Pair a veteran software synth maker with a traditional artist, throwback graphics with expressive interactive control of live sound, and what do you get? SynthX is an iPad synth that gives some hope for the genre, tailored to the medium by Way Out Ware and Jim Heintz, who created the critically-acclaimed TimeWARP ARP simulation (as endorsed by 2600 creator Alan Pearlman) and versatile synth KikAXXE. It’s a synth that actually feels like it fits the iPad, but one that also seems ready to coexist with other tools in your studio or stage rig.

I think there’s a common notion that iPad synths are gimmicks. The sequence goes something like this: you see a popular, growing platform with some unique features and run off to make something that fits it, whether it’s musically useful or not. Toys and mass-market noisemakers win out over real tools. That’s true to an extent, of course – and maybe there’s not even anything wrong with it – but people who have been doing computer music for some time may see it differently. The iPad, in that view, is an outgrowth of the possibilities of computing. It’s a chance for ideas that have been gestating for some time to become practical, provided the design is matched to the platform.

SynthX, following in the footsteps of apps like Jordan Rudess’ MorphWiz, centers around a horizontal touch area for playing the instrument. In addition to touch surfaces for playing expressively, there’s a grid layout and lots of visual feedback.

We got to speak to creator Jim Heintz about his creation and how he put it together – an ideal companion to an extended interview we did last week with another iOS synth designer:
Imagining a Tablet Synth: Developer Christopher Penrose Shows Us SynthTronica for iPad

The synth engine itself is retro, virtual analog territory with rich sounds. Jim says he wanted to pair that sound with a visual aesthetic – in his mind, it was his beloved Amiga. But don’t think that means this is primitive; he tells us that, while it required a lot of optimization work, he didn’t have to make many compromises in terms of sound quality. (That said, he also says he’s eager to get his own iPad 2.)

For a review, I can’t improve upon what Len Sasso has written for GearWire:
WayOutWare SynthX Review by Len Sasso: Surprising Playability From An iPad Synth

But here’s Jim with a behind-the-scenes look at how the design came to be.

CDM: Can you tell us a bit about how SynthX came about?

Jim: SynthX actually has a pretty interesting background. I started on it initially because I was working on an enhanced iPad version of iSample, and I decided that it needed a killer synth to go along with it. This made me consider my options for about 30 seconds, at which time I realized that I had a great synth that might just work quite well. The synth I was considering was the AXXE emulation in our plug-in product KikAXXE. This had a couple of nice advantages: first, it sounds great and has a big library of professionally designed patches, and secondly, it is a pretty easy synth to understand and program, so beginners, and novices wont be out of luck it they try their hand a sound design, not to mention the fact that I designed and wrote it.

What went into programming the synth engine? Was this something you built from scratch — in fact, is that generally how you work — or are you able to build upon things you’ve done in the past?

Initially I was very concerned about the amount of processing required for virtual analog on the iPad, so I focused on optimization from the very start and re-coded the whole synth engine in fixed-point Integer math because the ARM processor handles this quite well. I was surprised to find that it work very very well, and on an iPad 1 SynthX is capable of 6 voices. (probably more, but I felt 6 is a good starting point). As far as the genesis of the code base, I drew on KikAXXE for most of it. A lot of the UI basics came from KikAXXE as well, however, I have re-coded all of the actual rendering to take advantage of OpenGL ES so as to unload the main processor as much as possible.

It feels like a lot of thought went into the user interface, both visually and in terms of interaction. How did you develop that interactive paradigm, and the visualization for the sound?

The UI design was a collaboration. I have been working with an artist named Nigel Robertson ( | contains fine art nudity) who is currently studying at the Florence Academy of Art. He and I wanted to produce a UI that looked like the fond memories that we both shared of 80’s era computer/gaming devices in order to give it a retro feel. Sort of to make you feel like a kid again, or to bring back the vibe of the era that these sounds would have been heard in, and I was bored of the rendered 3D hardware look that everything else seems to have these days.

