Wyn compares the SDRplay RSP and Airspy


After posting about the price reduction in the SDRplay RSP, Wyn Evans commented with his comparison of the SDRplay RSP and Airspy (another popular low-cost wideband SDR). Wyn writes:

I have both and Airspy and the SDRplay RSP. I like them both, but on balance I prefer the RSP. The pluses of the RSP over the Airspy for me are:

1. Sensitivity – At least with my Airspy, I find the sensitivity a bit disappointing. The RSP is on the other hand excellent. I read on another forum one user claiming that the difference between the two was as much as 3 dB. I can’t verify the number, but I would not be surprised if it were about right

2. HF support – Absolutely fantastic, no up-converter needed

3. ZIF or Low IF. In ZIF mode, with calibration, you can get image free reception

4. Programmable filters. You can change the selectivity from as low as 200 KHz to the full bandwidth of 8 MHz, This is a huge plus for DX-ing if you live in an area with very strong local stations

The plus for the Airspy is that there is does cover the gap between 380 MHz and 430 MHz, with the RSP doesn’t. For some people, this is a really big deal.

Both seem to have about the same dynamic range, which isn’t surprising as despite using different tuners, the ADCs seem to be virtually identical.

So in summary, I think both are pretty good products with pluses and minuses, but at this new price point, as long as you don’t need to use 380 – 430 MHz, there is really only one I would choose now.

Many thanks for your comparison, Wyn. As I stated before, my impression of the SDRplay RSP is quite good so far. I live in a very RF quiet area–I am curious if anyone has used the SDRplay in urban areas, near local broadcast stations and experienced any overloading or serious imaging.

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32 thoughts on “Wyn compares the SDRplay RSP and Airspy

  1. Steve Packard

    What is the software support like for both? I use a bunch of programs, but probably SDR# is my favorite for simple things.

  2. Pingback: SDRplay RSP | Shortwave Radio Index

  3. 13dka

    Patrick (I have to continue here because the comment function doesn’t let me reply directly anymore) –

    100W is even better of course but it’s the signal that counts. BTW, I can receive a 100W station too with the RSP, but one that’s 120km away! 🙂 (Ever so slightly elevated conditions needed tho)

    I hear you, I absolutely prefer SDR# too (so awesome to have the station labels on the spectrum) but the author’s choice of alienating RSP buyers among the SDR# fans by blocking the RSP from new SDR# versions (1400+) also kept me from even considering an Airspy. If you google carefully you should find a link to v1361, which still works great with the RSP1.

    On a sidenote – I’m currently listening to a 5kW station 426km away, with absolutely no tropo conditions, low noise with a grain of digital noise reduction, very little variation in the weak-ish signal while other stations from 250km away fade in and out. I’m doing this since I got the RSP 10 days ago because it’s so strange and while this is probably an incredibly odd propagation anomaly (I checked output power and frequency allocation with the station engineer, they’re really 426km away and have only 5kW) for the most part, the RSP1 does certainly play a role too.

    Alas I’m not really an FM-DXer yet and hence I have no other radios apt for that job (except for an RTL dongle) to make any comparisons and it’s probably needless to mention that I can see a hint of that station on the waterfall with the RTL dongle but there’s almost nothing to hear, not to speak of identifying that while I can have that station playing like a local one all day.

    I’m not always happy with the RSP on other bands yet (it has a million settings that let you mitigate or fix an IMD/imaging problem and needs some deeper understanding of its architecture to use it properly, which is a problem of its own), but it doesn’t stop amazing me on FM and I can’t wait for some tropo conditions coming up. Upcoming FMBC afficionado here! How could this happen? 🙂

    On the 17th this month we had a smidge of tropo weather and almost each of the few free channels around here was populated with clear signals from up to 270km distance. I’m very curious what it will pick up for me in the future!

    1. Patrick

      I already own an ELAD S2, which I find OK on FM. But I read from serious DXers that it was actually a bit deaf. As I have nothing to compare with, I can’t comment on that. That’s why I thought of purchasing a 2nd SDR, considering it would be more sensitive (I don’t intend to use it at home only).

      For aero listening, the ELAD is not fine, because it is *for sure* deaf between 115 and 130 MHz. Sensitivity ig good above, up to 160. The 2nd SDR would be very helpful there.

      A side by side test by Ron who owns those 3 receivers will probably help. He will maybe tell that’s it’s not worth replacing the S2 with either a RSP or an Airspy for Band 2. Then, a simple RTL dongle could be OK for irregular aero listening …

      BTW, where are you located ?

