Review – ImageLine’s Harmor Synthesizer

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The Harmor software synth from Image-Line debuted several years ago, but it has just recently matriculated to 64-bitness. As such, a fresh look at this instrument is warranted.

by David Baer, Sept. 2013

Harmor Grows Up

The Harmor software synth from Image-Line debuted several years ago, but it has just recently (at last!)  matriculated to 64-bitness.  As such, a fresh look at this instrument is certainly warranted.  But let me say up front: Mac users, read no further or you’ll just end up very disappointed.  I’ll be saying some extremely complementary things about Harmor.  But it’s PC-only, and that’s never likely to change.

Harmor’s author is Didier Dambrin, a brilliant (and I suspect slightly mad, but in a very good way 🙂 ) software innovator.  Harmor is written in Delphi, a powerful development environment, but one that will never find life on the Mac platform.  For a geek moment, read the sidebar “Why Delphi?”.  Harmor is a thoroughly unique innovation.  There’s nothing quite like it out there, except for its predecessor, Harmless, which also just got the 64-bit upgrade treatment.  Harmless is a worthy instrument in its own right, but it’s overshadowed by its vastly more competent successor, Harmor.

Harmor offers an additive synth engine.  So what’s all the fuss about?  Other synths like Alchemy and Image-Line’s own Morphine are additive synths.  But Harmor does something unique.  It maintains the sound representation in an “additive state” much longer than more conventional additive synths.

If this is making no sense, let’s review how additive synthesis works by working backward from a single cycle waveform.  Any such single cycle can be decomposed into component sine waves with frequencies that are exact multiples of the fundamental wave.  These are called “partials”.   Partials may be in phase with the fundamental frequency, but they do not have to be.  When all the partials are summed, the result is a single-cycle wave that is invariant as long as the partials all retain the same characteristics of amplitude and phase.

If we alter the characteristics of partials over time, which is standard operating procedure for additive synths, we get a changing or evolving sound.  Alchemy does this, as does Morphine.  But those synths sum the partials fairly early on in the signal chain and pass them on to the familiar processes that are staples of subtractive synthesis, filters in particular.

What makes Harmor stand out from the crowd is that it keeps the sound in the form of component partials much longer, or as Image-Line would put things, it keeps the data in the frequency domain.  And it does this up to and including the filter stage.  Filtering in the frequency domain dramatically rewrites the rulebook.  This feature is emphasized not to demean other additive instruments, but Harmor does things rather differently than the others. Frequency-domain filtering is by no means the only reason Harmor is an innovative wonder, but it’s a highly significant reason.

Harmor Architecture

First, let’s look at the big picture.  The figure above shows the GUI for Harmor.  Yes, it’s crowded and a bit intimidating, but there is oh-so-much functionality.  There are two identical parts that independently produce sound that is combined (if both parts are enabled) and passed on to a global effects section.  The effects available are a typical collection of delay, distortion,  They are of good quality but are nothing unique, so we’re mostly going to overlook then in this review.  The area of immediate interest is in the parts, the area in the upper portion of the interface with a purple background.

There’s a lot going on here, and it can be a little overwhelming.  We’ll look at the individual components in varying amounts of detail, but the important thing to keep in mind is that everything here is operating in the frequency domain.

Let’s start with the dual “oscillators.”  Into these you can select a stock waveform.  You can also open an additive editor that lets you designate individual partial levels, and there’s a randomization function that should allow you to come up with arbitrarily complex single-cycle forms.  Finally, you can supply your own single-cycle wave.

Whatever the single-cycle waves look like in the end, they are not used in that form.  They merely serve as the source of the amplitude and phase characteristics of the partials, upon which further manipulations will be done in the signal chain in the part.

There’s more here that’s worthy of note, such as the sub-oscillator capabilities, but there are just so many capabilities in Harmor that we can’t discuss them all.

Moving on, we have the Blur process.  Horizontally (that is, in the time dimension), Blur can affect the attack and decay of partials.  This can be set to favor the processing   of upper or lower frequencies.  Blur is not something you’re likely to have seen elsewhere, and like any number of other things in Harmor, it takes some work to come to grips with what it does.

Next there’s tremolo … at last, back in familiar territory!  This is very basic.  Too bad this wasn’t taken a little further in terms of leveraging the frequency domain possibilities.  On the other hand, there’s not a whole lot of room on the interface for more controls.

Three other easy-to-grasp processes are the Harmonizer section, pictured, the Unison section and the Pitch section in which frequency, detune, vibrato and legato behavior are controlled.  There’s nothing too far off the beaten path here, so we won’t linger.

Harmor Filter, the Great and Powerful

And now we get to the filters, where much of the Harmor magic is enacted.  Here’s the thing about filtering partials: the filter can be anything you can imagine.  Want an infinite-slope filter?  Easy, just completely mute all the partials above the cutoff frequency.  There are unlimited possibilities, as you’ll see.

Because the filters work as per-partial, time-variant amplifiers, the results are quite pristine sounding.  If you’re looking for a cruder analog filter experience, Harmor is not the synth for you.

