In this guide: Short answer · The two ranges · Audio and latency · Spectrum and licensing · Channels in Ch38 · Setup and control · Racking · Batteries · Capsules · Encryption · Head to head · Which to buy · Picks · FAQ

Once a buyer decides their next wireless microphone system will be digital, the shortlist usually shrinks to two: Sennheiser’s Evolution Wireless Digital (EW-D) and Shure’s SLX-D+. Same rung of the ladder, different design. EW-D is a single-channel-receiver platform built around an equidistant frequency grid and a phone app that does setup for you. SLX-D+ is a receiver family with single, dual and quad boxes, wired networking and encryption throughout.

The short answer

Buying one to four channels and want the fastest setup with the least RF knowledge in the room? EW-D is excellent, its Smart Assist app is the easiest deployment in this class, and its published latency is the lower of the two.

Building a rack that will grow past four channels, or needing dual and quad receivers, wired networking, Dante or encryption? SLX-D+ is the more scalable platform. Neither compromises on sound, and no audience will hear the difference.

The two ranges

EW-D is the entry point to Sennheiser’s digital line-up, taking the slot the analogue evolution wireless G4 100 series held. Above it sits EW-DX: up to 88 MHz of switching bandwidth against EW-D’s 56 MHz, AES-256 link encryption, a two-channel half-rack receiver (EW-DX EM 2), a Dante variant and a four-channel EM 4. It is the growth path rather than a change of brand, since the two share BA 70 batteries, chargers, the ASA splitter and antennas.

SLX-D+ launched at NAMM in January 2026 and replaced SLX-D, which Shure discontinued from 1 February 2026. It keeps the same 24-bit core and the SB903 battery, and adds a wider tuning range, lower latency, AES-256 encryption and more receiver options. Our Shure BLX vs SLX-D+ guide covers run-out SLX-D stock. Above it sit QLX-D, ULX-D and Axient Digital.

Audio path and latency

Sennheiser publishes a 20 Hz to 20 kHz (-3 dB) response for EW-D, THD of -60 dB or better at 1 kHz, and a system latency of 1.9 ms. The figure it makes most of, though, is the transmitter’s 134 dB audio input dynamic range: there is enough headroom that you never set a sensitivity trim. Plug the microphone in and the system handles the level, removing the commonest cause of bad radio mic sound in non-specialist hands.

Shure publishes 24-bit digital audio with greater than 118 dB dynamic range, a 20 Hz to 20 kHz response (microphone dependent) and 2.8 ms latency, trimmed from 3.2 ms on SLX-D. Both quote up to 100 m range in clear conditions.

UK spectrum and licensing: identical rules, different windows

This is the most misunderstood part of the comparison. The rules are identical for both: Ofcom regulates the frequency, not the brand. The UK variants are:

• Sennheiser EW-D, S1-7: 606.2 to 662 MHz, up to 56 MHz of switching bandwidth. Sennheiser sells twelve band variants and publishes no UK label, but S1-7 is the one whose grid starts inside Channel 38.
• Shure SLX-D+, K55: 606 to 694 MHz, an 88 MHz tuning window.

Both start at 606 MHz, so both include Channel 38: TV channel 38, 606 to 614 MHz, with the Ofcom UK Shared licence covering 606.5 to 613.5 MHz inside it. Both stop below the cleared 700 MHz range, so neither holds spectrum handed to the mobile networks.

Here is the part that catches people out: only Channel 38 is covered by the shared licence. Everything above 614 MHz in either band, whether EW-D’s reach to 662 MHz or SLX-D+’s to 694 MHz, is interleaved TV spectrum needing a coordinated licence for a specific site and dates. SLX-D+’s wider window helps only if you hold coordination. On the shared licence alone, both have exactly the same 8 MHz of usable spectrum.

The 1.8 GHz option on EW-D

EW-D has one trick SLX-D+ does not offer here: a Y1-3 variant covering 1785.2 to 1799.8 MHz, inside the 1785 to 1805 MHz range carried by the same shared licence as Channel 38 and not available in Northern Ireland. Nowhere near congested UHF, it is a legitimate escape route for a venue whose Channel 38 is full or shared with a neighbour, at the cost of shorter range and much greater sensitivity to obstruction. Sennheiser publishes 12 mW ERP for Y1-3 against 10 mW ERP on UHF; neither is switchable.

Channel density in Channel 38: the number that actually matters

Shure quotes up to 85 simultaneous systems on its widest SLX-D+ bands and up to 14 in an 8 MHz TV band. Sennheiser quotes up to 90 channels across EW-D’s 56 MHz range at 200 kHz per channel, but publishes no per-TV-channel figure and repeats that claim on all twelve band variants, so read it as a range-wide maximum.

