“Glue” Compression – Best Glue Compressors for Mastering

One of the audio mastering key techniques used to achieve a cohesive and polished sound is known as “glue compression”. This process involves using a glue compressor, a type of audio compressor designed to bind the mix together, making it sound more unified and complete.

But what exactly is glue compression, and why is it so important in audio mastering?

What is Glue Compression?

Glue compression is a compression technique used in audio mastering to create a cohesive and polished mix. It involves using a glue compressor to subtly compress the audio signal, thereby reducing the dynamic range and making the various elements of the mix sound more unified.

This technique helps in blending the different tracks together, creating a more consistent and professional-sounding final mix.

Glue Compressor Vs. Normal Compressor

While both glue compressors and normal compressors are used to control the dynamic range of audio signals, they are used in different ways.

• Normal compressors are typically used on individual tracks to control their dynamics and prevent them from peaking.
• Glue compressors, on the other hand, are used on the master bus to blend the entire mix together.

Many of the most renowned glue compressors are VCA compressors, often emulating classic hardware units known for their iconic sound.

What is a VCA Compressor?

A VCA (Voltage Controlled Amplifier) compressor is a type of audio compressor that uses a voltage-controlled amplifier to adjust the gain of the audio signal passing through it.

This type of compressor is known for its precision, speed, and versatility, making it a popular choice for both mixing and mastering applications.

VCA compressors are particularly favored for their ability to provide transparent and punchy compression, which is ideal for glue compression on the master bus.

Best Glue Compression Plugins

There are many glue compression plugins available, each with its own unique features and characteristics. Here are some of the best glue compressors for mastering:

1. Waves SSL G-Master Buss

The Waves SSL G-Master Buss Compressor is renowned for its ability to bring mixes together, adding a professional polish and cohesiveness that is essential for mastering. Its faithful emulation of the SSL G Series bus compressor ensures that you get the classic punch and glue associated with the original hardware, making it a staple in many mastering studios.

Best Glue Mastering Settings:

• Threshold: Adjust to achieve 2-4 dB of gain reduction. The threshold determines the level at which the compressor starts to reduce gain.
• Ratio: 4:1 for a strong glue effect, or 2:1 for a more subtle compression.
• Attack: Medium (10 ms) to retain transients while providing glue, or faster for tighter control.
• Release: Auto for a dynamic program-dependent response, or manual settings around 0.3 seconds for a musical release.
• Sidechain High-Pass Filter: Engage and set around 150 Hz to let low frequencies pass uncompressed.
• Make-up Gain: Adjust to ensure the output and input levels are consistent, correcting for the gain reduction.

Buy at Waves: SSL G-Master Buss Compressor

2. Bx_Townhouse Buss Compressor

The Bx_Townhouse Buss Compressor by Plugin Alliance is modeled after the legendary custom-built SSL bus compressor from Townhouse Studios. This VCA compressor is known for its ability to add character and glue to mixes, making it a favorite among mastering engineers. It captures the unique qualities of the Townhouse Studios’ compressor, providing a warm, analog feel to your final mix.

Best Settings For Glue Compression:

• Threshold: Set to achieve 1-2 dB of gain reduction.
• Ratio: 4:1 for strong glue compression, or 2:1 for a more subtle effect.
• Attack: Medium-fast (10 ms) to allow transients to pass while gluing the mix.
• Release: Medium (0.3 seconds) for a musical response, or auto for program-dependent release.
• Sidechain High-Pass Filter: Engage and set around 150 Hz to let low frequencies pass uncompressed.
• Dry/Wet Mix: Adjust to blend the compressed signal with the dry signal, typically around 50% for mastering.
• Make-up Gain: Adjust to balance the output level with the input level, compensating for the reduced gain.

Buy at Plugin Boutique: bx_townhouse Buss Compressor

3. Lindell SBC

The Lindell SBC is a versatile compressor that offers a warm, analog feel to your mixes. Although it is not a direct emulation of any specific hardware, it draws inspiration from various vintage compressors, providing a unique and effective glue compression effect. This compressor is particularly well-suited for mastering, where the goal is to achieve a cohesive and polished sound.

Best Glue Mastering Settings:

• Threshold: Set to achieve 2-4 dB of gain reduction.
• Ratio: 2:1 for subtle glue, or 4:1 for stronger compression.
• Attack: Slow (30-50 ms) to retain the natural transients.
• Release: Auto for dynamic response, or manual settings around 200-400 ms for smooth release.
• Make-up Gain: Tune to match the output level with the input level, offsetting the gain reduction.

