- Written by Jim Clements
- Published on 16 April 2009
Design and Setup
The Z-Base 550 is a pedestal base that is designed to be placed on a shelf and then a flat screen TV can be placed on top. It's about 1-1/2 times the size of a typical turntable. It has five 2" main drivers and a single 5-1/4" subwoofer. These drivers are driven by a "60 watt" bi amp. I put the power rating in quotes because the manufacturer does not reveal the particulars behind this power spec. I must say, however, that the Z-Base 550 played to a decent sound pressure level in my master bedroom. It has a vinyl veneer top and piano gloss end caps. I placed it on my TV stand, supporting my 42" Panasonic plasma TV. It coincidentally raised the TV to the correct height as my stand is wee bit too low.
Three of the main drivers are clustered in the middle of the front baffle. The other two are placed as close to each outer cabinet edge as possible. These drivers are protected by a metal cage type of grille that is for all intents and purposes non-removable. The sub is down-firing and is also protected by a metal cage. A port exits the back of the cabinet. The manufacturer does not specify the type of loading for the sub.
Although I don't have firsthand experience with the other ZVOX products, I think I can safely say that they all have an endearing quirkiness. In the case of the Z-Base 550, there are some obvious and some not so obvious design elements that support this statement. One example is the front LED. It responds to IR commands, communicating with the user by blinking as the commands are received. That's pretty typical. The quirky part is that it glows green when the unit is off and turns blue when the unit is on. That's not exactly the most intuitive arrangement. To be fair, I have a standalone stereo amp with an LED that is red when it is on and glows green when it is off. So no harm, no foul I suppose.
There is another idiosyncrasy with the audio inputs. There are two stereo analog inputs on the back of the Z-Base 550. These are "mixing" inputs. The first input is always active. The second input goes active only when the first one is connected to a source component. As I said, they are "mixing" inputs. So the Z-Base 550 mixes the two signals together when they are both receiving a signal.
My first thought was that nobody in their right mind would want to mix two signals. (OK, DJ's but that's not who the Z-Base 550 would be for.) But later I decided that maybe if I had this unit on my desktop, then I may want to have the Z-Base 550 playing music and then mix in audio signals from my computer. That's not a concern for me because I personally don't want one of these on my desk. I probably wouldn't get a lot of work done if I did because I'd be listening to music all the time!
There is a master power toggle on the back of the unit and the Z-Base 550 turns on automatically when it senses a signal. The Z-Base 550 uses what ZVOX refers to as "PhaseCue" to simulate a surround effect from the single box solution. It simply takes the out of phase signal from one channel and adds it to the signal of the opposite driver and vice versa. This is the same way Dolby Surround used to synthesize the ambiance signal that went to the rear speakers: take the out-of-phase signals (add delay and contouring) and then feed the rear speakers with this new signal.
With the Z-Base 550, you don't have rear speakers, but adding the signal to the opposite speaker fools your mind into perceiving that the sound is coming from the sides/back. The remote has a phase cue adjustment that controls the proportion of the out of phase signals versus the direct signal which expands and contracts the perceived sound field. If you dial in too much PhaseCue, then the sound can lose specificity, become "mushy" and even sound like reverb. If you dial in the right amount, then the sound opens up nicely while retaining solid voice intelligibility.
I was concerned that the PhaseCue control would turn out to be too fiddly, but I generally found myself using one setting for movies and live music and another setting for studio albums. I wanted more phase cue for the first scenario and less for the second. Remember the flashing LED? Each control (PhaseCue, sub and treble) has 9 possible settings. So I found myself backing each control all the way off and then counted button pushes to get it to "3" or "5" or whatever. Be sure to watch the LED as the remote signals didn't always register with the unit. The steps between each setting are a little coarse, but the overall range of control is subtle enough that you can't mess up the sound too much.
One last quirky quality of the Z-Base 550 is the "tube" that connects the outer drivers. The backs of the outer drivers are connected by a tube which is built into the cabinet. ZVOX calls this their "Infinite Compliance" concept. It effectively augments the PhaseCue system by using the back pressure from each driver to mechanically couple the out of phase signals with the opposite channel. According to the designer, this makes the system sound bigger than its actual size. I can confirm that the Z-Base 550 system sounds much bigger than you would expect based on its looks.