Beat-Sonic encore X Toyota GR86 / Subaru BRZ 4 Channel input vs 6 or 8 Channel output Explanation

For the 8 speaker the GR86 (and ZD8 BRZ), only the 2 x door woofers are connected to the factory amplifier. This factory amp is connected via high level inputs from the factory head unit front channel outputs. The dash mounted tweeters and dash mounted mid-range speakers are connected in parallel and also connected to the factory head unit front channel outputs. So a total of 3 speakers are connected to each of the front left and right channels...but the woofers are connected via the amp and the tweeters have a high pass filter so the nominal impedance is maintained at 4 ohm. The rear speakers are connected to the factory head unit rear channel outputs as normal.

The factory head unit is 4 channel, and the factory amp is 2 channel, but this is still considered to be a 4 channel system as the source unit (head unit) is 4 channels. Note that this is different to the JBL system that uses 2 or 4 channel outputs from the head unit. In this system, a separate control signal is sent from the head unit to the JBL amp to separate the signals to each output channel on the amp. MOST digital is different again and the the MOST amp can conceptually be considered as part of the head unit.

So this system has a total of 8 speakers but only 2 of them are connected to the factory amplifier.

When adding the Encore X, all speakers are benefitting from the additional power from the DSP amp, but more importantly, we can control (optimize) the sound coming from each channel. The front woofers, mids and tweeters are connected to the same channel but we can control the delay, equalizer settings and power to get the best possible sound. In thus configuration, you can imagine the front speakers as a single 3-way speaker connected to the Encore X amplifier. In very high end systems that use 8 or 10 channel DSP amplifiers, you can connect each speaker individually to each channel however this would require rewiring of the factory speaker connections (no longer plug & play) and a more expensive multi-channel DSP amplifier.

8 Speaker Model: