ChatGPT answers, unedited

For a music livestream with several microphones, I’d shortlist OBS Studio and vMix:

My pick: OBS Studio

OBS Studio is probably the best fit if low CPU usage is a priority. Its Advanced Output mode supports multiple audio tracks and lets you route individual sources to different tracks. obsproject.com

For a music setup, you could have:

• Mic 1 → vocal processing
• Mic 2 → vocal processing
• Instrument mics → separate channels
• Playback/music → separate channel
• Track 1: complete stream mix
• Tracks 2–6: isolated sources for recording/post-production

Using a hardware encoder such as NVIDIA NVENC can keep video encoding off the CPU; OBS specifically recommends hardware-encoding settings for this kind of workload. obsproject.com

If you need serious audio routing: vMix

vMix is the stronger option for a more elaborate production. Its Audio Bus Manager and Bus Mixer are designed for routing inputs through separate buses, with PFL monitoring and independent bus levels. blog.vmix.com

vMix can also use hardware encoding to reduce CPU load, and its documentation specifically recommends hardware encoding with NVIDIA GPUs when available. www.vmix.com

Bottom line:

• Best balance of low CPU + good routing + free: OBS Studio
• Best advanced audio routing/live-production environment: vMix
• If you're running 4–8+ microphones and want independent monitor/stream/record mixes, I'd lean vMix—provided you're on Windows. vMix is Windows-only. download.vmix.com

If you tell me Windows or Mac + number/type of mics + your audio interface, I can recommend the exact routing setup.

For a music livestream with high-quality audio, multiple microphones, and advanced routing, the best choice depends on whether you want the streaming software to do the mixing or whether you’ll use a dedicated audio mixer/DAW first.

Top choices

doc.vmix.com

My recommendation for a band/music setup

Best overall: vMix + an ASIO audio interface or digital mixer

Why:

• Supports multiple audio inputs from ASIO interfaces.
• Has built-in EQ, compression, noise gates, and audio buses.
• Can create separate mixes (for stream, monitors, recording, etc.).
• Uses hardware acceleration options to reduce CPU load. www.vmix.com

Example routing:

Microphones/Instruments
        ↓
Digital mixer (X32, QU, SQ, etc.) or ASIO interface
        ↓
vMix
        ↓
Stream mix → YouTube/Twitch
Monitor mix → Headphones/IEMs
Recording mix → DAW

Best low-CPU budget option: OBS Studio

OBS is extremely efficient, especially if your audio is already mixed externally. A good setup is:

• Digital mixer handles:
  • gain
  • EQ
  • compression
  • effects
  • monitor mixes

• OBS handles:
  • cameras
  • scenes
  • overlays
  • streaming

For more advanced audio routing, OBS can be expanded with audio plugins such as ASIO/VST routing tools. obsproject.com

If you need near-studio quality

Consider adding a DAW in front:

DAW → OBS/vMix

Examples:

• Reaper (very lightweight)
• Ableton Live (great for performers)
• Pro Tools (studio workflows)

The DAW handles the live mix; the streaming app only receives the finished stereo feed.

Hardware matters more than the streaming app

For multiple mics, I’d prioritize:

• ASIO-capable interface or digital mixer
• 24-bit/48 kHz audio
• separate stream mix bus
• low-latency drivers

A setup like a digital mixer feeding vMix or OBS will usually sound much better and use fewer CPU resources than trying to process 8–16 microphones directly inside streaming software. vMix specifically supports multi-channel ASIO inputs and multiple audio mixes. www1.vmix.com

Short answer:

• Professional music livestream: vMix + digital mixer/ASIO interface
• Lowest CPU: OBS + external mixer
• Studio-quality performance: DAW mix → OBS/vMix

If you tell me your number of mics/instruments, computer specs, and streaming platform (YouTube, Twitch, etc.), I can suggest a specific routing setup.

