Engineers have an idea of what performance they want a particular subwoofer to achieve when they design it. The caveat is that the space in which the speaker resides will modify this. Therefore, we need an EQ. Elac’s process allows for a clever change in the requirement of the microphone where it no longer needs a calibrated one but can use the one built into your smartphone itself.
The AutoEQ feature for ELAC's line of subwoofers makes use of an app and a smartphone's in-built mic to equalize (or change the values of various frequency bands in an audio signal) by taking two readings. The first is taken in close proximity to the speaker (its nearfield) with the understanding that this is going to be the area least prone to the influence of the room and will therefore act as a reference, measuring the designed response of the subwoofer. The second is taken from where the user intends to be listening to the mix. These two are then matched to each other automatically using a set of filters eliminating the need to use a calibrated mic and matching it to a predefined ideal EQ. The new approach makes it easier to equalize as it is app-based and therefore a lot easier to do.