All-Pass Reverb in Bitwig Grid That Sounds Diffused
Tutorial | Apr 24, 2026
Learn all-pass reverb design in Bitwig Grid with the all-pass reverb calculator to choose non-multiple delay times and build smoother custom ambient reverbs.
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Quick Answer #
- To make a reverb from all-pass delays, use several all-pass modules with delay times that are not multiples of each other; this creates a more diffused, smeared reverb tail instead of a clearly repeating echo.
- Bad delay choices for reverb: values like 100 ms, 200 ms, 300 ms line up as multiples, so the repeats reinforce each other and sound like delay/feedback rather than reverb.
- Better all-pass timing strategy: choose irregular, spread-out times such as 2 ms, 110 ms, 134 ms, 149 ms, 164 ms, 175 ms, 189 ms, 200 ms to increase diffusion and reduce obvious rhythmic repeats.
- To improve the sound further, add modulation and filtering: a chorus or slight delay-time modulation makes the tail wider and more alive, while high-pass and low-pass filters remove muddy lows and harsh highs.
- A practical workflow is to calculate diffuser delay times with an all-pass reverb calculator and then paste those values into a modular grid/patch; cascading multiple diffuser lines with different non-multiple timings produces denser custom reverbs and shimmer-style ambient effects.
Short Overview #
All-pass reverb design in Bitwig Grid offers a practical way to build custom diffusion networks without relying on standard VST reverb plugins. The key factor is delay-time selection: when all-pass delays use multiples of each other, the result sounds like a patterned echo, while irregular, non-related timings create the smeared, diffuse response associated with reverb.
Using calculated delay values makes it easier to control density, early reflections, and overall decay character with only a small number of modules. This approach is especially useful for ambient sound design, shimmer effects, and lightweight in-patch reverbs where custom tone, modulation, and feedback structure matter more than stock presets.
Key Takeaways #
- Chaining several all-pass delays can create a reverb-like diffuser, but the delay times must not be simple multiples of each other; values like 100/200/300 ms produce obvious rhythmic echoes instead of a smeared reverb tail.
- A practical way to improve diffusion is to use irregular, non-related delay times across the all-pass stages, which spreads reflections more evenly and reduces audible buildup from synchronized taps.
- The demonstrated calculator workflow generates delay-time tables for different reverb styles such as room, plate, hall, and shimmer, with controls for start delay, end delay, spacing curve, randomness, minimum gap, and seed.
- Entering the calculator’s generated values manually into the Grid’s all-pass modules helps build a custom diffuser, but there is currently no preset export, so the times must be copied by hand.
- The Grid interface rounds displayed delay values after entry, even though the typed decimal value is still used internally, so visible values may not exactly match the source numbers.
- Adding a chorus in the feedback/recirculation path introduces slight delay-time modulation, which creates pitch wobble and makes the reverb sound more alive, wider, and more diffuse than static delays alone.
- Post-processing the diffuser with high-pass and low-pass filters helps remove low-end buildup and excessive highs, and a gain stage can be used afterward to compensate for level loss.
- A more advanced structure uses multiple serial diffusion lines with progressively longer all-pass stages, mixed in stages and fed back through filtering and chorus; including an early output from the first line preserves an immediate response before the later, longer diffusion paths emerge.
Building a Custom Reverb with All-Pass Delays #
Creating a reverb from scratch is not always about replacing a polished plug-in. The value is in sound design, experimentation, and understanding how diffusion works. A small network of all-pass delays can produce a useful, characterful reverb inside a modular environment such as The Grid, and the exact sound depends heavily on the delay times chosen.
What It Does #
An all-pass delay network can turn a dry sound into something more diffuse and spacious. With the right timing relationships, the result begins to resemble reverb rather than a simple echo.
A dry piano signal, for example, becomes more ambient when passed through several all-pass stages. The effect is especially effective for soft, sustained material and for sound design contexts where a standard plug-in reverb feels too familiar.