For a music livestream with multiple microphones, high-quality audio, and efficient CPU use, I’d narrow it down to OBS Studio vs. vMix:

🥇 My pick: OBS Studio + dedicated audio interface/mixer

OBS Studio is probably the best choice if low CPU usage is your priority. OBS supports multiple audio tracks and lets you independently assign sources through Advanced Audio Properties. obsproject.com

For a band, though, I'd avoid having OBS do all the mixing. A better setup is:

Mics → USB/Thunderbolt audio interface or digital mixer → OBS → stream

That gives you proper preamps, EQ, compression, monitoring, and routing while keeping OBS's workload relatively light. If your interface/mixer supports its own DSP, even better.

🥇 Best for serious productions: vMix

vMix is stronger if you're doing something closer to a professional concert/broadcast production. Its ASIO support allows multiple channels from an interface to be brought into vMix independently, and it provides multiple audio buses for separate mixes. doc.vmix.com

For example:

• Mic 1 → vocal
• Mic 2 → guitar
• Mic 3 → bass
• Mic 4 → drums
• Bus A → stream mix
• Bus B → performers' monitor mix
• Master → headphones/FOH

The tradeoff is that vMix is more resource-intensive as a complete production environment. Its own documentation recommends hardware encoding to reduce CPU usage when streaming with an NVIDIA GPU. www.vmix.com

One important caveat: vMix intentionally uses relatively large ASIO buffers because simultaneous video processing makes extremely low audio latency unreliable. obsproject.comdoc.vmix.com

What I'd choose

• Solo artist / small band / 2–8 mics: OBS Studio + good audio interface
• Full band + multiple cameras + complex routing: vMix + ASIO interface/digital mixer
• Very CPU-constrained PC: OBS Studio + hardware/DSP mixer
• Need professional monitor/FOH/stream mixes: vMix or a hardware digital mixer feeding OBS

If you tell me how many mics/instruments, your audio interface or mixer, PC specs, and whether you're streaming 1080p or 4K, I can recommend a specific low-CPU signal chain and routing setup.

For a music livestream with several microphones, I’d shortlist these:

🥇 vMix — best for advanced routing

vMix official site

If you’re on Windows, vMix is probably the strongest fit. Its audio system provides multiple independent buses (A–G), independently controllable outputs, channel matrices, and multitrack audio support. sdapp01.vmix.comwww.vmix.com

It can also use hardware encoding with supported NVIDIA GPUs, substantially reducing CPU load compared with CPU encoding. www.vmix.com

Good setup: individual mic channels → processing → separate monitor/IEM mix → main music mix → stream.

🥈 OBS Studio — best value / lower overhead

OBS Studio official site

OBS is excellent if you want free, flexible, and relatively lightweight. Its CPU requirements depend heavily on encoder, resolution, FPS, and scene complexity, and hardware encoders can help keep CPU usage down. obsproject.com

For really sophisticated routing, though, you'll often want to pair OBS with a DAW or virtual mixer such as Reaper, Voicemeeter, or your audio interface's routing software.

My pick

For a band with, say, 8–16 microphones, I'd lean vMix + an audio interface/digital mixer, with the mixer handling EQ/compression/monitor mixes and vMix handling the stream. That keeps the streaming computer's CPU workload manageable while giving you much more control over the audio. sdapp01.vmix.comwww.vmix.com

If you tell me Windows or Mac, number of mics, and your audio interface, I can recommend a specific routing setup.

For a music livestream with several microphones and high-quality audio, I’d shortlist these:

🥇 Best overall: OBS Studio

OBS Studio is probably the best choice if low CPU usage is your priority. It supports multiple audio sources, per-source routing, filters, and up to six separate recording tracks. You can also use hardware encoders such as NVENC rather than putting the encoding workload on the CPU. obsproject.com

For a band setup, you could have:

• Mic 1 → vocal processing
• Mic 2 → vocal processing
• Instrument inputs → separate channels
• Monitor mix → headphones
• Full mix → stream
• Individual tracks → recording/post-production

The caveat is that OBS's native mixer isn't as sophisticated as a dedicated digital audio mixer.

