Hexcast – A Self-Contained Streaming VST Plugin for testing Mix Translation

[hexmarkrecords]

TL;DR

Hexcast is a self-contained plugin (VST3/AU/AAX) that lets you stream your mix over HTTP/HTTPS to any device on your local area network. There are no cloud streaming services, no app installs, and no subscriptions. It’s the fastest, easiest way to hear your mix the way your listeners will — on phones, laptops, TVs, Bluetooth speakers, etc.







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Why I Built Hexcast

Mix translation has always been a frustrating process for producers and engineers. You export your mix, send it to your phone or laptop, and realise it sounds completely different to the studio.

I wanted to eliminate that workflow friction — so I built Hexcast: a VST plugin that instantly streams your mix to any device with a web browser.

• No exporting.
• No apps.
• Just instant playback on any phone, tablet, laptop, or TV.

I also wanted to avoid relying on cloud infrastructure for streaming. By building Hexcast as a fully self-contained plugin, there’s no need for hosted servers or ongoing subscriptions — something I know many of us find frustrating. As a music producer myself, I really value owning my tools outright. It gives me confidence that my setup will stay consistent for years to come, and that I’ll always have full control over my workflow. Buy it once, and it’s yours for good.

Promo / Overview Video
Watch on YouTube:

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Key Features

Embedded Web Server Inside the Plugin – No cloud streaming, no internet required. Your DAW becomes the server.
No App Required – Just scan a QR code and stream immediately.
Low-Latency Streaming – Uses WebAssembly (WASM) for ultra-fast lossless compression (if supported) or direct PCM streaming.
Self-Signed SSL Certificate – Auto-generated to permit use of low-latency browser APIs.
🛜 Up to 6 connected devices (Hex... see what I did there ) – Plus a feature called “steal the focus” to mute all but the active device.
Per-client volume control – Volume is stored per device, so you don’t need to rebalance.
Automatic Port Detection – Finds a free port to avoid clashes — no config required.
Optimised for Engineers – Minimalist OpenGL UI, focused on function over fluff.
Wide Device Support – Compatible with both modern and legacy browsers.
AAX Support – Works across VST3, AU, and AAX — including Pro Tools.

With Hexcast, there’s:
No cloud latency
No privacy concerns (your mix never leaves your network)
No subscriptions — pay once, own it for life

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Tutorial / Walkthrough
Watch on YouTube:

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Under the Hood (Technical Notes for the Curious)

Most mix-checking tools rely on cloud services or native apps. I wanted Hexcast to be completely self-contained, so I built it from scratch in C++, with a Web App written in JavaScript and integrated with WebAssembly (WASM).

A unique feature is its ability to generate a self-signed certificate based on the host IP address. This allows the browser to trust the plugin and unlock low-latency Web Audio features like:

• Audio playback runs in a background thread, not the UI thread — keeping it smooth and glitch-free.
• FLAC lossless decompression using WASM for high performance.
• Modern wakelock support to prevent browser sleep mid-stream.

The UI was built in OpenGL for a unique, responsive view of the server’s state. I had a strong vision for how Hexcast should look — something unlike any other plugin. But to bring that vision to life, I needed help.

My good friend Darran Holmes of Stomping Creation Studios — a talented illustrator who worked on props for Lord of the Rings — stepped in. We used Confluence to ideate everything from mascots and colors to UX goals. With his creativity and my rough sketches, we iterated until we reached the final design.

Collaborating with Darran was one of the most enjoyable parts of this project. I’d highly recommend him to any developer looking to bring something visually distinctive to life.

TL;DR
Real-time audio streaming in a multi-threaded environment
FLAC audio compression (or PCM pass-through)
Embedded networking stack — no external dependencies
GPU-accelerated OpenGL UI featuring a custom mascot (Darran Holmes)
WebSocket server for instant, local playback

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Code Quality

“Code isn’t done when it works. It’s done when it’s tested.”
— Uncle Bob (Robert C. Martin)

From day one, Hexcast was built with long-term maintainability, cross-platform reliability, and performance in mind. I approached this not just as a musician, but as a developer who cares deeply about the internal quality of the tools I use. The result is a plugin that’s tested, hardened, and clean — not just “working,” but engineered to last.

2,012 unit tests
Nightly Jenkins builds with Valgrind, ASAN, UBSAN
GCC Code Coverage at 98%
JavaScript Code Coverage at 100%
Static analysis via Cppcheck and Sonar
pluginval tested at Level 10 in CI
Tested across macOS, Windows, and Linux
Debugged with Valgrind, ASAN, UBSAN, and Xcode Instruments — zero leaks, clean memory usage

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Why This Matters for Mixing & Mastering

When your track hits Spotify or YouTube, your audience isn’t using studio monitors — they’re listening on phones, TVs, laptops, and Bluetooth speakers.

