Does a laptop keyboard rig sound better than a stage piano?

For a long time, keyboard players preferred hardware stage pianos over computers for live performance. But can a laptop’s superior performance make you sound better on stage?

Using a computer at the heart of your live music performance rig brings many benefits over an all-hardware setup, one of which is sound quality. Computers have tons of memory and processing power — way more than your average sample-based keyboard — so you have more space for deeply multisampled, high-quality sounds, plus the DSP power to run effects and model sounds more accurately. 

When it comes to RAM, there are clear differences between modern computers and hardware keyboards. To talk about what I mean by this, it's useful to have a quick look at how something like a piano is sampled to use in a hardware keyboard or a software instrument.

The most accurate instruments use data-hungry sample libraries

In general, to recreate something like a piano sound accurately, you need to sample each note at each velocity (volume) that you are likely to play it. And that is a lot of samples, which take up a lot of memory. For example, if you wanted to have 16 different velocity layers of all 88 notes on the piano, and let's say each note lasts approximately 10 seconds (higher notes will be less, lower notes will be more), and you want to have samples with and without the sustain pedal down, that would be about 470 miutes of samples (88 x 16 x 10s x 2), which in stereo at 24bit is around 8GB of sample data. For one sound!

Clearly this isn't a workable solution, even for laptops with lots of RAM! (Unless you wanted to only use a piano sound, but I think most people maybe want to use other sounds as well.) So to cut down on RAM use, some manufacturers will sample, say, every other note, or one in three notes, and pitch shift the "missing" notes to fill in the holes, and the more you do this, the less smooth the transitions become as you play up and down the keyboard. It’s the same with velocity layers. The more you have, the less likely you are to hear a clunky transition between one velocity and the next. So there's always a trade off between the number of samples you want, and the amount of RAM that they will use up. Companies like Nord actually let the user make some of these choices by offering the same sampled piano in different sizes, so you can decide how accurate you want the sound to be vs how much of the RAM is used up.

RAM is king, and often lacking in hardware keyboards

Though hard drive space is cheap these days, RAM (Random Access Memory) is still a valuable commodity, and there is a gulf between the RAM available in hardware keyboards versus what an average laptop will provide. RAM is used for quick-access data, and typically the sounds of the instrument preset you’ve selected will be loaded entirely into RAM. So, no matter how large your library of samples, if you don't have the RAM available to play them back responsively, the performance is going to suffer.  

Admittedly it’s hard for keyboard manufacturers to compete with the fast-paced consumer laptop industry, and the comparison is not necessarily like-for-like because obviously the keyboard is a purpose-built product, not an all-round performer. But even the best hardware keyboards have limited RAM space compared to computer counterparts. Here are some examples: Nord Stage 4 and the Korg Kronos both run all their sounds and operating functions in RAM, each having 3GB in total. (the Nord Stage 4 has an impressive 2GB RAM dedicated to the piano alone.) The latest Yamaha Montage M has 4GB of user flash memory and another 10GB of onboard presets, but it’s unclear how big the RAM allocation is. Most laptops on the other hand have a minimum of 8GB, of which maybe you could use 6GB for sampled sounds once the OS and apps are running. Bigger, more expensive laptops could have up to 32 or 64GB of RAM, which could mean more like 25 or 50GB of RAM available for sampled sounds. And in terms of the quality of sounds that you could have access to with 25GB of RAM vs 2GB, there is a huge difference.

Now this isn't to say that more RAM always equals better sounds. One of the issues with software companies having access to lots of RAM is that sometimes they stop being as careful or creative with what to do with what they have. For example, Keyscape, which is my favourite sampled piano, uses about 5GB of my laptop RAM to play one piano sound. Is it five times better than the Nord that uses 1GB? Well, probably not, but I do prefer it! I also like the fact that with a laptop and a decent amount of RAM, I have access to many many more options of sounds readily available compared to a hardware equivalent.

So as you can see, there are pros and cons to the hardware vs software debate. But if I was to pick a piano that worked most of the time for most things, it would be Keyscape, and that is a really big sample set that needs a lot of RAM.