: 15 September 2026 (Asia/Manila)
Research note: LegitGameplay has not hands-on A/B tested RNNoise, Speex DSP, or NVIDIA Broadcast for this article. This piece is Research-based from OBS docs, NVIDIA docs, and dated 2025–2026 guides/reviews. Do not treat quality rankings or CPU/GPU cost as lab-measured by us. How we label work: Testing Methodology · Editorial Policy.
This is Creators Broadcast #2 from the Creators & Streaming desk — a decision piece on when free OBS filters win versus NVIDIA Broadcast for mic noise, not a shopping list. Desk context and section status: Creators & Streaming section status (Sep 2026). Amazon / affiliate purchase CTAs remain blocked on this article; see Affiliate Disclosure. Questions: Contact.
Related desk guides: Stream Deck MK.2 vs budget pads / Touch Portal · USB vs XLR mic for streaming · Capture cards: Elgato vs AVerMedia · Best gaming headsets 2026.
The problem: keyboard, AC, and fan noise on stream mics
Stream mics pick up more than your voice: mechanical keyboard clacks, AC hum, PC fan whoosh, room reverb, and distant household noise. Software filters try to keep speech while attenuating the rest. They do not fix a bad gain chain, a mic sitting next to a case fan, or a cavernous untreated room — they sit after capture.
Filtering typically lives in one of three places:
- OBS filters (per source) — Noise Suppression on the mic (or Audio Input Capture) source only affects what OBS hears for that source.
- System-wide AI apps (e.g. NVIDIA Broadcast) — virtual mic/speaker devices Windows apps can select; noise removal can apply to Discord, Zoom, and OBS alike.
- Mic hardware / firmware — some USB mics and headsets ship onboard noise reduction; guides often warn against stacking duplicate effects (NVIDIA FAQ: turn off device-side noise removal if you use Broadcast).
OBS’s own Noise Suppression Filter page (retrieved 2026-09-15) states the filter is for mild background/white noise (PC fans, environmental hiss) and is generally not effective at large amounts of background noise in a loud room. That framing matters for expectations.
Speex DSP — classic OBS Noise Suppression
What it is: Speex (via SpeexDSP) is the older, classic noise-suppression method in OBS’s Noise Suppression filter. OBS UI locale strings label it roughly as Speex (low CPU usage, low quality) versus RNNoise (good quality, more CPU usage).
Where it lives: Filters → Noise Suppression on an audio source → Method: Speex. Speex exposes a Suppression Level slider. OBS docs: 0 is off; moving the slider left strengthens suppression and can distort other sounds (including voice). Default listed in OBS KB: -30 dB.
Tradeoffs (sourced — not LG lab scores):
- Light on CPU (OBS UI + consensus of 2025–2026 creator guides).
- Configurable strength — useful when RNNoise feels too “processed.”
- Stronger settings raise robotic / artifact risk (OBS docs + SimpleClean / Krisp guides).
- Generally framed as the fallback for low-spec PCs, not the quality default.
RNNoise — modern OBS default path
What it is: RNNoise is a small neural-network denoiser (Xiph/Mozilla lineage). OBS integrated it into the Noise Suppression filter.
When OBS shipped it: OBS Studio 26.0 (September 2020) release notes: new AI-based RNNoise method with significantly better results for voice than Speex. OBS Knowledge Base lists Method default = RNNoise and describes RNNoise as higher quality at the cost of greater CPU usage; Speex is the configurable alternative.
How it differs from Speex (docs + PR framing):
| Aspect | Speex | RNNoise |
|---|---|---|
| Approach | Classic spectral / SpeexDSP suppression | Pre-trained neural model |
| Tunable in OBS | Yes — Suppression Level | No user strength slider (OBS PR/docs: no settings) |
| CPU (OBS framing) | Lower | Higher than Speex |
| Quality (OBS framing) | Lower / configurable | Higher / default when available |
| Hardware | None special | None special (CPU path) |
OBS still positions RNNoise for mild environmental noise — not a substitute for fixing the room or mic placement.
