Free UAD Plug-ins with Every Apollo Purchase!

Save $300 on UAD Accelerators through 12/31! Find a dealer ›

Get up to 70% savings on UAD plug-ins storewide! Shop 12 Days of UAD ›

Hello world 4!

Hello world 5!

Big Savings on Our Most Classic Emulations. Shop UAD Plug-Ins ›

Shop Holiday Deals on UAD Spark. See My Offers ›

  • Overview
  • Features
  • Customer Reviews
  • 4.9/5

Regular Price: $199.00


You'll Save 75%


The only AKG-licensed emulation of this one-of-a-kind spring reverb.

Introduced in the late 1960s, the AKG BX 20 reverb was a high-water mark for AKG’s esteemed engineers. An ingenious assembly of mechanical and electronic componentry, the BX 20 offered the glorious depth and color of spring reverb without any of the limitations.

The AKG BX 20 Spring Reverb plug-in for UAD-2 hardware and Apollo interfaces is exclusively endorsed by AKG Acoustics, Austria and envelops your sources in gorgeously dark, dense ambience that only spring reverb can provide.

Mix with the only licensed and endorsed AKG Acoustics BX 20 reverb plug-in

Envelop instruments in dark, dense, clear ambience with original dual spring tank configuration

Harness new "plug-in only" features like stereoized A/B Tank Select, Direct signal defeat, and BX 10 Tone controls

Mix with artist presets from Patrick Carney (The Black Keys), Vance Powell (Jack White), and Jacquire King (Kings of Leon)

Take a Listen

Take a Listen
5-Minute UAD Tips
5-Minute UAD Tips

5-Minute UAD Tips

Featuring the AKG BX 20 Spring Reverb.

Unparalleled Density

Unparalleled Density

The AKG BX 20's utterly unique character makes it a versatile tool for ambience as well as tone shaping. Its sonic personality features the quick onset of a classic plate reverb, and also the natural-sounding density and diffusion of a chamber — with little of the flutter or “boing” artifacts common with other spring reverbs. Unlike other spring reverb emulations, Universal Audio's hybrid delay network/convolution design provides the only plug-in representation of this mechanically controllable, acoustic ambience system. To that end, UA obsessively emulated a “golden unit” BX 20 from legendary producer, Jon Brion.

Spring Time

Spring Time

The BX 20 plug-in expertly captures the hardware’s unique two-stage decay. This yields warm, organic sounds whether it’s applied on percussion, vocals, or guitars, adding a unique timbre that can make individual tracks stand out — or melt away — in your mix. Short textures are chock full of colorful depth and dimension, while longer decays are rife with lush three-dimensionality, while never washing out.

New Features, More Control

New Features, More Control

The BX 20 plug-in provides the complete sound and features of the original, plus new "Mk II" features for an expanded sound palette. Tank Select provides the exact sound of the original A/B dual tank system, but includes a “stereoized” tank A or tank B, for more balanced stereo imaging. The Direct function allows you to mute the tank's direct signal for more control and minimizing conflict with the source audio — perfect for buses. The Baxandall-type tone controls — borrowed from the smaller AKG BX 10 — offers the last bit of seasoning to tailor your reverbs.

Watch The Reviews


      Input Select, Mono/Stereo: Changes input between summed mono or stereo
      Tank Select, A / B / A+B: Under stereo use, changes tank options among stereoized "A" and "B" and original "A+B" configurations
      Direct, Off / On: Disables/enables the spring tank's naturally occurring direct sound component
      Low Cut, Off / 80 Hz: 12 dB per octave, 80 Hz filter
      Bass, ±10: Continuous tone control borrowed from the AKG BX 10, ±8 dB at 150 Hz
      Treble, ±10: Continuous tone control borrowed from the AKG BX 10 ±4 dB at 5 kHz
      Dry/Wet, 0 to 100%: Continuously adjusts Dry and Wet signals under insert use case
      Wet Solo, Off/On: Disables/enables Wet Solo function
      Predelay, 0 to 250 milliseconds: Continuously adjusts Predelay amount
      Channel 1 Decay, 2 to 4.5 seconds: Continuously adjusts Channel 1 Decay time
      Channel 2 Decay, 2 to 4.5 seconds: Continuously adjusts Channel 2 Decay time
      Channel 1 Volume, ∞ to +24 dB: Continuously adjusts Channel 1 Volume
      Channel 2 Volume, ∞ to +24 dB: Continuously adjusts Channel 2 Volume
      Channel 1 Pan, ±100: Continuously adjusts Channel 1 Pan
      Channel 2 Pan, ±100: Continuously adjusts Channel 2 Pan
      Link, Unlinks/Link: Unlinks/Links Decay, Volume and Pan parameters
      Mix: Continuously blends processed and unprocessed signal
      Power, Off/On: Disables/Enables plug-in (all DSP processing is bypassed)

