I have long been of the opinion that $500 is the absolute maximum you should spend on a sound bar -- especially when something like the Dolby Atmos-toting Vizio SB36512-f6 offers all you need. Yet, while I loved the Vizio SB36512, it's not the best Dolby Atmos sound bar. The Sennheiser Ambeo Soundbar is. 

My colleague David Carnoy first heard the Ambeo sound bar at Sennheiser's booth at CES 2018 and it impressed him, but back then it didn't seem like a real product. Fast-forward 18 months and now it's here, and it's real. It's good, too; nay, great!

This spectacularly expensive speaker ($2,500, £2,220, AU$4,000) is without a doubt the best single-unit system I have ever heard. The Sennheiser delivers the greatest possible movie sound out of one speaker with spookily good simulated surround and deep bass without rears or a sub. It also offers plenty of connectivity for even the biggest setups.

The Ambeo may not do everything right -- it's only OK with music, and movies lack punch without a dedicated sub -- but these are small, somewhat-fixable problems. Especially when you consider the Sennheiser's complete mastery of surround soundtracks. If you don't have the room for a full surround setup, but have the money to burn, you should get this sound bar.

What it is

The Sennheiser Ambeo is a cutting-edge sound bar with features such as Dolby Atmos/DTS:X, HDMI 2.1 and Wi-Fi streaming support. There is very little the Ambeo won't do either now or in the foreseeable future.

The Ambeo is the latest sound bar to simulate Atmos surround from a single bar -- the $2,000 Yamaha YSP-5600 and the $1,500/£1,200 Sony HT-ST500 also do Atmos. The Ambeo achieves this effect with a combination of 13 high-end drivers firing from the front, sides and top of the unit. These include five dedicated high-fidelity tweeters and six long-throw woofers, enabling the system to reach down to a claimed 30Hz. 

It's a tall unit at 5.3 inches high, and 50 inches wide, which means it won't fit under any TVs -- most people will need to put this speaker on a credenza and wall-mount the TV. However, Sennheiser does offer an optional speaker wall mount for $60 (£50) . 

Connectivity includes three HDMI inputs and an HDMI eARC output. It has optical, stereo analog, Bluetooth and onboard Wi-Fi. Google Chromecast ($55 at eBay) makes casting from your phone or Google Assistant that much easier.   

The Sennheiser Ambeo comes with a unique calibration microphone. Many AV receivers include plastic pucks and a cardboard tower to perch them on, but Sennheiser's model is a 2-foot-plus steel rod on a hinged base with the mic at the top. It reeks of quality or science or both. Sennheiser makes microphones for a living, so if I was going to trust any company's calibration system, it's going to be this one. In this case, calibration helps the sound bar determine the acoustics of your room so it knows where to shoot surround effects.

The sound bar includes a candy bar remote with most functions, and changes are visible on the super-readable OLED screen. The Smart Control app allows more in-depth changes from your mobile device.

If you want to stream music from your phone -- or another Bluetooth-equipped audio device -- there is a Bluetooth in connection. However, like with most other sound bars, there's no Bluetooth out for sending sound to a wireless headphone. Nor do you get a headphone jack for plugging in a wired headphone. Not too many people will care about that, but I sort of hoped for it in a $2,500 sound bar from a company known for its headphones.

The high-end competition

The number of high-end sound bars that can justify their high price is small. Even less so ones that support Atmos. I was a fan of the original (non-Atmos) Bowers and Wilkins Panorama, which was one of the first to use sound-bouncing technology. Since then, companies such as Bose and Sonos have been able to achieve similar or better results for much less.