If your mix doesn’t translate, they’ll skip it.
If they skip before 30 seconds, you lose streaming revenue.
If your mix translates across all devices, your audience stays engaged.

Hexcast gives you real-time insight into how your mix sounds on real devices — before you release.

It’s also great for in-person sessions. An engineer can invite the client to approve the final mix right on their own phone — in the exact context they'll experience it.

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One-Time Purchase – No Subscriptions
Hexcast is a one-time purchase (£87 per major version).

No monthly payments
No app store restrictions
Just insert on your master bus, scan, and stream

KVR Launch Offer – 20% OFF
Use code KVRHEXCAST20 at checkout
Offer ends: 30/06/2025

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Thanks + Call to Action

Hexcast is my first plugin — built to solve a very real problem I face in my own mixing work. I’d love your feedback:

• What works?
• What’s missing?
• What would make it more useful in your studio?

Drop a comment, try it out, or ask anything.

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Download + Info

KVR Link: Hexcast on KVR
Learn more: https://hexcast.com
Website: https://hexmarkrecords.com
Download: https://hexmarkrecords.com/store/plugin/hexcast
Docs/FAQ: https://hexmarkrecords.com/store/plugin/hexcast/help
Contact Us: https://hexmarkrecords.com/contact

[Ah_Dziz]

That's a handy tool. I've been using my phone and Bluetooth to check my stuff for ages now. When I'm done working on something I just dump it to my phone and listen to it on various consumer crap. This seems neat. Is it just a web portal back to a saved folder on your DAW system or do you need to be on the LAN?

[hexmarkrecords]

That's a handy tool. I've been using my phone and Bluetooth to check my stuff for ages now. When I'm done working on something I just dump it to my phone and listen to it on various consumer crap. This seems neat. Is it just a web portal back to a saved folder on your DAW system or do you need to be on the LAN?

Thanks Ah_Dziz. Yeah, that’s exactly the kind of workflow I built Hexcast to streamline. Instead of bouncing and transferring files to your phone, Hexcast streams straight from your DAW in real time over your local network.

So no, it’s not a file portal - it runs an embedded HTTP server inside the plugin itself, so any device on the same LAN can connect instantly via a browser and hear your mix privately in real time.

My new mixing workflow involves checking important mix decisions against reference tracks using ADPTR Metric AB, with Hexcast placed after it in the mastering chain. That way, I can ensure my music hits like the competition across the various devices I have lying around - and I avoid surprises later (like bass flapping on a phone etc).

I really wanted to make quick translation checks mid-session as frictionless as possible (faff kills the vibe) - or even enable client sign-offs right in the room.

[morphex]

@hexmarkrecords - massive respect! This appears to be a very well thought out solution for an issue that we all face at some point. Creating mixes that properly translate across multiple playback systems can take an ungodly amount of time, especially for beginners, or even DJ's who want their mixed sets to sound good on a phone and in a car.

I also have ADPTR AUDIO's Metric AB, which has definitely saved me precious time. So I'm interested in any tool that can streamline that process, and it looks like you may have a great solution. I hope that people find it very useful. I'll have some time to check it out this weekend and see for myself. And thanks for the intro discount as well.

[hexmarkrecords]

@hexmarkrecords - massive respect! This appears to be a very well thought out solution for an issue that we all face at some point. Creating mixes that properly translate across multiple playback systems can take an ungodly amount of time, especially for beginners, or even DJ's who want their mixed sets to sound good on a phone and in a car.

I also have ADPTR AUDIO's Metric AB, which has definitely saved me precious time. So I'm interested in any tool that can streamline that process, and it looks like you may have a great solution. I hope that people find it very useful. I'll have some time to check it out this weekend and see for myself. And thanks for the intro discount as well.

That’s awesome, @morphex

Massively appreciate the support. Seriously, cheers for taking the time to write that - it's made my day, in fact.

Yeah, whether you're just starting out, trying to balance frequencies in a big mix, or spinning DJ sets, getting that translation right can be seriously frustrating. It means a lot to hear that you recognise the same pain point Hexcast was built to solve - because it's a real one.

I also think it can be a really helpful learning tool. Sometimes the quickest way to understand what does or doesn't work in a mix is to hear it instantly on a sonically limited device. It forces you to focus on core balance and clarity without needing perfect monitoring.

I hear you on Metric AB too - I use it religiously. I usually run Hexcast after Metric AB in my mastering chain, so I can A/B both my mix and reference tracks across real-world devices without having to bounce it to a file.

If you get a chance to try it out this weekend, I'd love to hear how it fits into your workflow. Thanks again for the kind words and encouragement - it truly means a lot.