How It Works #
An all-pass delay alters phase and timing without emphasizing any particular frequency range in the same way a typical filter would. When several all-pass stages are chained together, they smear transients and increase diffusion.
The key point is that the delay times must not line up in obvious multiples of each other.
Why simple multiples sound like echoes #
If the delay times are set to values such as:
- 100 ms
- 200 ms
- 300 ms
the repeats reinforce a predictable pattern. Because those values are multiples of one another, the delayed taps accumulate in a structured way, making the result sound more like a feedback delay or echo than a reverb.
This is expected behavior. Regular spacing creates audible rhythmic repetition.
Why irregular timing sounds more like reverb #
For reverb, the goal is a more:
- diffuse
- smeared
- stretched
- non-periodic
response.
That requires delay times that are not simple multiples of each other. Even a handful of irregular values can make the network sound much more natural and less like a patterned delay.
Using values such as:
- 9 ms
- 38 ms
- 71 ms
- 110 ms
- 149 ms
produces a denser and less obviously rhythmic result. Adding more stages increases the diffusion further.
Choosing Delay Times #
Selecting good delay times by hand can be awkward, because interactions between stages are not obvious. A set of values may accidentally contain relationships that reinforce each other.
A practical solution is to use a calculator that generates unevenly spaced delay times for a given reverb style. Parameters can include:
- Preset type such as room, plate, hall, or shimmer
- Start delay for the first all-pass stage
- End delay for the last stage
- Spacing curve to control how values spread across the range
- Randomness to avoid regular patterns
- Seed to generate alternate distributions
The result is a table of delay values that can be entered manually into each all-pass module.
Workflow #
A simple reverb can be built with a chain of all-pass delays and then improved with a few supporting modules.
Basic setup #
- Start with a dry source.
- Insert multiple all-pass delay stages in series.
- Enter delay times that are uneven and not simple multiples.
- Listen for whether the result feels like diffusion rather than echo.
Even without a feedback loop, this can already create a usable short reverb texture.
Extending the tail #
To make the effect longer, route the output back toward the input path through a delay or recirculating structure. That creates a longer reverb tail.
Making it more alive #
A chorus can be especially useful in the feedback path or after the diffuser stages. Chorus introduces slight delay-time modulation, which adds:
- subtle pitch movement
- width
- animation
- extra smearing
This often sounds smoother and more spacious than a completely static delay network.
Shaping the tone #
A simple reverb chain benefits from filters at the end:
- High-pass filter to remove low-frequency buildup
- Low-pass filter to soften the top end
A gain stage can then compensate for level loss.
A More Layered Network #
A more advanced design can use several diffusion lines in sequence, with mixing between them.
One effective structure is:
- Input signal
- High-pass filter
- Optional pitch shifter for shimmer
- First all-pass diffusion line
- Mixer
- Low-pass and high-pass filtering
- Output
At the same time, part of the signal from the mixer is sent back through:
- a chorus
- a second diffusion line
- another mixer stage
- a third diffusion line
- and so on
In this design, each diffusion line is typically longer than the previous one, but the delay values still need to avoid simple multiple relationships.
This gradually increases diffusion and can produce a soft, ambient reverb with a slow bloom.
Early Output vs Delayed Bloom #
If the signal only emerges after several long diffusion stages, the effect may feel disconnected from the played note. A useful solution is to take some output from the earlier part of the network.
That gives an initial early-reflection-like response when the note is played, while the deeper diffusion lines continue building the long tail behind it.
Without that early output, the listener may hear nothing for a noticeable fraction of a second while the signal travels through the entire network.
Practical Uses #
This kind of all-pass reverb is especially useful when:
- a custom reverb character is needed
- standard plug-ins feel overused
- ambient or generative patches need an internal reverb
- CPU efficiency matters and only a few modules are available
- the goal is to learn how diffusion-based reverbs behave
It is also a strong creative tool for making reusable presets. Small variations in delay times, feedback routing, modulation depth, and filtering can produce very different spatial characters.