Two filters are provided which can be combined in some combination of parallel or series mix.  For each of these, there are stock filter types of all the usual variety on hand (low-pass, high-pass, etc.).  Things start to get a bit unfamiliar when we look at resonance, where the choices include such options as “Cuberdon,” “Pedistal, “Sedge Hat,” and so forth.  We’re definitely not in Kansas anymore.  And if you don’t find a filter that fits what you need, you can simply draw one of your own design.

If you want a demonstration of how uniquely Harmor’s filters can affect sound, check out the Pads/Dreamland preset.  One of the parts uses the Noise resonance-type in such a way that a wondrous wind-chime type of randomness is achieved.  I don’t believe there’s another synth available today that could do this sort of magic.

One final note, a single knob marked “Pluck” is part of the filter section.  It applies a pre-configured time/LP-filter pattern that allows easily programming a pluck-type sound.  Extremely convenient and useful!


 We need to take a detour from the upper panel now to look at another key part of Harmor – maybe its most powerful feature of all.  But before discussing that, it’s time to bring up Harmor’s most problematic issue.  This is a complex and powerful instrument with much that is non-intuitive.  Such an instrument requires first-rate documentation and lots of it.  Sadly, Harmor’s documentation comes nowhere close to being adequate.  It’s far too sketchy throughout, but nowhere more so than in the area we’re about to look at.


There’s an obscure thread on the KVR forum ( ) that talks about the resynthesis/image-synthesis (hereafter R/IS for brevity).  The expert (who I understand is an Image-Line technologist) talks about how the R/IS acts as a time-variant filter that operates on the composite wave generated by a part’s two oscillators.  Seems like this might be important information, right?  However, there’s no mention made of this in the documentation, and it’s a critical aspect of how this feature works.

Those familiar with Alchemy’s resynthesis capabilities will have a clue as to what’s going on with R/IS here.  In this, Harmor and Alchemy do have some common ground.

R/IS operates in two modes: resynthesis and image-synthesis.  In the former, a wave file can be loaded and analyzed such that it can be reproduced with reasonable accuracy using Harmor’s additive sound generation capability.  Once so decoded, playback speed and various other time-related manipulations can be applied.  A decoded audio clip can be converted to images (one for amplitude and one for frequency).  These can be copied and pasted into an external image editor for further manipulation.  Or, you can just court serendipity, import any random image, and then see what kind of sound is produced.

There is a very good demonstration of this starting at 6:40 in the following video:

In fact, this video does a very good job of demonstrating a number of Harmor’s synthesis capabilities, a far more complete picture than I can paint here.  I recommend it highly.


Finally let’s look at modulation.  While Harmor may implement this in a way that’s a bit different from what you might be accustomed to, it’s thorough and powerful.  Once again, the video above does a nice job of illustrating how modulation is applied.  Both envelopes and LFOs have some capabilities that are extremely powerful (I seem to be using phrases like “extremely powerful” a lot in this review!) LFOs give you as the ability to apply an envelope of arbitrary complexity to an LFO wave sequence.  For envelopes, you can drag and drop an external wave file onto the envelop panel and its amplitude envelope is analyzed to create a complex Harmor envelope.  Both LFO and Envelope functions are pictured.


Is Harmor for You?

Harmor is one of the most impressive instruments in my collection.  It provides an ample list of factory presets, but so far there seems to be little activity in the sound design community for third-party preset libraries (hopefully the 64-bit version availability will change this).  Harmor has a decidedly digital sound, as you might expect, so it’s not going to be a “this is the only synth you’ll ever need” type solution.

I hope I’ve been able to convey just how remarkably innovative this synth is.  There’s honestly nothing else quite like it (at the moment anyway … who knows what Alchemy is cooking up for their upcoming Alchemy 2.0 which we’ll hopefully see in 2014).  If you purchase Harmor, you’re guaranteed to not be duplicating something close to what you already might have.

Image-Line uses a customer friendly authorization scheme.  In fact, when I downloaded the 64-bit upgrade, I didn’t even need to reapply the authorization.  And Image-Line generously has a free-upgrades-for-life policy.  You rock, Image-Line!

But there are some downsides to Harmor, the inadequate documentation being the principal one.  If you’re a preset-only type musician, this shouldn’t be of concern.  But if you like to dig into an instrument and do some of your own sound design, be prepared for a non-trivial learning curve.  You’re probably going to need to do a lot of reverse engineering of factory sounds to get your head around how some of these features function.

Harmor currently lists for $149 USD at the Image-Line site.  Sales of Image-Line gear are not unheard of (in fact, all four of the Image-Line synths that I purchased were obtained with very attractive discounts), so patience may pay off for you.

Find out more here:


Why Delphi? A Geek Moment


Some of you may wonder why a developer would choose a Windows-only development environment and lock themselves out of the Mac marketplace.  The cross-platform C++ language is the conventional choice for use in plug-in development.  Having worked with Delphi extensively in the 90s (and having been a regular contributor of articles for The Delphi Magazine to boot), I know something about it.  I can say without reservation that I have never encountered anything more productive and enjoyable to work with than this technology.  For some of us anyway, Delphi, now relegated to a fringe niche, was at one time the most effective technology for rapidly developing complex, efficient and graphically complex software.  I can’t fault Mr. Dambrin in the slightest for making this choice, even though he realized that it would limit the potential customer base.


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