# FM4 — user reviews > 45 indexed App Store user reviews of FM4 by Primal Audio I/S, rated 4.63/5 from 19 ratings. - Source: https://appshunter.io/ios/app/fm4/id910545680/reviews - App overview in markdown: https://appshunter.io/ios/app/fm4/id910545680.md - Rating breakdown: 5★ 14 · 4★ 4 · 3★ 0 · 2★ 1 · 1★ 0 ## Newest reviews (11 of 45) ### 5/5 — Pretty good *2016-06-01, version 1.2.2* The thing I really love about this, and the reason I'm giving it 5 stars, is that I love the edit screen. There are almost no sub menus; almost everything you need to edit the sounds is fit very nicely and functionally on the screen. But that being said it's a good thing the sounds are easy to edit, because the presets are mostly pretty bad. It has a tendency to get very noisy very quickly, meaning it can be hard to avoid producing hissy artifacts that don't sound very good. I'm don't know too much about FM synths to know if that's normal, but I don't hear it on say Yamaha DX7 presets on YouTube demos. I've found the most sure fire way to eliminate it is to switch it to "Model 1," then if that doesn't work turn down feedback on oscillator 4. YouTube tutorial by Tim Webb on this app was very helpful. ### 5/5 — Clean, well designed and sounds great *2016-05-26, version 1.2.2* Best DX7 recreation I have tried. Better designed and layed out than DXi and more true to the original than TR7. Really quick to get into and the interface makes tweaking easy and fun. ### 5/5 — Simple and full featured *2015-12-01, version 1.2.2* Primal Audio really makes me smile with this one.. The FM4 is that classic frequency modulated synthesis that still has the power to rule the world of music today. Crafting a custom sound is easy and fun. ### 5/5 — FM made easy *2015-08-28, version 1.2.1* FM4 is great. Sounds are simple to create and edit, and the GUI is logical and easily navigable (unlike original DX synths). The option to import sysex data from old 4-operator FM synths would be the icing on the cake! ### 5/5 — So nice *2015-08-22, version 1.2.1* That clean fm sound. I love the organic sort of tech wobbelies and that shimmer flop stuff. Been a fan of fm synth sound since having the first pc sound card, the adlib. This sits so well with thor and magellan in cubasis. The three play so well together in terms of audio spectrum and just performance, cpu etc. a nice dependanble program with new discoveries all the time ### 4/5 — simple,immediate fm fun *2015-05-24, version 1.2.1* wow i love the layout and sound of this app.. great sounds are so fast to create it seems like madness that we had to program a tx or dx the way we did way back when...sounds brilliant ### 5/5 — Solid Synth *2015-05-23, version 1.2.1* This might be my favorite synth in the market right now. I pushed up the polyphony in Settings and use it create some lush pads. My only request would be to add separate envelops to modulate the pitch of operators but I'm pretty happy with the variation in sound I'm getting now. ### 5/5 — I like it more than the "original" *2015-05-21, version 1.2.1* excellent sound and a well put together UI ### 5/5 — Brilliant simple UI *2015-02-06, version 1.1* This is a absolute bargain great patches and easy to change them very quickly just by changing the routing ### 5/5 — Awesome! *2015-01-30, version 1.1* Finally made compatible with 7.04! Great sound and great looks. Lots of possibilities! Thank you for the support! ### 5/5 — Very Awesome, Thick and Unique Sounds. *2015-01-28, version 1.1* I am so far loving everything about this FM synthesizer. The sounds that it produces are just killer in my opinion. I am not previously familiar with this classic synth like so many other reviewers purport to be. But, after using this amazing tool I can completely understand their enthusiasm for this synthesizer. I haven't explored every nook and cranny of the app yet, but, I just wanted to give my initial impression. To me it seems like these iOS versions of classic and popular synths are a dime a dozen and usually I find many of them to be nothing special. And while your experience and opinion may differ from my own, I am just finding this synthesizer to be incredibly fun to play with and am very satisfied with my purchase thus far. I will report back and update my review later after I have become well accustomed to the app or if I stumble upon any issues. My sincere thanks to the developer for bringing this surprise to the App Store. As I said, I had no previous experience or exposure to this particular hardware synthesizer. But after seeing what it can do and what it sounds like, well, I will now be on the lookout on eBay and other places for an original one of these. Thanks again and God bless. iPad Air 2/ iOS 8.1.1 P.S. Thanks also for offering the light/demo version of this application. Messing around in the demo was what really sold me on making the purchase of the full paid version. In my opinion other developers are foolish when they don't offer a demo of their app's for customers to try out. I would think that you would increase your sales percentage big time by doing that. Unless your app is just garbage to begin with and you know this and want to sucker people into throwing away good money on your lackluster crap. ## Most critical reviews (10 lowest-rated) ### 1/5 — Not Even Close..save your $ *2015-05-23, version 1.2.1* I own a 81z. Bought new back in the 80's. This app does not even come close. Sounds like a Casio with a broken built in speaker. 