      Customer Reviews

      AKG BX 20 Spring Reverb

      Overall Rating


      T. Laja

      May 20, 2024

      AKG BX 20 Spring Reverb

      For my reverb's collections: A great reverb.

      M. Schneider

      May 10, 2024

      love the sound!

      The best spring reverb out there. Try the demo.

      s. marc

      May 6, 2024

      Like the real one !

      Like the real one I use !!!!

      s. marc

      May 6, 2024

      Like the real one !

      Like the real one I use !!!!

      J. Kelly

      March 24, 2024

      Electric Guitar Magic!

      My mainstay on guitars!

      J. Kelly

      March 24, 2024

      Electric Guitar Magic!

      My mainstay on guitars!

      c. maskell

      January 30, 2024


      Love this.great feeling of space

      J. Janev

      January 14, 2024

      A very special reverb!

      This is the biggest and warmest sounding reverb I've ever tried! It sounds wonderful when it's louder and with more length to clearly hear the beauty in its sound! It's great that it has two different reverbs on the left and right channels, giving the sound even more space! Fits great on synths, guitars, drums, and anything you want to add some massive space to!

      w. gause

      December 14, 2023



      C. Nardi

      November 20, 2023

      This reverb unit offers a lot of creative solutions

      While I prefer the EMT reverbs as room simulation, this spring reverb still has a nice spot on my workflow. When I want to obtain an unrealistic effect on an individual instrument or just create some depth, the AKG BX 20 opens a lot of creative solutions without requiring much DSP usage. It is can also be used more subtly than, for instance, a tape echo. Another reason why I find it useful is for rehearsal: I often place it on an Aux on my Console and feed it with some signal from the input while I am playing the flute or saxophone.

      F. ALAIN

      November 9, 2023

      The AKG BX 20 Spring Reverb

      This amazing reverb is great, natural, and very easy to use

      J. Berthier

      October 17, 2023

      Very full, warm, vintage sound

      I was looking for owning this plugin and finally took advantage of the last promos/coupons !
      Very full, warm, vintage sound, think 60's reverbs style vocals...
      So glad I can get rid of my cheap spring reverb that get constantly broken-down !
      The only drawback I see is that it uses a lot of processor % on my apollo twin, I hope the native version will come soon so I can use it everywhere !!!

      B. Barr

      October 10, 2023


      Like a warm mug of chocolate milk. This reverb is smooth and warm.

      S. Barone

      September 30, 2023

      AKG BX 20

      Pleeeease Make It Native!

      B. George

      September 20, 2023

      Excellent Spring Reverb

      Authentic Spring Reverb sound. Responds well to guitar playing.

      A. Lee

      September 17, 2023


      Amazing depth of field and sound quality to this. Different from any other spring reverb plugin out there

      J. Otshudi

      September 12, 2023


      The sound I have been looking for…

      A. Dahlback

      August 6, 2023

      THE spring reverb!

      Back in the days BX 20 was the dream reverb - lush, smooth and with a lot of space added. But int came to a price - about $ 5000 back in the 80's.
      UAD's emulation is by far the best I've ever heard of a state-of-the-art spring reverb. Period! It gives the true analog feeling.

      E. Peterson

      April 13, 2023

      Best spring reverb plug-in I own

      This one sounds pretty unique and is lots of fun for tons of uses. I use it on acoustic guitar and vocals the most. Very cool sound

      I. Hwang

      April 3, 2023

      perfect spring reverb I've been looking for

      so good