Review: Zu Soul 6

If you have been following Utah-based Zu Audio for any of the many years they have been producing high fidelity equipment, you will know that founder Sean Casey likes to do things to the beat of his own drum. The speakers he designs typically buck the usual audiophile trends, and tend to embrace a more mid century modern sensibility to them. For years, Sean offered many a young (in experience, if not age) audiophile a doorway into HiFi with his $1k Omen speaker (and more recently the Omen Dirty Weekend Special). The Omen offered a cool styling and engaging tone for the same price or cheaper of most the floorstanding drivers found at big box retailers. 

With strains on supply and general inflation, the days of $1k speaker pair are now unfortunately behind us. The Omen DW and Omen II are no longer standard offerings and a new wave of Zu options are clearly presenting themselves. This new reshuffling of the product line comes hot on the heels of the release of the sixth generation of Zu’s smaller profile, high end offering called Soul. 

Equipped with a single point source for delivery, a coaxial tweeter is embedded in a 10” paper cone driver with additional 2” whizzer cone (tapered out to 3.75″ from the center core) for full range sonic capabilities. This formula is now emulated throughout the lower range of speakers from Zu, including the new Union Series which currently comes in Union 6 and Union 6 Supreme flavors. The high end Druid 6 we reviewed is still available, now at $11.5k and Sean is currently teasing out the idea of a new $20k flagship called Definition 6. 

The Zu Soul 6 should hit the sweet spot for a lot of budgets, the intent here is to give a step up in performance from the Union line, without having to compete directly with the rush of options at the $10k level in the market. Another big differentiator is the form factor. The Soul deviates from the square shape of the Union and Omen with a pyramid-shaped, more-narrow-top-than-bottom look and a very friendly 32” height. In short, they take up very minimal space for a floorstander. 

Many of Zu’s models incorporate some form of their “Zu-Griewe acoustic impedance room adaptive system”. On the Soul 6, this is represented as 4 slots that line the sides of the undercarriage of the speaker. With the new, thick carpet that covers the floor in the main listening room, very little bass was found with the standard bolt feet that came on the review sample that was sent. Even at their fullest height, it still wasn’t enough to lift the speaker off the carpet to achieve any type of gap. Swapping out the hard floor bolts for a pair of tall carpet spikes resulted in an easy gap, and filled out the bass to more preferable levels as well as improving the mid range response just a tad. One might consider that out of the box Zu speakers take a little more tinkering than your average speaker, but even the most basic setup efforts require adjustments of some level to achieve any type of bespoke experience. Roughly a quarter inch to ⅜ off the top edge of carpet provided plenty of balance to the sonic equation, allowing for the bass to reach deeper and with obvious benefits to the overall presence. How much bass exactly? Pumping a full range paper cone driver does have its limits on both sizes of the frequency range. With the coaxial tweeter, Zu looks to make up a lot of the compromises with the supplemental driver.

On the low end side of things, the Zu Soul 6 was surprisingly robust. Centering around the bass drum, plenty of kick could be found in the mix and never felt lacking for any rock or pop music. With the on-hand reference Sonus Faber Olympica Nova III’s, some music feels right, while others feel too big or bouncy at times. The Zus suffered no such ills in the bass department. There was a much more even keeled presentation jumping from genre to genre. Even though the album When We Fall Asleep, Where Do We Go by Billie Ellish might be getting a little long in the tooth for some (and a non starter for others) the record continues to offer an interesting look at how bass can be produced from a desk that inhabits a lot of “in box” instruments – but still sound really good. Some of the complexity in the low end, which includes bass lines that drive the meat of the song rather than just acting as a support system, can really challenge the clarity in that frequency range for a pair of speakers. The Zu Soul 6 had no issues handling the quick changes or the low depths represented throughout the album. Dynamics were aggressively tight, in a good way. 

This sense of tight dynamics carried up into the mids with excellent vocal detail that deftly trumped the transient response from the classic Omens I dug out from the garage. Also significantly upgraded was the overall detail retrieval, bringing a good sense of depth and realism to songs like Hell Freezes Over Hotel California and classic audiophile Jazz like Diana Krall and Norah Jones. Detail was high comparatively, even to the higher cost SF Nova III, but the sound stage differed slightly as well. The Nova’s threw a slightly wider soundstage overall, with the Zu Soul 6 landing closer, with a more directional feel. There was a slight bump to the intimacy for the Zu’s and coupled with the high level of detail retrieval, might be the preference for some, even at half the going price. 

The high end was light and airy, ripe with the aforementioned detail but low on any harsh edginess or over extension. Changing from track to track, it was easy to pick out the “room” in each recording. Often this sensation is simulated, amplified by artificial reverb and echo during production. Nonetheless, it is a subtle queue that should be present in any good recording. Our ears may not gravitate towards it initially, but a sense of space or room should be available in both the recording and speaker reproduction in order to give music a sense of realness or breathable space around the notes. The Soul 6 managed this easily, and receives high marks for a clear picture through the window for all kinds of sonic variations. 

If we were to pick out the standout qualities of the Zu Soul 6 listening experience, it would start with the good looks, detail retrieval and fun bass recreation. The unique aesthetics can be more than just a talking piece, they could also complement or fit into a look in the right room. Custom colors are usually available from Zu, and they do a great job putting the whole visual experience together with the simple angles and interesting textures. With the supplemental coaxial tweeter, high transparency to source and vivid acoustic images are easy to discern. Properly adjusted bass through the Zu-Griewe system is punchy and engaging. A fair amount of low end detail can be discerned through the full range driver which really excels with rock and pop music. 

While Zu has always been known to be a late night rock-and-roll brand, the Zu Soul 6 shows that the company is capable of producing a middle road between the fun of cool and the increased sonic restraints required by the high end. If the looks and profile agree with you, then you will likely not be disappointed by the musical reproduction either. The outsides are part and parcel to the innards, and perhaps reflect the designer’s intent proportionally. Looks good, sounds good.

More info: Zu Soul 6