The Midium


teenage engineering's description of the teenage engineering OB-4 hi-fidelity bluetooth loudspeaker and ambient machine


the magic radio.

OB–4 is our ultra thin 'orthobook' bluetooth loudspeaker with a sound larger than its appearance and really long battery life. discover deep bass and crystal clear, open and natural audio that fills the entire room.

listen using line-in, bluetooth, FM radio and disk mode. the unique mechanized interface is minimal with intuitive functionality. yet ifyou look beneath the surface, there's more than meets the eye. 

ultimate portable loudspeaker.

made to be played wherever you need, however you want. outside on the porch, at a picnic, or take it from your home to your holiday. then use your custom mesh carry bag to play OB–4 on the move.

or why not give it a home in your kitchen? the adjustable handle not only houses an extra antenna, but makes it a breeze to carry – it can also be used as a stand for a more relaxed listening position.

natural sound.

four tailor-engineered speaker elements deliver pure quality sound and a stereo field that fills the entire room. a flow-optimized bass reflex duct delivers deep natural bass.


72 hours listening.

on one charge you can listen to the radio for three sleepless days (nothing we recommend) or get 40 hours of listening via bluetooth. all thanks to the high capacity li-on battery.

the wireless part.

OB–4 is a wireless speaker that supports bluetooth classic for audio streaming and bluetooth low energy for wireless volume control via the orthoplay app and ortho remote.

slim and portable.

big sound in a small package. OB–4's compact size and built-in handle means you can take quality sound anywhere, from your living room to the studio and beyond.

motorized user interface.

use your fingers to grab, spin and interact with the sound.
teenage engineering ob-4
digital-motion controlled volume knob and tape reel. we call it the next level of user experience.

turn your mind on with disk mode.

beyond the traditional features like line-in, bluetooth and FM radio, you can find disk mode. this is where we update OB–4 with new features that push beyond the usual. it's our public research space where we explore and prototype everything that this media instrument could be. right now, functions on disk include: ambient, karma, metronome, noise and loop. the orthoplay app is where we reveal the latest updates. 


zone out to a drone generated by snippets of any audio source.


sync with metronome, including 808 with pitch adjustment.


30 in 1 musical mantra box.
  your spiritual companion.


induce calm and focus with white, brown and pink noise frequencies.


create audio loops, store them and beat match, all on OB–4.


what's all the hocus pocus about?

have you ever wished you could instantly rewind when listening to the radio to hear the title of the song just played? OB–4 memorizes everything you listen to on an endless looping tape*.
rewind, time-bend, loop, keep time or zone out, all at the flick of your fingertips. on purpose, or by accident. OB–4 let's you listen like never before, and that's just the beginning of its many magic tricks.



magic studio monitor.

the low latency line input makes OB–4 the ideal portable studio speaker. plug-in your instruments,a record player, any device that has an audio output. or use the fm signal to connect to OP–1 field.

while you play, use OB–4 as part of the performance. play around with ambient mode, use the metronome to keep time, or loop your beats to create something new. live remix and experiment in the moment.


speaker principle: flow optimized bass reflex ductand semi unified chamber.
frequency range: 52 – 25000 Hz
dimensions: 232.5 x 284 x 57.5 mm
weight: 1.7 kg

materials: amorphous polymer glass fibre reinforced pc and milled aluminum.

design: features fine pitch tweeter grille, gel dampened handle, custom direct drive volume knob and tape dial.
max SPL @ 1 m stereo configuration: 92 dB unsupported wideband
bass capability @ 1 m: 104 dB SPL supported

active crossover frequency: 3.5 kHz

configuration: stereo 2 + 2

tweeter: high efficiency ferrofluid cooled neodymium driver.

woofer: long throw high power capacity neodymium driver.

amplifier: 2 x 38 Wultra high efficiency class D

wireless: Bluetooth® classic (AAC)Bluetooth® 5 LEFM radio
inputs: 3.5 mm stereo in(2.8 Vpp for 0 dBFS)

battery life: normal volume FM: 72 hours, bluetooth high volume: 8 hours
general power requirements: AC 100-240 V 50/60 Hz universal built-in power supply

included accessories:mains power cable, antenna

product nameOB–4 (ortho book 4)

HARM code: 8518220000
country of origin:czech republic