Macworld USA – August 2019

AUGUST 2019 MACWORLD 105

When listening to speakers in

a room, the high frequencies

are directional, while

the low frequencies are

omnidirectional, resulting

in more reflections from

the room boundaries and

thus tending to emphasize

the bass. PSB’s RoomFeel

technology aims to simulate

this effect in the M4U 8.

onboard DAC (digital-to-analog converter),
amplifier, and active noise cancellation (ANC).
This function uses four microphones in the
headphones to sample ambient sounds that
are phase-inverted and mixed with the
original to reduce their level by means of
phase cancellation. When the onboard power
amp is active (with or without ANC), pushing a
button engages Transparency Mode, which
temporarily drops the audio by 30dB and
amplifies ambient sounds so you can hear
the outside world.
One important feature is PSB’s RoomFeel
technology, which is engaged when the
power amp is active with or without ANC.
Based on research performed by PSB and
Harman, RoomFeel simulates the sonic
signature of high-end speakers in a good
listening room, which tends to emphasize
lower frequencies because of omnidirectional
reflections and roll off higher frequencies
because they are more directional with fewer
reflections. According to the M4U 8
datasheet, RoomFeel will “Take away the

room and the music sounds limited to the

space between your ears with an unnatural

emphasis to the treble. RoomFeel opens up

the soundstage while adding natural warmth

to the sound.” We shall see.

The M4U 8’s four microphones are also

used to answer calls on your mobile

phone. If you receive a call while listening,

hit a button, and the music pauses while

you answer the call. Once you’re done, hit

the button again to resume playback.

Unlike some wireless headphones, the

M4U 8 still act as passive cans if the batteries

are drained or you wish to conserve them by

keeping the power off. In that case, you must

connect an analog cable to the source, and

there is no ANC, Bluetooth, or RoomFeel.

Still, I heartily welcome this feature for those

times when the batteries are dead and

there’s no AC outlet to charge them.

USER INTERFACE

The controls are found on the back of the

right earcup. Starting at the top, the