Our full review of the AMBEO soundbar is below, but the original magazine pages add additional information and an interview with Sennheiser's Uwe Cremering, Director of Immersive Audio. you can read the original magazine pages as PDFs by clicking the image above.

Sennheiser’s AMBEO breaks the soundbar barrier

Sennheiser’s AMBEO soundbar is a truly remarkable product in several ways. Most notable when you first encounter it is the sheer size — not so much its width, which at 126.5cm is not exceptionally wide in the soundbar world, but add in the height and depth and it’s a large 18.5kg enclosure. So while some companies have tried to minimise soundbar size, using a subwoofer to boost lower frequencies, Sennheiser has gone the other way — no subwoofer here, no separate rears, it’s just the soundbar. But a big ol’ four thousand dollars’ worth of soundbar...

Equipment
As you’ll read, that $4000 nets you not only what we think to be the biggest soundbar on the market, but also the best sonic performance we’ve yet heard from a bar. For this the AMBEO soundbar contains 13 drivers, the most visually obvious being the nine drivers arrayed in three sets along the main forward-facing frontage, each set comprising a one-inch aluminium-dome tweeter and twin 6×4-inch longthrow woofers with cellulose-sandwich cones. As you can see in the grille-off image above, the tweeters sit inside small cones which allow the frontage to present nine matching driver sites.

Two more tweeters sit in the angled ends, ready to use nearby reflective surfaces to create a surround effect. The final two are on the top — two smaller 3.5-inch full-range drivers firing upwards to deliver the height content available from today’s immersive soundtrack mixes.

The bar’s height of 14cm pretty much prevents you simply popping the AMBEO soundbar in front of your TV — it will cover the bottom of the screen and likely the remote-control sensor of any TV on the market. You can’t have it in a cabinet under the TV either, because of the upfiring speakers. So you’ll need your TV raised or wall-mounted, with the AMBEO bar benched below.

Making the connections was easy — roll the bar onto its front (protect the front on a soft surface while doing this) and you can feed all the cables through a rubber loop which serves as cable management. There are a generous three HDMI inputs, and one HDMI output to your TV, the output supporting not only the Audio Return Channel (ARC) to play stereo audio back down the cable from the TV and sources connected to the TV, it also supports eARC, the new ‘enhanced ARC’ which potentially carries multichannel audio from the TV to the bar. As eARC is new, it appears only on this year’s premium model TVs and a few from last year, but when you do get your next TV, Sennheiser’s bar is ready for it.

In addition to HDMI there are full-size optical and analogue audio inputs, a subwoofer output (available but not required!, says Sennheiser’s Uwe Cremering in our interview), while for networking you have the choice of Wi-Fi or Ethernet network connection; we gave it Ethernet.

There are other ways to send audio — there’s Bluetooth with NFC connection, and Chromecast audio. We noticed after returning the review unit that the specs also mention Media (UPnP), implying network streaming, but we didn’t find or test that ability.

Setting it up
When you power it up, the bar starts playing some nice Eno-like ambient music which incorporates plenty of depth information, so it sets you up nicely for the size of sound to come. The front-panel display then tells you to plug in Sennheiser’s calibration microphone to optimise the AMBEO performance. This is entirely worth doing as it identifies reflective surfaces above and to the sides which it can use to create the most accurate and widest possible soundfield. How effective this process is can be heard later by using the app to turn the calibration results on and off.

The calibration microphone is unusually large, having a big base plate and a stick which rises roughly the average height of a human from arse to ear, so that you just pop the base on the couch and the mike will already be at ear height. This is far easier than attaching the usual flat mikes to a tripod or cardboard stand or trying to hold it motionless in front of your nose. The usual sonic whoops act to establish the levels while you stand out of the way, and you’re done.

This is a good time to download and connect the Sennheiser Smart Control app to the soundbar — it’s not essential for use, but it gives access to some settings and information not otherwise available. It pairs quickly, requesting (for security, it says) that you press two buttons on the bar to make the connection. Buttons on the bar include source selection, volume control, mute, and the AMBEO button, which invokes immersive sound. The nicely-weighted remote control adds direct access to the six variations on AMBEO — Movie, Music, News, Sports, Neutral, and Night.

The AMBEO button
As Uwe describes in our interview following this review, there was a desire to combine the two very different types of surround already provided by the market — the ‘press a button for fake surround’ type of soundbar, and those that deliver a more purist approach but simply aren’t as exciting for many listeners, even though they deliver more accurate sound. Traditionally the biggest problem with fake surround has been the effect is has on central elements, including dialogue, and of course inaudible dialogue is somewhat self-defeating in a soundbar. So we were impressed when we pressed the AMBEO button, positioned dead centre below the power button on the remote control. Sennheiser has achieved the trick of spreading the sound wildly impressively, yet without buggering up the individual elements of the mix. Indeed the spaciousness assists the clarity.

