What We Like

What We Don't Like

Despite not having the most creative brand name, Definitive Technology routinely wins awards for the quality of their audio equipment and is known as a serious competitor within the industry. Let’s take a look at how their latest line performs.


Available only in black, the SM45s are a good looking design that does not do much to draw attention to itself. Simple but effective, the most notable element of the build is the cabinets are as deep as they are tall which means you will have to think carefully about which shelves they are placed on if you opt to follow the title of ‘bookshelf speaker’ to the letter of the law.

The black vinyl veneer feels premium, and should suit most interiors without appearing in any way ostentatious or out of place. The baffle is the most interesting element from a visual standpoint; it is glossy, smooth, and has rounded edges which should help to cut down on direct reflection if you have placed the speakers under or near a light source.

With a height and depth of just 11 11/16” (or 29.69cm), this is a fairly compact speaker which lends itself well to a variety of physical applications. Bumpers are included to affix to the bottom of the unit in order to protect them when placing them directly onto a surface, and this also means you’re able to move them around as much as you like.


The cabinet features a good deal of bracing on the inside to limit unnecessary vibrations which could disturb the sound during playback. Similarly, dampening of the cabinets has been well implemented as you will be able to tell with a short, sharp knock on the outside. The sound immediately dissipates and is swallowed up. This is a good sign, and means that the speaker should not put out any extraneous, unwanted noise caused by the vibrations of the track itself.

If you so choose, the front grille can be removed to access the drivers directly. We don’t recommend that you do this during regular use however, not least of all because the holes into which the grille is affixed don’t look great when exposed, but also because it may have a negative impact on the overall listening experience. On the rear of the speaker unit, you will see a reflect port and a terminal which accepts all of the usual connectors. This is all, for the most part, pretty standard fare.


As any audiophile will tell you, different speakers can take radically different times to ‘warm up’ to their true sound potential. This is more than just a psychological effect of getting used to the kind of sound signature the speaker is outputting, it’s actually a measurable process by which the drivers are ‘worn in’ in a similar way to buying a new pair of shoes. Once they’re ready to go—however long that takes—, they should stay that way until they start to degrade over time.

The first thing we noticed, then, is that the SM45s took a long time to warm up. And we mean a long, long time. The initial sound was, honestly, quite disappointing. It was flat and unengaging in a way that you would not expect for a speaker of this price range. Even significantly cheaper speakers are usually brighter and more exciting to listen to than the out of the box experience we had with these.

After a couple of days (more like three, actually), the speakers were thoroughly broken in and the difference in audio performance was night and day. Whilst still an undeniably controlled sound, it was at least engaging, natural, and precise. A wholly enjoyable experience.

The Rumble:

The SM45s feature a simple, appealing design in which just as much effort has gone into function as it has on form. They took a few days to reach their potential, but the eventual performance was hard to fault.