Best SPL Plugins 2023 (EQs, Compressors & More)

Best SPL Plugins (EQs, Compressors & More) |

SPL PQ By By Brainworx

More Info & Price (Trial Available)

The newest Plugin Alliance SPL PQ is a five-band parametric EQ based on SPL’s famous mastering hardware.

SPL PQ Mastering Equalizer – Model 2050 has been updated to become the PQ Mastering Equalizer. Their 120 Volt Technology is at the heart of both of these products. Just like its predecessor, PQ is of superior quality.

The five bands can be toggled on or off, and you can select each of the five independently. A circuit like this has yet to be implemented in any equalizer. In addition, thanks to the bypass function, you can switch on or off all channels at once and set the timing for this to happen automatically.

Key Features:

  • 120 Volt Technology
    These schematics make it easy to see how our 120-volt technology outperforms those that use a lower voltage. Again, the direct association between operating and maximum levels is crucial for the classification: the higher the operational level, the higher the maximum \slevel a circuit can withstand.
    Because of this correlation, increasing the operating voltage improves the dynamic range, distortion limit, and signal-to-noise ratio, which are all crucial acoustic and musical factors. The result is a more laid-back and natural sound.
  • Auto Listen
    When Auto Listen is used, the sound of everything outside of a selected eq band is muffled as long as the frequency or q slider is held down. This lets you hear the impact of a single eq-band based on Its frequency and q. Gain is kept constant during listening.
  • TMT
    Tolerance Modeling Software was initially implemented as a set of bx console plugins. It accounts for the tolerances of audio components typically found in audio circuits and provides several channels of analog audio with realistic variations in frequency response, material constants in dynamic parts, etc.
    The result is digital music that sounds as close to analog as feasible, even though the L and R channels would react slightly differently, even in a stereo instance.
  • AutoBypass
    It’s preferable to have the original and processed signals alternate automatically so that you can evaluate the processed content fairly. Another significant perk is staying in your sweet spot and focusing more on the music while evaluating the processing. The Interval control controls the time before the compressor toggle switches between the raw and processed signals.
SPL PQ Walkthrough | Plugin Alliance


The OS requirements for this plugin are Windows 7 or higher for PC and macOS 10.9 or higher for Mac. It comes in VST/RTAS/AU/AAX formats and supports 32 and 64 bit systems.


The SPL PQ is a great, analog EQ that with its ten bands can handle even the most complex of fixes. Q mode’s remarkable proportionality also enables artistic and beneficial alterations. Good quality construction and handling justify the “Made in Germany” label. The PQ is never cheap, but it is always worth the price.

SPL Passeq

More Info & Price (Trial Available)

SPL Passeq Review - 6 Best Passive EQ VST Plugins |

The traditional hardware for this plugin came at a price of about $5499 and weighed around 12 kg which meant that only a few people could actually manage to have one.

Thankfully, SPL has managed to release a plugin version that offers similar qualities for a small fraction of that price.

The interface of this plugin may come across as very confusing at first, but the workflow is clear, and you’ll get used to it in no time. Frequency bands are situated whereby the cut knob is on the left, and the boost knob is on the right for every band. You have control over 3 cut ranges, i.e., 1. LF-LMF, 2. MF-MHF, 3. MHF-HF and 3 boost ranges, i.e., 1. LF, 2. LMF-MHF, 3. and HF.

Much like the hardware version, the plugin uses an attenuator to gain control. The reasoning behind it is to maintain a low noise floor, linearity, and have enough headroom space. The main difference between the plugin and the hardware version is in the additional recall buttons, M/S operation, and stereo channel linking. In addition to that, the plugin version has a space-saving Passeq Single, which shows only one set of controls for you working in stereo only.

Key Features:

  • The plugin has 2 modes of operation, i.e., the standard stereo and a mono version
  • Mid/side (M/S) processing is available
  • Manages to successfully reproduce the workflow of the original hardware passive eq, which translates into similar sound signatures
  • Made up of 72 filters spread over 6 bands per channel
SPL PASSEQ Plugin Review


The SPL Passeq is compatible with Windows 7 or higher for PC and macOS 10.9 or higher for Mac. It comes in VST/VST3/AU/AAX formats and supports 64-bit systems. 


The Passeq by SPL is one of the most powerful passive EQs in the market. This is due to the detailed design of the plugin to perfectly replicate the sound signature of the original Passeq hardware, which was already considered the industry-standard passive equalizer. It comes at a reasonable price for its capabilities, and we definitely recommend that you try it out.

SPL Iron By Brainworx

More Info & Price (Trial Available)

Yet another vari-mu on our list, this compressor packs a massive punch for mastering. 

Based on the hardware compressor with the same name, Brainworx’s SPL Iron provides many controls for shaping and toning your sound. In essence, the plugin is a parallel dual-tube compressor, where each audio channel is processed separately.

It results in a transparent and musical sound thanks to different response curves between the two signals. Furthermore, the plugin adds several features that the hardware version does not have.