4. SPL Iron

The SPL Iron from Plugin Alliance is a mastering-grade tube compressor that adds warmth and glue to your mixes. Inspired by vintage variable-Mu compressors, it provides a rich, analog sound that is perfect for mastering applications. This compressor is particularly known for its ability to impart a smooth, musical compression that enhances the overall cohesion and warmth of the mix.

Best Glue Mastering Settings:

• Threshold: Set to achieve gentle compression, typically 1-3 dB of gain reduction.
• Ratio: 2:1 for subtle glue, providing a smooth and cohesive effect.
• Attack: Medium (20-30 ms) to allow transients to pass through while still providing glue.
• Release: Medium (200-400 ms) for a natural, musical release.
• Rectifier Setting: Choose based on the desired character; for mastering, a softer setting can add more warmth.
• Sidechain High-Pass Filter: Engage around 150 Hz to let low frequencies pass uncompressed.
• Mix Control: Adjust to blend the dry and compressed signals to taste, typically around 50% for parallel compression.
• Make-up Gain: Modify to align the output level with the input level, addressing any gain reduction.

Buy at Plugin Boutique: SPL Iron

5. SSL Native Bus Compressor 2

The SSL Native Bus Comp is renowned for its ability to bring mixes together, adding a professional polish and cohesiveness that is essential for mastering. Its faithful emulation of the SSL G Series bus compressor ensures that you get the classic punch and glue associated with the original hardware, making it a staple in many mastering studios.

Best Glue Mastering Settings:

• Threshold: Set to achieve 2-4 dB of gain reduction.
• Ratio: 4:1 for a strong glue effect, or 2:1 for a more subtle compression.
• Attack: Medium (10 ms) to allow transients to pass while providing glue.
• Release: Set to ‘Auto’ for a dynamic response, or 0.3 seconds for a musical release.
• Sidechain High-Pass Filter (S/C HPF): Engage around 150 Hz to let low frequencies pass uncompressed.
• Make-up Gain: Adjust to ensure the output level matches the input level, compensating for gain reduction.

Buy at Plugin Boutique: SSL Native Bus Comp

6. Cytomic The Glue

Cytomic The Glue is specifically designed to emulate the SSL G Series bus compressor. This plugin is known for its transparency, punch, and ability to add glue and cohesion to mixes, closely mimicking the characteristics of the original SSL G Series bus compressor.

Best Glue Mastering Settings:

• Threshold: Set to achieve 1-3 dB of gain reduction.
• Ratio: 4:1 for a strong glue effect, or 2:1 for subtle compression.
• Attack: Medium-fast (10 ms) to retain transients while providing glue.
• Release: Auto for dynamic response, or manual setting around 0.3 seconds for smooth release.
• Sidechain High-Pass Filter: Engage around 150 Hz to prevent low frequencies from triggering compression.
• Range Knob: Adjust to control the maximum amount of gain reduction.
• Wet/Dry Mix: Blend to taste, typically around 50% for parallel compression.
• Make-up Gain: Adjust the output gain level to compensate for any gain reduction.

7. SSL Solid State Logic G Comp Bus Compressor

The SSL G Comp Bus Compressor is ideal for adding the final touch of glue to your mix, ensuring that all elements blend seamlessly while maintaining clarity and punch. Its classic design and proven effectiveness make it a go-to choice for many mastering engineers seeking that signature SSL sound.

Best Settings For Glue Compression:

• Threshold: Adjust to achieve 2-4 dB of gain reduction.
• Ratio: 4:1 for strong compression, or 2:1 for more subtle glue.
• Attack: Medium (10 ms) to allow transients to pass through, or faster for tighter control.
• Release: Auto for a smooth, program-dependent response, or manual settings around 0.3 seconds for a musical release.
• Make-up Gain: Adjust to ensure the output level matches the input level, compensating for the gain reduction.

8. Ableton Live Glue Compressor

Ableton Live’s Glue Compressor (available only inside the Ableton Live DAW) is a versatile tool that emulates the SSL G Series bus compressor. It is particularly popular among electronic music producers for its ability to add glue and cohesion to complex mixes. This VCA compressor helps to bind various elements of a mix together, creating a polished and unified sound.

Best Settings For Glue Compression:

• Threshold: Set to achieve 2-4 dB of gain reduction.
• Ratio: 4:1 for strong glue, or 2:1 for a more subtle effect.
• Attack: Medium-fast (10-30 ms) to retain transients while providing glue.
• Release: Auto for a dynamic, program-dependent response.
• Soft Clipping: Engage to add analog-style warmth and saturation.
• Make-up Gain: Adjust to ensure the output level matches the input level, compensating for the gain reduction.