Limits #
This is a simple diffusion-based approach, not a full replacement for every polished reverb algorithm.
Some limitations are clear:
- It takes manual tuning.
- Poor delay-time choices quickly produce obvious echoes.
- A fully developed reverb usually needs more than a few all-pass stages.
- Entering values manually is cumbersome without preset export.
- Rounded display values may differ slightly from the internally entered numbers.
Still, even a compact setup can sound surprisingly good when the timing relationships are chosen carefully.
Why Build One at All #
Using a plug-in is a completely valid choice. But building a reverb from all-pass delays offers something different: control over the underlying behavior.
The appeal is not only the final sound. It is also the ability to:
- shape diffusion directly
- create unusual spatial textures
- understand why some reverbs sound smooth and others sound like delays
- design unique tools for later use in tracks
For ambient, generative, and exploratory patching, that process can be as valuable as the result.
Transcript #
This is the transcript of the video. The text was generated automatically and may contain small mistakes. The timestamps jump to the matching part of the video.
Click to expand transcript
[00:00:00] So welcome back. So I know each of you wants to create your own reverb. That's what people tell me in the comments, at least
[00:00:06] No, it's exactly the opposite most of the time people tell me why not just use a VST plug-in?
[00:00:11] Why not just download some samples? Why not, you know, do that or this? Why?
[00:00:15] Do this on your own. What's the purpose? So the idea or the purpose is for me at least creativity so I can
[00:00:22] create my own reburbs. I can create my own tools my own sounds and
[00:00:27] It's fun and you learn something. So why not do it? So here we have a piano tech instrument. It sounds like this
[00:00:34] It's very quiet probably let's increase this
[00:00:39] Yeah, it's very dry
[00:00:42] So we want to put the reverb on this right and usually just go for a VST plug-in
[00:00:47] but here we go for the grid and we go for
[00:00:50] all pass delays looks like this and
[00:00:54] When you dial in here a number let's say 100 it sounds more like a delay or echo
[00:01:01] You can hear the individual echo tabs and that's that is expected
[00:01:15] But then you go for another one and a third one and here we go for 200 milliseconds and then we go here for
[00:01:23] 300 milliseconds. So now it sounds like this
[00:01:25] So instead of sounding like a reverb because we use multiple pass delays
[00:01:35] It sounds more like a weird echo or delay with feedback
[00:01:39] So this is expected because of the numbers we have your numbers or milliseconds that are
[00:01:47] Adding up over time. There are multiples of each other. So right. So 200 here is basically 102 times, right?
[00:01:54] And this one here is what 200 plus 100 and three times 100 is 300
[00:01:59] And then we have these delay tabs that kind of add up over time. There are multiples of each other
[00:02:05] You can really hear this how they add up so the idea is
[00:02:14] When you want to create a reverb, maybe you want to create a very creative echo
[00:02:19] So then this is completely fine, of course
[00:02:21] but maybe you want to create a reverb for reverb we need to more have like more like a
[00:02:26] diffused stretched out smeared sound and for this we need to have here some random
[00:02:33] Numbers that are not kind of multiples of each other and that is sometimes hard to do because we need to calculate and you
[00:02:41] Don't know what's actually happening. Maybe you dial in here for three of these actual multiple
[00:02:47] Multiples of each other I need you don't see it. So it's very hard to do but sometimes it's just enough to dial in some
[00:02:53] random numbers
[00:02:56] But this sounds much better already
[00:02:58] Maybe use more here more pass
[00:03:12] So it sounds much better than what we had before in terms of our goal, which is a reverb
[00:03:19] So you get the idea these numbers are actually very important and they depend on each other
[00:03:26] So that's that's the main message
[00:03:28] So what we can do now is we can go to my web page because I did some kind of calculator here
[00:03:34] It's called an all-pass reverb calculator diffuser delay time so a bit regret
[00:03:40] And you can change here a preset a room. That's a very short reverb
[00:03:45] Plate or hall or maybe shimmer and then gives you here a table of
[00:03:52] delay times
[00:03:55] That you can choose so we have here nine milliseconds 38 and so on so we can just take these numbers
[00:04:01] You can also see a graph of how it looks like
[00:04:05] In terms of timings, we have the first starting out pass here, which uses nine milliseconds
[00:04:10] We can also go down and say we want to start here with two milliseconds delay
[00:04:15] It's the first tap and we also can type in where the end delay is so the last
[00:04:20] I'll pass right where we want to end up. Maybe we want to end up on 150 here or
[00:04:26] Maybe you can actually delete this here on 200
[00:04:32] Something like this and then it spreads out here these numbers in between and also change here the
[00:04:39] Spreading there are some advanced controls here for the spacing curve and the randomness if you want to change this
[00:04:45] Minimum gap
[00:04:50] Spacing curve we have a seed
[00:04:52] So if you change the seed it spreads out here some numbers randomly
[00:04:59] And you end up with a different reverb sound so you can create your own reverbs basically out of all past devices just with this
[00:05:06] table here
[00:05:08] Can I actually zoom in can zoom in so we start here with two milliseconds with the first our pass
[00:05:14] Type this in and then use the second one. You have to copy it, right?
