Kawai ES120 vs Casio Privia PX-S1100

Key Action

Kawai's key action is the Responsive Hammer Compact, often abbreviated RHC. The supplied facts state that it provides a smooth and even weight across the keys. It uses two sensors per key and does not include escapement simulation. The key tops are plain matte without any texture. In the scoring breakdown, Kawai received 25 out of 30 for key action.

Casio uses the Smart Scaled Hammer Action. The listing does not specify the number of sensors or whether escapement is simulated. According to the cons, this action is lighter than the Roland PHA-4 and the Kawai RHC. Casio's key action score is 24 out of 30, just one point behind Kawai.

The difference in scores is small, but the described character differs. Kawai emphasizes a smooth, even response that many players describe as natural, while Casio prioritizes a lighter feel that may suit faster playing or longer sessions. Buyers who want a more substantial hammer feel will likely prefer the Kawai, while those who prefer less resistance may like the Casio.

Piano Sound and Speakers

Kawai's sound engine is Harmonic Imaging with 88-key sampling. This means each of the 88 keys was sampled from a Kawai grand piano, which the pros describe as warm and natural. The Kawai has 25 onboard voices and 192 notes of polyphony. Its two built-in speakers are rated at 10 watts each. The piano sound score is 24 out of 25, nearly perfect.

Casio uses the AiR sound engine with string and damper resonance. It offers 18 onboard voices and the same 192 note polyphony. Its two speakers are rated at 8 watts each, slightly less powerful than the Kawai's. The cons note that the speakers are small for the engine's quality, suggesting external amplification helps. Casio's piano sound score is 22 out of 25.

Kawai has the edge in overall piano tone according to the supplied scores and pros. The 88-key sampling is praised as warm and natural, while Casio's engine includes resonance modeling but gets two fewer points. The speaker wattage difference is modest, but Casio's smaller speakers are called out as a limitation. For the purest onboard piano sound, Kawai appears stronger.

Features and Modes

Kawai includes 25 voices and 192 note polyphony. Its Bluetooth support covers both audio and MIDI and is built in with no adapter needed. An F-10H sustain pedal is included, and an F-350 triple pedal is optional. The Kawai does not offer USB audio, only USB MIDI. Its feature score is 12 out of 15.

Casio includes 18 voices and 192 note polyphony. Bluetooth audio and MIDI are available through the included WU-BT10 adapter, not built in. A sustain pedal is included, and an SP-34 triple pedal is optional. Casio's features include a touch-sensor panel that is invisible until powered on, which the cons say takes getting used to. Its feature score is 13 out of 15, one point higher than Kawai.

Despite fewer voices, Casio scores slightly higher on features, likely because of its battery capability and the touch-sensor panel adding a modern feel. Kawai counters with built-in Bluetooth and more voices. Neither piano offers USB audio, which is a limitation for direct recording to a computer. Both include sustain pedals and have optional triple pedal upgrades.

Build, Design and Portability

The Kawai ES120 is a portable slab weighing 26.5 pounds, or 12 kilograms. Its form factor is standard for a stage piano, with no mention of battery operation. The build and portability score is a perfect 10 out of 10. It includes quarter-inch line outputs, which are useful for connecting to a PA or audio interface.

The Casio Privia PX-S1100 is described as ultra-slim and battery capable. It weighs 24.7 pounds, or 11.2 kilograms, slightly less than the Kawai. Its depth is 232 millimeters, making it the slimmest full hammer-action piano in its class according to the pros. The build and portability score is also 10 out of 10. It has quarter-inch line outputs as well.

Both pianos score perfectly on build and portability, but they achieve it differently. Casio wins on slimness and battery power, making it easier to carry and use away from outlets. Kawai remains light and portable but does not offer battery operation. If ultimate portability is the goal, the Casio has a clear advantage in dimensions and power flexibility.

Connectivity

Kawai includes Bluetooth audio and MIDI built in, so no separate adapter is required. Its USB port provides USB MIDI, but not USB audio. The quarter-inch line outputs allow connection to mixers, monitors, or recording interfaces. The listing does not state the number of headphone jacks. The connectivity score is 9 out of 10.

