🎹Yamaha P-125 vs Casio PX S-1100 - Digital Piano Review & Demo Comparison 🎹

There are several massively popular models in the sub $1,000 88-key portable digital piano category given how high the current quality level is for digital pianos across the board, and the fact that the $1,000 marker is a line many folks prefer to stay under when choosing a digital piano.

Perhaps no instrument is more popular in this category than the Yamaha P-125 digital piano (aside from perhaps the stripped-down P-Series Yamaha P-45), but the Casio PX-S1100 is proving to be not far behind in terms of sales volume. And what if we told you that for some people, the PX-S1100’s total offering might make it a better offering than the Yamaha P-125?

This statement might come as a bit of a shock to you if you’re only really familiar with Yamaha products, hadn’t been considering anything other than a Yamaha up to this point and simply aren’t aware of how well received the Casio Privia PX instruments have been.

If you’ve been strongly considering a Yamaha after checking out some Yamaha P-125 reviews then this video and companion article are for you as we’ll be comparing and contrasting the Yamaha P-125 vs Casio PX-S1100 to see if, in fact, the S1100 might be a better choice as a piano keyboard for you.

Thanks for being here, let’s get into it.

Yamaha P-125 vs Casio PX-S1100 – Background

Yamaha P-125 vs Casio PX-S1100 Background
Yamaha P-125 vs Casio PX-S1100 Background

Well into the year 2022 and these two instruments have been some of the best-selling 88-key digital pianos on the market. The P-125 has been around for several years but it’s still very much a relevant product. The PX-S1100 is the recently released update to Casio‘s PX-S1000 (while the PX-S3100 replaced the PX-S3000) and has the claim to fame of being the slimmest 88-key weighted action digital piano on the market.

Both of these instruments are built to serve as digital replacements for acoustic pianos, primarily for students, hobbyists or those seeking a practice instrument with the flexibility that a digital piano provides, with a focus on high-quality grand piano sound, a weighted key action, and a user-friendly interface.

We’ll now move to a comparison of everything sound related on each instrument.

Digital Piano Sound – Speaker and Sound Engine Comparison

Casio PX-S1100 Speaker System

Casio PX-S1100 Speaker System
Casio PX-S1100 Speaker System

We’re going to start by discussing each piano’s built-in speaker system as one of the PX-S1100’s key improvements over the PX-S1000 is an improved speaker design here.

We’re working with two speakers here with 8 watts on each side for 16 watts of total amplifier power. The speakers are rear-facing, however, there are front-facing tone ports to deliver high frequencies directly to your ear.

In terms of the speaker redesign, what’s changed from the S1100 is the shape of the speaker’s inner diaphragm. We’ve also heard that they’ve changed the coating on the speaker cone as well.

The result is more definition in the upper register, more detail and generally just more punch – there’s virtually no way to get these speakers to distort.

Yamaha P-125 Speaker System

Over on the P-125, and while we’re dealing with less overall power here with 14 watts of rated output, it’s a 4-speaker system here as opposed to a dual system with two downward-facing mains and two upward-facing tweeters.

The result is a very well-balanced playing experience from the players’ perspective. Despite a lower overall power output, the presence of the two tweeters here means the P-125 is delivering a clearer overall piano sound, though the sound engine itself is less complex (which we’ll get to more below.)

Casio’s Multi-Dimensional Morphing AiR Sound Source vs Yamaha’s Pure CF Sound Engine

Casio PX-S 1100 Sound Engine
Casio PX-S 1100 Sound Engine

The PX-S1100 is using Casio’s very well-regarded Multi-Dimensional Morphing AiR Sound Source. It’s surprisingly complex when you consider the price range that the PX-S1100 is available for. The nuance and sophistication they’ve been able to pack into this tone engine is right up there with the kind of complexity and control you’ll also find with the SuperNATURAL sound in the Roland FP-10 and the Harmonic Imaging engine in the Kawai ES110.

The Pure CF engine, based on a sample of the CFIIIS concert grand piano (which has since been replaced by the newer CFX concert grand), isn’t a slouch by any means, it’s just not delivering the same level of detail, control and recreation of a real piano as the S1100’s AiR engine.

With that in mind, when you’re choosing between these two instruments, from a sound perspective the choice comes down to a more advanced tone generator with a less clear speaker system versus a clearer speaker system with a simpler and less nuanced piano tone.

If you’re going to be using an amp or playing frequently with headphones the speaker disparity goes away, and courtesy of the Hall Simulator reverbs and Acoustic Simulator, you can actually tweak the tone of the S1100 to get pretty close in clarity to the P-125.

Both pianos actually offer a nice level of sound editing control with access to parameters like damper resonance, string resonance and more.

The P-125 has a couple of neat sound-related features like a Sound Boost that is worth noting as well, while the PX-S1100 has a Surround sound feature.

Other Preset Sounds

In terms of the number of sounds to choose from, the S1100 offers 18 compared to an extra 6 on the P-125 for 24 in total. There’s quite a bit of overlap of sounds with a couple of acoustic pianos, electric pianos, organs, synths and strings.

Some sounds are stronger on the P-125 while others are stronger on the S1100. The e-piano sounds on the P-125 are very lush and modern, while the string patches on the S1100 are a real standout.


Polyphony is dead even on these instruments at a cool 192 notes each. This is more than enough for solo piano playing which is of course the main function that each of these pianos is made for.