[00:05:19] So there's no preset export or anything like this at the moment
[00:05:23] one on ten
[00:05:27] Then we have 134 and we need some some new ones
[00:05:33] Then we have 149
[00:05:40] Also when you type this in you can see here, it's it's rounding right we type in 149.53 and get return
[00:05:49] And it shows you here the 150
[00:05:52] internally it uses our number we typed in
[00:05:57] I think so, um, yeah, you're aware of that
[00:06:00] 164 and we have three more
[00:06:04] Yeah, and then we just use also here to numbers
[00:06:12] 175
[00:06:16] And 189
[00:06:20] And the last one is 200 nice
[00:06:27] Okay, so now it sounds like this
[00:06:29] So without using
[00:06:42] Using a delay or like a feedback loop we can already create a nice sounding reverb just by
[00:06:51] Adjusting here the delay times so we can then go and use a long delay and bring this down to
[00:06:59] zero milliseconds
[00:07:01] Just bring it back into the beginning of the delay
[00:07:06] Time wise it's so slow
[00:07:09] So something like this
[00:07:12] Maybe we group this here a bit
[00:07:22] Okay, let's see how it sounds
[00:07:28] And even better would be probably to use a chorus because we have slightly delay delay time modulation there
[00:07:51] And
[00:07:53] Yeah, that's much better so maybe we can also go here for a low low pass at the end
[00:08:12] And high pass
[00:08:16] Just to cut out the low frequencies and
[00:08:21] The top frequencies and maybe you want to compensate for the loudness we use again up here
[00:08:27] And maybe go to 5 db plus
[00:08:31] Yeah, you can see it's very easy to create these
[00:08:48] Reverbs in the grid and if you modify the delay times here and how the setup is you get a different reverb sound
[00:08:56] That's so fun to just be creative with this and create your own reverb presets
[00:09:02] even if you do ambient and you just use the same
[00:09:06] Reverb plug in all the time, I don't know native instruments realm or maybe Valhalla and you know me
[00:09:13] I use it every time you get the same sound and here you can influence it bit more
[00:09:19] This is a very simple setup, of course, but I just want to give you a demonstration of how it's built
[00:09:25] We can also go here for maybe
[00:09:28] This reverb here I built a few days ago
[00:09:33] This setup is a bit different
[00:09:37] So here we have audio coming in into a high pass then we have a pitch shifter because I like to have some shimmer in my reverbs
[00:09:44] And then we go into the first delay or alpass
[00:09:48] Network here just one line
[00:09:51] And we go out into a mixer and then the mixer goes again into a low pass filter high pass filter and then to the audio output
[00:10:00] But then also on top of that we go back into a chorus then the chorus goes into the second line and this one here
[00:10:07] Diffuses the signal even more goes out into the mixer mixer that mixes this with the first delay output here
[00:10:15] And then goes back into the third line and so on right and each time here each delay
[00:10:20] Line is a bit longer
[00:10:23] But these these are all values that are not multiples of each other, which is very important
[00:10:31] And sounds like this
[00:10:33] And what you can do with this is you can change here
[00:10:56] The mixer you can change each output differently so you can say I want to have the first diffusion
[00:11:01] Not played back that loud initially, right?