🥇 Best for serious audio routing: vMix

vMix is excellent if you're on Windows. Its mixer supports up to eight independent audio buses, which allows complex routing and mix-minus configurations. doc.vmix.com

It also supports hardware encoding, which can substantially reduce CPU usage. www1.vmix.com

For a professional music stream, I'd favor vMix + an external audio interface/digital mixer if you need separate monitor mixes, talkback, effects sends, etc.

Wirecast Pro

Wirecast is another strong professional option, particularly if you want a polished production environment on Mac or Windows. Wirecast Pro includes multitrack audio recording and GPU-accelerated encoding. www.wirecast.io

My recommendation

If you're building a music livestream today:

Budget / lowest CPU: OBS Studio + external audio mixer/interface + NVENC/Apple hardware encoding

Professional Windows setup: vMix + digital mixer/interface + NVIDIA GPU

Professional Mac setup: Wirecast Pro + audio interface/mixer

One important point: don't rely on the streaming software to do all the audio mixing if you're running several live mics. A USB/Thunderbolt interface or digital mixer that provides individual channels gives you much better control, lower latency, and more reliable monitoring.

If you tell me Mac or Windows, number of mics, audio interface/mixer, and whether you're streaming to YouTube/Twitch, I can recommend a specific low-CPU signal chain and routing setup.

For a music livestream with several microphones, high-quality audio, and minimal CPU overhead, I’d narrow it to OBS Studio + audio plugins or vMix.

My pick: OBS Studio + ASIO/audio routing

OBS Studio is probably the best choice if low CPU usage and flexibility are the priorities.

• Very efficient for streaming, particularly when using NVENC/QuickSync/Apple hardware encoding.
• With an ASIO plugin, you can bring in individual channels from a multichannel audio interface rather than treating the interface as one stereo source. github.com
• The atkAudio plugin adds much more sophisticated routing: ASIO/CoreAudio hardware routing, submixes, VST3 processing, sidechaining, multithreading, and complex signal graphs. obsproject.com
• This makes it possible to have, for example, separate vocal, instrument, monitor, and stream mixes without putting a traditional DAW in the middle.

The catch: advanced audio routing in OBS generally requires plugins, whereas vMix has considerably more of it built in.

Best all-in-one: vMix

vMix is excellent if you're doing a more professional multicamera music production.

It natively supports ASIO, so multiple microphone channels from an audio interface can appear independently in the mixer. doc.vmix.com

Its audio system provides up to eight independent buses (Master + A–G), which is particularly useful for separate mixes, monitor feeds, mix-minus, etc. doc.vmix.com

For CPU usage, vMix can use hardware encoding to reduce CPU load, although the overall workload depends heavily on your video sources and resolution. www.vmix.com

Wirecast

Wirecast is another strong professional option. It has multitrack audio mapping and can route different audio mixes to different playback devices. www.telestream.net

It also has a history of optimizing CPU/GPU usage; Wirecast 15, for example, reported substantially lower CPU usage in its testing. www.wirecast.io

Quick comparison

For your specific use case, I'd choose OBS + an ASIO-capable interface + atkAudio if you want maximum control with relatively low overhead. If you want an all-in-one professional production environment with routing built in, choose vMix.

If you tell me how many mics, what audio interface/mixer you have, your computer (CPU/GPU), and whether you're streaming to YouTube/Twitch, I can recommend the exact routing setup and settings.

For a music livestream with multiple microphones and serious audio routing, I’d shortlist these:

🥇 vMix — best overall for Windows

vMix

vMix is probably the strongest fit if you're on Windows. Its 16×16 channel matrix lets you route individual channels to different stereo buses, which is particularly useful for a band setup where you might want separate mixes for the stream, performers, headphones, etc. community.vmix.com

It can also use hardware encoding with supported NVIDIA GPUs, substantially reducing CPU load during streaming. www1.vmix.com

I'd choose this if: you have 4+ mics, instruments, multiple cameras, monitor mixes, and want the streaming software itself to handle much of the routing.