Keyboard Action Comparison

Casio PX-S1100 Keyboard Action
Casio PX-S1100 Keyboard Action

Casio’s Smart Scaled Hammer Action Keyboard

Casio’s relatively new Smart Scaled Hammer Action Keyboard was first introduced in the PX-S1000 and PX-S3000. It’s been brought back here and is definitely a responsive action that’s right down the middle in terms of its weighting.

Now, this action is highly compacted, so there are some dynamic quirks here that you should be aware of. One quirk is that the black keys have been intentionally weighted heavier than the white keys, and this is a result of the black key being so short.

The compacted key length also means that the weighting of the keys will feel different depending on where your fingers happen to be physically playing the keys. We’re also working with a double sensor here and escapement sensation for the same reasons.

Because of these factors, this action probably isn’t the best action for a beginner to start with if your intent is to become a high-level classical player. If that happens to be your end goal, we’d recommend going with an action with a longer pivot length that feels more like a real acoustic piano.

In terms of the keytops. we’ve got an ivory texture on the white keys and a matte finish on the black keys. Having some type of finish on the keytops is a huge plus as it provides some glide if your fingers get sticky during longer playing sessions.

Yamaha’s Graded Hammer Standard Action

Over on the P-125, and we’re looking at Yamaha’s Graded Hammer Standard (GHS) action. The GHS action has been on the market for quite some time now, and it’s regarded as a very reliable and generally well-liked action.

It’s also using a double sensor and doesn’t have any escapement like the Smart Scaled action, and the overall touch sensitivity seems pretty close between them. On the other hand, the GHS feels lighter than the Smart Scaled action, and the keybed also feels a little more shallow, meaning you can’t dig into the action as much.

The biggest difference between these actions though is the fact that the GHS does not have any type of texture on the key surface. Instead of simulated ebony and ivory textures, the key surfaces are glossy.

The challenge with a glossy surface is that during longer playing sessions your fingers can end up sticking to the keys which can actually start to peel the skin back on your fingers.

Now, there are a lot of people who love this action and have never had this issue, but that’s certainly something to be aware of.

Additional Features and Connectivity

When it comes to the features, we’re looking at some fairly dramatic differences here, to the point that this particular area could be what sways you to one instrument or the other. We’ll start with the PX-S1100.

Casio PX-S1100 On-Board Features, Connectivity

Casio PX-S1100 - Bluetooth Adapter
Casio PX-S1100 – Bluetooth Adapter

The first feature that really stands out when looking at the S1100 is the fact that you have the option to run it on battery power as opposed to a cabled power adapter. Prior to Casio’s PX-S instruments, it was practically unheard of to find a battery-powered digital piano with such a realistic pianistic experience as what we have here. Yamaha for example doesn’t offer a battery-powered product in the same vein.

For folks looking for maximum portability and the flexibility that battery operation provides, such as buskers for example since another power supply may not be readily available, the PX-S1100 is a truly unique offering in the price point.

Secondly, the PX-S1100 offers both Bluetooth Audio and Bluetooth MIDI (the S1000 only offered Bluetooth Audio). This means you can wirelessly connect the S1100 to computers and smart devices to extend the functionality without a cable courtesy of the free WU-BT10 Bluetooth adapter.

In terms of the rest of the other connectors, the S1100 also has 1/4” line outputs (L/MONO, R means no fiddling with adaptors when connecting to a PA system), USB Type A and B, a stereo mini line-in, dual headphone outputs, a sustain pedal input and a slot for the optional 3-pedal unit.

Thirdly, the S1100’s weight needs to be mentioned; the S1100 is the slimmest digital piano on the market and among the lightest, which is of course becoming increasingly important to consumers.

Yamaha P-125 On-Board Features, Connectivity

Over on the P-125 and we still have a very light instrument, in fact, it’s only a half pound heavier than the S1100, but it’s not as slim and as mentioned, does not offer battery power despite an otherwise minimalistic design.

The P-125 also oddly doesn’t offer any Bluetooth connectivity, whether wireless MIDI or audio, so if you want to connect to Yamaha’s great Smart Pianist App for Android and iOS Devices, you’ll need to do so via the USB port.

Now, on the other hand, the P-125 has a feature that alone makes it many people’s top choice, that feature being a built-in USB audio interface. Having a USB audio interface means you can connect to DAWs to send and receive audio information and do direct audio recording without the need for additional equipment, which can really have a big impact on gigging musicians.

The P-125 also has a solid onboard arranger function taking the form of an auto-accompaniment system. It’s loaded with a number of rhythms, and the accompaniment follows the harmony outlined by your left hand.
In terms of other connectors, other than Bluetooth, the P125 is basically the same as the S1100 with a 1/4” line out, USB to Host, a stereo mini line-in, dual headphone jacks, a sustain pedal input and a slot for the optional 3-pedal unit.

Standard Functionality Across both Instruments & Accessories

When it comes to standard functionality, things are pretty much the same between these two pianos as both come with things like a basic MIDI recorder, playback, split mode, transpose, a metronome, and some reverb engines. Both pianos have some built-in songs as well.

Both pianos come with a very basic footswitch sustain pedal that we would recommend upgrading to a more substantial damper pedal, and a music stand for sheet music.

Both pianos are available with an optional designer keyboard stand 3-pedal unit.

Closing Thoughts

To wrap things up, we’ve got two instruments here offered at almost the same price point to a piano-focused end user, and yet, the finer details around each instrument are quite different.

It’s a battle of equals, but where you place specific value, i.e. do you want the superior tone engine, Bluetooth and a small frame, or do things like auto-accompaniment and a USB audio interface matter more to you?

There’s no right answer here, but hopefully, this comparison has been helpful in answering some questions for you.