8 Free Plugins That Will Improve Your Mixdowns

You don't need an expensive plugin folder to get a clean, loud, translatable mixdown. Most of the problems I hear in tracks sent for mastering (wide subs, phase issues, harsh resonances, mixes pushed too hot) can be caught and fixed with free tools.

These are the free plugins I'd point any bass music producer to first. Every one of them is made by an established developer, and all of them run on both Mac and Windows.

1. Basslane by Tone Projects: keep your low end mono

Basslane narrows the stereo width of everything below a crossover frequency you choose, so your kick, sub and bass stay centred. Wide low end is one of the most common problems I see in dubstep and DnB mixes. It loses weight on mono systems and club rigs, and it causes problems for vinyl cuts.

How to use it: put it on your bass bus or your master while mixing, set the crossover just above where your sub sits, and use the solo and monitoring options to hear exactly what's being collapsed. Use it to check and tidy your mix, not to fix a mix that's fundamentally too wide.

Formats: VST3, AU and AAX on Mac; VST3 and AAX on Windows. There's also a paid Basslane Pro with extra features.

2. SPAN by Voxengo: see your frequency balance

SPAN is a real-time spectrum analyser and the most widely used free one around. It shows where the energy in your mix is sitting, with mid/side views, correlation metering, true peak and clipping detection.

How to use it: put it on your master and compare your mix against a reference track you love at matched loudness. Look for a sub that's much louder or quieter than the reference, build-ups around 200–400 Hz, and harsh peaks in the top end. Then trust your ears to make the fix.

Formats: VST, VST3, AU and AAX, 64-bit Mac and Windows.

3. Correlometer by Voxengo: catch phase problems by frequency band

A normal correlation meter gives you one number for the whole mix. Correlometer splits it into frequency bands, so you can see if your low end is out of phase while the top end is fine. It's brilliant for checking kick and bass phase alignment and mono compatibility.

How to use it: watch the low bands. If they drop towards or below zero, your low end will lose energy in mono. Check layered basses, stereo sub patches and anything you've widened.

Formats: VST, VST3, AU and AAX, 64-bit Mac and Windows.

4. Youlean Loudness Meter 2 (free version): know your LUFS and true peak

Youlean's free version gives you integrated, short-term and momentary loudness, true peak, loudness range and a loudness history graph. That's everything you need to know how hot your mix really is.

How to use it: for a pre-master, don't chase a loud number. Use it to make sure you're not clipping, and to keep an eye on how much your mix moves. If you're mastering your own tracks, it's an honest way to compare against releases in your genre.

Formats: standalone plus VST2, VST3, AU and AAX on Mac and Windows. A paid Pro version adds streaming presets and exports.

5. TDR Nova by Tokyo Dawn Labs: dynamic EQ for resonances

TDR Nova is a free dynamic EQ. Each band can cut only when a frequency gets too loud, which makes it perfect for taming harsh synth resonances, boomy notes in a bassline or a vocal that gets sharp on certain words, without dulling the sound the rest of the time.

How to use it: find the offending frequency, set a narrow band, then bring the threshold down until it only reacts on the problem notes.

Formats: VST2, VST3, AU and AAX, Mac and Windows.

6. TDR Kotelnikov by Tokyo Dawn Labs: clean bus compression

Kotelnikov is a transparent wideband compressor aimed at buses and the master. It handles peaks and overall level separately, and its Delta button lets you hear exactly what it's taking away.

How to use it: on a drum or music bus, aim for a dB or two of gain reduction to glue things together. Use the Delta preview to make sure you're not squashing the transients that give bass music its punch.

Formats: VST2, VST3, AU and AAX, Mac and Windows.

7. Ozone Imager 2 by iZotope: check and control stereo width

Ozone Imager 2 gives you a vectorscope, a correlation meter and simple width control. It's useful for seeing how wide your mix really is, and for widening pads and effects without touching the low end.

How to use it: use the vectorscope to spot elements that are far wider than the rest of the mix. Be careful widening anything with low-frequency content, and pair it with Basslane.

Formats: VST, AU and AAX, Mac and Windows. It's free, but you need an iZotope account to download it.

8. DC1A by Klanghelm: fast, musical compression

DC1A is a compressor with just two main knobs, input and output. It goes from gentle levelling to heavy pumping, which makes it great for drums and quick character. Extra switches add parallel compression and a "Deep" mode that stops bass-heavy material from making it pump.

How to use it: try it on drum groups and percussion. Push the input until it breathes with the groove, then blend it back with parallel mode.

Formats: Mac and Windows.

How I'd put them together

On your master bus while mixing: SPAN to see your balance, Youlean to watch level, and Correlometer or Ozone Imager to check phase and width. On your bass bus: Basslane. On problem sounds: TDR Nova. On drum and music buses: Kotelnikov or DC1A.

Meters only tell you something might be wrong. Your ears and a good reference track tell you whether it actually is.

Once your mix is sorted, read how to prepare your track for a pre-master in Ableton Live 12 before you export.

Want it all in one window?

Full disclosure: I also make a metering plugin myself. GreyMeter puts LUFS, true peak, spectrum, phase and tonal balance targets for bass music genres in one window. It's £10 for Mac, currently in beta, with a 14-day free trial. Everything above is free and does the job brilliantly, so start there.

Prices and features are correct at the time of writing. Always download plugins from the developer's official website.

Got a mix that's nearly there? Send me a test export and I'll tell you honestly whether it's ready for mastering.