SPL Iron Review - Top 11 Plugin Alliance Plugins 2021 (And 5 Free Effects) |

Key Features:

  • 120v Operation
    The plugin is an emulation of hardware that runs with 120v of electricity, the highest-ever operating voltage used for audio processing. It results in a hugely higher dynamic range, less noise and distortion, and maximum input levels. 
  • Detailed
    As you know, vari-mu compressors perform based on the input signal. And the plugin provides some detailed controls to adjust how it reacts to the input. It includes the value of the input rectifier and tube bias. In general, the rectifiers change the reaction time of the plugin, whereas the tube bias controls compression level (comparable to the ratio in other compressors). 
  • Side-Chain
    At the right of each of the channel sections, you will find a knob labeled Side-Chain EQs. It lets you select from six modes of side-chaining ranging from Off, four side-chain filter-presets, and an external side-chain signal. The external side-chain is handy when you want to create the ducking effect in dance music. And you can refer to the manual to learn more about the internal side-chain presets. 
  • Stereo Features
    In addition to being a dual-channel plugin, you can also set the stereo mode to mid/side, which is handy for mastering and balancing your stereo image. The plugin features a bass Mono Maker (with selectable low-pass frequency) and a stereo widener.
Plugin Alliance - SPL IRON - Mixing With Mike Plugin of the Week


SPL Iron is available for Windows 7 or higher and macOS 10.9 or higherboth 64-bit only. It comes in VST 2/3AUAAX, and RTAS formats.


Overall, the plugin is helpful and efficient for processing vocals, bass, strings, and guitars or busses other than full mixes for mastering. The various rectifier and tube bias settings deliver subtle but valuable character changes.

Similarly, the proprietary TMT technology offers multiple plugin channels with accurate component modeling. And finally, you can link the two channels to make editing easier too.

SPL Vitalizer MK2-T

More Info & Price (Trial Available)

Vitalizer is an enhancing plugin with a patented filter network that can bring up clarity and focus in individual stems and even in busy mixes. 

This plugin is far more than a simple exciter. Plugin Alliance modeled this plugin on the hardware bearing the same name. The concept is that by creating a set of filters based on research findings on people’s hearing perception, you can create highly effective and musical results.

It has another feature called “unmasking,” which uses both loudness and length of sound to enhance the perceptive loudness of desired frequencies. The result, combined with its stereo widening circuit, is a truly effective sound-enhancing plugin.

We recommend using this plugin on vocals and individual instruments. Tightening up or enhancing the bass, widening and adding clarity to synth, etc., are just a couple of its many uses. And while it can be applied on busses, building up its effect per track results in a truly pristine mix with barely any EQing.

SPL Vitalizer MK2-T Review - Top 7 Exciter Plugins & 3 Best Free Exciters (For Mixing & Mastering) |

Key Features:

  • Innovative Filters
    There are two high-frequency enhancement parameters on this plugin: the Mid-Hi Tune and the LC-EQ. The Mid-Hi Tune enhances the high frequencies and attenuates the frequencies below the set value. The LC EQ is a passive coil EQ that enhances over a broad high shelf. What’s special about a passive coil filter is that it can enhance the high frequencies without making it sound sharp.
  • Bass Enhancer
    On the left are two parameters named Bass and Compression. The Bass knob sits in the middle by default, and by simply turning it to the left, it becomes more rounded and loud. Similarly, turning it to the right makes the bass sound tighter. This simplicity is a huge time-saver.
  • Stereo Widener
    The Stereo Expander parameter utilizes a mid/side stereo widener. This means you will need stereo audio in the first place to hear any enhancements. However, it is certainly convenient to have that feature readily available.

Character & Sound:

The character and sound of this plugin are that of the original hardware, which has been tried and tested to give unmistakably outstanding results. Enhancing the bass using this plugin instantly lets you control its style without ever touching a transient processor.

Similarly, the LC EQ never lets the high frequencies become overly sharp and annoying. This is one of the few plugins that are really difficult to make sound bad.

A fact worth noting is that this plugin is based on tube components. So, it does add some warm, analog sound using the filter shapes and by itself too.

SPL Vitalizer MK2-T Plugin - Enhancing Bass and Highs on EDM


The plugin is available for Windows 7 or higher 64-bit and macOS 10.9 or higher 64-bit. It comes in VST 2/3, AU, and AAX formats.


If you are looking for an all-in-one sound enhancement plugin that actually works, you should give this plugin a try. While it may look simple, the features it offers for controlling both bass and treble are astounding. Interestingly, it tends to affect the entire frequency spectrum to give a highly desirable sound right off the bat.

SPL De-Esser Collection 

More Info & Price (Trial Available)

Get the sound of two of the most revered hardware de-essers by SPL with this emulation.

The two de-esser plugins include a classic single band and a modern dual-band version. Despite being analog emulations, these plugins also follow the modern route of detecting the sibilance automatically by analyzing the entire audio spectrum instead of letting you choose a frequency range.

