Making Filters

When measurement(s) is exported, as we seen, you have severals possibilities.

  • Variant 1 Create initial EQ filter in REW and import it into rePhase as a starting point
  • Variant 2 Go in rephase and start creating filter from scratch.
  • Variant 3 Use the filter creation tools from the plugin and create filter using DRC-FIR.

General tips

For best results with Volumio and BruteFIR I recommend sampling rate of 96000 and 65536 filtersize/taps.

When doing EQ in rePhase try to follow these simple guidelines:

  • Avoid high Q corrections as much as you can.

  • Remember that dips are not as hearable as rises, so flatten the rise points but avoid to flatten dips unless they are deeper than app -8dB.

  • Avoid high gains as much as you can. Don't go over +18dB, even better if you can stay bellow +12dB.

  • There is an initial 6dB attenuation in BruteFIR. If your max filter is (for example) set to +16dB then set additional 10dB of attenuation in BruteFIR settings to avoid clipping.

  • Measure carefully! your correction will only be good as was your measurement. Repat measurements unless you have good correlation between MMM (RTA) and sweep measurements (make at least 5 of them and average them).

  • Remember that Room EQ is not an exact science, so may the Force be with you. ;)

Variant 1 : Creating initial EQ filter in REW

  • On the right side of EQ window under Equaliser choose rePhase

  • Under Target settings configure settings for your speakers.

  • Under Target settings pressSet target level to have REW set the target level or configure it manually

  • Under Filter tasks hit Match response to target.

  • Hit EQ filters button to get dialog for additional manual filter adjustment

  • Hit Save filter settings to file to save REW EQ filter (which will be imported into rePhasse

  • Save your work under File/Save All Measurement

Variant 2 : Using rePhase

  • Choose Measurement/import from file to import REW measurement
  • Choose hide phase

  • Choose Ranges and adjust Amplitude to be from 0 dB to 70 dB (you should now have the same measurement graph as done in REW)

  • Under Paragraphic Gain EQ choose import REW filter settings to import REW parametric EQ filter

  • Configure following rePhase parameters: set taps to 65536, rate to 96000, filename to the name of of the filter and choose directory in which rephase will create filter

  • Hit generate to generate and save FIR filter

  • Save your work under File/Save settings

Variant 3 : Using DRC-FIR tools from the plugin

Creating filter with automatic tools in the plugin is easy. You have too put the exported impluse from REW in the shared folder of Volumio.

From your Windows files explorer, access to it by typing file://ipadressofvolumio

Then, go in brutefirfilter/filter-sources and put your Wav file here.

Go in the plugin setting page and in filter creation section, choose the file as file to convert.

Choose a target curve. 2 samples are provided with the plugin. This file define how the corrected curve should look like. You can create or adjust one of the sample given. These files are placed in shared folder of Volumio under brutefirfilter/target-sources

Choose a config.

We advice to start with 'soft' and see how it behaves..

You can give a name for your filter, or leaave empty the field to re-use the ipmort name.

The plugin will add samplerate+config+target-curves+.pcm to the name.

  • So, if name is left the generated filter will be left-44.1kHz-soft-hk5.pcm

Sample rate is taken from the value set in the plugin.

Warning : Do not set above 96Khz

Press Create filter and wait until the page is refreshed. Do the the samee for both channels.

Now, get ready to test your filter!