Monday, January 09, 2023

Piano plugins: an overview of inexpensive options (part one)

Sooner or later, everyone needs a piano. Whether you are making pop music, composing for soundtracks, scoring a game, or simply looking for wonderful tones to manipulate into crazy shapes, a piano is the most versatile and timbrally-rich instrument you can find. A classically-trained pianist will prefer a "proper" physical grand piano. A jobbing musician will own a portable electronic instrument of high quality. But this article is directed to everyone else: music-makers who need a software solution and don't have a fortune to spend.

This is the first of two articles on the subject. Here I will discuss approaches to creating digital instruments, popular software samplers, and how to judge a sample library. In the second article I present capsule reviews of no fewer than 23 piano plugins, so that you can find those that suit you best. A companion YouTube video is now available, so you can listen to all the instruments. 

Detailed coverage of commercial products are readily available on YouTube and other sites (for example this round-up on Music Radar). But here I will focus on free and inexpensive options. Be sure that I am not arguing against spending €500 on a piano if it's an important part of your compositional practice. But I also realise that students and independent producers often can't afford such options. 

I first started using raw piano samples for sound design about twenty years ago. This approach suited me well, since I wasn't approaching a piano as something I would play in a conventional fashion. But at the end of 2020, following the passing of Harold Budd, I felt the need to compose a simple piece using a piano as an instrument. This began the journey that led to this massive comparison, which I have managed to finish over the holiday season. (Not coincidentally, this is when software goes on sale.)

I'll begin by explaining the two ways that software developers create instrument plugins.

Physical modelling

A physical model is an algorithm that defines an instrument entirely using mathematical operations. Sounds are created ex nihilo. To accomplish this in real-time has only been possible in recent years, with advances in processing power. 

This approach has distinct advantages. The software application can be small and memory efficient. Internally the code will have hundreds of parameters that shape the sound. The developer can choose to expose these through the user interface (GUI), allowing the user a high degree of customisation. Entirely new mutant instruments can be created from the same software that renders realistic piano timbres. This is especially fun for sound designers and others who wish to experiment. 

The most popular physically modelled piano is Pianoteq by Modartt. This consists of a host application and various instrument models. The pricing can be confusing, but the least expensive option I'd recommend is Pianoteq Standard, since the cheapest offering doesn't allow control over micro-tuning, morphing, layering, hammer hardness, soundboard length, and so on. You can also select various virtual microphone models in five different positions. That's a lot of sound shaping potential. 

With Pianoteq Standard (€269) you get three instrument packs of your choosing (additional packs are €49) plus over a dozen free historical instruments. Some of the instrument packs contain individual pianos (Steinway, Bechstein, Steingraeber, Grotrian, Yamaha K2 and U4, etc.), while the two historical packs include four instruments each. You are not limited to choosing pianos. Harp, harpsichord, vibes, celeste, and other instruments are available.

You can find plenty of reviews and demos of Pianoteq online, so I have not included this product in my own testing. The consensus is that the models are very good, but fall behind the best sampled pianos. In a mix, Pianoteq is all you need, but you might choose something different for solo piano works. 

Sampled Pianos

Sampling is the second and most prevalent approach to creating software piano. The method is time-intensive, since it involves recording an actual piano, key by key, at different dynamics. Sample libraries are hence large in terms of disk storage and also require significant memory (RAM) when operating. Several techniques are used to minimise resources, including file compression, decay looping, and sample masking. 

Several standard sample formats have existed, including Soundfonts (developed back in 1996) and SFZ (an old open standard still incorporated into many current file formats). Today the most popular sampler is Kontakt from Native Instruments (Windows and macOS). This product lists for €300, but like most music software goes on sale from time to time. (I bought it for €200.) Kontakt has the advantages of twenty years of development, widespread support, and efficient coding. The interface has been updated in the version 7 but is still annoying to use on high-resolution displays. In a production environment, I recommend having a 1080p screen reserved for your Kontakt windows. Even then, be sure your eyeglass prescription is up to date!

Kontakt has a free version, Kontakt Player, but it's important to realise that many libraries/instruments require the paid version. This is because developers must pay a license fee to distribute for Player. Smaller companies, along with those distributing instruments for free, cannot bear the cost. This leaves us in a paradoxical position: free libraries inevitably require the paid version of Kontakt to function, while many commercial libraries will work fine in Kontakt Player.

So what we really need is a free sample player that can be adopted as a standard. Decent Sampler is such an application. It doesn't support scripting to the same degree as Kontakt, but that is a minor drawback. 

I immediately discovered that the plugin was processor-intensive, so decided to make some measurements. Consider that I have a 12-core processor running at 4.2 GHz with 64 GB of RAM. This should be enough to run any software quite comfortably. With my DAW (Samplitude) playing one track with no effects, the CPU utilisation is 1%. When I use any of the other plugins in this roundup (including Kontakt instruments, Spitfire Labs, etc. ) the utilisation increases to 4-5%. But Decent Sampler gobbles up 8-10%. 