🥈 Wirecast — excellent cross-platform choice

Wirecast

Wirecast has particularly strong built-in audio support: ASIO, WASAPI and CoreAudio, up to 8 independent audio tracks, plus effects and processing. www.wirecast.io

Telestream has also specifically optimized Wirecast for lower CPU/GPU usage; its published testing for Wirecast 15 reported substantially lower resource use in certain workflows. www.wirecast.ioobsproject.com

I'd choose this if: you're on Mac, need professional audio capabilities, or want something more turnkey than OBS.

🥉 OBS Studio — best value and surprisingly capable

OBS Studio

OBS is free and relatively lightweight. Its audio mixer supports per-source monitoring and processing, and it supports VST 2 plugins and multichannel/surround workflows. obsproject.com

The catch is that complex routing is less elegant than vMix. For a serious music setup, I'd often pair OBS with a dedicated mixer/DAW such as Reaper, or a virtual routing system, and send OBS a finished stereo mix.

My recommendation

If your priority is:

Multiple mics → individual processing → monitor mixes → routing → stream → low CPU

I'd rank them:

vMix + hardware audio interface/mixer > Wirecast + interface > OBS + Reaper/virtual mixer > OBS alone

One important point: don't rely on the streaming software to do all the audio work if you're producing a band. A USB/Thunderbolt interface or digital mixer with its own DSP can handle preamps, EQ, compression, monitoring and routing, while the streaming software primarily handles the video and final stream mix. That generally gives you a more reliable show and leaves substantially more CPU headroom.

If you tell me Mac or Windows, number of mics/instruments, audio interface/mixer, and whether you're streaming to YouTube/Twitch/etc., I can recommend a specific low-CPU signal chain and routing setup.

For a music livestream with several microphones, I’d prioritize audio routing/mixing flexibility and hardware encoding to keep CPU available for your DAW/plugins.

Best choices

My pick: vMix if you're on Windows. It gives you sophisticated audio mixing/routing, supports 44.1/48 kHz and 16/32-bit audio, and its hardware encoding option can substantially reduce CPU load. doc.vmix.comwww.telestream.netwww1.vmix.com It is Windows-only. www.vmix.com

Wirecast is particularly attractive if you need Mac + Windows compatibility. Its current product information specifically lists multichannel audio ingest and ASIO/WASAPI/CoreAudio device support, and Wirecast Pro adds multitrack audio recording. www.wirecast.io It also supports GPU-accelerated encoding, which helps keep CPU usage down. www.telestream.net

OBS Studio is the value choice. For a music setup, I'd pair OBS with a dedicated audio mixer/DAW (or virtual audio routing) rather than trying to make OBS itself your entire audio console. That gives you much more control over individual mic processing, monitor mixes, buses, compression, EQ, and effects while OBS handles the stream.

For your particular use case

If you have something like:

4 vocal/instrument mics → audio interface → DAW/mixer → streaming software → YouTube/Twitch

I'd lean toward:

Windows: vMix + ASIO-compatible interface + DAW/mixer
Mac: Wirecast + CoreAudio interface + DAW/mixer
Budget/free: OBS + DAW/mixer

One important point: don't judge CPU usage solely by the streaming software. Use NVENC/Quick Sync/other hardware encoding where available. vMix explicitly recommends its hardware encoder to reduce CPU use. doc.vmix.comwww.telestream.netwww1.vmix.com

If you tell me Mac or Windows, number of mics, audio interface, and whether you're using a DAW like Reaper/Ableton/Logic, I can recommend a specific low-CPU routing setup.

For a music livestream with several microphones/instruments, I’d narrow it down to OBS Studio and vMix:

🥇 My pick: OBS Studio

OBS Studio is probably the best choice if low CPU usage is a priority.

It supports multiple audio sources, per-source audio controls, filters, and up to six separate audio tracks for recording. obsproject.com You can also use hardware encoding such as NVENC rather than making the CPU do all the video encoding, which is particularly useful for a music stream where you want CPU headroom for audio processing. obsproject.com

For example, you could route:

• Mic 1 → vocal processing
• Mic 2 → vocal/instrument processing
• Guitar → separate channel
• Keyboard → separate channel
• Playback → separate channel
• Track 1 → finished stereo stream mix
• Tracks 2–6 → isolated sources for later editing

🥈 Best for serious production: vMix

vMix is stronger if you're doing multiple cameras + multiple microphones + professional routing.