      1. 13dka

        Well, being an aviation nut myself I compared the RSP on the aviation band(s) with my Alinco DJ-X11 and the RTL dongle of course and it certainly picks up our local little airstrip’s tower (the only constant signal I’m getting on the air band here) much better than both the dongle and the Alinco (the latter being a surprise for me, I always thought it’s quite sensitive, the reviews said so). Listening on the various ACC frequencies around here (northern Germany, at the coast) I’m just having an impression that it goes better than the other two of course. No VORs within the radio horizon here. I have to reduce IF bandwidth to 200kHz to get rid of a TETRA station image that shows up on the waterfall in the air band at some places. It’s never interfering but it bothers me that it’s on the screen.

        However, it just came to my mind that I recently discovered multiple DGPS stations around here on the VHF maritime band around 160MHz, which emit nicely steady pulses and again the RSP brings them 5 dB above the noise and triggers the SDR# squelch threshold reliably, and I can hear that they’re carrying a data signal while I can barely hear that they’re there on the Alinco and I can see a pale trace of the two strongest ones on the waterfall with the RTL dongle (among all the USB noise the dongle picks up) but not hear them.

        I’m actually a bit disappointed that the Alinco perfoms so much on par with the dongle, or I could also put it this way, I’m delighted how well a 12€-TV dongle compares with a 400€ allband/allmode luxury handheld scanner. 🙂

        This doesn’t really help you with the decision Airspy vs. RSP1 but since those two are so much on par overall (at least according to the latest comparison on rtl-sdr.com, where the RSP won in the FMBC category) I can say that you’ll get a top sensitive receiver no matter how you’ll decide. What it might help you with is getting the idea of getting a dongle for the airband out of your head. 🙂

        1. Patrick

          Sorry for the late reply.
          That’s interesting … I thought a RTL dongle would be a fine performer on the aero band. I own a ‘respected’ Yupi MVT-7100, and I’d be curious to see how it performs against a ‘serious’ SDR (I never tested it against my ELAD on the top of the band, where the latter shows a fine sensitivity ; will do it !!).

          I can pick up some VOR and ATIS here, that’s fine for comparing radios.

  4. Rich Carlson

    I am curious about the report of lack of coverage on 380-430 MHz. on the SDRPlay. I have an RSP1 and it seems to work fine there using HDSDR software.

    Is it just early models that do not cover this?

    1. Bill L

      They bought an advert, not the website nor its views.
      SDRPlay gets little notice, other than the 2015 review in the WRTH. And they only just got a distributor for the 350 million population US.
      Other than the UK customers, it was unknown.

    2. Thomas Post author

      Hi, Jon,

      Note that we are also sponsored by Universal Radio, DXtreme Software, Bonito, CommRadio and Elad in addition to SDRplay. We invited SDRplay to sponsor us a few months following our purchase and review of the RSP because we were impressed with both their product and customer service.

      There are costs associated with hosting, protecting, and backing up a website like the SWLing Post. Our sponsors, as well as those who contribute to the coffee club, help defer some of those costs. We hand-pick sponsors relevant to shortwave and ham radio; their sponsorship is intended to compliment our content. The sponsorship agreement states that they understand we will be honest in assessments and reviews. Invariably, our sponsors openly accept and even welcome criticism of products, understanding that customer feedback is key to iterative agility in a competitive niche market. In short, these are companies with integrity.

      Because my reputation rides upon each review, and my readers let me know if I’ve overlooked something–either negative or positive about any product–my reviews are always my honest opinion. I publish and curate this website because it gives me immense satisfaction to share my passion for radio with others who share my interests.


  5. Truth

    I just got my brand new SDRPlay and I’m a bit disappointed. The sensitivity is very good and is on par with my first generation Airspy, but no matter I lower the gain the SDRPlay gets saturated by the strong FM stations nearby and I see many spurs everywhere. The 2m band is unpractical. I never had that with the Airspy or even the RTL-SDR dongles using the same Diamond antenna. May be a design problem?
    The other issue I have is in HF with an inverted L antenna. I can hear AM broadcast stations in all amateur bands which is very annoying. It works better with an attenuator and a sharp tuned filter. But yet, my SV1AFN converter + RTLSDR handles this situation without any extra help.
    Bottom line, SDRPlay is still good bang for the bucks, but I will put it in the RTL-SDR dongle category in terms of strong signal handling in a real HAM setup. The RSGB review by Andy G4JNT seems to confirm my conclusion.


