Room and manual EQ
Introduction
SC15 Prisma MK2 provides both automatic Room EQ (equalisation), and Manual EQ, using functions included in the Prisma app. The EQ function can be used with any iOS or Android mobile device; iOS devices can use their own built-in microphone, but Android devices require the use of the Zen microphone described below.
Note that the Room EQ or Manual EQ is applied to the WiSA speakers and analogue output, but it doesn’t affect the digital output.
Room EQ
Room EQ automatically creates an equalisation profile for the listening room. It uses a one minute measurement sequence during which pink noise is played through the speakers while you move a microphone around the room in large circular motions. The EQ function then calculates an appropriate equalisation profile to compensate for the room characteristics, and applies it to the speakers.
Since the room impacts the lower frequencies the most, the compensation will correct the bass range below 500Hz. However, full frequency data is captured during the measurement process so that the low-frequency output is aligned with the high-frequency output, providing a naturally even response within the room at the listening position.
The Room EQ function can use the iOS microphone on iOS devices, or a Zen Wireless microphone, available separately, on both Android or iOS devices.
Manual EQ
The Manual EQ function allows you to define custom filters and apply them to the sound from the SC15.
It is possible to have both Room EQ and Manual EQ activated at the same time.
Zen Wireless Microphone
The Zen Wireless Microphone is a rechargeable battery powered microphone, making it an ideal calibration tool for collecting room acoustic data when using an Android mobile device. It can also optionally be used with an iOS device.
See Zen Wireless Microphone user guide at this link.
EQ functions
To select the EQ functions in the Primare App:
- Select the SETTINGS panel.
- Expand the Audio settings section of the menu.
- Select the EQ option.
The EQ screen is displayed:
Room EQ
To select Room EQ:
- Press the Room EQ icon, read the instructions, and click Got it!.
The following page allows you to specify the roll-off frequency of your loudspeakers, from 20Hz to 200Hz:
As a guide, enter 20Hz for large floor-standing speakers, or 100Hz for small shelf or wall-mounted speakers.
- Press the tick button to continue.
The next page allows you to start the Room EQ measurement.
- Press the Begin button to continue.
Any audio you were listening to will be muted, and pink noise will be played through the loudspeakers.
The progress is shown by a bar around the button, and the front panel display of the SC15 Primare MK2 shows:
Calibrating
- Stand 1.5 meters or more away from the speakers.
- Do not get in between the phone/microphone and the speaker.
- Move around the entire room.
The process will take up to 60 seconds but can be stopped after 30 if the entire room has been covered.
When the measurement has finished the measured room characteristic is displayed as a red curve:
- Press the Calibrate button.
The corrected room EQ will be calculated and shown as a green curve on the response graph:
- Press Enable.
The correction is automatically uploaded to the SC15 and applied to the speakers.
The added Room EQ can be changed at any time by clicking the Redo button. For example, if you have changed the furnishings in your room you should recalculate the Room EQ profile.
To activate or deactivate the Room EQ
Either:
- Press the radio button under the Room EQ icon on the main EQ screen.
Or:
- Press Enable or Disable on the Room EQ screen.
Manual EQ
Manual EQ allows you to create up to three custom filter presets, according to your own preferences, and apply one of them to the SC15.
On the main EQ screen:
- Press the Manual EQ icon, read the instructions, and click Got it!.
The following screen allows you define up to three presets, each consisting of up to three combined filters:
- Press the + button to create a filter.
The following screen allows you to select the type of filter you want to add. The Filter Type menu gives you a choice of five different types of filter:
The options are explained in the following table:
Filter | Description |
Parametric EQ | Boosts or attenuates sounds around a specified frequency. |
Low shelving | Boosts or attenuates sounds below a specified frequency by a fixed amount. |
High shelving | Boosts or attenuates sounds above a specified frequency by a fixed amount. |
12dB highpass | Progressively attenuates sounds below a specified frequency. |
6dB highpass | Progressively attenuates sounds below a specified frequency. |
For the Parametric EQ filter you need to specify the amount of gain or attenuation between -10dB to 10dB, the Q between 0.01 (wide) and 30 (narrow), and the centre frequency between 10 and 20000Hz:
For the Low shelving and High shelving filters you need to specify the shelf frequency between 10 and 20000Hz, and gain or attenuation between -10dB to 10dB:
For the 12dB highpass and 6dB highpass filters you need to specify the cutoff frequency between 10 and 20000Hz:
When you have specified the filter:
- Press Save.
Once each filter has been created it will be shown as an icon at the bottom of the Manual EQ page. You can create up to three filters, and their combined effect will be shown by the curve on the Manual EQ page:
To disable a filter
- Press the radio button on its icon.
To delete a filter
- Press the trash button on its icon.
To save the filters as a preset
- Hold down the preset button for the preset number you want to define, and confirm by selecting YES to the prompt Replace existing data.
The Manual EQ page will then show the preset you have defined, and it will be applied to the SC15:
To activate or deactivate the Manual EQ preset
- Press the radio button under the Manual EQ icon on the main EQ screen.
Warning!
Because the Manual EQ function allows you to create arbitrary filters there is a risk that you could create signals that exceed the levels that your loudspeakers are designed to withstand for normal sources. Increase the filter gain in small steps, and test first at low listening levels.