Quick answer: The Casio PX-S1100 is a slim, 88-key digital piano with a real hammer action, 192-note polyphony, and genuinely portable battery operation — a solid pick if you want acoustic-piano feel in a console-free chassis. The catch: it’s barely different from the older PX-S1000 it replaced. According to Merriam Music’s side-by-side review, the sound engine, the hammer action, and the polyphony are all unchanged — the main addition is a bundled Bluetooth adapter that PX-S1000 owners previously had to buy on their own.
Our best digital piano roundup already picks the PX-S1100 as the best slim/portable option. This review goes deeper on what you’re actually paying for versus the model it replaced, and whether that “1100” in the name buys you anything real.
Casio PX-S1100 at a glance
| Spec | PX-S1000 (previous) | PX-S1100 (current) |
|---|---|---|
| Action | Smart Scaled Hammer Action II | Smart Scaled Hammer Action II (same) |
| Polyphony | 192 notes | 192 notes (same) |
| Speakers | 2 x 8W | 2 x 8W, redesigned housing/cone |
| Bluetooth | Optional add-on adapter | WU-BT10 adapter included |
| USB audio recording | Not supported | Records to USB memory stick |
| Weight | about 24.7 lbs | about 24.7 lbs (same) |
What you’re actually getting
Casio PX-S1100
- 88 weighted keys on Casio's Smart Scaled Hammer Action Keyboard II — the same action used in the PX-S1000.
- 192-note polyphony, per Casio's spec sheet, with 18 built-in tones and 60 preloaded songs plus storage for 10 of your own.
- Runs on 6 AA batteries (about 4 hours alkaline) or the included AC adapter — one of the few full 88-key pianos that's genuinely cordless-capable.
A digital piano this size still arrives in a surprisingly heavy box — try Amazon Music Unlimited free to pull up a reference recording of whatever you’re learning while you wait for delivery. Once it’s set up, the PX-S1100 is one of the easiest 88-key hammer-action pianos to actually move around a house or carry to a lesson: it’s slim enough to balance on most keyboard stands, and the AA-battery option means you’re not hunting for an outlet every time you want to practice somewhere else.
The naming trap: “1100” sounds newer than it is
Here’s the part most retail listings don’t spell out. Merriam Music’s own PX-S1100 vs PX-S1000 comparison found the sound engine, the Smart Scaled Hammer Action Keyboard II, and the 192-note polyphony carried over unchanged from the older model. The real addition is the WU-BT10 Bluetooth adapter, now bundled in the box for MIDI and audio streaming — something PX-S1000 owners had to buy as a separate accessory. Casio also redesigned the speaker housing and cone material, but reviewers describe the resulting sound bump as modest rather than dramatic, not a meaningfully louder or clearer instrument.
Practically, that means two things. First, if you already own a PX-S1000, a standalone Bluetooth adapter is almost certainly a cheaper upgrade path than replacing the whole piano. Second, if you’re buying new and see a used PX-S1000 at a steep discount, you’re not giving up meaningful sound quality or key feel by going older — you’re giving up a bundled dongle and a slightly redesigned speaker box.
Who should (and shouldn’t) buy it
The PX-S1100 earns its spot in our best digital piano roundup specifically for portability: it’s the only piano in that lineup that runs on AA batteries, which matters if you’re setting up in a dorm, a studio with unreliable outlets, or moving it between rooms often. MusicRadar’s review backs this up on value, calling it worth the price for most buyers — but it also flags the action as a touch light and “clicky” compared to console-style pianos, a trade players coming from an acoustic instrument should expect going in. If key-feel weight is your top priority over portability, our best digital piano, weighted keys guide ranks the heavier-feeling Roland FP-10 and Yamaha P-225 actions above it for that reason.
The 4-hour alkaline battery runtime is also worth planning around rather than assuming. A single practice session is fine; a multi-hour rehearsal or gig on battery power alone is pushing it unless you’re running rechargeable NiMH AAs or keeping the AC adapter within reach as backup.
The bottom line
The Casio PX-S1100 is still a genuinely good slim 88-key piano — real hammer action, solid polyphony, and battery portability nothing else in this price range matches. Just don’t pay for it expecting a meaningfully different instrument from the PX-S1000: Casio’s own upgrade is mostly a bundled Bluetooth dongle and a mild speaker tweak, not a new action or sound engine. Buy it for the portability and the price, not for the model number.