  6. Aussie

    After the initial excitement at buying the Airspy, I wish I had waited and gone for SDRplay. AIRspy is poorly manufactured. Sloppy soldering has had some USB connectors just fall away. It certainly is hungry on power and a lot of USB ports cannot handle the demand resulting in stuttering. I have overcome this by obtaining an external USB hub that has its own power. It has lessened the demand on the motherboard. But the big issue is the support. I have not had to deal with him but his posts are outrageous. So rude to people and its certainly not a way to run a business. Already the reputation is severely tarnished. Its a pity he does not see it. It’s a trust issue. A lot of people feel let down.

  7. Ron L.

    With al respect to Wyn I had both the SDRplay and Airspy running trough their paces on the same software (SDR-console) and simultanious on the same antennas via a decent splitter. I could only compare the common shared frequency range what is obvious. I noticed that the Airspy was 4 dBm more sensitive on vhf and 3 dBm on uhf (2meter and 70 cm).

    On HF I found the SDRplay to show lots of IMD so I had to reduce the gain substantially when near the BC bands. I use a ELAD FDM-S2 on HF and to be fair I admit that both radios can not be compared but I had to mis out on the true DX signals. The antenna used on HF is a passive quiet SuperKaz. I seem to remember that my former Funcube pro+ had an better dynamic range on HF.

    I had the SDRplay on loan from a friend as I was interrested to buy one. The Airspy is lacking HF and that is in its disadvantage if you like HF. But I find the Airspy a decent performer on its frequency range what I can confirm comparing it to my Icom IC-9100 on the Ham bands.

    You can Google for several video’s made by Leif Asbrink on Youtube who has made a series of benchmarks wich points out the not so decent dynamic range of the SDRplay.

    I do agree that the designer of the Airspy is fanaticly defending its product and it is surely not perfect on its hardware as I have experienced.

    1. Patrick

      Hi Ron,

      There are so many opposite comments and figures regarding those SDRs, I don’t know what to think.
      Some people claim the first one is more sensitive by 3 to 6 dB (using a professionnal equipment), some other pretend that’s wrong … Well, all in ll, I’m totally confused !!

      From the most objective point of view, assuming I’m living in a very dense FM location (200 stations audible under normal conditions, using a basic dipole), should I go for a SDRplay or an Airpsy ?

      I also read that the USB socket is not robust at all (reported as broken by several users). What is your experience in this regard ? R2 connector is supposed to be OK.


      1. 13dka

        That depends on what you plan to do with the radio of course.

        How many stations you can hear on FM is not deciding, it’s how much signal the strongest of them can create at your location. If you’re receiving 200 stations (which is an awful lot, every channel on the entire band filled) because you’re living in a flat part of the country and none of them is closer than 30 miles the problems will be manageable. If one of these stations is really close, neither the Airspy nor the RSP will do any good. If you have all 200 channels filled on the FM band, that may or may not suggest that you’re already getting lots of images with your normal radio, and/or live in a large metropolitan area. Other strong stations other than FM radio may be near you.

        Have you seen this


        comparison too?

        1. Patrick

          There are actually only 2 strong nearby stations (abt 1 and 3 km from home, 1 kW output). Images should not be an issue then, excepted if running a RTL-SDR dongle maybe.

          My main interests are FM DX (some channels allow tropo / Es skip reception because of low signals), aero traffic (long distance only, such as ‘VOR DX’ing) and some listening around 150-160.
          Say, I’m only interested in the 80-160 MHz range.

          Of course, I’ve seen the comparison you mention but the comments posted below got me even more confused 🙁

          1. 13dka

            Now that’s a constellation that is really hard to assess from here.

            1. Even one strong FM station can pose a problem for both radios, likely a bit more for the RSP than the Airspy. 1 and 3km is awfully close even at 1kW.

            2. On the other hand, the RSP is likely the better FMBC DX receiver, in fact it’s performing brilliantly on FM in terms of sensitivity and SNR (and the software doing the selectivity part then), I recently read a FM-DXer blog with someone comparing it to his meritorious Onkyo receiver and the RSP won. I’m pretty stunned what this little box picks out of the noise with absolutely no tropo conditions (and 1m of large diameter wire stuck out of the attic window as a stand-in for an antenna) myself. That it’s so good on FM is maybe also a part of its IMD problems.

            If you have a directional antenna (or plan on getting one) I’d say it should be possible to mitigate any problems with big signals on your location. Buying it with a return option would take care of the remaining risk, and lets you try it. If it works, I’m pretty sure you will be happy with the RSP1!

          2. Patrick

            Dear 13dka,

            Thanks for your comments and advice.
            I made a mistake about the closest FM station : output is 0.1 kW, not 1.