9. FabFilter Glue Compressor

FabFilter Pro-C 2’s flexibility and advanced features make it a powerful tool for mastering engineers seeking precise control over their compression settings. FabFilter Pro-C 2 has a “Bus” mode that can be very useful for achieving glue compression. The “Bus” mode is designed to handle the dynamics of an entire mix or group of tracks, making it ideal for adding cohesion and glue to your mix.

Best Settings For Glue Compression:

• Threshold: Set to achieve gentle compression, typically around 1-3 dB of gain reduction.
• Ratio: 2:1 to 4:1 for smooth, cohesive compression.
• Attack: Medium-fast (10-30 ms) to retain transients while still providing glue.
• Release: Auto for program-dependent release, or manually set around 200-400 ms for a natural release.
• Knee: Soft knee to ensure smooth compression onset.
• Sidechain EQ: High-pass filter around 150 Hz to prevent low frequencies from triggering compression.
• Make-up Gain: Adjust to ensure the output level corresponds with the input level, compensating for any decrease in gain.

Buy at Plugin Boutique: Fabfilter Pro-C2

10. FL Studio Glue Compressor

FL Studio’s built-in glue compressor provides a simple and effective way to add glue to your mix. The FL Studio’s built-in compressor, specifically the Fruity Limiter and Fruity Compressor, does not explicitly emulate the SSL G Series bus compressor. However, it can still be used effectively to achieve a glue compression effect.

Best Settings For Glue Compression:

• Threshold: Set to achieve 2-4 dB of gain reduction. Use the Fruity dB Meter to visualize the gain reduction.
• Ratio: 4:1 for strong glue, or 2:1 for more subtle compression.
• Attack: Medium (10-30 ms) to allow transients to pass while providing glue.
• Release: Auto for a dynamic, program-dependent response.
• Make-up Gain: Adjust to match the output level to the input level, compensating for the gain reduction.

11. UAD SSL 4000 G Bus Compressor

The UAD SSL 4000 G Bus Compressor is a meticulously modeled emulation of the iconic SSL G Series console bus compressor, renowned for its ability to bring cohesion and punch to mixes. Developed by Universal Audio, this plugin captures the character and response of the original hardware, making it a go-to choice for many mastering engineers.

Best Settings For Glue Compression:

• Threshold: Adjust to achieve 2-4 dB of gain reduction.
• Ratio: 4:1.
• Attack: Medium-fast (10 ms).
• Release: Auto or 0.3 seconds for a quick, musical response.
• Make-up Gain: Adjust to match the output level with the input.

12. Tokyo Dawn Labs TDR Kotelnikov

Tokyo Dawn Labs TDR Kotelnikov is a highly transparent digital compressor designed for mastering applications. While not a direct emulation of any specific hardware, it is engineered to provide clean and precise dynamic control without coloration, making it ideal for subtle glue compression.

Best Settings For Glue Compression:

• Threshold: Set to achieve gentle compression, typically 1-2 dB of gain reduction.
• Ratio: 2:1 to 4:1.
• Attack: Medium (30-50 ms).
• Release: Auto or set manually around 200-400 ms for a smooth release.
• Soft Knee: Enable for a more natural compression curve.
• Make-up Gain: Adjust to ensure the output level matches the input level.

13. PSP Audioware VintageWarmer2

PSP Audioware VintageWarmer2 is a versatile multi-band compressor/limiter that combines analog-style warmth with modern precision. It is not a direct emulation of any single piece of hardware but is inspired by the characteristics of vintage analog compressors. This plugin excels at adding warmth, saturation, and glue to mixes.

Best Settings For Glue Compression:

• Threshold: Adjust to achieve 1-3 dB of gain reduction.
• Ratio: 2:1 to 4:1.
• Attack: Medium (20-40 ms).
• Release: Auto or set manually around 100-300 ms for a natural release.
• Drive: Increase to add desired saturation and warmth.
• Make-up Gain: Adjust to match the output level with the input level.

In Conclusion

My go-to tool has always been the Waves SSL G-Master Buss compressor. There’s something about the way it brings the mix together, adding that final polish and cohesion that makes everything sit perfectly.

Also, read my guide on How To “Glue” Your Mix Using the Waves SSL Bus Compressor

However, I don’t limit myself to just one tool. Cytomic The Glue is another fantastic plugin that I often reach for. It offers a similar SSL-style compression with great transparency and punch, in the same time preserving the mix’s natural dynamics.

When working in Ableton Live, the Glue Compressor is a reliable choice. It’s simple, effective, and integrates seamlessly into my workflow. I appreciate how it provides that familiar SSL compression feel, making it an excellent choice for mixing a few tracks or even more complex mixes.

In the end, the best glue compressor can vary depending on the project and the specific needs of the mix.

You may also like to read: 10 Mistakes to Avoid When Mastering