Indeed ‘AMBEO off’ seems to switch the bar into stereo. Even when given an Atmos input signal, there was no output from the height or centre or side channels, just the left and right sets of drivers.

The AMBEO badge on the lower right of the bar lights up when AMBEO is engaged, though this is hardly necessary, as the sonic spread is impossible to miss! Sennheiser was immensely sensible in popping Dolby’s latest Atmos test disc in the box for reviewers — but they should do this for all purchasers, as it is the perfect material with which to demo the AMBEO bar to themselves and their friends, how it delivers gut-thrumming bass, how it can spread a bed of natural sound with width and front depth beyond all expectation from a front bar. Forest atmosphere or rainfall and thunder emerge as a joined-up and detailed soundfield; it’s bewitchingly immersive.

The Dolby disc also reveals the width of the sound. Indeed while physically the AMBEO bar more or less matches a 55-inch for width, it rather dominates it in bulk, and more importantly the imaging it creates, at least in its AMBEO movie mode, stretches so wide that while the centre content is locked to the screen, wide left/right content seems to map beyond a 55-inch screen. This size of sound will do for a 65-or 75-incher without any problem, even a projection screen. It’s that big a sound.

Of course Dolby’s demo tracks are one thing, but what about real-world content?

We gave it the talk-fest of Woody Allen’s Blue Jasmine, which has the usual Allen jazz band over the opening credits, and this sounded like it does in a movie theatre, pumping out rhythm from a contained but acoustically defined area in the centre, though not quite using only the centre driver trio only, so tied to the screen and yet also imbued with a tangible acoustic (just as stereo can be three-dimensional, mono is by no means one-dimensional). Then Cate Blanchett’s vocal enters, impeccably edged yet smooth in tone. It seemed a ‘wow’ soundfield to emerge from a bar, even remembering of course that it’s a big one. And if the ‘movie’ mode option does, as we suspect, slightly exaggerate the width, there’s never a sense of fakery of phase-manipulation.

The only time we identified a significant tonal change was when we played Laurence Olivier’s Hamlet, a mono soundtrack which the AMBEO button tried to give some spread and which did then slightly phase the speech, but even then not to the point of unpleasantness or incomprehension.

We ran through action sequences. Occasionally we missed the deepest depth that a separate subwoofer would bring, to the Laketown firestorm before the death of Smaug in the third Hobbit movie, or the climax of the dust-storm in Interstellar. As Uwe says in our interview, you can add a subwoofer if you really crave it. But there’s no shortage of impact or level without one; the bar creates a massive movie sound.

A soundbar for music
Remembering AMBEO’s roots in music, we pulled out some Atmos music. It takes a few minutes to settle into the ambience of the Pure Audio Blu-ray of the Choir of King’s College Cambridge, recorded in Atmos in their chapel (accompanied by His Majesty’s Sagbutts and Cornetts, no less); the delivery from the soundbar was spacious and fully loaded with the chapel ambience. While we’ve heard a more complete rendition via a full surround system, this is the best soundbar delivery ever!

We also played a series of the excellent Katzenberger Music Productions on SACD and Blu-ray; these are high-res stereo and 5.1 DTS HD MA rather than having height-content, but they showed how impressively musical the AMBEO bar is. For the jazz of Heinrich von Kalnein we selected the ‘Neutral’ AMBEO soundfield, and were impressed when selecting and defeating it that the AMBEO effect enhanced the spaciousness entirely naturally, without affecting the tone of the central acoustic bass or the subtle cues of finger on string.

▲ The Smart Control app offers an
additional handheld control, along
with access to some settings and
information not otherwise available.

Roger Waters The Wall has a full Blu-ray Atmos mix of his stadium concert with extras — and here there was a huge split between the AMBEO sound and the non-AMBEO rendition, not only in the shifting of crowd noise far and wide, but in the opening up of the whole musical sound. One of My Turns, with its deep rumblings and side-channels of found audio and hotel room breakage, was utterly transformed by the AMBEO button from a box-bound sound with a dry, slightly muddy central vocal into an immersive and intriguing surround mix with more of a PA-real vocal supported by stadium ambience and low crowd effect. This was in many ways a more enjoyable performance than from a full surround system, where the subwoofer channel can dominate. Here there was also a marked difference between the sound modes — ‘movie’ perhaps added a little too much additional ambience, where ‘music’ pulled things a little tighter and bumped up the bass, ‘neutral’ was perhaps the most natural. But in the end it was hard not to like the additional excitement engendered by the wider ‘movie’ setting.