[00:11:05] But I want all the sound coming out of this into the second line
[00:11:09] Which means you can dial down each level here and just leave the last one
[00:11:13] Which is basically going into here and going the whole thing and then it comes out
[00:11:19] So it takes a while until it comes out at the end of course
[00:11:26] So
[00:11:28] It's nice for ambient sounds having this and I'm using your chorus of course for some
[00:11:45] Delay time modulation gives a bit of pitch wobble and makes the sound a bit more alive and spread out and you know white
[00:11:55] And uh, yeah
[00:11:57] And the reason why i'm going out here in the first delay line because it's I want when the mix is up 100% I want to have a
[00:12:03] Initial reaction the sound coming in right so now when I play a sound it takes a while
[00:12:09] Maybe one at 900 milliseconds until I hear a sound because it needs to go through all of these delays
[00:12:15] So here it comes out first and I get a nice initial early reflection reaction
[00:12:21] right
[00:12:25] When I play this you can't hear anything it just takes a while
[00:12:29] So I put this preset also in my dispenser so you can download this for free if you want to
[00:12:53] Uh, also the website is completely free
[00:12:55] um, I use this sometimes when I
[00:12:58] create my generative patches and I want to have like a
[00:13:02] reverb
[00:13:05] Inside of the patch just a small little reverb that is kind of efficient and I don't need to have too many
[00:13:11] All-pass modules and I just want to use a few maybe four or five what I want to get the maximum
[00:13:19] Diffusion out of that so I use her to calculate or to have some nice numbers. I can start with
[00:13:25] The website is also free. Of course, uh, link is in the description below
[00:13:29] Let me know what you think if you use all-pass do you
[00:13:32] Actually do your own reverbs. I don't know most people probably don't
[00:13:36] I find it very interesting and creative. It's fun to do
[00:13:40] And sometimes if I'm not in the mood of creating a track
[00:13:44] I do stuff like this or I do generative patches just because I'm
[00:13:49] You know, I'm in the mood of doing something but I don't want to start the track with the arrangement and you know
[00:13:54] selecting sounds and
[00:13:56] Thinking about other stuff. I just want to go into the grid and I want to create something and I want to play around with
[00:14:02] sound
[00:14:03] And then sometimes I get something out of this like this here and I save it as a preset and I use it later in the track
[00:14:10] So it's not wasted time or anything like this
[00:14:13] Um, anyway, there are multiple things you can do with this setup already
[00:14:18] um
[00:14:20] Of course, you can then go back here make a delay
[00:14:23] Or a feedback loop going out and back into the beginning make it even longer
[00:14:29] Add some more pitch modulation delay time modulation to make it more wide and more
[00:14:34] interesting and smeared out
[00:14:37] Um, yeah many directions you can go
[00:14:39] Anyway, I want to close this video just to give you an inspiration for the weekend. Try this out in the grid
[00:14:47] Uh, if you haven't already and um
[00:14:50] Go to my website use the numbers try it out. Let me know what you think if it works for you
[00:14:56] Anyway, you can also just use a plug-in. That's completely fine with me, right?
[00:15:01] It's not like the wrong way of doing it
[00:15:03] But if you are fed up with all your reverbs and you want to start to create your own reverbs and you are
[00:15:09] You know into ambient and you want to have a special sound and you want to understand how
[00:15:14] The reverb works or how this kind of ambient stuff works. You can do something like this and it's fun to do
[00:15:20] anyway
[00:15:22] Let me know what you think in the comments down below leave a link leave leave like and go to the links, of course and
[00:15:28] Yeah, that's it. Thanks for watching. See you then. Bye