Touch is a challenging medium in some ways for playability, because of the lack of tactile feedback. That said, have you seen other examples that inspire you?

This is why I felt it necessary to display the waveforms on the tip of your finger… I think it helps a lot as far as feedback goes. I find it really stimulating to see the exact waveform my ears are hearing when I play SynthX. As for inspiration, Bebot and Jordan Rudess’ MorphWiz were an inspiration for the XY screen, and Roger Linn Design’s Linnstrument and Mugician were inspirations for the grid screen. I play the violin, so I have been interested in being able to play in an expressive manner on a touch screen for a long time. I think we are just at the beginning in this area. I feel there is a long way to go before the possibilities for this paradigm are realized, and I hope to be part of making that reality.

A big concern users raise – tablet lovers and naysayers alike – has to do with workflow, especially for people accustomed to the versatility of plug-ins and such. How do you imagine people will use SynthX? Do you think tablets could benefit from the kinds of technologies for interoperability on the desktop? Or should everyone stop worrying, plug in that minijack (or USB audio interface, even), and play?

Well, this is a very good question. First, I believe there are a lot of different ways to incorporate tablets into music workflows. I believe that MIDI, in-app recording, file sharing, and AudioCopy/Paste are all ways that can be used to incorporate tablets. Of course the mini-jack works as well. I think as time goes on, the options will continue to expand. It would not surprise me to see a plug-in format appear in iOS, but I don’t expect it right away. I think as tablets get more and more powerful, that this will become necessary at some point. Customers will demand it.

I believe that if we try to turn a tablet into a desktop computer, you will loose many of it’s benefits. From an app designer standpoint, being able to rely on the fact that my app will occupy the whole screen when it is active, and not be partially exposed, or otherwise reduced in functionality gives me more to work with and allows me more freedom to create. I think that at some point, it will be possible to create apps that work together better when backgrounded as well. It will be interesting to watch how this all works out.

SynthX on the iTunes Store

  • Peter, great interview! The SynthX is really good. Nice sounds and very low latency (including MIDI). These and the different layouts for playing make the SynthX a complete tool for playing live with the iPad.

  • Cassidy

    Sorry.  iOS = not serious.  This is like an article about how to redecorate your prison cell.  Why would I invest in or depend on a platform that hates me and supports its shareholders with a business model that is predicated on defective-by-design products and release cycles, savagely proprietary hardware and software, and basic amenities like rights, privacy, and security omitted from its “user experience”?  I wouldn’t.  Why wouldn’t I?  Because music is my love and more importantly my profession and the source of my wealth and the wealth of my company.  I’m not dumb enough to embrace this platform because to me music matters.  If you do embrace this platform then it’s your way of telling the world that music doesn’t matter to you.  Ironically, if music doesn’t really matter to you then instead of pissing away your time and money on something like iOS, make a friend, learn an instrument, and reduce your dependence on other people and the materialism and energy consumption of modern times.  Fools.  

  • GreaterThanZero

    That argument goes both ways.  When you place the platform above the tools that run on it, you've declared pretty strongly you don't care about music either.
    I don't have an iPad, and I may never own one.  I'm still very interested in reading about apps such as this — their inspiration and design transcend platform.  This article has very little to do with iOS, if you're receptive.

  • Nice interview. 

    Not sure why some readers are distracted by platform dogma that they miss out on the fact that developers like Heintz are figuring out some pretty cool shit. 

  • the sad thing about this type of very creative design is that it looks like the coupling of a deeply expressive control surface with an interesting and flexible synthesis engine. unfortunately, its not addressing the basic, fundamental observation made here:

    which was that to get the control surface right (in the sense of having the same depth of control as acoustic instruments) you need a massively higher sampling rate for the surface than devices like the iPad provide.

    as a result, something like synthX is really cool but actually much more like a modular synth and nothing more. that's still pretty damn cool, but what irks me is that it looks more like randall's kind of device but actually has none of that subtlety.

    in a 2-clause conjunction: iPad controls == knobs + buttons + sliders ; instruments == something else.

