Stress test: Is the HTC One M9 really a brilliant music player?

If music be the food of love, the M9 is a real Casanova

7 days using the HTC One M9 as my only music player

As part of Phone Week here on TechRadar each member of the phones team is taking a top end phone and giving the key feature a stress test. I was handed the HTC One M9 and decided that the audio abilities the brand keeps making a noise about needed a good going over.

One of the key features on the One M9, and its two flagship predecessors, is the firm's focus on music with its BoomSound audio technology and dual front-facing speakers.

The Taiwanese firm has worked tirelessly over the past few years to improve the audio experience you receive from your smartphone and the M9 bears the fruits of the third generation of this technology.

HTC has teamed up with Dolby Audio for the BoomSound tech inside the One M9, so I've spent a week trying out all the features to find out if the noise is worth listening to.

Day 1 - Here comes the Boom(Sound)

Take the HTC One M9 out of its box and its musical potential is immediately obvious thanks to the sizable dual-speaker grills which adorn the front of the handset.

They're not quite as wide as those found on the One M8, but the holes have been drilled slightly larger, and there's more vertical space between them, offering a cleaner, fresher look and feel.

It may not have the Beats Audio technology - and the logo on the rear - like the original HTC One, but the Taiwanese firm has continued to develop its audio boosting tech even after the split between itself and Dr Dre's Beats.

I went directly to the YouTube app to get my first taste of BoomSound in action (Gangnam Style, PSY followed by Now You're Gone, Basshunter*) - and although the icon in the notification bar told me the audio tech was in full swing it wasn't necessarily immediately noticeable.

HTC One M9
Gangnam Style on the One M9

Sure music sounds good - surprisingly good actually for a smartphone - but in isolation and without the ability to toggle BoomSound on and off when using the internal speakers I struggled to really appreciate what was happening under the hood.

I enjoyed what I'd heard however and promptly downloaded Spotify, cranked up the volume and relaxed listening to an eclectic mix of dance, pop, DnB, dubstep and jazz - no closer to finding out if the One M9 is really delivering a superior audio experience.

*phone fans: check out the old school LG Shine and Nokia N73 used in this video!

Day 2 - Tunes on steroids

One of the good things about BoomSound is the fact it doesn't just work with the built-in speakers. HTC has stuck an amp on the 3.5mm headphone jack, allowing you to enjoy the enhanced beats on the move without distracting others.

Having plugged in my Panasonic RP-HC700 headphones I was pleased to find the 'HTC BoomSound with Dolby Audio' option in the Settings menu now allowed me to switch it on and off - giving me my first clear comparison between normal music and HTC's tunes-on-steroids version.

Is there a difference to be heard? Absolutely. Is it life changing? Err, no.

HTC One M9
Hook up the M9 to a wired set of headphones to enjoy BoomSound

Flicking BoomSound on and off does give you a clear audible difference to the track you're listening too - no matter the genre - and the BoomSound enhancements provided a better listening experience.

Thanks to the over the ear headphones I was wearing I could really appreciate the subtle upgrades it was bringing to my songs, from deeper bass to better clarity in the trebles and vocals.

Switching to the bundled in-ear headphones the difference wasn't quite so pronounced, but it's still noticeable and I'd always pick BoomSound being on, rather than off.

Day 3 - Wired versus wireless

Wired headphones are all well and good, but they're a bit of a pain as I dash through London's underground train stations at the height of rush hour. The wire always seems to get in the way, or get snagged on a piece of clothing, unceremoniously ripping the buds from my ears.

I much prefer Bluetooth headphones, with their hassle-free wireless design allowing me to dart between bleary-eyed commuters. My Sony DR-BTN200 headphones however, did prove a problem for the One M9 and its BoomSound beats.

HTC One M9
There's no BoomSound on Bluetooth headphones

BoomSound is not available over Bluetooth, HDMI, Miracast or USB audio out - meaning I was instantly transported back to songs which sounded the same as pretty much any other smartphone I'd previously listened to them on.

Having spent the whole of the previous day enjoying the BoomSound enhancements through my wired Panasonics, the experience I was getting on my much-loved Sony cans was one of disappointment.

There are, of course, technical limitations and reasoning as to why the BoomSound technology can't be transferred wirelessly, but it feels like a huge disconnect in today's world where wireless is fast becoming king.