Neither figure is reachable in UK Channel 38, because it is 8 MHz wide and the ceiling is not the radio. Ofcom publishes a ten-channel frequency plan for the Channel 38 shared licence, and roughly ten systems is what to plan for whatever either spec sheet says. Both comfortably exceed that, so on the shared licence channel density is a draw. Above 614 MHz it reappears: SLX-D+’s 88 MHz window and cascading quad receivers are built for dense coordinated use.

One EW-D claim is engineering rather than marketing. Most systems must place frequencies carefully so intermodulation products do not land on other channels, which is why planning software exists and usable frequencies are unevenly spaced. Sennheiser states EW-D eliminates intermodulation, letting channels sit on an equidistant grid 600 kHz apart: the app just hands out the next slot.

Setup and app control

EW-D’s headline feature is the Smart Assist app for iOS and Android, which talks to receivers over Bluetooth Low Energy rather than a network. Open it, it finds the receivers, auto-scans the spectrum, assigns clean frequencies on the equidistant grid and syncs them to the transmitters. For a setup done by a volunteer, a teacher or a duty technician that is transformative: no cabling, no switch, no IP addressing, no laptop. The limits matter too. Bluetooth Low Energy is short range, one phone pairs to a receiver at a time, and the app handles up to sixteen channels. It is for standing at the rack, not watching RF from the mix position.

SLX-D+ comes at it from the professional end. Every receiver has a Guided Frequency Setup routine for group scan, channel assignment and infrared sync, so a single system sets itself up from the front panel with no app. Beyond that, receivers link over Ethernet so one group scan coordinates a whole rack, monitored from Wireless Workbench or the WWB Mobile app, with ShowLink Ease remote management, audio summing and digital feedback reduction alongside. If you want a rack you can watch all show from front of house Shure gives you the tools; if you want four channels working in ninety seconds with a phone, EW-D wins.

Racking, receivers and antennas

Both use metal receivers with two detachable rear-panel BNC antenna inputs and include rack hardware. The difference is the shape of the range. EW-D has one receiver: the EW-D EM, a single-channel half-rack unit of 212 x 44 x 189 mm with switching diversity, a balanced XLR output at up to +18 dBu and a 6.3 mm jack at up to +12 dBu. The GA 3 rackmount set is included, so two sit side by side in 1U out of the carton. There is no dual or quad version.

SLX-D+ has four rack receivers. The SLXD4+ single and SLXD4D+ dual are both half-rack, so a dual puts two channels in half the width. The SLXD4Q+ puts four channels in a full 1U, the SLXD4QDAN+ adds Dante to the same quad chassis, and the quads cascade antennas so up to three share one setup. There is also a battery-powered SLXD5+ portable receiver. Eight channels means eight EW-D boxes in four rack units against two SLXD4Q+ receivers in two, sharing one antenna feed and one Ethernet run: the clearest structural argument for SLX-D+ at higher channel counts, and irrelevant below four.

Both have proper antenna and distribution ranges. Sennheiser’s EW-D ASA splitter runs as two 1:4 feeds or one 1:8, covers 470 to 694 MHz in its Q-R-S variant, and has a useful trick: up to four EW-D EM receivers draw power through their BNC connections, needing no individual power supplies. On either platform, once you pass about four channels inside a metal case, get the antennas onto a paddle at the front of the stage.

Batteries and charging

Both take two AA cells as a fallback, and both offer a lithium-ion pack that drops into the same compartment, reports runtime to the receiver and charges in a dock. Sennheiser’s BA 70 is published at up to 12 hours against up to 8 hours on AAs, charges in the L 70 USB station, and is shared across EW-D, EW-DX and EW-DP. Shure’s SB903 carries over unchanged from SLX-D, with single-bay, dual-bay and eight-bay rack-drawer chargers, and publishes up to 8 hours either way. Sennheiser has the longer runtime, Shure the deeper charging range for fleets.

Capsules and microphone options

Both handhelds take interchangeable screw-on capsules, so a vocal system bought today can become a different microphone later without a new radio.

Shure’s advantage is familiarity. The SLXD2+ takes the standard Shure thread, and UK stock covers SM58, Beta 58A, Beta 87A, SM86 and the newer Nexadyne 8/C and 8/S heads, all microphones engineers know by ear. The SLXD1+ bodypack uses Shure’s TA4F connector and the whole Shure lavalier, headset and instrument catalogue.

