21 Jul 2015

Review: CTP Systems dBbox 2

Portable audio testing convenience


Some people get oddly enthused by test equipment – typically they’re the kind of people who rely on such equipment to make their working days easier.  dBbox 2 from CTP Systems is a test device and it’s clearly been designed with audio professionals in mind.

The dBbox 2 is a fairly compact device, but not so small that it’s hard to operate – around the same size as an early series Nintendo Gameboy.  Unlike the Gameboy though, it’s made of a combination of folded and milled metal.  I’m confident it could sustain a few drops onto concrete and still work.  An array of connectors populate the top, right, and bottom side panels.


I thought maybe CTP designed the dBbox 2 for left-handers, since really that’s the only way to hold it once the inputs are connected.  Upon further reflection though I decided it was probably not the case, and the design intent was instead to make it easy for the majority of people to plug and unplug connectors with their dominant hand.  Try operating an XLR with the hand you wouldn’t normally use – it’s oddly harder than you expect.

Unlike on my mobile phone, you don’t need hyper-mobile thumbs to operate the dBbox 2, since all the control are all nicely concentrated toward the centre of the unit.  It sounds like a really dumb thing to talk about, but when you use the device regularly ergonomics like this actually matter quite a bit.

Let’s talk IO.  The dBbox 2 is not only a tester but also a signal generator.  It has dual XLR inputs and outputs for analogue audio, the Left of which can double up for AES/EBU duties.  There’s also a pair of BNC connectors to handle AES or SPDIF signals, dual MIDI ports, dual headphone connectors (3.5 and 6.5mm), and a mini USB port for an external power supply.



At this point, it’s probably worth talking about the unit actually does.  First up, mono or stereo mic or line analogue or digital signal monitoring with both VU and PPM metering as well as headphone output.  Volume is adjustable with dedicated buttons, there’s a phase meter, and the digital scale can be switched between -20dBFS and -18dBFS.  AES signals can be analysed to show sample rate, status and data errors.  MIDI signals can be analysed in a similar way, with channel, note and velocity information available.

The dBbox 2 can output a selection of signals, including white and pink noise, as well as the signal from the internal or an external mic.  +48V is supported for external mic connection, and the mic pre-amp output can also be routed to the AES outputs.  In 4 wire mode, the internal speaker and mic allow the dBbox 2 to act as a 4 wire transceiver – you’ll know the true value of this if you work on outside broadcast gigs as a comms tech.


There are a few other aspects to note – gain for the mic pre-amp is adjustable, there’s an internal 3 band EQ, 2 wire listen mode, and of course a cable test function.  The way in which the menu is structured makes it quick to get to each of these functions, and the backlit LCD screen lets you see what you’re doing when you get there.  The dBbox 2 runs off a single 9V battery, and intelligent power management shuts down the parts of the unit not required for the selected function in order to prolong battery life.

There’s not too much more to say really – the dBbox 2 does the things it’s meant to do.  It isn’t cheap but it is a very versatile tool, and I think the savings are to be found in the long-term efficiency and time savings it affords.

  • Brand:  CTP Systems
  • Model:  dBbox 2
  • RRP: $795.00 inc GST
  • Product Info:
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