Polk Audio Signature S15e

Different countries having varying expectations when it comes to sound is not as bizarre a concept as you might first imagine. After all, variations in room size, partnering equipment, music being listened to and even different expectations of how it should sound all play their role in ensuring that what delivers the goods in one part of the world won’t necessarily be the same in another and has led to ‘tuning’ products for a particular market. Certain brands have been keen advocates of the idea and as part of the Sound United group – one of the biggest speaker suppliers in the US – Polk’s latest additions to its Signature series have been tweaked to what it considers to be a more European ear.

The S15e – ‘e’ for European – is a new version of the S15 standmount we saw in HFC 420. The fundamental spec hasn’t changed and still combines a 25mm soft-dome tweeter with a 133mm mica/polypropylene mid/bass driver augmented by a rear bass reflex port to give a claimed sensitivity of 88dB/1W/1m. Beyond the numbers, the Polk is slightly different to the standard pattern of a compact speaker.

The Terylene tweeter claims to reproduce frequencies up to 40kHz – and sports a Hi-Res Audio logo – while the 133mm mid/bass unit uses Mica-reinforced polypropylene with butyl rubber surround and ceramic motor structures. The drivers are integrated by what Polk calls Dynamic Balance Technology, which considers the speaker’s output and works on the relationship of each of the drivers to achieve the best possible performance.

Also worthy of note is the bass reflex port. This is a rear-mounted cylindrical type, but instead of simply venting out the back of the cabinet there’s an additional plastic surround structure that’s designed to smooth the airflow. Polk calls this a Power Port, with the additional apparatus intended to deliver deeper bass than a traditional bass reflex design while allowing the cabinet to be placed right up against a wall. There’s even a keyhole to facilitate direct wall mounting, should you so wish to.

To tweak this basic starting point for tuning to European tastes, a series of changes have been implemented. The cabinet bracing has been subtly revised, the crossover has also seen some alterations and the bass port leading up to the Power Port assembly has been lengthened. There are also some minor changes to the mid/bass driver dust cap. None of this sounds particularly dramatic, but given that renowned speaker consultant Karl-Heinz Fink had a hand in the tuning these are surely all that’s needed to affect the sonic adjustments.

There are some minor cosmetic tweaks too – the baffle is matt black rather than gloss and it now uses black fixing screws, and there have also been some changes to the finish of the Power Port. It’s not an especially pretty or elegant looking speaker design when compared with price rivals, and it comes across as a little fussy and old fashioned by UK standards. A white finish is also available, which is slightly better but regardless of colour it is reasonably well made and has some neat touches like magnetic speaker grilles. While it does little for the overall aesthetic of the cabinet, the presence of the Power Port apparatus means it should be easy to accommodate in most rooms. Crucially, the changes have been applied without impinging on the elements of the performance that were so appealing about the original incarnation of the S15.

Sound quality
First connected to my resident Naim Supernait 2 integrated amplifier, costing more than 10 times the price, the S15e is admirably consistent and a very entertaining speaker to listen to. It powers through The Comet Is Coming’s Super Zodiac with the sort of drive and determination that is unusual in a relatively small speaker. Polk’s claim of there being more bass than rivals is debatable, but the bass it does have is well defined, light on its feet and well integrated with the rest of the frequency response.

The upper registers blend seamlessly with the bass and it’s here that demonstrable improvements have been made. The presentation has been significantly altered without impinging on the sense of fun that permeates the entire performance. It gains an element of civility that is the difference between it being a model that will delight a specific group of listeners to something that will attract many more admirers.

The potent bleakness of Believe It by White Lies is a thoroughly modern recording that can be a little congested and hard edged. The Polk balances it neatly, sounding refined and much more spacious than the mastering really should allow, but without losing the propulsive force needed to make music like this work. Despite the extended frequency response it isn’t the most detailed standmount, but it is competitive at the price and the sonic space it creates is a compelling one. The stereo image doesn’t extend much beyond the outer edge of the speaker – so a relatively wide placement is required for the best soundstage – but the space between the cabinets is convincingly filled and crucially manages to impart a feeling of front-to-back depth.

Ask the S15e to slow things down and be more delicate, and the scope of the refinements becomes more apparent. The wonderfully sweet and flowing Shadow Queen by the Alba Griot Ensemble isn’t rendered with unnatural scale or force and everything has a sense of proportion that feels entirely in keeping with the material. The unique combination of Celtic and West African influences are left to flow effortlessly together, unhurried, but never sound languid. As before, tiny little details that I know to be in the recording – like the movement of fingers across the harp strings – aren’t so readily apparent here as they are on some more upmarket designs, but the overall handling captures the tone and the intent extremely well.

Swapping to a Rega Brio integrated amplifier (HFC 446) doesn’t change the speaker’s sense of refinement and rhythmic energy, and when connected to the £180 Tangent Ampster BT II, the Polk still manages to deliver its virtues without significant change, too. Given that the Tangent integrated is a more likely partner, this is a very useful skill and along with the claimed 88dB/1W/1m demonstrates that driving this standmount in the real world really shouldn’t present significant problems.

The S15e is a convincing all-round option for entry-level audiophiles. Without sacrificing any of the virtues that were so appealing in the original S15 loudspeaker design, the US brand has been able to extract greater refinement and control that means it’s more likely to keep delighting listeners, where the original tended to over stay its welcome. The subtle tweaks that have been applied have turned it into a suave European citizen, making this a very attractive option for anyone starting out. ES    

Product: Polk Audio Signature S15e
Price: £250
Origin: USA/China
Type: 2-way standmount loudspeaker
Weight: 5.9kg
Dimensions: (WxHxD) 191 x 305 x 259mm

● 1x 25mm Terylene dome tweeter
● Inputs: 1x 133mm mica/polypropylene mid/bass driver
● Quoted sensitivity: 88dB/1W/1m

Read the full review in May 2019 issue 449

Sound United UK (UK distributor)
02890 279830