The Sennheiser MM 450 headset packs in buckets of technology offering up pretty much everything you could look for in a headset. It can be wired, wireless, with or without noise cancellation and they fold-up too. Could these be the ultimate headphones for travel and leisure?

Our quick take

There is little to criticise with the MM 450. They are expensive, but they don't lack features. Whether you want to relax with music, take calls, use them in the street or on your travels, the MM 450 step up to the task.

They deliver on the audio front and come with everything you need in the box, so we think the cost is justifiable for such a versatile set of headphones.

Sennheiser MM 450 Bluetooth headphones - 4.5 / 5

The Sennheiser MM 450 are on-ear headphones and as such they offer some of the audio benefits of a proper set of headphones, without the bulk. The construction is typically solid, with enough padding around the headband on the "cans" themselves to be comfortable. They are adjustable enough to fit a range of head shapes and sizes, with the swivel joint that allows them to fold up making them easy to fit to your ear.

With prolonged wearing they do get a little hot inside, but we did find them comfortable to wear for long periods of time. The various buttons and controls are easy to get to, so once on your head it is easy to take advantage of everything on offer.

The MM 450 are principally sold as a Bluetooth headset, with a built-in mic so you can use them for listening to your tunes and for taking calls when connected to your mobile phone. But they also have a cable jack on the headset, so you can plug in the included cable into any 3.5mm source for those moments when you can't, or don't want to, use Bluetooth.

As they stand the MM 450 offer a reasonable level of noise isolation, but not to the level that you get from a set of in-ear headphones with a decent seal in your ear. However, Sennheiser's NoiseGard technology is built-in too, which aims to cut out background environmental noise by producing phase-inverted anti-noise. This is especially effective against residue background noises like the hiss of an aircraft or the rumble of an engine and in our tests we found it effective, meaning we could turn down the volume of the music we were listening too.

When NoiseGard is working, it can cause a slight imbalance in your ears, but it isn't as severe as some noise cancellation headphones we’ve tried and you soon get used to it. You can also turn it off to save battery life, or when you don't need it, using a dedicated button.

The NoiseGard button has another feature, which is the Talk Through feature. With a press of the button, the music will be shut off and the microphone lets you hear everything around you. It is for that moment when the cabin crew asks you what you want to drink, or you need to ask directions or pay for your Mars Bar. We like the fact that you can turn it on and off, meaning you don’t have to stand there and hold down the button whilst you talk. The NoiseGard continues to work too, so voices are loud and clear.

Plugging in a cable turns the MM 450 into a standard set of headphones, you lose the ability to make and receive calls, but you still get the benefits of NoiseGard and the Talk Though feature whilst you have battery power. With a flat battery you can still use them normally so these are versatile headphones overall.

The battery is removable and lives in the left-hand ear piece. It has a Micro-USB connection and can be charged whilst in the device, or separately, so you can buy an additional battery for when you're away from a power source, although we haven't been able to track one down to confirm the price.

As you'd expect from Sennheiser, the audio performance is very good indeed. There is plenty of bass to bring body to your music with detail right through the range. The MM 450 performed excellently across genres as well as performing well with movies. Callers can sound a little distant, but you don't always want them blasting through anyway.

We noticed little difference in performance whether wired or using Bluetooth. We also found that the Bluetooth connection was solid and didn't drop the connection to our mobile phone, which isn't always the case.

Callers reported that they could hear us clearly, although it was obvious that we were using a headset. The microphone is mounted on the outside of the ear cup, so it is some distance from your ear, and callers reported that they could hear background noise too. You can still have NoiseGard engaged when taking a call although it does make you feel a little detached from the world around you.

In terms of controls the right-hand ear cup has the Bluetooth and NoiseGard buttons as already mentioned. These will light up in red or blue to indicate status, which shows when any button is pressed, rather than being permanently illuminated. In the centre of the ear cup you get a central button (power/call answer and end) with volume controls and track skip buttons, which are all easy to find and responsive.

The MM 450 also come with a range of accessories in line with their travel remit. They fold down into a soft case which will also house the cable and aircraft adapters. It would be a squeeze to fit in the power pack, but it is a simple USB unit with a selection of international plug pins, so a versatile addition to any travel kit.

The battery life depends on whether you are using NoiseGard or not, with life ranging from 8 hours at the short end (Bluetooth and NoiseGard), through 10 hours (Bluetooth only) and up to 20 hours at the top end (NoiseGard, no Bluetooth). Of course, once the battery is flat, you can still use them with the wire.

To recap

There is little to criticise with the MM 450. They are expensive, but they don't lack features. Whether you want to relax with music, take calls, use them in the street or on your travels, the MM 450 step up to the task