# Applying Modulation

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## **Applying Modulation to a Device Parameter**

1. Open **Mapping Mode** by holding **\[MOD]** and navigate to the desired modulator using one of the four **\[ACTION] buttons**
2. While holding **\[MOD]** navigate the S4's devices by using the **\[DEVICE] buttons**
3. Turn a **PARAMETER encoder** to apply modulation to the corresponding parameter
4. Let go of **\[MOD]** to exit **Mapping Mode**

{% hint style="info" %}
Parameters be modulated in either positive or negative directions, depending on which way **PARAMETER encoders** are turned while in **Mapping Mode**.
{% endhint %}

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## **Unipolar and Bipolar Modulation**

There are two options when applying modulation to a parameter.

* **Unipolar Modulation:** Applies modulation in one direction, either positive or negative
* **Bipolar Modulation:** Applies modulation in both directions using the parameter value as its center

Toggling between the two modulation modes can be done directly from within **Mapping Mode**.

1. Open **Mapping Mode** by holding **\[MOD]**
2. While holding **\[MOD]** tap a **PARAMETER encoder** to toggle **bipolar modulation**
3. Tap **PARAMETER encoder** again to return to **unipolar modulation**

<figure><img src="https://662554179-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FHdBRp4PsMPb4tP3f8vi8%2Fuploads%2FaNqBIZz6e3bErS9yxyaQ%2FUnipolar%20illustration.png?alt=media&#x26;token=3479eb9e-e9ba-496e-921e-2dbab45af036" alt="" width="338"><figcaption><p>An icon in the top right of the parameter box,<br>indicates bipolar/unipolar modes</p></figcaption></figure>

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## Visual Indication of Modulation Mappings

Both the graphical user interface and the device button LEDs provide clear visual feedback on how modulation is applied to specific parameters. This helps identify which parameters are being modulated at a glance:

* A small indicator bar appears on the slider of any modulated parameter, reflecting its current value.
* When in **Mapping Mode** or the **Modulation Source View**, the **\[DEVICE] button** LEDs light up in the corresponding modulation color (blue, yellow, green, or red), indicating that modulation has been applied to that device.

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## Clearing Modulation Mappings

[Follow this link to learn about clearing and resetting on the S4.](https://docs.torsoelectronics.com/miscellaneous/clearing-and-resetting)

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