👎👎👎👎 ### 1/5 — Nice sound but update has added more bugs *2015-01-02, version 1.0.1* Bought this one and really enjoyed it at first but the latest update has created a bad lag with the GUI, too much noise and too much aliasing. Early FM had a little noise and some aliasing artifacts, not this much though! It's close but not done yet imo. ### 2/5 — Needs Keyboard Resize *2016-11-14, version 1.2.2* Might be cool if it had a touchpad-style scalar keyboard like Magellan or at least a resize key option, but it just seems like another skeuomorphic iOS synth at this point. A better design than DXi though. ### 2/5 — Sounds fantastic but not MIDI in. *2015-08-31, version 1.2.1* This app sounds good as a nice interface. But there's no midi in. And this is the type of app you would want to use an external sequencer to control. It's funny is but there's no midi in. ### 4/5 — Will we ever see an update? *2021-05-03, version 1.2.2* Tired of being scared every time I update iOS that this synth will finally have to be archived in my frozen (from iOS 13) iPad. Synth is worth getting an iPad for alone so please, do it for us, I’m sure there’s enough of us out there…Either way, thank you for the years of service! ### 4/5 — Splendid little 4op FM synth with a great sound *2019-06-29, version 1.2.2* Very simple to use and has that rare quality where all the sounds made seem to work well in the mix. Please, please (pretty please) update for AUV3 ### 4/5 — It’s okay... *2018-12-15, version 1.2.2* Seems like an okay app, but, not remembering the last preset is annoying and no update in 3 years is a worry. ### 4/5 — Awesome 4 OP FM *2018-03-17, version 1.2.2* Super easy to use and sounds really GOOD. One of my favs. I’d give it a 4.5 if I could. Wish list would be: 1.) randomize button (yes, every synth needs one) 2.) MIDI CC control 3.) import TX/DX patches (because I have 1000’s) My poor old TX81z is sitting in the corner getting dusty since I got FM4. ### 4/5 — Great synth, 2 bad it’s not being updated *2018-02-27, version 1.2.2* This is a great fm synth, especially if you’re just getting into fm synthesis, unfortunately it appears to be abandoned. The only thing it needs is to be an audio unit, which probably won’t happen. The landscape has changed with Auv3 support and I really use non audio unit less and less so this probably won’t remain on my iPad much longer but it was nice while it lasted ### 4/5 — Very good *2016-09-21, version 1.2.2* Update with surprise improvements coming? It's fine as is, but it's been a while now. ## Most praised reviews (10 highest-rated) ### 5/5 — How did I forget … *2023-01-24, version 1.2.2* … I had this. Sounds great … ### 5/5 — Sounds amazing. *2020-10-14, version 1.2.2* This synth sounds very good. The sounds are not digital in their character. The user interface is well thought out and straightforward. I wish the keyboard width could be changed. I also hope this app will be updated. ### 5/5 — You can’t get a TX81Z for $7 *2018-03-03, version 1.2.2* So get this program, instead. First the bad: the envelopes are different, as there is only a single “decay” setting (standard ADSR, vs 2-rate decay with a mid-point level); it’s monotimbral. Now the good: The on-screen controls make it feel like a DX synth in an analog synth body, and allows for some great sounds with editing. The FM synthesis on this is very similar to the TX81Z or DX11, which is an enhanced version (adds non-sine waves) of the 4 operator DX-100/27/21 family. This thing sounds much better than my old DX-100, but you can switch it into “mode 3” if you miss the noise :-) Lately I’ve been using this with my Casio CTK (or sometimes Roland Juno DS) to fake a poor man’s Montage: plug the USB Midi into my iPad Mini, aux cord the iPad audio back into the keyboard, use it to add an FM layer with velocity to a rompler patch. Sounds pretty darned cool. It’s a great tool. It would be nice for them to make a separate upgraded version that works as an AU, so you could embed different patches on different MIDI channels within an iOS DAW. Someday... ### 5/5 — Fm4 amazing *2017-08-13, version 1.2.2* This app is brilliant need i say anymore !! The sounds its produces and easy the use. Sound design your own patches and samples. ### 5/5 — Fantastic *2017-07-26, version 1.2.2* Just bought on the strength of Cuckoo's review. Awesome sounds and control. Devs - please keep this alive! ### 5/5 — Super App! *2016-12-21, version 1.2.2* This is excellent value for such an inexpensive synth. The simple one screen interface is so easy to use and cook up some wonderful thick fm/analogue sounding patches. I look forward to seeing a similar app having 6 operators and a separate LFO for each operator ... wishful thinking? ### 5/5 — FM Synthesis for beginners? *2016-12-02, version 1.2.2* This is a great app based on the TX81Z synthesizer! Despite what Primal Audio claims about the display bugs, I had no problem running it on an iPad Air 2. The presets are great and show what four operators can really do (beyond Sega Genesis sounds). If you have problems, get DXi instead. I am so happy that this app has every single parameter on a single screen! ### 5/5 — Lovely fm synth! *2016-10-21, version 1.2.2* One page interface, lo-fi settings, unison, arp, sweet sounding. Please consider adding AU support. ### 5/5 — Simple and brilliant. *2016-07-31, version 1.2.2* This synth is exactly what I wanted...simple four op Fm. It sounds warm and dirty. Exactly like my old tq5 used to. ### 5/5 — Great app *2016-06-14, version 1.2.2* Very good synth. Buy it --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-29.*