SDRplay vs RTL-SDR Blog V4: RSP1A and RSPdx Compared
SDRplay builds some of the most capable receivers in the sub-$300 SDR market. Their RSP1A and RSPdx use 14-bit ADCs, support up to 10 MHz of bandwidth, and cover 1 kHz to 2 GHz. Is the jump from an RTL-SDR V4 worth it? For some buyers, yes. For most, no.
The Short Answer
Buy the RTL-SDR Blog V4 first. If you hit its limits — HF dynamic range, wideband spectrum analysis, or you want three antenna ports — then step up to an SDRplay. The RSP1A is the sensible mid-range choice. The RSPdx is for HF serious enough to justify $200+. The V4 still handles 95% of scanner, ADS-B, weather satellite, and trunked radio work at a quarter of the price.
Spec Comparison
| Spec | RTL-SDR V4 | SDRplay RSP1A | SDRplay RSPdx |
|---|---|---|---|
| Frequency range | 500 kHz – 1.766 GHz | 1 kHz – 2 GHz | 1 kHz – 2 GHz |
| ADC | 8-bit | 14-bit | 14-bit |
| Max bandwidth | 2.4 MHz | 10 MHz | 10 MHz |
| Antenna ports | 1 (SMA) | 1 (SMA) | 3 (2 SMA, 1 BNC HF) |
| Pre-selection filters | Improved in V4 | Yes (8 filters) | Yes (with HDR mode below 2 MHz) |
| Bias tee | Yes | Yes | Yes |
| Native HF | Yes (triplexer) | Yes | Yes (HDR-mode) |
| Primary software | SDR#, SDR++, SDRTrunk | SDRuno, SDR++, SDRangel | SDRuno, SDR++ |
| Typical price | $35-45 | $109–$129 | $219–$249 |
SDRplay RSP1A: The Sensible Upgrade
The RSP1A is SDRplay's entry-level receiver and the one most often compared to the RTL-SDR V4. For about $100 you get a 14-bit ADC, 10 MHz of selectable bandwidth, eight pre-selection filters, and coverage from 1 kHz to 2 GHz. The front-end is more resistant to strong-signal overload than an RTL-SDR, which matters if you live near an FM broadcast tower or pager system.
What you gain over the V4: cleaner HF, wider bandwidth for spectrum work, better dynamic range for weak-signal decoding, and the ability to run a single-dongle SDRTrunk setup on P25 Phase II systems.
What you give up: cost (about 3× the V4), a slightly more complex driver install, and lock-in to SDRuno if you want SDRplay's officially supported software (though SDR++ and others work fine).
SDRplay RSPdx: Premium HF
The RSPdx is aimed at HF listeners who want a single receiver that also covers VHF/UHF. Its party trick is HDR mode below 2 MHz: pre-selection filters snap in that give broadcast-band and medium-wave listeners a receiver that rivals dedicated HF radios costing thousands. It has three antenna inputs (useful if you keep a dedicated HF antenna separate from a VHF vertical) and handles strong-signal environments better than almost any sub-$300 SDR.
For scanner-style use, the RSPdx is overkill. For a ham radio operator who wants one receiver to cover everything from 160 meters to 70 centimeters, it's arguably the best value in the premium SDR category.
Alternative for HF-only use: the Airspy HF+ Discovery often edges out the RSPdx on pure HF weak-signal work. See Airspy vs RTL-SDR for that comparison.
Software Reality
SDRplay's own SDRuno is the most feature-rich software for their receivers and is Windows-only. It has a learning curve that's steeper than SDR#. Good news: you don't have to use it.
- SDR++ runs SDRplay devices on Windows, Linux, and macOS
- SDRangel has native SDRplay support
- GQRX works with SDRplay on Linux/macOS
- SDRTrunk supports SDRplay via the SDRplay API
- CubicSDR works with SDRplay
- DSD+ Fastlane works with SDRplay via audio piping or RSPtcp
The driver install is a little more involved than plugging in an RTL-SDR — you run the SDRplay API installer, then configure each SDR program to find it. Our SDR software comparison covers the full ecosystem.
Best Overall / Best Value / Best Premium
Best Value
RTL-SDR Blog V4
$35-45
The V4 handles most scanner, ADS-B, weather sat, and P25 use cases. Buy two if you need trunking.
Check Price →Best Mid-Range
SDRplay RSP1A
$109–$129
14-bit ADC, 10 MHz bandwidth, continuous 1 kHz – 2 GHz coverage. Best single-dongle P25 setup.
Check Price →Best Premium HF
SDRplay RSPdx
$219–$249
HDR mode for pristine HF, three antenna ports, the most capable SDR under $300.
Check Price →Which One Should You Buy?
I'm new to SDR
Start with an RTL-SDR V4 and the dipole kit. You'll learn faster and the failure cost is low.
I mostly want P25 trunking
Two RTL-SDR V4s or one SDRplay RSP1A. See our SDRTrunk guide.
I want serious HF
SDRplay RSPdx or Airspy HF+ Discovery. RTL-SDR is sufficient for casual shortwave.
I want wide spectrum analysis
SDRplay RSP1A or RSPdx. 10 MHz bandwidth beats RTL-SDR's 2.4 MHz.
Frequently Asked Questions
Is SDRplay better than RTL-SDR?
For HF and wideband work, yes — SDRplay's 14-bit ADC and wider bandwidth outperform the RTL-SDR V4's 8-bit ADC. For scanner-style monitoring, ADS-B, and casual use, the V4 is sufficient at a fraction of the cost. SDRplay also requires their proprietary SDRuno software or compatible plugins, while RTL-SDR works with nearly every SDR program out of the box.
What frequency range does the SDRplay RSP1A cover?
The RSP1A covers 1 kHz to 2 GHz continuously with no gaps. That's a wider range than RTL-SDR V4 (500 kHz to 1.766 GHz) and it does HF natively without a triplexer. The RSPdx extends performance lower (down to 1 kHz with pre-selection filters) and is specifically tuned for HF work.
Can SDRplay decode P25 trunked radio?
Yes, using SDRTrunk or DSD+. SDRplay's wider 10 MHz bandwidth means a single RSP1A can often cover an entire P25 trunked system in one tuner, while RTL-SDR users typically need two dongles. Note that SDRTrunk with SDRplay requires the SDRplay API to be installed and may need the RSPtcp bridge depending on your OS.
What's the difference between SDRplay and RTL-SDR software?
RTL-SDR uses open rtl-sdr drivers and works with SDR#, SDR++, GQRX, SDRangel, SDRTrunk, and DSD+ natively. SDRplay uses their own API and ships with SDRuno, but also supports SDR++, SDRangel, GQRX, and SDRTrunk through plugins or bridges. Setup is a bit more involved but not difficult.
Is the SDRplay RSPdx worth $200+?
Only for serious HF listeners. The RSPdx has three antenna ports, pre-selection filters that protect the front-end from broadcast overload, and genuinely excellent HF performance. If you're comparing it to an Airspy HF+ Discovery, it's close on HF and wins on frequency coverage (2 MHz vs 2 GHz range). If you mostly monitor VHF/UHF, the premium isn't worth it — grab the RTL-SDR V4.
Can I run SDRplay on Linux and macOS?
Yes. SDRplay provides drivers for Linux (x86, ARM, Raspberry Pi) and macOS. SDRuno is Windows-only, but SDRangel, GQRX, SDR++, and CubicSDR all run SDRplay devices on Linux/macOS via the SDRplay API.
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