Both split tasks are actively working: TX is pruning RX-only circuitry; RX is pruning TX-only circuitry and replacing the XLR. I’ll give them one more wait window before reporting final status.
RF Module Selection and Architecture Notes — Munkrofon
Current Decision Status
Updated: 2026-07-26
The RF-module selection has been re-opened per user instruction: DA14AVDDECT and RTX1090 are not mandatory, and the design must be based only on modules with reviewable public documentation.
Engineering conclusion:
Best professional ultra-low-latency DECT audio candidate:RTX A/S RTX1090 / RTX1090R1 MLM DECT Module with RTX Sheerlink / Sheersound.
Best public-datasheet integration candidate:Renesas DA14AVDDECT-SF01 Audio Voice Data Module.
Hard blocker for PCB layout: I did not find a fully public, official reference-design package — schematic, PCB layout/Gerbers, stackup, BOM, and antenna/reference layout files — for either RTX1090/RTX1090R1 Sheerlink or DA14AVDDECTDEVKT. Therefore I should not claim a production-ready schematic/PCB layout based on the selected RF module yet.
Recommendation
For the stated product goal — professional, ultra-low-latency, non-Bluetooth wireless microphone audio — the best 2026 RF/audio-module direction is:
RTX A/S RTX1090 or RTX1090R1 MLM DECT Module using RTX Sheerlink / Sheersound, with external low-latency audio codec/front-end and external professional balanced line-output circuitry.
This is the strongest fit because RTX explicitly positions the RTX1090/Sheerlink platform for wireless microphones, instruments, live-event/studio audio, and stage equipment, and RTX/RMED public materials cite analog-to-analog latency in the roughly 2–7 ms class depending on configuration. That is substantially stronger pro-audio latency evidence than I found for DA14AVDDECT.
However, this recommendation is conditional: the full RTX integration package appears vendor-gated rather than completely public. If we strictly require public, reviewable reference-layout files before continuing, the project is blocked until RTX/RMED provides them or until we accept a lower-confidence public-datasheet prototype around DA14AVDDECT.
Best pro-audio positioning; compact 15.4 × 21.6 mm; DECT 1.9 GHz; public materials cite <2 ms, ~2.5 ms, under 3 ms, or <7 ms depending configuration; designed for high-end microphones/stage equipment
Full schematic/layout/reference-design package not publicly found; likely requires RTX/RMED customer engagement; external codec/audio hardware required
Best technical/pro-audio candidate, but documentation-gated
DA14AVDDECT-SF01
Renesas Electronics DA14AVDDECT-SF01 Audio Voice Data Module
Official Renesas product page; official Renesas DA14AVDDECT-SF01 datasheet; DA14AVDDECTDEVKT quick-start guide
Active module; official public datasheet; integrated DECT radio, DA14495, DA7218 codec, flash, battery-management features, integrated printed antenna; public pinout, BGA geometry, antenna keepout, layout guidelines
No public numeric end-to-end latency found; current public datasheet notes current software implementations support mono audio; full EVK schematic/Gerber/layout files not found publicly; 17 × 26.65 mm module complicates 25 mm-wide PCB
Best public-datasheet integration fallback; not proven best latency
SC14WAMDECT
Renesas/Dialog SC14WAMDECT SF Wireless Audio Module
Official Renesas product page and datasheet
Public datasheet includes microphone/tour-guide use, latency table, RF/audio/PCB guidelines; known 14.2 ms PA-mode latency
Not Recommended for New Designs; older 12 kHz-class audio; 14.2–18.3 ms is not ultra-low-latency by current pro-audio expectations
Reject for new 2026 professional design
DECT NR+ platforms
Nordic/Renesas/industry DECT NR+ silicon/platforms, not a turnkey wireless-mic module
No obvious public, production-ready wireless microphone module/reference layout found
Monitor; not selected now
RTX1290 / 2.4 GHz proprietary
RTX1290 with Sheerlink in 2.4 GHz variant
RTX/RMED public material
Similar low-latency Sheerlink audio path; footprint-compatible concept
Not DECT; 2.4 GHz band is crowded and violates the preferred DECT requirement
Backup only if DECT is relaxed
Why RTX1090 / RTX1090R1 Wins Technically
Public RTX/RMED materials connect the RTX1090/Sheerlink platform directly to professional wireless-microphone and stage-equipment use. Reported public latency claims vary by source/configuration, but are consistently in the low single-digit to sub-7 ms class:
RTX Sheerlink public page: extreme low latency less than 2 ms, depending on configuration.