Sennheiser’s answer is a shorter list with a higher ceiling. The EW-D SKM-S is published as compatible with fourteen heads, including the dynamic MMD 835-1, MMD 845-1, MMD 935-1 and MMD 945-1, the condenser MME 865-1 and MMK 965-1, and notably the Neumann KK 204 and KK 205. A Neumann condenser on an entry-tier digital handheld is a real argument for choral, classical crossover or high-end spoken word. The EW-D SK bodypack uses a 3.5 mm locking jack and comes in sets around the ME 2 omni lavalier, ME 4 cardioid lavalier, ME 3 headset and a Ci1 instrument cable.

Encryption: a clear win for SLX-D+

This is the one specification where the two are not comparable. SLX-D+ ships with AES-256 encryption on every component, one of the headline additions over the outgoing SLX-D. Sennheiser does not publish an encryption specification for EW-D: there is no mention of encryption or AES anywhere in the EW-D system specification, and its AES-256 link encryption documentation is scoped to EW-DX.

For most buyers this changes nothing: a church service or function band has nothing to protect from a scanner in the car park. For a council chamber, boardroom, legal or medical setting, or an announcement confidential before it is public, it is decisive. Do not assume digital transmission is inherently private: unencrypted digital modulation is harder to eavesdrop on casually than analogue FM, but it is not secure.

Head to head

Which should you buy?

Choose Sennheiser EW-D if

• Setup speed by non-specialists is the priority. Smart Assist needs no network, laptop or RF knowledge.
• You want gain setting to disappear, courtesy of the 134 dB input dynamic range.
• You already own Sennheiser evolution wireless kit. Batteries, chargers, the ASA splitter and antennas carry across.
• Your Channel 38 is congested. The Y1-3 1.8 GHz variant is a real option under the same licence, with no SLX-D+ equivalent.
• You want the longest rechargeable runtime, or a Neumann KK 204 or KK 205 capsule at this tier.

Choose Shure SLX-D+ if

• You need encryption. AES-256 on every component settles it for council chambers and boardrooms.
• You are building past four channels. Dual half-rack and quad 1U receivers with cascading save rack units, accessories and cabling, and the saving compounds.
• You want wired networking. Ethernet linking, rack-wide group scan and Wireless Workbench are control EW-D does not offer.
• You hold coordinated frequencies, or want Dante without stepping up a range.
• You already own SLX-D, or your engineers know Shure capsules by ear. SB903 batteries and chargers carry over, and SLX-D+ transmitters work with SLX-D receivers at SLX-D feature level.

The honest summary: EW-D is the better small system, SLX-D+ the better big one, and the crossover sits around four to six channels. It moves in Shure’s favour the moment encryption, Dante or coordinated spectrum enters the brief. Undecided at two channels? Buy whichever brand’s microphones you already own. Still weighing up system types? Start with our wireless microphone buying guide.

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Frequently asked questions

Is Sennheiser EW-D or Shure SLX-D+ better?

Neither across the board. EW-D wins on setup speed, published latency, rechargeable runtime and the 1.8 GHz band option. SLX-D+ wins on scalability and security: dual and quad receivers, Ethernet linking, Wireless Workbench, Dante and AES-256 throughout. Below four channels decide on setup and existing microphones; above four, SLX-D+ is the more rational rack.

How many channels can I run on either system in the UK?

Plan for around ten on either platform. Channel 38 is 8 MHz wide and Ofcom publishes a ten-channel plan for it, whatever the makers quote for a full band. Beyond ten you need coordinated frequencies in interleaved spectrum, where SLX-D+’s 88 MHz K55 window beats EW-D’s 56 MHz S1-7.

Which band variants should I order for UK use?

S1-7 (606.2 to 662 MHz) for EW-D, or Y1-3 for the 1.8 GHz option, and K55 (606 to 694 MHz) for SLX-D+. Both include Channel 38 and sit below the cleared 700 MHz band. EW-D is sold in twelve band variants worldwide, so check the code: anything else may be illegal to operate here.

Which has lower latency?

Sennheiser publishes 1.9 ms system latency for EW-D against Shure’s 2.8 ms, so EW-D is lower on paper. Sennheiser does not publish what its figure is measured across, and both are inaudible for vocals and speech. Treat it as a tiebreaker.

Does EW-D have encryption?

Sennheiser does not publish an encryption specification for EW-D. AES-256 link encryption appears in its digital range from EW-DX upwards, while SLX-D+ includes it on every component. If you need encryption, specify it explicitly rather than assuming digital means private.

Can I mix EW-D and SLX-D+ on the same stage?

Yes, provided frequencies are coordinated. They are separate radio systems: each receiver pairs only with its own transmitters, and no hardware is shared, capsules included. Many venues run both.