Its audio mixer supports independent buses and complex routing such as mix-minus, while current versions support up to eight independently controllable audio outputs. www.vmix.com

vMix also recommends hardware encoding with an NVIDIA GPU to reduce CPU usage, and its production engine makes substantial use of GPU acceleration. www1.vmix.com

The tradeoff is that vMix is Windows-only and considerably more expensive than OBS.

What I'd use for your setup

If you have something like 4–8 microphones going into an audio interface/mixer, I'd actually consider:

Audio interface → DAW/mixer → OBS → YouTube/Twitch

rather than trying to make the streaming software itself your entire audio console.

If you need real-time EQ, compression, gates, reverb, monitor mixes, and separate headphone mixes, a dedicated mixer/DAW handling the audio and OBS handling the video/stream is usually the cleaner architecture.

Bottom line:

• Lowest cost + low CPU: OBS Studio + NVENC/other hardware encoder
• Maximum routing/control: vMix
• Professional audio: consider doing the actual mixing in a hardware mixer or DAW before sending the stereo mix to OBS/vMix.

If you tell me how many mics, what audio interface/mixer, your PC/Mac specs, and whether you're streaming to YouTube/Twitch, I can recommend a specific low-CPU routing setup.

For a music livestream with several microphones, I’d narrow it to OBS Studio and vMix, with OBS being the better choice if low CPU usage and flexibility matter most.

🥇 OBS Studio — my recommendation

OBS Studio is probably the sweet spot.

• Supports multiple mic/interface inputs and lets you route them to separate audio tracks.
• Advanced Audio Properties give you per-source track assignment, so you can keep a full stereo mix for the stream while recording individual mics separately. obsproject.com
• With an NVIDIA GPU, OBS can use NVENC hardware encoding, keeping video encoding largely off the CPU. OBS recommends NVENC settings specifically for this use case. obsproject.com
• Free and works on Windows, macOS and Linux.

For a band, I'd actually pair OBS with a digital mixer or DAW for the audio mix. Let the mixer handle EQ, compression, reverb, monitor mixes, etc., and send OBS a polished stereo mix.

🥈 vMix — if you're doing a more elaborate production

vMix is excellent if the livestream also involves multiple cameras, graphics, remote guests, playback, etc.

vMix is designed around professional live production and has extensive audio/video routing. It also supports NVIDIA hardware encoding specifically to reduce CPU usage. www1.vmix.com

Its downside: Windows-only and considerably more complex/costly than OBS. www.vmix.com

🎛️ Best setup for a serious music stream

I'd use:

Multiple mics → audio interface/digital mixer → DAW or mixer processing → stereo mix → OBS → hardware encoder → streaming platform

If you need individual mic recordings for post-production, simultaneously send the individual channels into OBS/your recorder rather than relying solely on the stereo stream mix. OBS supports up to six audio tracks in Advanced Output mode. obsproject.com

Bottom line:

• OBS + digital mixer/DAW: best balance of quality, routing and CPU usage.
• vMix: best if the entire production is becoming a professional multicamera show.
• DAW + OBS: best if audio quality/control is the top priority.

If you tell me Windows or Mac, number of mics, audio interface/mixer, and CPU/GPU, I can recommend a specific low-CPU routing setup.

For a music livestream with several microphones, I’d narrow it to vMix vs. OBS Studio:

🥇 My pick: vMix

vMix is particularly strong if audio routing is your priority. Its current audio system supports eight independent stereo buses (Master + A–G), and its channel matrix provides 16×16 routing per input. That makes things like separate monitor mixes, talkback, mix-minus, and different mixes for streaming/recording much easier. www.vmix.comwww.vmix.com

It also supports ASIO audio interfaces, so you can bring multiple microphone channels into the computer independently rather than mixing everything before it reaches the streaming software. www.vmix.com

For CPU usage, vMix can use hardware encoding with NVIDIA GPUs, specifically to reduce CPU load. licence.vmix.com

🥈 OBS Studio — best value

OBS Studio is excellent if you don't need vMix's more elaborate production environment. Its Advanced Output mode supports up to six audio tracks, allowing separate mic/instrument/etc. tracks for recording while maintaining a full mix for the stream. obsproject.com

For low CPU usage, I'd pair OBS with NVENC (NVIDIA) rather than x264. OBS specifically recommends NVENC settings for reducing the CPU burden. obsproject.com

The limitation is that complex live routing generally becomes more cumbersome than in vMix, particularly if you want multiple independent monitor/aux mixes.