  • Peter, thank you for the great article!

    I was attracted to the form factor of the iPad.  As a musician and software synth designer, I like the notion of cutting the muck out of the way of me playing my instrument.  If I want to play SynthX, all I need to do is swipe my finger to unlock the iPad, click the icon for SynthX and start playing.  No booting my laptop, plugging in my controller, opening a DAW, or inserting a plug-in… non of that… just music…

    I can understand why some people might be turned off by that, its not for everyone, but I really like to play music, and that is what I am able to with this environment.  As for serious,  a classical violinist should use a violin to be taken seriously, likewise, an electronic musician should probably use something electronic to make their music.  Last time I checked, an iPad is electronic…  To each his own.

  • Velocipede

    Call me shallow, but the retro gui makes me not want to try it. Not that i want faux wood panels and knobs, but how about some other skins?

  • Robert


    Your post is offensive to many readers, I'm sure, and the cherry on top is when you call iOS users "fools" at the end.

    In my experience, usually when such vitriol comes from a commenter, it points to the fact that they are bitter and jealous that they cannot afford to buy the gear in question, and I suspect that you are no different.

    Because the iPad and all of it's exciting possibilities are financially beyond your reach, you feel the need to bash it instead, even though you don't understand it.  There's a word for people like that, and that word is "fools"…

  • Bynar

    When do you think we will see a software programming language for one of the tablets? I would really be interested in a new graphical programing language software program for the ipad. If these apps can't host plugins it would at least be nice to see them get a little deeper. One of my biggest fears is that the new computer (tablets and netbooks) connected to the cloud networks will replace the traditional computer(laptops and desktops) that was used to create content. 

  • loopstationzebra

    Great article and interview Peter, tnx.

    @Jim. Recently picked up SynthX and I believe it's the finest synth app to date for the iPad. Truly, truly excellent. And huge props FOR BEING THE FIRST DEV TO FINALLY AND SUCCESSFULLY IMPLEMENT MIDI CLOCK INTO A SYNTH APP. Now we've got two apps (Molten and SynthX) that can do this. The fact that the clock remains pretty stable throughout extended Ableton Live use is fantastic.

    I love how deceptively simple this synth is… I love how it's actually got some nasty analoguish GRIT. I love the Atari-like graphics (take that, clean interfaces! lol). I DON'T love that the delay is not sync'd. That needs t be fixed, bro. Stat! 🙂

    This synth app is another example of the total viability of the iPad as a serious music creation platform. The fact that it doesn't take up valuable CPU power on my laptop is just another in a long list of iPad bonuses.

    Bravo, Jim.

  • Peter Kirn

    @Paul: I most definitely want to revisit the designs, and yes, I generally agree that the tablet capacitive screen falls short of the tactile interfaces. Audio rate sampling – well, very possibly, but I'm a long-time MIDI keyboardist, so I've managed to get by. Actually, I will say that when I talked years ago to those folks who were working to reproduce classic piano performances from audio recordings, they found that timing on the piano was very precise, and they claimed the differences were audible. So presumably even keyboards benefit from greater timing resolution. (Another relevant question – how good a musician you are.)

  • Peter Kirn

    @Cassidy: I'm obviously biased toward digital instruments because it's the topic of this site.

    If the platform were not iOS – if it were Linux or Android, for instance – would you feel the same way? Is the fundamental problem you have the restrictions on iOS? (If so, there are options.) 

    I also like acoustic instruments.

