There are few upright pianos available from any manufacturer for less than $5,000 that would be considered anything but an entry-level instrument; however, the Kawai K15 and Yamaha B1 are two that defy that stereotype. They’re well-made with the same level of craftsmanship we all expect from both companies, use quality components and the same design principles of far pricier instruments, and have shown themselves durable even in institutional settings. Yamaha and Kawai are of course two of the largest and most well-known manufacturers in the world, building upright pianos, grand pianos, and digital pianos for the entire global market. They are known to have some of the highest production costs, and certainly both Kawai and Yamaha standards are bench-marks for the global industry.

Stu Harrison at Merriam Pianos sits down for an objective, candid discussion of the two musical instruments in this video review and accompanying article. We hope you find it useful!

Kawai K15 vs Yamaha B1 Upright Piano Comparison Video Transcription

Hi, everybody, and welcome to another piano review. My name is Stu Harrison and we’re here at Merriam Pianos just outside of Toronto, Canada, in our Oakville showroom. And today, we are going to be comparing head-to-head the Kawai K15 the entry point into their K Series of Uprights, and the Yamaha B1 upright piano from Yamaha’s B Series pianos. Both are 44-inch acoustic pianos from the 2 Japanese giant manufacturers in the piano space. We’re going to be talking about their action, their sound, and most importantly, we’re going to be doing back-to-back comparisons of their tone. We’ve mic’d the pianos exactly the same way. Both pianos are approximately the same age. They’re both just about a year old or so. And so this should be a really good objective lined up comparison for you at home if you are looking at a new instrument in the under $5,000 category. I’m sure one or both of these instruments is already on your radar. So sit back, relax, enjoy the review. We’re going to get started right away.

So when we’re talking about these two instruments, it’s very easy to talk about what is the same or at least what’s in common between the two instruments. Besides the fact that they’re both designed and manufactured by one of the two largest companies in the world, Kawai Pianos and Yamaha Pianos, both are Japanese manufacturers, both of these instruments are made in their respective Indonesian factories. Both the Kawai K15 and Yamaha B1 are built in Indonesia, a country and a labor force which is increasingly becoming more respected for their piano-making and their piano-building. And they’re exactly the same height. They also have the basic commonalities like a muffler rail (mute rail in some lingo), use high-grade hammers (when compared to alternatives in the same price range), and are both available in Polished Ebony and Mahogany.

So where exactly are the differences? One thing I notice is that Yamaha refers to the B1 as an affordable entry-level upright, whereas Kawai doesn’t – and there are some technical reasons why Kawai may legitimately be able to claim a higher standard with the K15. Additionally, I can tell you is that the playing experience between the two is quite different. What I can’t promise is which one you’re going to like the most. Ultimately, you’re going to have to get into a showroom yourself, compare these two, and find out what is more responsive to your playing style, your playing touch. And I would say, undoubtedly, that the biggest two differences, which, of course, is always the big two when you’re talking about pianos, is how they feel and how they sound.

Comparing Piano Actions

So let’s talk about the action first. Now, the Kawai K15 makes use of Kawai’s ABS action. It’s not the carbon-fiber version, which they named the Millennium III. So this is an action which goes back to an earlier generation that they had designed and this would have been available, for example, on a lot of the previous K series like the K25, the K30. You saw this on a lot of the BL series and US series. So this is an action which, although it doesn’t use the absolute latest in Kawai’s technology, has like more than 30 years of use out in the field, very respected by technicians, lots of great write-ups on some of the benefits, mostly on the mechanical and maintenance side of things that make the ABS action so reliable.

And, in fact, not many people use this know this, but Yamaha upright pianos actually use an ABS component in their action as well. So it’s a material which is proven, but it’s also a material which multiple manufacturers, including Yamaha and Kawai, are both making use out of.

So what does this mean for the playing experience? Well, out of the box, these are the two differences I noticed between these two instruments, both in the Kawai K15 as well as the Yamaha B1. The increased use of the ABS in the Kawai – obviously – and the fact that, in my impression, Kawai is spending a little bit more time on factory prep on the K15 than what the Yamaha factory is on the B1. The action out of the box feels more fluid and it feels like there’s less mechanical resistance to the instrument with the K15. And so, I do find that the repetition speed and then just generally the sense of fluidity that you have on the action is just a little bit more. Again, this is out of the box.

And it’s hard to say what the B1 would be capable of if you were to spend, say, three or four hours or five hours with a really great technician concert level or just an experienced technician who could maybe ease that action a little bit and reduce some of the stiffness. But I also think there’s a geometry difference in those two actions. And I think Yamaha’s going for, you know, a very easy to control sort of one-size-fits-all, whereas the Kawai I think is going for something where the control in the lower dynamic range is excellent and the repetition speed is excellent. So there’s just some different priorities, I think, in what the two companies are trying to deliver through the actions.

