New FM Synthesizer For iPad, FM4, Recreates Classic Yamaha DX Sound


Primal Audio has announced FM4 – a new FM synthesizer for iPad, modeled on classic 1980s Yamaha DX series keyboards.

According to the developers, “Great care has been put into analyzing and replicating inherent sonic characteristics of the original hardware, such as internal quantization errors and digital-to-analogue conversion.”

Here’s their video teaser for FM4:


  • Four operators configurable via eight different routings
  • Three sound engines modelled on 1980s hardware units
  • Eight waveforms derived from classic FM synths
  • 2x, 3x, and 4x polyphonic unison
  • Tempo-syncable arpeggiator with up, down, up-down, and random patterns
  • Microtuning with eight different temperaments
  • Supports Inter-App Audio, background audio, and MIDI (support for Audiobus is planned)
  • Up to 24 voices of polyphony
  • Import/export presets through iTunes
  • Works on all iPads supporting iOS 7.0 and up

Here are audio demos of FM4 in action:

FM4 will be available in the App Store in December 2014, with an introductory price of $0.99. See the Primal Audio site for details.

25 thoughts on “New FM Synthesizer For iPad, FM4, Recreates Classic Yamaha DX Sound

    1. I see this sentiment related a lot. But honestly, I personally find 6 ops is overkill. When I write a patch on my DX27, I usually only use up to three. And often, I’ll just use that third op as a pure overtone. It doesn’t take much to build up a spectrally-rich tone with FM.

      1. Yep 0 not an easy task. Managed a bit on DX21 but arghhh… spent ages trying to find a proper editor for them too, but there was always some kind of problem with that particular synth.

        I still really like the idea of Behringer doing a FM hardware synth – I’ be very interested if it was a desktop module.

          1. Nice!! They are great sounding synths, just a very unfriendly interface 🙂

            My mate had it sounding like Boards of Canada at one point, it was freaky close. Which is strange because I always associate BOC with analogue gear.

            FM rules!!!

    1. I also initially thought – another 4-op FM-synth, but fm4 has the extra base waveforms the TX81Z has – not so shabby!! I’m definately buying this once available sinche the alternatives on the ipad in this price range are… none!

  1. My only gripe about the iOS FM’s is that they seem to be trying too hard to emulate the DX series.

    Is anyone here familiar with Big Tick’s Rhino? One thing that is cool there is that there is this kind of matrix where any oscillator can modulate or be modulated by another with FM or AM. Oscillators can be waveforms, additive or samples. The other thing is that it has much fancier envelops and velocity programming. So you can do FM but with ridiculous flexibility. (Oh, and tuning maps).

    I’m just bringing that up as an example of how you can take FM and add some new features to make it more flexible– but you can still get… you know— those awful FM sounds. 🙂

    1. Agreed on the DX7 emulation. I’d prefer to see someone just do a clean modern FM synth. Something like Ableton Live’s Operator on iPad would be perfect. But this still looks really fun.

      The interface is very reminiscent of Thor.

  2. The FM4 is one of the easiest FM synths to program. Very intuitive and well laid out. If you have been stuck on other FM synths, this would be a good place to start.

    The only one I’ve tried that is easier to program is the FM part of the new “Rounds” from Native Instruments, but that is not nearly as complex.

  3. Given the surplus of 4-operator synths and the shortage of 6/7/8-operator synths, I am beginning to suspect that the sound engines aren’t built from scratch but are instead built on widely available Yamaha sound chip emulation code used in game console emulators (e.g. MAME) that emulate the Sega Genesis or other video game hardware that used FM synthesis…

    I’d like to see some more powerful FM synths – something like FM8, Operator, PX7 or Rhino on the iPad…

    1. Listening to the sound demos I don’t think FM4 sounds anything like MAME. Also, if somebody gave you the code for a four operator synth, I guess it wouldn’t require a geniuos to extend it to six operators. Finally, MAME or none of the other game console emulators include the waveforms from Yamahas TX81Z, as FM4 does judging from the screenshot.

  4. As a counterpoint to the above: Although their FM implementations are extremely basic (usually just 2 or 3 FM pairs), I still enjoy using the hybrid FM+subtractive synthesis in Cassini, Magellan and Thor. If you work at it, you can definitely get some of that unmistakable FM growl as well as nice plucks, sub-bass, tuned drums, blocks, brass, solo strings, toy rhodes/piano, and the ever-popular bells, clanks, and ear-splitting digital noise. 😀

  5. Very late but better late than never. Please do not waste money on this, absolutely nothing to do with dx fm series synths, far from the dx7, do not be fooled by bogus explanations of synth engine s and so on, these are all cheap sample based toys. Fake oscillators sometimes too, they ae just sample selectors, not real oscillators. And this one fm4 is far from fm. Have a good day all.

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