            The RSP is probably a great receiver for band 2, but though it’s not critical, I must admit that my favourite software is SDR# … You guess what I mean ?!!! I don’t like HDSDR, SDR Console is fine but lacks many plugins, Linrad is a pain to use, well …

      2. Ron

        Yes, the USB chassis was not kosher and have mine broke to. I got a new Airspy send to me by the seller. Now on revision 2 there is a other model mounted that seems more sturdy and here no more complaints.

        Also in the new revision a cleaner signal is shown on the waterfall. I did some live receiving with both. Measurements with generators etc. are not always conclusive, but a help. I prefer to judge by my ears (and eyes with a sdr). What I can receive is what counts for me and why I buy a radio, and less what the figures say.

        Good luck finding you new companion.

        73′ Ron

        It can be hard to make up your mind.

        1. Patrick

          Thanks Ron !
          But you confirm that, from your own experimentation, Airpsy wins against the RSP on VHF, right ?

          What about both SDR Vs ELAD S2 on FM band ? I read some comments about the latter being a bit deaf there … It’s rare to meet people using these 3 RX !!

          1. Ron

            Patrick, I do not own a SDRplay, but had one on loan for a week last summer. I did not tested it Band 3 tough. The Airspy and the FDM-S2 are about equal on this band. I also had a brief test @ a friends place comparing the Perseus with the converter and the FDM-S2 on band 3 and also they performed equal.

            I considered buying a SDRplay but seems by the end of the year something very nice will be born in the €200 price range so I will be waiting until that day comes. I do however have no details at hand. Time does not stop and newer stuff is coming on the market for shure. Tik tok…

            I live just south of Antwerp in Belgium.

            See ya

          2. Patrick

            I assume you’re referring to band 2, not 3 ?

            This means it’s not worth pourchasing an Airspy for FM DX when already using a S2 … Once more, it’s surprising how views can differ from a listener to another. Finally, it’s very tough to decide, having so many opposite advices to deal with !

            Oh oh …

  8. RadioGentleman

    I was originally set to buy an Airspy, but in a forum discussion on the merits of Airspy versus SDRplay, I read how the developer of Airspy (known as prog in the forums) absolutely trashed his competition and was wildly defensive about his product, all with little comparative proof and over-exaggerated claims. I had a hunch I would be better off NOT ordering his Airspy dongle. Luckily, while looking for an alternative upgrade to my R820T2, SDRPlay cut their dongle price in half. The lowered price was very near my price point and actually cheaper than Airspy. Once I read reviews where users found the SDRPlay has 3 dB better sensitivity I bought it immediately. Something about supporting an immature egotist, even if he is a talented engineer, always rubbed me the wrong way.

    1. Dan

      yep every time i think about getting an airspy i read yet another unhinged post from prog and it turns me away from the product.

    2. Paul Jones

      Yes the designer berates and belittles people on the forums, it’s his way or no-way, while SDR# is good, I find HDSDR & SDRRadio better, and the audio on SDR-Radio is so much better than SDR#. I have to was looking at the Airspy, just around the time of the SDRPlay price drop, it was a no-brainer.. and I’m VERY pleased with it, in fact my second arrived today, and will be in the shack permanently running online via sdr-server…

  9. Dan Srebnick

    One problem I’ve seen with the inexpensive DVB-T dongles is the lack of preselection. I live within a mile of a highly populated LMR/paging tower and need a radio that will not easily overload. How does the SDRplay RSP perform in this regard compared to a basic R820T + RTL2832U dongle?

    1. Wyn Evans

      To be honest, they are like night and day. The RTL dongles are essentially ‘wide open’ with an 8 bit sampled bandwidth of 6-8 MHz. More recent products like the SDRplay RSP have 10-12 bit ADCs which give you at least 12 dB more headroom.
      In terms of pre-selection, the SDRplay seems to have a significant advantage in that it has programmable IF filters that are (as I understand it) 5th order chebychev, so they are pretty sharp. This will help you with ‘in-band’ blockers. For out of band blockers, the units uses switchable discrete band-pass filters.
      On the other hand, the Airspy uses an integrated 1st order tracking filter, so in this regard, I think the performance is likely to be pretty similar, but to be honest, this isn’t something I have looked at in any detail as strong out of band blockers haven’t been a problem for me.
      The only other factor effecting blocking is likely to be the phase noise and compression performance of the RF tuners. Both the Airspy and the SDRplay use TV tuners (albeit from different manufacturers), so I would expect the performance in this regards to be pretty similar. But again, this is something I have not looked at in any detail.

  10. Paul Jones

    The gap is no big deal to me, I have other radios that cover that gap, I’m mainly interested in the HF side anyway, and not having to use an upconverter is a big plus…


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