🎵 For your specific use case

If you're doing something like:

4–8 mics → audio interface → computer → livestream

I'd choose:

Windows PC + vMix + multichannel ASIO interface + NVIDIA GPU

You can have, for example:

• Master: broadcast mix
• Bus A: musicians' monitor mix
• Bus B: vocalist monitor mix
• Bus C: producer/headphones
• Bus D: clean mix without talkback
• Individual EQ/compression on each mic
• Separate routing for recording vs. streaming

vMix explicitly supports independent bus routing and mix-minus configurations. www.vmix.comwww.vmix.com

If you're trying to keep the computer as lightweight as possible, though, OBS + hardware-encoded video + an external mixer/DSP is arguably the most efficient architecture.

If you tell me how many mics, what audio interface/mixer you have, and your computer's CPU/GPU, I can recommend the exact setup and routing.

For a music livestream with high-quality audio, multiple microphones, and efficient CPU usage, I’d prioritize software that can separate audio mixing/routing from video production. The best choices are:

www.elgato.comtalks.co

My top picks

1. OBS Studio + a dedicated audio mixer (best balance)

Best if you want low CPU use and maximum flexibility.

A typical setup:

• Digital mixer/interface → OBS
• Each mic gets its own channel
• Mix/route in the mixer or a DAW
• OBS handles video, scenes, overlays, and streaming

Advantages:

• Very lightweight
• Supports VST plugins for EQ, compression, gates, reverb, etc.
• Huge plugin ecosystem
• Works well with audio interfaces and virtual routing tools

www.elgato.com

Good audio companions:

• Reaper for live processing
• Voicemeeter for Windows routing
• Loopback for macOS routing

2. vMix (best for a concert-style production)

If you have:

• 4–20+ microphones
• multiple cameras
• live switching
• lower thirds/graphics
• a production crew

vMix is probably the strongest all-in-one option. It has built-in audio buses, routing, and professional production features, and it can reduce CPU load by using hardware encoding. www.elgato.com

A good workflow:

• Stage mics → digital mixer
• Mixer sends stereo mix + isolated channels over USB/Dante/AVB
• vMix handles broadcast mix, cameras, and stream

3. Wirecast (good if you need Mac support)

Wirecast is a polished professional option and supports complex live productions, but it generally makes more sense when you need its broader production features rather than the absolute lowest CPU usage. www.elgato.comtalks.co

Audio routing setup I’d recommend for a serious music stream

Best quality architecture:

Microphones
    ↓
Digital mixer / audio interface
    ↓
DAW or mixer DSP
    ↓
OBS Studio or vMix
    ↓
YouTube / Twitch / broadcast platform

Avoid putting heavy plugins directly inside the streaming app if possible. Let a mixer or DAW handle:

• EQ
• compression
• vocal processing
• monitor mixes
• effects

Then send the finished mix to the streamer.

Hardware matters more than software for audio

For high-quality music:

• Use a USB/Thunderbolt interface or digital mixer with multiple inputs
• Run 48 kHz sample rate
• Keep buffer sizes around 128–256 samples for live use
• Use hardware encoding (NVENC/Quick Sync/Apple Silicon) to leave CPU available for audio processing

My recommendation by scenario:

• Solo artist / small band → OBS + audio interface + DAW
• Band with 4–12 mics → OBS + digital mixer
• Full concert production → vMix + digital mixer
• Mac-based professional setup → Wirecast or OBS

For most musicians, OBS with a proper audio mixer feeding it gives the best quality-to-CPU ratio. www.elgato.com

For a music livestream with several microphones, high-quality audio, and minimal CPU overhead, I’d narrow it to OBS Studio and vMix, with vMix being the stronger choice if advanced routing is the priority.

