Tags: posts polarity-music OpenSource Reverb VST-Plugin

Reev-R Free Open Source Convolution Reverb Plugin

Tutorial | Jun 11, 2025

Reev-R is a free, open-source convolution reverb plugin available for Windows, Mac, and Linux that allows detailed envelope shaping, sample stretching, and automated reverb control. It supports custom impulse responses and includes additional features like integrated delay and various envelope curve options, making it highly flexible for sound design. Recommended for users seeking an alternative to paid creative plugins, Reev-R offers professional-grade functionality and is actively developed with community feedback.

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Short Overview

I just checked out Reev-R, a free and open source convolution reverb plugin from the same developer who made Gate 12, Time 12, and Filter. You can grab it for Linux, Mac, and Windows, or even build it yourself from the source code on GitHub. Reev-R lets you shape the envelope, adjust the mix, and control how much signal goes into the reverb, which is really handy for creative sound design. There’s a default impulse response included, but you can load your own library for more variety. I really like how flexible it is and how you can stretch the impulse responses without changing their pitch. It also comes with features like a built-in delay and various envelope and sequencing options. If you’re looking for powerful shaping tools similar to Shaperbox, but for free, this plugin is definitely worth checking out. If you find it useful, consider supporting the developer with a donation.

Introduction to Reev-R

Today I am excited to share another free and open source plugin that you can download and start using right away. This plugin is called Reev-R, and it comes from the same developer who brought us other utilities like Gate 12, Time 12, and Filter. Reev-R is a convolution reverb plugin, and just like the others, it is fully open source and free of charge. You can easily grab it by heading over to its GitHub page. There, you will find binaries for Linux, macOS, and Windows or the source code if you want to build it yourself. If you find it helpful, please consider leaving a donation to support the developer.

What is Convolution Reverb

Reev-R functions as a convolution reverb. A convolution reverb simulates the reverb response of actual spaces by using recordings known as impulse responses (IRs). An impulse response is typically a recording of a short burst of sound in a real environment, capturing how the space reflects it. The plugin then "convolves" your audio with this response, imparting the same room characteristics to your signal.

Using Reev-R in a DAW

After installing Reev-R, I loaded it up in Bitwig to demonstrate. By default, it comes with a single impulse response sample, but you will want your own library if you desire different spaces or effects. Changing the impulse response is simple. You just click on the default sample within the plugin interface, and then select from your own impulse response directory.

I used my own Polarity pack impulse responses, which are also available for download on my Patreon. These can be multi-channel, for example, in Ambisonic B-format. Once you select an impulse, it quickly appears in the window and becomes active.

Controls and Envelope Shaping

Reev-R gives you fine control over how much of the signal is affected by the reverb. There are mix and send controls that shape the dry and wet balance, as well as the gain that feeds the convolution engine. Unique to Reev-R is the use of an envelope to control these parameters dynamically, letting you send only specific parts of the input audio into the reverb process. This means you can, for example, send percussive transients into the reverb and leave the rest dry, while still hearing the full reverb tail ring out. In Bitwig, I often automate or modulate this, but having this built-in makes things easier.

Stretching Impulse Responses

One standout feature is the ability to stretch the impulse response sample itself. By increasing the stretch value, you can dramatically lengthen the reverb tail. What is distinctive here is that this stretching does not alter the pitch of the impulse. This allows you to customize the size and character of your virtual space without making things sound unnatural.

Feature Requests and Suggestions

Some features could be made more accessible. For instance, randomizing the envelope is possible, but the function is buried in a menu. I think it would be nicer as a clearly visible button on the interface. A workflow I would love to see is cycling through an entire directory of impulse responses via some automation or selectable randomization, which does not currently exist in any plugin I know of.

Additional Features

The envelope itself is fully controllable. You can move points, curve transitions, and apply tension to curves for custom shapes. There's also a sequencer included, which can add rhythmic or dynamic movement to your modulation. The plugin lets you ease out the envelope for a smoother transition and even reverse or change the start and end points of the sample.

There is also a built-in delay that can be placed after the convolution reverb. It is time-based and offers standard note divisions like sixteenth or eighth notes. However, I would like to see a dedicated mix knob for this delay, to control its balance with the dry signal and perhaps more time division options.

Comparison to Other Plugins

With the release of Reev-R, there are now four free, open source plugins by this developer: the reverb, gate shaper, time shaper, and filter shaper. If you do not own commercial solutions like Shaperbox, these plugins provide most of the same functionality and perhaps even more flexibility depending on your workflow.

Final Thoughts

In summary, Reev-R is a versatile and well-designed convolution reverb plugin that fits nicely into creative music workflows, especially for those wanting open source tools. I encourage everyone to download it, experiment with their own impulse responses, and consider supporting the developer for their significant contribution to the music community.

If you have questions for the developer or ideas for more features, leave feedback on the project. Thanks for checking out this summary, and stay tuned for more plugin introductions.

Full Video Transcription

This is what im talking about in this video. The text is transcribed by Whisper, so it might not be perfect. If you find any mistakes, please let me know.
You can also click on the timestamps to jump to the right part of the video, which should be helpful.

