Shure SLX-D Wireless Review

Headliner puts Shure’s new SLX-D wireless system to the test. Unlike its predecessor, it comes in two flavours: dual and single receiver; this makes it easier to build and rack up systems with larger channel counts with fewer ariels, twice as many channels per distribution unit, and smaller switches. Another eyebrow raiser is the price; these new units, while a little more than the range they now replace, are actually about the same price as the SLX range was when it was launched. So let’s dive in...

First off, let’s break down this impressive system: I’ve got two SLX-D2 handheld mics (one with an SM58 capsule, one with a Beta 58 capsule), an SLX-D1 body pack, and two single SLX-D4 receiver units. After unpacking and attaching the aerials and power supplies, I linked them together with short Ethernet cables to the back of my Cisco switch which forms part of my home and studio network.

I could have just connected them to each other via the single Ethernet port on each unit, but I was interested to see if they would find each other through a switch without having to configure any IP addresses. The switch is a level three with a couple of virtual networks, but I have left a section which allows automatic connection between devices in similar ranges and the same subnet.

Bearing in mind you can have up to 32 channels of SLX-D in one local system, a network switch is a must if you’re going to be setting these up in different locations. After powering up, both units displayed the same thing: G:1 CH:1, so I picked the first unit and pressed the button that said ‘push’ on it.

I was prompted to turn off any transmitters and set the unit up, including a full scan, just by holding down said button when prompted. Shortly after, both units flickered for a couple of seconds and new frequencies were allocated to each receiver.

The first receiver was then prompting me to sync a transmitter to the first channel, so I picked up a handheld, turned it on, and held the IR window up to the receiver. Almost immediately the message ‘sync complete’ flashed up on the screen. Well that was easy! After switching on the second handheld and moving its IR window in front of the next receiver, I pressed the sync button on the second receiver – and job done.

The whole process took less than three minutes, which is amazing, actually...I have more complicated DI boxes!

Shure’s new SLX-D range sounds like an updated replacement for the SLX range which has been around now for 15 years - probably the most popular budget analogue radio mic ever - and with the move from analogue to digital, that’s exactly what this is. However, holding the handheld microphone tells you this is not just a simple upgrade.

For starters, this unit looks and feels like it could belong to one of Shure’s top end ranges: the body is of a solid metal construction while the old plastic battery cover is now a machined piece of aluminium; the recessed controls are not likely to be accidentally turned off during the performance; and I had to use my fingernail ends to get into the menus, which is also good, as it affords a little ‘over-exuberant musician’ proofing.

One of the things I’ve always liked about Shure’s wireless systems is the interchangeable mic capsules, meaning you can pretty much put anyone’s favourite mic capsule on before you go out to a job. You’re also not restricted to the capsule options that this system ships with.

I have a number of different high-end condenser mic capsules from DPA and Audio-Technica as well as Shure’s excellent KSM9, and all worked superbly on the SLX-D. I know you’re gonna say that all of the big radio mic manufacturers do this – true, but it was Shure who did it first. Another feature that improves on the SLX-D’s predecessor is channel count.

Shure claims up to 32 simultaneous channels can be used within the available UHF bandwidth, and that is also the reason this system has stayed with UHF as opposed to utilising the licence- free WiFi frequencies like so many other manufacturers’ budget systems which struggle to achieve drop-out free operation with channel counts anywhere near this capacity.

At this point you should know that the SLX-D is not configurable from within Shure’s ‘wireless workbench software’, but I’d be shocked if potential users of the SLX-D could actually find a benefit in using [Shure’s] Wireless Workbench over the unit’s lightning fast onboard setup procedure. Really impressive.

This system is, of course, digital - and with all digital systems there is a certain amount of latency introduced by the ADA processing of the audio from the capsule through the transmitter and from the receiver back to the analogue outputs. Here, Shure claims a figure of 3.2ms, and while that represents listening to the resulting audio from a speaker less than 1.2m away from you, you also have to consider the additional latency of any other equipment in the signal path, such as a digital desk, for example.

In this case, I was using an Allen & Heath SQ, which only has 0.7ms latency. I popped a set of my JH Audio JH16 IEMs in, and had a listen to my voice. Unpleasant though my voice is, it still wasn’t audibly possible to detect the resulting total sub 4ms latency within the system.

The SLX-D1 is an impressive little pack, and nice and light. I managed to double its weight just by putting in the batteries! Immediately, I could see a few guitarists who’d appreciate the benefits of a light oval-shaped plastic pack; for starters, this little device can clip onto your guitar strap and you wouldn’t even notice it was there.

Now some might say that a plastic pack would be history the first time you drop it, and that it would’ve been far better to have made the pack out of metal and the mic casing out of plastic, but the interesting thing is, because it’s so light there is far less chance of it jumping off your belt or strap; and when I was clumsy enough to drop it, it simply bounced on my tiled floor, no damage whatsoever.

The other ergonomic feature which I think is a lovely touch is the elliptical shape. This is going to sit comfortably concealed behind clothing and in pockets or pouches without displaying any sharp angles and lines.

Artists will forget they’re wearing this little pack, which is fantastic. Connection is via Shure’s standard TA4F 4-pin mini XLR with the added protection of a screw thread locking ring, something which is a must for maintaining a good connection between devices in an environment which is inherently prone to mishap – this is also a welcome upgrade from the SLX range.