Zo Personal Subwoofer

Zo by Digizoid. It’s called a personal subwoofer and with all the mathematical algorithms they’ve put that includes a “patent-pending SmartVector sound contouring technology that dynamically contours acoustic energy to counterbalance signal loss due to the inefficiencies of a speaker and the human ear” and computational prowess that’s as mind boggling as an Intel quad core processor, it promises to shake the ground of your feet with, well, bass. And not just bass but huge, fat, pounding bass at that. And at $120.00 in Amazon, is it any good? Most of it is really marketing and PR talk to be honest and to use less slightly complicated terminologies, it is very much a portable amp.

What’s special about Digizoid though, is that this would be the first serious product I have seen to introduce portable amps to the mass consumer market and not just audiophiles. Digizoid is perhaps hoping for the Zo to do what Beats by Dre did for headphones – that is to make products that could be used by audiophiles but to be largely bought and used by the mass market. Will they gain equal success or not is yet to be seen but they are surely off to a good start.


The Zo is basically a rather small device. It’s even a bit shorter compared to the old ipod Nano. It feels very light and almost cheapish in a certain manner. The high gloss finish hopes to add more class to the product as with the sleek multi-colored LED that serves as a visual volume indicator. It’s as simple as powering it up, plugging your source and headphone then increasing or decreasing the volume of the bass in your song. On the other side is a mini usb port that will serve as your means of charging the internal batteries. You can use the Zo while charging but there will be a lot of noise added to your music due to the electrical noise entering the signal circuitry so that is not recommended.

For the sound itself, I failed to test it against the similarly priced FiiO E7 and so I decided to compare it with something that’s priced twice its value but is currently my favorite bass amp – the C&C XO2. If you are not familiar with this amp, wait for an upcoming review. As for this article, my aim really was just to compare the Zo to what bass amps can really do when done properly. In short, I will simply describe where it does good and where it can definitely use improvements.

First and the most problematic of all is that the lineout of your DAP cannot be used to send line-in signal to the Zo. The volume will be unbearably loud and you should never do this because it might just end up damaging your IEM or headphones. This means, you have to connect your player to the Zo using your headphone out. To the average consumer, this is nothing but for audiophile who know better, this is definitely a huge concern. Second, the switch for the volume controls are rather numb. You really have to push up or down to get the volume moving. The multi-colored LED does not help as much because sometimes, the color change when adjusting volume is so subtle you are barely noticing any change except for what you hear. Other than that, let’s move to how it sounds.

As far as bass is concerned, it definitely adds a lot. You can control this and with my setup of an HM602, volume level 2/10, the Zo only needs two clicks as well to bring enough bass and energy to my Superlux 381f before I felt it to be overpowering and with at least 8 more clicks until max level, there is definitely much more bass in this personal sub. The not so nice part about the bass is this. It is not just bass that is bumped up but the mids as well. It is inevitable honestly but the mids are bumped up way too early that the track gets muffled and dark quickly. If you prefer dark sounding signatures then this might be good for you but if you are very keen on details and texture and air, the Zo will quickly dissipate those as you add more bass into the music. Also, the bass is not beautifully added bass. When you start using high end cans with the Zo like the Edition 8, it will reveal all that is wrong about the Zo. The bass is badly textured and has a rattle at the very edge that is clearly heard. This will not be a problem with lower ends cans or mid-fi cans which the Zo is really targeted at though so you are definitely limited with what cans you can and cannot use with the Zo. Lastly, because of the fact that the signal must always come from a headphone out, the internal amps of your source will have already affected the sound signature before it even passes through the Zo hence changing from one source to the other will create significant changes to what you hear.

So for synergy, I would say the Zo is good for what it is intended to do. If you own an iPod and use the Apple earbuds, the Zo will definitely make you smile. As long as you steer clear of high resolution players and top tier cans, the Zo can definitely add much more to your music especially for Rap, R&B, House, etc. But if you had the extra cash and prefer something much more civilized, wait for my review on the C&C XO2. For thrice the price, it will offer you added bass that is simply sublime and just to tease you, its power output on single ended is equal to the power output of the iBasso Toucan as balanced mode.





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