W371A and 8381A have the special feature of multiple bass drivers and can be calibrated and operated in different modes.

We recommend to run multiple calibrations with different mode settings to compare and evaluate the results using different groups in GLM.

The two standard modes are Continuous Directivity Mode and Complementary Mode. Both modes pursue the same goal: to create the flattest possible frequency response at the listening position. We utilise the different physical positions of the bass drivers (front and bottom back for W371A, top and bottom side for 8381A) in the room and their acoustic coupling. Both modes deliver a very similar directivity behaviour.

Continuous Directivity Mode

The Continuous Directivity Mode uses the two woofers of the W371 or the three woofers of the 8381 simultaneously. In this mode the crossover is fixed between the top (or front) and bottom woofers. It's the most robust mode for very challenging acoustics, in case it's hard for tor the algorithm to find the perfect settings that are used for Complementary Mode. 

Complementary Mode

The Complementary Mode offers a higher flexibility for the algorithm to adapt the settings to your specific room acoustics. The woofers are used independently (front and back for W371, top and lower woofer pair for 8381). The calibration algorithm will detect an optimal crossover point between the woofers to find a summed response that is the flattest at the measurement point (=listening location). In most cases this mode will deliver the best results.

Back, side, floor reduction (W371A only)

The Anti-reflection Mode uses the two woofers in the W371 simultaneously to generate regions of silence (known as ‘nulls’) in certain orientations. These nulls reduce the levels of reflected audio in the operating frequency range of the W371 caused by various surfaces in the listening room. This also reduces the acoustic coupling of low frequency energy into room reverberation, thus reducing any detrimental effects of the room’s acoustics.