And, of course, the increased amount of wood content in the B1’s action simply means that it’s a slightly heavier mechanism, so that is going to require a little more energy to activate and there’s a chance that, you know, in a climate where you’ve got a wider variation of humidity, perhaps that B1 action is going to require a little bit more regulating over time. But, generally speaking, both actions are mechanically quite sound. It’s just, as I said, when you get them both out of the box, the K15 just is going to feel a little more fluid than the B1.

Soundboard & Backposts

Some of the other big differences between these instruments, you actually can’t see on the inside or from the front. They’re on the back of the piano. And that comes in the form of back posts and soundboard. So the Kawai K15 is equipped with two back posts plus the two on the very end, so I guess some people would say that’s four back posts, as well as a solid spruce soundboard, in addition to it’s strong cast iron frame.

And so what does this translate into? Well, the back posts on an acoustic upright piano (and just heavier construction generally) are going to do a few things: manufacturers will claim that this increases the rigidity of the overall instrument. And so that increases the tuning stability, especially if the instrument is going to be moved or, you know, just how well it stands up to a bit of climatic change over time. But, musically speaking, what back posts normally do is it increases the amount of energy that can sort of flow through the overall structure. So the more back posts, so the theory goes, the more the energy overall is able to resonate through the whole body of the piano and so you actually get more sympathetic resonance. So you’re not just hearing the soundboard, but you’re actually starting to hear parts of the piano, structural piano, start to resonate and create piano tone.

The solid spruce soundboard, however, I would say probably has the biggest impact in terms of the tonal difference between these two instruments. And this is something that is a little hard to pick up on unless you have a side by side comparison like we do right now. And, as I said, in just a minute or two within this video, we’re actually going to give you an opportunity to hear side by side exactly what we’re talking about. Between it and the backpost, the K15 plays like a piano of much larger dimensions, and in the right acoustic setting, will astonish the ear with how open and clear the bass tone is.

And so this comes down to physics. A laminated soundboard or a surface tension soundboard is excellent for a few things. It is excellent for tuning stability, and it is excellent for longevity because the chances of that soundboard cracking are literally zero. And the level of how much it’s going to sort of swell and shrink, depending on the humidity level, again, is dramatically reduced because you’re layering wood and you’re sort of crossing the direction in which the wood grain is. And so, you create this very strong, very resistant structure that isn’t going to change very much when the temperature or the humidity goes up.

Musically speaking, a laminated soundboard it has some drawbacks. And the drawbacks are, of course, when you’re adding that glue and you’re adding all of that extra tensile strength, you’re actually increasing the amount of energy required to activate the soundboard. So in other words, in order to get some really great tone out of a piano with a surface tension soundboard like the B1, you actually have to put more in before the piano kind of comes alive. So below a certain dynamic range, really all you’re hearing is a little bit of the soundboard, some string tone, and very little sympathetic resonance through the rest of the instrument. On the Kawai, at a lower dynamic range, because it’s using that solid spruce soundboard, you have to put less energy in before that soundboard really becomes active. And so this, to me, is the number one difference between those two instruments is how active the soundboard or how active the instrument becomes, tonally speaking, at a lower dynamic range.

And so what does that translate into? What it means to a parent is that you’re going to be able to have an instrument like a K15, possibly take your son or daughter further along the musical spectrum before they need to upgrade something. Because the more responsive and the wider the dynamic range of an instrument, the more they’re going to be able to grow and develop their muscle control and develop their ear. And so there is a chance, of course, every situation is a little bit different, but I would say, generally speaking, any piano with a solid spruce soundboard compared to a surface tension soundboard, all other things equal, is going to allow somebody to just expand their music horizons a little bit more because of that increase in the dynamic range that you get from the solid spruce.

Conclusions and Summary

So, that pretty much concludes what I would assess as sort of the major similarities and differences between those two instruments. Virtually the same price point, same country of manufacturer, same height, two extremely respected companies building these instruments. But, again, main differences are the feel of the action, a little more fluid versus a little more stiff out of the box. And then, of course, we’ve got back posts versus no back posts and a solid spruce soundboard versus the surface tension soundboard.

All in all, you can’t go particularly wrong with either one of these, as an alternative to a used taller upright. They will thrive more in smaller rooms vs larger, and both obliterate lesser competitors in the price category for overall build quality and stability / longevity.

So let’s hear what they sound like back-to-back. So we’re going to listen to them back-to-back now, and it’s important for people to know at home that we are mic’ing these instruments in exactly the same way. We’re going to use an AKG C 414 microphone, which is a very well-known, very popular studio-grade microphone. It’s going to be placed exactly the same place on both pianos. And we are not using any compression, any EQ, or any other affecting whatsoever. You’re going to be hearing at home exactly what we’re hearing here in the showroom, or at least as close as possible with the same microphone so that you at home are getting a true comparison. Enjoy!