Worse yet, if I increase the volume of a plugin to produce nominal output, crackling digital distortion became obvious in every case. This is indicative of a serious defect of the internal gain staging. Identical instruments sounded fine in Kontakt.. So, with regret, I gave up on Decent Sampler until such a time that major architectural improvements are made. 

Pianobook and Spitfire Audio

Pianobook is a site founded by Christian Henson (of Spitfire Audio) in 2018, specifically to create a community for the development and sharing of sample-based virtual instruments. Many of these are idiosyncratic, suited to specific musical contexts. Several file formats are supported, commonly including both Kontakt and Decent Sampler.

If you've even dabbled with samples you'll have heard of Spitfire Audio. This company has rapidly become a large and popular vendor. Their line-up is rather bewildering, but is divided into three main categories. Besides the mainstream libraries, which focus on deep offerings for professional scoring, they offer Spitfire Originals and Spitfire Labs. The Originals are €29 each and focus on being "instant writing tools", which is to say small libraries with a specific sound or mood. There are five pianos available as Originals. But there's a sixth piano hidden in the Originals Media Toolkit, and that's my choice for this comparison. (By the way, all proceeds of this particular collection go to charity.)

Spitfire Originals have been criticised for their technical flaws and minimal number of velocity layers. Certainly they are limited compared to libraries costing ten times as much. But are they appropriate for bargain hunters? We will find out in the comparison!

It's worth mentioning that Spitfire has a 30% educational discount (open to students and teachers) that applies to every product. Unlike other companies, this is very easy to access. Their website even applies the discount directly to the product pages, so you can see your actual price.

The third product category they offer is Spitfire Labs. This is a free collection of quirky libraries (currently 25 in number) that run in a dedicated Labs plugin. I've included the Soft Piano in this comparison.

How to judge a sample library?

A sample library is a complicated beast. Quality depends first on the acoustic instrument that's being sampled, but also on the recording environment, the skill of the audio engineer, post-production and sample preparation, plus the interface provided to the end user. A thorough library will include different microphone locations and models, so that the sound can be tuned by way of transducer choice. 

I am most interested in close-miking for one good reason: reverb can readily be added, but can't easily be removed. An instrument with too much "baked in" reverberation is limited in utility. Besides the room sound recorded by microphones, many pianos come with artificial reverb. This can make demos sound more pleasant, but again I prefer to add my own reverb to suit the mix. 

A good plugin will allow control over tone, perhaps through conventional filtering and EQ. But it's not a big deal if these options are missing, since this functionality can be provided by inserting an EQ further along the signal chain. Envelope control is more critical, since this is best handled at source. For example, the ability to fade in the attack can turn a piano into an instrument that sounds more like bowed strings, for useful pad sounds and other atmospherics. 

For realistic reproduction, each note on the keyboard needs to be captured at different dynamics. Consider that five layers might translate to score markings of pp, p, mp, mf, and f. Eight layers are required to range from ppp to fff. Since a note will sound slightly differently each time a key is hit, a complete implementation will also have multiple "round robins" to reduce timbral fatigue. The number of velocity layers and round robins provide useful metrics. 

After recording, samples need to be uniformly processed, trimmed so that the attack is consistent, avoiding inconsistent latency. Many libraries (including some from Spitfire) have flaws in such post-processing. 

From the player's perspective, bass notes are to the left and treble notes to the right of the keyboard. Some plugins allow panorama control, allowing you to adjust this spread. Some instruments even allow changing to a performance or audience perspective. "Intimate" instruments might have excessive pedal noise, something of a trend in recent years. 

But I don't think that any vendor has yet introduced a squeaking stool or Gould's humming... surely a missed opportunity?

How I tested

I am not a pianist by any stretch of the imagination. In order to source a professional performance, I went to the website of the E-piano Junior Competition, an annual event. To facilitate international judging, the performers have their work recorded on a Diskclavier system, producing MIDI files. These are provided for download, though the page is very difficult to find.

From the available performances I selected Johannes Brahms' Intermezzo Op. 119 as performed by Jean-Selim Abdelmoula of Switzerland. My rationale was simple: I needed a piece I could listen to repeatedly without going mad. This must also exercise a piano plugin through a range of pitches and dynamics. This particular MIDI file includes notes from F#0 to E5 (30 to 88), with velocities from around 10 to 94. I truncated Op. 119 to the first 78 seconds and allowed 2 second intervals. 

Each selection was rendered in Samplitude, normalising volume to a certain degree. This task is actually quite impossible. Many of the instruments (the felted, "cinematic" and "scoring" pianos) are designed to be played at low and medium volumes. They don't sound good when pushed, since they don't have enough velocity layers. So I decided on two categories, allowing the levels of the "full-range" pianos to be louder, but limiting the "niche" pianos to about 8 dB quieter. 

Rather than use the default instrument preset, I turned off artificial reverberation and any other effects, removed excess noise, and made other fine adjustments. Naturally it was impossible to balance tonality from one instrument to the next. Indeed, such differences are key to evaluating the plugins. 


That's enough preamble. In the next article I will present the 23 piano instruments. 


No comments:

Post a Comment