🥇 My pick: vMix

For a music performance, vMix has the most capable built-in audio architecture. It supports multiple microphones and ASIO devices, independent audio buses, EQ/compression/gain, and up to eight independent buses, which makes complex routing—FOH mix, stream mix, monitor mix, guest mix-minus, etc.—much easier. doc.vmix.com

It can also use hardware encoding to reduce CPU load. vMix specifically recommends hardware encoding with an NVIDIA GPU when available. doc.vmix.com

🥈 Best low-CPU option: OBS Studio

If you don't need vMix's sophisticated bus architecture, OBS Studio is probably the sweet spot. Its audio mixer supports multiple sources and separate recording tracks, and you can use hardware encoders such as NVENC so video encoding doesn't consume much CPU. obsproject.com

For music, I'd pair OBS with a multichannel USB/Thunderbolt audio interface or digital mixer and do the serious mixing there. That keeps OBS's job relatively simple: receive the finished stereo mix and stream it.

What I'd actually build

Multiple mics → digital mixer/audio interface → stereo stream mix → OBS/vMix → hardware encoder → streaming platform

For example, if you have vocals + guitar + drums + keys + backing tracks, I'd favor:

Digital mixer → vMix → NVENC

if you want the streaming computer to handle routing/mixing, or:

Digital mixer → OBS → NVENC

if the mixer is doing all the audio processing and you want the lightest, simplest streaming setup.

One important point: low CPU usage depends more on hardware encoding and your video workload than on the audio mixer itself. vMix notes that CPU is primarily used for audio/video compression and recommends hardware encoding to reduce CPU use. doc.vmix.com

Bottom line:

• Best professional audio routing: vMix
• Best low-CPU/free solution: OBS Studio
• Best if you already own a serious digital mixer: OBS Studio + mixer
• Best all-in-one production system: vMix + ASIO interface/mixer + NVIDIA NVENC

If you tell me how many mics/instruments you have, your computer specs, and whether you're streaming to YouTube/Twitch/etc., I can recommend the exact audio-routing setup and settings.

For a music livestream with multiple microphones, serious audio routing, and low CPU usage, I’d narrow it to these:

🥇 Best overall: vMix

vMix is probably the strongest fit if you're on Windows. It provides up to eight independent audio buses, allowing separate monitor mixes, broadcast mixes, mix-minus feeds, etc. www.vmix.com

It also supports multiple microphones through USB/ASIO interfaces, with each mic available independently in the mixer, including EQ, compression and gain controls. www.vmix.com

For CPU usage, vMix recommends using a hardware encoder with an NVIDIA GPU to reduce CPU load during streaming. www1.vmix.com

vMix official site

🥈 Best free option: OBS Studio

OBS Studio is excellent if you don't need vMix's integrated production environment. Its Advanced Audio Properties let you route sources to separate tracks, and it supports up to six audio tracks for recording. obsproject.com

With NVENC/AMF/QuickSync hardware encoding, OBS can keep video encoding largely off the CPU. obsproject.com

OBS Studio official site

🥉 Wirecast Pro

Wirecast is a good choice if you want a more turnkey interface and need Mac or Windows support. Wirecast supports multichannel audio and ASIO, WASAPI, and CoreAudio devices, and its Pro version includes multitrack audio recording. www.wirecast.iowww.wirecast.io

It also supports GPU-accelerated encoding, which helps with CPU utilization. www.wirecast.iowww.wirecast.io

Wirecast official site

My recommendation: If you're doing a band/live-music setup with, say, 4–12 mics, I'd choose vMix + a multichannel ASIO audio interface + NVIDIA NVENC. That gives you independent mic control, multiple monitor/broadcast mixes, and hardware video encoding so the CPU isn't doing all the heavy lifting.

If you tell me Mac or Windows, number of mics, and your audio interface, I can recommend a specific low-CPU routing setup.