Unlike traditional de-essers, the SPL De-Essers use phase cancellation to achieve their effect. According to SPL, this method delivers a cleaner and transparent result without tweaking the plugin much.

Similarly, it offers a male or female option for you to choose from for the detection algorithm. This option helps the de-esser adapt better to your recording. Combine that with the mid/side mode, and you have a powerful de-esser with far fewer knobs than one would expect.

SPL De-Esser Collection Review - Top 7 De-Esser Plugins 2021 (And 4 Best Free Alternatives) |

Key Features:

  • Single Band Version
    The single band classic de-esser analyzes your audio, detects the sibilance, and processes all the sibilant frequencies with equal strength. However, this doesn’t mean that it will compress all the high frequencies. Instead, it uses narrowed filters to phase out the sibilance alone, leaving the rest of the spectrum untouched.
  • Dual-Band Version
    This version of the de-esser uses two frequency bands that you can use independently or together using the on/off switches. In this variant, the male/female option affects only the Low band.
  • Auto Threshold
    Both variants of the de-esser have an automatic threshold adjustment feature
    , which changes the threshold based on the level of sibilance detected. So, all you must select is the reduction range, and the plugin will ensure the same level is being reduced in every case of sibilance.
SPL Classic De-Esser Demo


SPL De-Esser is available for Windows 7 or higher and macOS 10.9 or higher, both 64-bit only. It comes in VST 2/3, AU, AAX, and RTAS formats.


If you’d like to have a moderate level of control, but with automated features, this plugin collection is a must-try. Its processors are based on the manufacturer’s hardware units, and so they sound excellent. However, you may find that they are quite a bit on the pricier side.

SPL TwinTube 

More Info & Price (Trial Available)

TwinTube is an analog-modeled saturation effect plugin by SPL. It mimics hardware SPL tube modules that achieve saturation and harmonic enhancement.

TwinTube is designed to replicate the saturation effect of tubes. The original hardware module used two different tube circuits to affect the incoming signal in two different ways. The user would then blend the two effects to create a complex saturation effect.

SPL TwinTube - Top 10 VST Hardcore Plugins (Doomcore, Breakcore, Speedcore, Happy Hardcore) |

Key Features:

  • Dual-purpose
    The name twin is not a coincidence; just like the original hardware, TwinTube uses two circuits to affect the incoming signal in two different ways. The first way is saturation, which helps fatten up sounds and add audible coloration. The second way is by applying harmonic enhancement to the signal. It basically uses a circuit that adds overtones to the signal in relation to its dynamics. The harmonics button lets you choose the frequency focus of the enhancement, choosing from 2, 3, 6, and 10 kHz.
  • Compare
    TwinTube allows you to load up to four different presets in one instance of the plugin. You can switch from one to the other to compare and settle for the best one. There’s also a power button for comparing the dry and wet signal with ease.
  • Analog sound
    An essential thing in saturation plugins is the overall sound tone and quality, and TwinTube delivers on its analog promises. The saturation will add pleasing roundness to your low end and thicken up your higher frequencies without getting fuzzy or gnarly. The harmonic enhancement similarly adds pleasing overtones. However, this is not a plugin for over-the-top distortion, so look elsewhere if that’s what you are looking for.
SPL TwinTube Processor Plug-In for the UAD Platform Demo


TwinTube is available on Windows 8 or higher and macOS 10.11 or higher in AAX, AU, VST2, and VST3 formats.


TwinTube is a rich and warm-sounding analog-modeled saturation plugin. It will sound great on vocals and guitars and offer pleasing roundness to your bass and drums. It’s not meant for nasty distortion, fuzz, or gnarly sounds but rather for subtle and tasteful analog-style saturation.

SPL Free Ranger

More Info & Download

Despite being a free alternative to the SPL Full Ranger EQ, this plugin produces high-quality sounds thanks to SPL’s technical and advanced algorithms. 

SPL Free Ranger is an easy-to-use graphic equalizer with one of the simplest user interfaces. It covers the crucial parts of the frequency spectrum and is suitable for a fast-paced mixing workflow. Furthermore, as the plugin is so simple, it barely consumes any CPU at all.

SPL Free Ranger Review - 5 Free Plugins On Plugin Alliance |

Key Features:

  • Controls
    The Free Ranger plugin has nine fader controls, eight of which control the most critical sections of the frequency spectrum and one the output level. And you’ll find four buttons labeled A, B, C, and D on the right side. These are the slots you can use to save your configuration and make comparisons. 
  • Easy
    The interface itself is pretty self-explanatory. It has an input signal LED, and an overload LED to indicate clippings. I would suggest starting with this plugin if you intend to get the hang of graphic equalizers. 
Plugin Alliance SPL Free Ranger | Free Plugin


Free Ranger is available for Windows 7 or higher and macOS 10.9 or higherboth 64-bit only. It comes in VST 2/3AUAAX, and RTAS formats.


Despite being a ridiculously simple plugin, the internal SPL engine makes the plugin useful. You could make a comparison between a regular EQ and this EQ, and you’ll likely find this one more effective and appropriate.

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