NVIDIA Broadcast — Noise Removal / Room Echo (GPU path)
What it is: The NVIDIA Broadcast App (retrieved 2026-09-15) offers AI Noise Removal and Room Echo Removal on mic/speaker paths (plus camera effects). Noise Removal targets distracting background sounds; Room Echo Removal targets reverb in untreated rooms (NVIDIA Broadcast FAQ, retrieved 2026-09-15).
How it enters OBS:
- System-wide: Broadcast creates virtual Windows mic/speaker devices; select them in OBS (and Discord, etc.).
- Inside OBS Noise Suppression: OBS KB — install the NVIDIA Broadcast SDK redistributable; then NVIDIA Noise Removal appears alongside RNNoise and Speex in the Method list.
RTX requirement (cite NVIDIA — do not invent models): Per NVIDIA Broadcast FAQ / product requirements (retrieved 2026-09-15):
- GPU: NVIDIA GeForce RTX 2060, Quadro RTX 3000, TITAN RTX, or higher
- RAM: 8 GB+
- OS: Windows 10 64-bit
- Driver: 570.xx or higher (FAQ) / Display Driver 570 or higher (resources pages)
- CPU (recommended): Intel Core i5-8600 / AMD Ryzen 5 2600 or higher
- Internet required during installation (downloads AI models)
- FAQ: Broadcast app does not run on GeForce GTX (needs RTX Tensor Cores)
- Separate effects (e.g. Studio Voice / Virtual Key Light) may need higher GPUs per NVIDIA’s own FAQ notes — verify current FAQ if you care about those features; this article focuses on Noise Removal / Room Echo.
System-wide vs OBS-only: Broadcast virtual devices apply wherever Windows routes that device. OBS-only Speex/RNNoise only touch that OBS filter chain. Guides warn against stacking Broadcast + OBS noise suppression + headset firmware NR on the same path.
Performance (NVIDIA-stated, not LG-measured): FAQ notes impact depends on GPU, game, camera resolution/FPS, and effects count; NVIDIA cites roughly 5–10% impact measured on a GeForce RTX 5090 for effects in general — treat as vendor measurement, not our lab.
Snapshot comparison (researched — not LG lab scores)
| Factor | Speex (OBS) | RNNoise (OBS) | NVIDIA Broadcast Noise Removal |
|---|---|---|---|
| Cost | Free (built into OBS) | Free (built into OBS) | Free app; needs eligible RTX GPU |
| Where it runs | OBS filter, CPU | OBS filter, CPU | GPU (Tensor Cores); app and/or OBS SDK method |
| Scope | OBS source only | OBS source only | System-wide virtual devices or OBS Method |
| Tunable strength | Yes (Suppression Level) | No slider in OBS | App UI / intensity (product-dependent) |
| OBS default Method | Alternate | Default per OBS KB | Appears after Broadcast SDK install |
| Extra room tool | No | No | Room Echo Removal (separate effect) |
| Best researched “when…” | Low CPU headroom; Speex artifacts preferred over RNNoise “processed” tone | Most free/OBS-only setups with mild fan/AC/keyboard noise | Eligible RTX + want GPU offload, multi-app cleanup, or echo removal |
| Soft cons (guides) | Artifacts / robotic at high levels | More CPU than Speex; mild-noise limits per OBS | RTX lock-in; GPU load; setup; stacking risk |
No Amazon / affiliate links. Product names and official/guide sources only.
Decision framework: when free OBS wins vs when Broadcast is worth the GPU
When free OBS (RNNoise / Speex) wins
- You need mild fan, AC, or keyboard cleanup and OBS already captures the mic.
- You are on non-RTX, AMD, Intel Arc, or macOS/Linux where Broadcast’s RTX app path does not apply.
- You want zero extra apps and filter toggles next to Noise Gate / Compressor in OBS.
- Start with RNNoise (OBS default / higher-quality framing). Switch to Speex if CPU struggles or RNNoise tone is worse for your voice (guide consensus — not LG A/B).
- GPU is already maxed by game + encode + overlays; you refuse another AI effect on the card.
