Gear Box

NTi Audio XL2

by Jimmy Den-OudenW

ay back when it had only just beenreleased, we reviewed the XL2 from NTi.
Since then a few software revisions have
happened, and a range of companion
products have been released. It seems anappropriate time to take a look at what the current
software and hardware options offer, since it’s a lot
more than it used to be.
Overview
XL2 is an audio and acoustic analysis tool that canbe used with a variety of sources and inputs. It does
many things, and there are several accessoriesavailable which make it even more powerful.

40 | CX104 JUNE 2015 | www.juliusmedia.com | 25th Anniversary YearAs an acoustic analyser, the XL2 can provide FFTanalysis, make RT60 measurements, determine Polarity
and Delay, and optionally provide 1/12 octave analysis
as well as pass/fail measurements. Another option
is STIPA, which allows the device to make speech
intelligibility measurements in PA systems, and thisfunction includes automated averaging and ambient
noise correction. As an audio analyser, it can showlevel RMS, THD+N, Frequency, Scope, 1/3 or 1/1 octave
spectrum analysis, and FFT analysis.
Really though, the shining beacon of functionality
on the XL2 is its sound level metering functionality. Itsupports sound level metering to a number of different

international standards, it can display and log various
levels with several weighting options, logs data as well
as audio to an internal SD card, and can even be TypeApproved thus providing evidence admissible in court.

from your local distributor, which in turn makes available
an activation key for you to download. Plug the XL2 invia USB, copy the key across, and restart the device toaccess your new function.

Using the XL2 can be very simple or extremelycomplicated. The device allows for multipleFRQÀJXUDWLRQVWREHEXLOWDQGVWRUHG)XQFWLRQDOLW\RI
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be locked out. You can then set the XL2 to ask whichFRQÀJXUDWLRQLVWREHXVHGZKHQLWVWDUWVXSWKXVRIIHULQJ
a simple method of operation for less technical users. In
full mode, all options are available.

STIPA is a measurement system designed to determine
speech intelligibility in PA systems. This might notsound like a really exciting function, but for anyone
installing EWIS systems it’s more relevant. Such systems
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signed off, and being able to provide nice accurate
measurement data makes this a lot easier (which makes
getting paid for your installation a lot easier!). STIPAPHDVXUHPHQWVZLWKWKH;/DUHGRQHXVLQJDVSHFLÀF
test signal, which you can download from their websiteand burn to a CD.

Navigation of the device is done with a rotary encoder,plus menu, page and escape buttons. Additional
buttons allow start/pause and stop of logging, as wellas muting of the internal speaker, adjustment anddisplay of SPL limit parameters, and power / backlight.
It’s very simple to get around, and if you have agood understanding of the various parameters of themeasurement functions, you’ll have a good time with it.
If you don’t understand the parameters, you’ll dowell to get onto the NTi audio website and check out
their excellent range of webinars discussing all things
measurement.

Accessories
First up, licensing. Various options are available for theXL2 – Type Approval, Cinema Meter, Extended Acoustics
Pack, and STIPA among them. You don’t need to buy
a new device, or even send yours away to get thesefunctions added – you just need to buy the function

The MR-PRO is the pocket sized signal generator that isdesigned to accompany the XL2. It looks like a smaller
version of the same thing, and navigates in the sameway. MR-PRO has XLR output and input sockets, andcan act as a cable tester too. It can produce a varietyof sine and square wave signals at selectable frequency
and output levels. In addition to this it offers polarityand delay “chirp” signals, and even has an internal WAV
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can load your own content too.
NTi Audio offers a number of different reference
mic choices depending on your requirements. The
main choices are between type or class approval
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a ruggedised mic for outdoor measurement. A level
calibrator is available which allows the user to make sure

Gear Boxaccurate measurements are made regardless ofenvironmental and atmospheric conditions.
The Digital IO box and companion stack light
product are used for quick and obvious visualindication of SPL monitoring levels. The XL2 hasa tri-colour LED on its front panel which responds
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DIO box and stack light can be programmed in thesame way but with unique level parameters. TheXL2 can respond to any measurement parameter– not just slow or fast A weighted SPL. This means it
can be used for applications where measurements
like time weighted averages are important – it caneven handle gliding window measurements.

42 | CX104 JUNE 2015 | www.juliusmedia.com | 25th Anniversary YearIf you need to tie SPL limiting into the PA system tosatisfy council requirements or similar, the Digital IO
PCB gives you programmable outputs, which you canin turn interface to your system processing to engage
attenuators or mute outputs.

SoftwareSince muting the whole system isn’t always (or ever)an ideal solution, NTi has developed a level predictor
software program. It runs on an external PC andconnects to the XL2 via USB, and gives the user a clear
indication of level history as well as prediction of futurelevels. When SPL trends toward exceeding the preset
limits, the software shows the words “REDUCE LEVEL” in
big red text on the screen. Everyone can understandthat!

The XL2 Projector
application showsa large versionof the XL2 screen
and allows you tooperate the device
in realtime on anattached PC. Itworks very well andis largely plug andplay. When an SPL
limit is exceeded,
the on screen“backlight” ofthe app changes
colour to yellow or
red depending onthe level.
The XL2 supports very advanced data and also
DXGLRORJJLQJ<RXFDQGHÀQHWKHLQWHUYDODWZKLFKdata is captured (at up to 100mS frequency), as wellas which values are recorded. Spectra can also belogged, and you can even record audio on the SD
card automatically. All this data can then be copied
into a computer and analysed using the Data Explorersoftware.
Data Explorer gives a visual representation of recorded
sound levels over the duration of an event. Spurious
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the associated audio called up and played easily.
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excluded from logged values, better allowing event
organisers to accurately show compliance to relevant
authorities.

Conclusion
We liked the XL2 last time we looked at it, but welike it even more now. Whether measuring a room
acoustic prior to specifying a sound system or SPL
logging at a festival to prove noise complianceto a local council, accurate data is often worth
a lot more than the cost of acquiring it. The true
value in this product is to be found not by looking
at the shiny blue and silver hardware, but at theinformation that comes out of it.

Watch on CX-TV.com

Brand: NTi Audio
Model: XL2, IO box, stack light
RRP: XL2 with Class 2 mic $2720.00 inc GST.
DIO Box - $999.00 inc GST.
Stacklight - $480.00 inc GST.
Product Info:
www.nti-audio.com
Distributor:
www.ambertech.com.au