# Parameter Selection

On this page, you select the type of parameter that you want to train on.

![The Parameter Selection set-up window](/files/S3cAqgDNDgJ0d2PcX2TV)

{% hint style="info" %}
The Gain parameter is only selectable when either Shelving or Parametric Equalizers are selected in the previous step, because High/Low-pass, Bandpass, and Bandstop filters do not have a Gain parameter.
{% endhint %}

For High/Low-pass Filters, Q controls the level of the selected frequency. For example, a HPF at 100 Hz, Q 0.7 results in 100 Hz being attenuated by 3 dB.

For Shelving Filters, Q controls the bandwidth of the transition band. For Parametric Equalizers, Bandpass, and Bandstop filters, Q controls the bandwidth of the filter.


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://frequia.gitbook.io/frequia/advanced-training/parameter-selection.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.