When NVIDIA Broadcast is worth considering
- You already own a documented eligible RTX GPU (see NVIDIA’s list above) and want GPU-side removal.
- You need the same clean mic in Discord / Teams / Zoom and OBS without duplicating OBS-only filters.
- Room echo/reverb is the main complaint — Broadcast’s Room Echo Removal is a named product feature OBS Speex/RNNoise do not claim as a peer.
- Keyboard/AC noise still leaks through OBS RNNoise in guides’ framing and you prefer trying Broadcast before buying acoustic foam or a new mic path.
When to fix the room / mic first
Software cannot fully rescue a mic gain cranked into case fans, or a distant dynamic mic in a reflective room. Before chasing a third AI filter:
- Mic distance and gain (USB vs XLR tradeoffs: USB vs XLR mic for streaming).
- Headset boom placement if that is your mic (Best gaming headsets 2026).
- One noise filter + gate/expander — avoid stacking Broadcast + OBS NR + firmware NR.
- Treat OBS’s “mild noise” caveat seriously for loud rooms.
Desk stack: mute/filter toggles and capture path
Mute, scene, and filter toggles often live on a stream deck or software pad — see Creators Broadcast #1: Stream Deck MK.2 vs budget pads / Touch Portal. NVIDIA’s FAQ also notes Stream Deck can toggle Broadcast effects via Elgato’s marketplace plugin (vendor claim — not tested by us).
Capture cards are a separate video path decision: Elgato vs AVerMedia capture cards. Do not confuse HDMI capture noise with mic Noise Suppression.
FAQ
Did LegitGameplay hands-on A/B these filters?
No. This article is Research-based. We have not A/B tested RNNoise, Speex DSP, or NVIDIA Broadcast (Noise Removal / Room Echo) in a LegitGameplay lab for this piece. See Testing Methodology.
Should I start with RNNoise or Speex?
OBS docs default Method to RNNoise and call it higher quality / more CPU. Creator guides from 2025–2026 generally agree: try RNNoise first; fall back to Speex for lighter CPU or if RNNoise tone is worse. Not a lab ranking from us.
Do I need an RTX GPU for OBS Noise Suppression?
No for Speex/RNNoise. Yes for NVIDIA Broadcast App and the NVIDIA Noise Removal Method that appears after the Broadcast SDK install — per NVIDIA/OBS docs.
Can I use NVIDIA Broadcast and OBS RNNoise together?
Technically possible to stack, but NVIDIA and creator guides advise against applying the same effect twice (e.g. headset NR + Broadcast + OBS). Pick one primary noise path.
Will filters fix a loud room?
OBS KB: Noise Suppression is generally not effective for large amounts of background noise in a loud room. Fix placement, gain, and acoustics first; consider Room Echo Removal only if you meet Broadcast requirements.
Are there Amazon / affiliate links here?
No. Amazon and affiliate purchase CTAs are blocked on this article. Product names and official/review URLs only. Affiliate Disclosure.
Sources (retrieved 2026-09-15)
- OBS Project — Noise Suppression Filter
- OBS Studio — 26.0.0 release notes (RNNoise added)
- OBS Studio PR — Add RNNoise to noise suppression filter (#3263)
- OBS Studio source — noise-suppress-filter.c (method defaults / Speex vs RNNoise)
- NVIDIA — Broadcast App product page
- NVIDIA — Broadcast App FAQ (Noise Removal, Room Echo, RTX requirements, GTX note, performance note)
- NVIDIA — Broadcast download / SDK resources (driver/GPU notes; regional mirrors may vary)
- SimpleClean — Remove background noise in OBS (RNNoise vs Speex vs NVIDIA)
- Krisp Blog — OBS Noise Suppression guide (2026 framing)
- OBS Versions — Noise suppression comparison guide
- Haishin Sekai — Best OBS noise suppression plugins overview
- LegitGameplay — Testing Methodology, Editorial Policy, Affiliate Disclosure
- Desk cross-links — Stream Deck worth-it, USB vs XLR, Elgato vs AVerMedia capture, Best gaming headsets 2026, Creators section status (URLs above)
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