Kurzweil is a brand often associated with some of the most realistic sound keyboard pianos on the market.
They may not be discussed as commonly as Roland, Nord, or Yamaha instruments, but they consistently deliver high-quality sound.
In this review, we are looking at the SP6, a 16-part multitimbral, lightweight stage piano with a big sound.

Our verdict on the Kurzweil SP6
The Kurzweil SP6 is a fantastic keyboard with some remarkable sounds. It’s also very easy to use with an intuitive interface.
We feel it falls slightly short of the best stage pianos available, but the price reflects that, too.
Sound quality
The SP6 has a massive number of preset sounds. It features 256 single instruments and 130 multi-instrument presets.
The included sounds come from the Vast, VA1, and KB3 sound engines. The stars of the show are the high-definition nine-foot Japanese and German D Concert Grand Pianos.
As with any stage piano, you can tell a lot from the low-end. Too often, the bass notes lack clarity and depth. But, the SP6 delivers a rich low-end that doesn’t get muddy, whether you are walking basslines or anchoring chords with root notes or octaves.
The transition through the ranges is accurate and topped off with amazingly crisp highs.
A wide variation of sounds is available, covering electric pianos, clavinets, harpsichord, organs, and more. Beyond the acoustic pianos, the ToneReal organs stand out, ranging from jazzy and percussive to gritty.
The 130 multi-instrument voices offer many great examples of how big the SP6 can sound.
Also included are selected sounds from the Forte SE, PC3, and KORE 64.
The SP6 provides a versatile selection of high-quality sounds with a max polyphony of 128-notes.
Keyboard feel
It’s probably safe to say that we have never played a Kurzweil keyboard with a terrible feel. They tend to be pretty convincing in that area.
If we had a complaint, it would be that the action just doesn’t have enough life every now and then.
The weight is typically very good but sometimes lacks the action to play certain techniques, like trills confidently.
Thankfully, the SP6, with its fully-weighted hammer-action keys, is one of the most convincing that Kurzweil offers.
Still, we have scored it sensibly as it’s not quite as authentic as some of its competitors. See our picks for the best fully-weighted keyboard pianos.
Features
The Kurzweil SP6 doesn’t have the most flamboyant features, but it certainly packs in some extremely useful ones.
2 GB sample content
The SP6 comes with 2 GB of sample content covering a range of genres and moods.
Thanks to Kurzweil’s FlashPlay technology, sounds have zero-load time, which is perfect for recalling sounds on stage.
Effects engine
The impressively powerful effects engine features 32 FX units. The built-in effects cover most of the usual suspects with reverbs, delays, chorus, phaser, distortion, dynamics, and more.
You also get a lovely rotary speaker simulation that turns the average organ sound into something with much more life.
MIDI controllers
Although the SP6 is a relatively clean-looking instrument, Kurzweil still made room for 20 fully-programmable controllers.
Arpeggiators
There are four onboard arpeggiators with dedicated transpose buttons. They are a great way to add rhythmic content to your performance on stage or your production in the studio.
Dynamically-allocated polyphony
This feature is one of our favorite things about the SP6. Having a max polyphony of 128 notes seems like more than enough, and generally speaking, it is.
But one of the things that the SP6 does very well is split, and layer sounds across its four zones, which eats away at polyphony.
Dynamically-allocated polyphony prevents any nasty drop out even when you reach max polyphony.
It does so by selecting the most suitable or least obvious notes based on dynamics. Very clever.
In use
Scoring this stage piano is difficult in some ways because there isn’t much to complain about at all.
It falls in a price range that is a little short of legitimate high-end stage pianos. The problem is that, without anything being particularly bad, it falls a little short of high-end quality, too.
Having said that, it does have a pretty intuitive interface that provides a smooth workflow for performance.
Along with an LCD, the heart of the interface is the control section. The control section is where you can activate or de-activate zones and adjust various parameters using four assignable knobs and a shift button to move between three layers of parameters.
Navigated through sounds is quick and easy, too, with dedicated category buttons and favorites.
You can use the main encoder to scroll through selections with a category selected.
Build quality
In a departure from the usual Kurzweil style, the SP6 is a lightweight unit. In fact, at just over 27 lbs, it’s the lightest stage piano that Kurzweil has ever made.
Even more unusual is that it looks as substantial as more other models, so the lack of weight is very surprising.
While the weight makes it easier to get around when gigging or touring, it also means it’s not quite as robust as some previous models.
We have taken all of this into account when awarding our score.
Ultimately, we think the lightweight body is a triumph with no significant concerns over the build quality.
Connectivity
Connectivity is relatively basic, but the essentials are here.
The SP6 provides two 1/4″ audio outputs, a 1/4″ headphone out, MIDI in/out, and two USB ports (type A/B).
For the money, it has got what you’d expect; it’s only when you compare it to more expensive keyboard pianos it feels like it’s lacking a little.
Compared to other stage pianos
The SP6 sounds great and delivers value for money. Here are some more stage pianos that we think are worth checking out.
Kurzweil SP6 vs. Studiologic Numa X Piano GT
The Numa X Piano GT is outstanding if you can stretch your budget a bit more. If not, you might want to consider the Numa X Piano without real wooden keys.
Check out our Studiologic Numa X Piano GT review
Kurzweil SP6 vs. Roland RD-88
If you want something lightweight but aren’t convinced by the SP6 sound, Roland’s RD-88 would be an excellent choice.
It’s not the most robust unit available, but that’s to be expected with its weight.
Check out our Roland RD-88 review
Kurzweil SP6 vs. Yamaha P-515
The P-515 offers real wooden keys and fantastic piano voices at a reasonable price. It also has built-in speakers, making it easier to play anywhere.
Who is the Kurzweil SP6 best suited for?
It suits gigging musicians who want a lightweight stage piano that lets them do just about everything from a single keyboard.
- Fantastic piano sounds.
- Wide range of sounds.
- Dynamically-allocated polyphony.
- Intuitive interface.
- Lightweight.
- Average connectivity.
- Lighter weight means less robust build.