Casio includes Bluetooth audio and MIDI, but they require the included WU-BT10 adapter. Its USB to Host port also carries MIDI, not audio. Casio has quarter-inch line outputs and two headphone jacks, which is convenient for silent practice or duets. The connectivity score is also 9 out of 10.

Both pianos earn the same connectivity score. The key difference is that Kawai has Bluetooth built in, while Casio requires plugging in the small adapter. Casio adds two headphone jacks, a detail that Kawai's listing does not confirm. Neither piano offers USB audio, so external audio interfaces are needed for digital recording.

Setup and Accessories

The Kawai ES120 comes with an F-10H sustain pedal. An F-350 triple pedal unit is optional for those who want soft and sostenuto pedals as well. Because Bluetooth is built in, there is no adapter to connect or lose. Setup mainly involves placing the piano on a stand, plugging in power, and turning it on.

The Casio Privia PX-S1100 includes a sustain pedal. An SP-34 triple pedal is optional. The box also includes the WU-BT10 Bluetooth adapter, which must be plugged into the USB port to enable wireless connectivity. Setup may be slightly more involved because of this adapter, but it is included so no separate purchase is needed.

Both pianos provide the essential sustain pedal out of the box and offer triple pedal upgrades. The Casio's touch-sensor panel may require a short learning period, as noted in the cons, but this is not a setup issue. In terms of accessories, the included Bluetooth adapter for Casio is a plus, though Kawai's built-in approach avoids the extra piece.

Daily Use

For daily practice, the Kawai ES120 offers a warm, natural piano tone that is easy on the ears. The smooth RHC action is even and predictable, and the 10 watt speakers are adequate for home use but can be supplemented with line outputs. Built-in Bluetooth audio and MIDI make it simple to stream backing tracks or connect to piano apps without extra hardware. The lack of USB audio means you cannot record directly to a computer over USB, but the line outputs can feed an audio interface.

The Casio PX-S1100 is extremely convenient for small spaces and travel. Its battery capability lets you play anywhere without an outlet, and its 24.7 pound weight is easy to carry. The touch-sensor panel disappears into the flat surface when off, which looks clean but requires practice to operate blind. The smaller built-in speakers may feel weak for the engine's quality, so many users will want to use the quarter-inch outputs to external speakers or headphones. Its Bluetooth adapter is small but must be plugged in for wireless use.

Both pianos are suitable daily instruments. Kawai excels in acoustic-like tone and simple wireless setup, making it a strong choice for traditional practice and performance. Casio excels in portability and modern minimalism, ideal for those who move frequently or want a piano that can run on batteries. Your daily routine and space constraints will determine which trade-offs matter more.

The Deciding Question

The core question is whether you value a warmer, more natural piano sound and built-in wireless over ultra-slim design and battery power. Kawai gives you 88-key sampled grand piano tones, 25 voices, and Bluetooth audio and MIDI with no adapter, all in a light but conventional slab. Casio counters with the slimmest full hammer-action body, battery capability, two headphone jacks, and a touch-sensor panel, but its speakers are smaller and its Bluetooth requires an adapter.

Scores are nearly tied: Kawai 87 overall, Casio 86 overall. Kawai wins on piano sound (24 vs 22) and key action (25 vs 24), while Casio wins on features (13 vs 12) and value (8 vs 7). Both have perfect build and portability scores and equal connectivity scores. The deciding factor is not one spec but the combination of priorities: acoustic tone and simplicity versus size and mobility.

Who Should Buy Which

Buy the Kawai ES120 if you prioritize a warm, acoustic-like piano tone above all. It is the better choice for players who want built-in Bluetooth without fumbling with adapters, who appreciate 25 onboard voices, and who do not mind the lack of escapement and USB audio. The smooth RHC action and 10 watt speakers make it a reliable home or stage piano.

Buy the Casio Privia PX-S1100 if you need the slimmest and most portable full hammer-action piano available. It is ideal for musicians who travel, perform in small spaces, or want battery operation. You should be comfortable with the touch-sensor panel and willing to use the included Bluetooth adapter. If you often play through external amplification or headphones, the smaller onboard speakers matter less.