  • @peter: clearly there are a set of interesting and wonderful instruments that don't require highly sensitive mechanisms to play to their fullest extent. hammer-on-string keyboards and organs spring to mind, as do a number of pitched percussion instruments like vibraphones or marimbas. these all have the characteristic that the number of dynamic factors that influence the sound is fairly small (what you hit, how hard and when – aka "MIDI" :).

    randall's surface and the idea that it represents might be needed if you want to build electronic instruments that have more "continous control", which is going to include anything whose acoustic processes are intended to be similar to what happens when someone is beating a membrane of some kind, blowing air through some kind of resonant chamber or plucking/touching a string.

    for me, the jury is out yet on whether anyone can really tell that such an instrument has only 127 steps for each "parameter" or whether you really do need the kind of finesse that randall's system and others like it posseses. i think we don't know.

    if it is needed, then there's still a nice role for devices like the iPad, but its not where the magical new instruments will come from. on the other hand, that still leaves the class of percussion that was once tackled by a crazy program called "tao", which could do physical modelling of physical impossible (or at least unlikely) percussive objects. hooking up an iPad to something like tao (and i'm sure there are some proprietary equivalents) would be just about interesting enough to make me keep my mouth shut 🙂

  • Radiophobic

    Personally I the main issue I have with this is the size of the keyboard versus the sliders used to control the parameters. With all the screen real estate the ipad has, it seems like kind of a misuse to make that keyboard 3/4 of the screen, while the sliders are so skinny and close together. 

  • Bridge

    @ Cassidy, fine dude you keep being a hater. I am going to keep making the best music of my life on my iPad. Not only am I creating my best music on my iPad it's the most fun Ive had in ages. Synth X rules and is by far the best synth sound engine I've found for iPad yet. Interface is also top notch. A no-brainer purchase for sure.

  • This is a sweet synth!  The keyboard is a nice cross between MorphWiz and a Kaoss pad.   While the faders are a bit small, their compact design is clever;  they beg for a Japanese localization.  While the keyboard is big, it size does give more resolution for modulation along its vertical axis.   I get almost unusable lag with 6 voices — but 4 voices is passable (my own synth only does 4 atm 🙂 ).  The iPad 2 should help a lot with this.   Great work!

  • Max

    While I do like aliasing noise it kind of makes the top range useless for most people (1:15 in the video)…

  • @Max,  On that patch I have the distortion unit turned on… When the distortion is turned off, the top end is pretty much alias free.

    I agree though, that on that portion of the video due to the distortion setting, aliasing can be heard.

  • lbeing789

    Peter, I bought synthx after review this and I like it, but it crashes so often it's completely unusable in a proper work context… also there are clicks sometimes… if you can fix these problems you're onto a winner.

  • lbeing789

    yeah, the crashes are driving me insane, it's crashed 15 times so far, and I've only had 2 hours.

  • I have not had any crashing issues… Can you tell me what is happening?  Are you switching to another app?  If so, which app?
    Please email,  I would like to understand what is happening.

  • loopstationzebra

    @Jim. How's about delay sync? I too have noticed audio clicks here and there, but mostly when I've got the FXs panels showing. Using it in the all keys view usually helps.

  • lbeing789

    it hasn't been happening when switching apps, it just happens when using it.  It crashed whilst playing one of the horn patches.  It crashed when doing the xy effects… It's crashed about 6 times when using midi sync from ableton.  It's crashed when doing midi out to ableton 3 times.   It just crashes all the time regardless of what you're doing and regardless of what apps are open in the background.

  • lbeing789

    I've emailed support with some more details.

  • lbeing789

    update: wayoutware have been very helpful. Thank you Jim.  Upgrading to iOS 4.3 seems to have improved the coreMIDI implementation.  I haven't had any problems since updating.

  • @Ibeing789, I am happy that we were able to solve your issue, and also to discover that under iOS 4.3,  rtpMIDI allow Windows users to connect to SynthX via WIFI!

  • @loopstationzeb, delay sync is in the works. As for the clicks,  I am working on that as well.  It appears to happen more when there is more graphical activity happening on the screen, so the keyboard with the effects pane closed should be your best bet for now.  I should be able to tune it so it won't matter how you have things set in the update.

  • loopstationzebra

    Tnx Jim. Again, beautiful work.

  • After reading this and checking out the videos I downloaded SynthX and I've got to say it's a great interface. To me the emphasis on the control surface (rather than the sliders, etc) is spot on – it really feels like an expressive instrument.

    Also it seems to have avoided the cheese factor of MorphWiz…