So how about using the bar as your music system? One handy bonus here is the inclusion of Chromecast inside the bar, though this is audio Chromecast, not a video Chromecast — if you cast a tab of YouTube from a Chrome browser, say, this will send only the audio to the bar, as compared with a video Chromecast in a telly which will start streaming the YouTube video direct from the web,

But the audio Chromecast not only allows you to throw music from a good many apps, including Spotify, it puts the bar under the voice control of Google Assistant from any nearby Google Home.

This includes sending music to it, especially if you have Spotify linked to your Google account — “Hey Google, play Tom Waits on the Living Room speaker”, or if you make the AMBEO bar you default speaker for that Google Home, then just “Play Tom Waits”.

Also, while casting in this way, we tried “Hey Google, turn up the Living Room speaker”. We didn’t expect this to work on other inputs, but it does! So you have basic voice control of volume and mute. We couldn’t get it to change inputs (“but I’m learning every day”, said Google, sounding frighteningly like Eddie the shipboard computer from Hitchhikers).

Music can be played with or without the AMBEO modes engaged; sometimes we liked them, sometimes we didn’t. It was notable that lower quality sources like Spotify could get lumpier under some AMBEO modes, particularly the bass-lifted Music mode, than when played cleanly in stereo. Then again, open music — acoustic, chill, electronic — was highly enjoyable given the extra AMBEO spread. So you can decide for yourself.

Lip service
Something else you should decide for yourself, and before purchase, is whether you are sensitive to lip-sync delay. We had significant issues with lipsync both when playing sources directly connected to the bar, and when using ARC back from the connected television. The audio delay was greater than the video delay, and since the only correction available through the Sennheiser app is to add more audio delay, we couldn’t correct it on most sources. Our Oppo Blu-ray player allows video delay, so we could fix it for that source. If you have a TV that allows negative audio sync (not many do, some LG models), you can fix it that way. Sennheiser also reckons that the eARC which the bar supports would fix the problem for playback through the ARC channel, but we didn’t have an eARC-equipped TV to test this, and we doubt it would fix audio delay rather than video delay anyway. While we acknowledge being more sensitive to lipsync issues than most users, the delay here was enough for the missus to complain, even though she loved the overall sound. We’d put the delay somewhere above 50ms. If you have no corrective ability in your TV or sources, we’d recommend an audition of the AMBEO bar watching speech-heavy material or standard TV broadcasts to check this is not a problem for you.

[UPDATE: We have found only two other reviews which identify this sync problem with the AMBEO, and one of those indicates that it may have been largely fixed by a firmware update which was issued after our review.]

Conclusion
Sync issues aside, the AMBEO bar is incredible. Of course at $4000, it should be — that’s double the price of Samsung’s highest soundbar package which comes with wireless subwoofer
and wireless rears. But that’s a significant part of the AMBEO bar’s attraction — it doesn’t need all that to produce its amazingly immersive soundfield for movie soundtracks, while it also delivers enjoyable music, including that Chromecast bonus. We’ve heard what it can do with MPEG-H sports broadcasts (as described in the interview that follows), and while we may not get any of that in Australia for a long while, your AMBEO bar will be ready should it happen. To summarise, we can’t imagine anyone being less than amazed by what Sennheiser has achieved in this, its first soundbar, indeed its first ever consumer loudspeaker product. 

Sennheiser AMBEO SB01 soundbar
Price: $3999.95

+ Best soundbar ever!
+ No subwoofer required
+ Brilliant breadth of sound

– Size
– Price
– Lip-sync issues

Drivers: 5 x 2.5mm aluminium dome tweeter; 2 x 89mm full-range (up-firing); 6 x 10cm cellulose-sandwich woofers
Channel delivery: 5.1.4
Quoted power: 250W RMS total
Quoted frequency response: 30Hz–20kHz -3dB
Inputs: 3 x HDMI in (2.0a), HDMI out/ARC, 1x optical. 1 x stereo RCA analogue, 1 x USB (power/service), mic input, Bluetooth, Ethernet/Wi-Fi for UPnP/Chromecast.
Outputs: HDMI out/ARC, subwoofer pre-out
Dimensions: 1265 x 135 x 170mm inc. feet
Weight: 18.5kg
Contact: Sennheiser Australia
Telephone: 02 9910 6700
Web: en-au.sennheiser.com