Click to expand Transcription

[00:00:00] Hey folks, welcome back.
[00:00:01] So it looks like we have another free open source plugin that you can download.
[00:00:05] It's this one here called Reev-R and it's from the same guy who made also gate 12, time 12
[00:00:14] and filter.
[00:00:15] And now we have Reev-R, which is kind of a convolution reverb plugin.
[00:00:21] As I said, completely open source, completely free.
[00:00:24] Just make sure you head over to GitHub here.
[00:00:26] Go to the Rease page, download your binary for Linux, Mac OS and Windows or download the
[00:00:31] source code and build it for yourself.
[00:00:33] And also maybe make sure you leave a donation here, right?
[00:00:37] So this is now Reev-R, it's a convolution reverb and we can shape with the envelope here inside
[00:00:42] of this plugin, the mix and also descent, the gain that goes into the convolution reverb.
[00:00:51] So in BitWidth, it looks like this.
[00:00:55] We have basically here a default convolution sample on there.
[00:01:00] There's one sample coming with the plug in, but you have to have your own impulse response
[00:01:07] sample library if you want to choose something different.
[00:01:11] So we can do this here by clicking on default.
[00:01:14] And then we have here a directory.
[00:01:16] This is my impulse response directory here, and this is my polarity impulse response
[00:01:22] pack.
[00:01:23] You can download my Patreon if you want to.
[00:01:25] And I have here some sampled real places with, you know, in a bNorwell format, so four channels
[00:01:33] basically.
[00:01:34] So let's go to Floor here and you can see it's instantly appearing here in this window.
[00:01:42] And this 100 percent and reverb is also the mix here, 100 percent.
[00:01:48] So this is completely dry and completely wet, and we can also change here how much of the
[00:01:56] audio goes into the reverb.
[00:01:59] This is interesting because we can shape this here with the envelope, of course, and can
[00:02:03] only put certain parts into the reverb and still experience the whole reverb tail coming
[00:02:11] out of the reverb.
[00:02:13] So if you shape basically here the mix knob, you can hear, right, we have a reverb here,
[00:02:25] but the reverb tail is not ringing out because we just pull down the mix of the output here.
[00:02:34] So this is something you can do in Bitwig pretty easily by just automating the mix or
[00:02:38] modulating the mix knob.
[00:02:40] But what I do all the time in Bitwig is I construct something where I can send only
[00:02:46] certain parts from the audio into the reverb.
[00:02:49] So here I can say I just want to have this part going into the reverb and then keep the
[00:02:56] reverb tail.
[00:03:05] You can hear the reverb ringing out, and yeah, this is how you do it.
[00:03:11] So this is something I do all the time, so it's pretty handy to have this here in this
[00:03:15] plug-in also with the envelope.
[00:03:18] Also what you can do in Bitwig is stretch the sample, the impulse response sample, right?
[00:03:24] We can put this here to 100 or 200 percent, and then we have a much, much longer impulse
[00:03:30] response, but it's not pitched up or pitched down, it's basically stretched.
[00:03:35] So we keep the pitch of the sample intact.
[00:03:51] What you can do is change the impulse response with the envelope.
[00:03:55] This would be really nice if I could just take a directory and switch through all the
[00:04:02] impulse responses with an envelope in here.
[00:04:06] This would be super dope.
[00:04:07] I don't know any plug-in that does this, but this would be really interesting to have for
[00:04:16] some certain reverb effects.
[00:04:19] So I think the feature here that you can randomize kind of the envelope here with this button
[00:04:27] or with this menu here, that's way too hidden in my opinion.
[00:04:32] This could be some kind of button here where you just press the button and then you randomize
[00:04:38] kind of the envelope here.
[00:04:40] So it's a bit hidden, yeah, could be nice to have as a feature.
[00:04:44] Maybe if the developer is watching this, maybe make it happen.
[00:04:49] I don't know how complicated it is.
[00:04:56] And then of course we have all the rest of the features here that are also in Gate 12
[00:05:01] and Time 12 and so on.
[00:05:02] I also already showed this.
[00:05:04] We can ease out here the envelope a bit more, make it a bit more rounded, change the tension
[00:05:11] here of some of the curves.
[00:05:13] Everything is in there.
[00:05:15] There's also a sequencer here.
[00:05:18] But in my opinion here, having the stretch is dope and also that you can kind of automate
[00:05:25] the send into the reverb.
[00:05:27] You can also reverse here this and change the end and the beginning of the sample.
[00:05:50] Oh, yeah, by the way, there's also a delay integrated here with the reverb or the inputs
[00:06:03] with reverb.
[00:06:04] So if you just want to add after the convolution reverb, some kind of delay, you can do this
[00:06:08] here.
[00:06:15] And it's also time-based, so we can dial in 160 note, 108 note and so on.
[00:06:28] Could be great to have also here a delay mix knob maybe so you can just blend it in slowly
[00:06:33] and it's not full wet mix all the time.
[00:06:39] Maybe it's more the idea behind it's more like to mix it here with a dry signal.
[00:06:55] Clear this.
[00:07:13] Yeah, it could be nice to have your mix knob for the delay and maybe more timing options
[00:07:28] here.
[00:07:29] So yeah, that's Reef R completely free, completely open source.
[00:07:34] I want to make a video on this just to have all the plug-ins as a video kind of.
[00:07:42] I don't want to go into all of these details here because I already did this with the other
[00:07:46] plug-ins and it's kind of the same thing.
[00:07:49] So we have now four plug-ins if I'm not wrong.
[00:07:53] So we have a reverb, we have the gate shaper here, the time shaper and the filter shaper.
[00:07:58] So if you don't own Shaperbox, then you can just download this for free here and you have
[00:08:05] the same functionality more or less.
[00:08:07] Maybe even better.
[00:08:08] I have no idea.
[00:08:11] So pretty cool to have this.
[00:08:13] Make sure you donate to the project here.
[00:08:16] Leave a like on the video if you liked the video, leave some questions maybe for the developer.
[00:08:22] That's it.
[00:08:23] Thanks for watching.
[00:08:24] See you in the next video and bye.