RMED Sheerlink wireless microphone reference-design page: under 3 ms analog-in to analog-out, 48 kHz / 24-bit audio, 10 Hz–22 kHz frequency response.
RTX RTX1090 product-sheet summaries: Sheersound codec latency around 20 µs, complete-system latency less than 7 ms.
That makes RTX1090/Sheerlink the strongest fit for the phrase professional ultra-low-latency DECT audio link.
Why DA14AVDDECT Is Not Automatically Best
DA14AVDDECT-SF01 is much easier to document from public official Renesas material than RTX1090. It has a public datasheet with pinout, BGA dimensions, layout guidelines, antenna keepout, analog microphone pins, headphone outputs, PCM/USB, battery/charger pins, and an integrated DA7218 codec.
But for this project, the decisive missing proof is latency. I found Renesas marketing language for low-latency microphone applications, but I did not find a public numeric end-to-end audio-latency guarantee for the current audio stack. The datasheet also indicates that current software implementations support mono audio despite stereo-capable hardware.
Therefore DA14AVDDECT is a reasonable prototype fallback only if we accept that latency must be validated experimentally or confirmed by Renesas before freezing the product.
Documentation Required Before Continuing With RTX1090 / RTX1090R1
If we choose the best technical candidate, request this exact package from RTX A/S or RMED before schematic/PCB layout:
Current official datasheet for RTX1090 or RTX1090R1, not only mirrored copies.
Exact ordering variant and lifecycle/commercial availability confirmation.
Recommended land pattern and CAD footprint for the 88-pad LGA module.
Hardware integration guide including all required supplies, boot/config pins, programming/debug, and production-test signals.
Sheerlink / Sheersound reference schematic for transmitter and receiver.
EVK carrier-board schematic, PCB layout/Gerbers, stackup, and BOM.
Antenna/reference RF layout package, including integrated/inverted-F or external antenna options, matching network, diversity requirements, keepouts, stackup, and modular-approval conditions.
Audio interface guide: I2S/PCM/TDM/PDM support, codec recommendations, master/slave clocking, sample rate, bit depth, MCLK/BCLK/LRCLK requirements, jitter tolerance, and muting/AGC/limiter behavior.
Latency document: one-way and analog-to-analog latency, typical/worst-case values, test configuration, codec, sample rate, buffering, RF mode, channel count, and interference behavior.
Firmware/SDK/license package for Sheerlink/Sheersound, including production programming and pairing/provisioning.
Regulatory package: FCC/IC/CE/UKCA/MIC modular-approval status, labels, test modes, and integration conditions.
Documentation Required Before Continuing With DA14AVDDECT-SF01
If we choose the more public-documented fallback, request from Renesas:
Current official DA14AVDDECT-SF01 datasheet and lifecycle/distributor status.
DA14AVDDECTDEVKT schematic, PCB layout/Gerbers, stackup, and BOM; the public page appears to expose the quick-start guide but not full design files.
Written end-to-end wireless microphone latency spec for the relevant audio stack and configuration.
Audio-stack documentation for microphone transmitter and receiver operation, including mono/stereo limitations.
Confirmation that the integrated charger/battery path should be used, or guidance for safely using an external charger/power path.
Antenna integration and modular-approval guide, including exact keepout and whether an external diversity antenna is recommended.
I should not proceed to a production RF schematic/PCB layout until one of these is true:
RTX/RMED provides the official RTX1090/RTX1090R1 + Sheerlink design package listed above; or
Renesas provides the DA14AVDDECTDEVKT schematic/layout files plus written latency confirmation; or
The project intentionally relaxes the “official reference layout” requirement and proceeds with a clearly marked exploratory prototype using only public datasheet/layout-guideline data.
Until then, it is safe to continue architecture, power budgeting, audio front-end selection, and connector/support-circuit planning, but not safe to freeze RF-module footprint, antenna layout, or production PCB routing.
Current Decision Status
Recommendation
Candidate Comparison
Why RTX1090 / RTX1090R1 Wins Technically
Why DA14AVDDECT Is Not Automatically Best
Documentation Required Before Continuing With RTX1090 / RTX1090R1
Documentation Required Before Continuing With DA14AVDDECT-SF01