Compactness, Durability and Mobility

Engineers’ thoughts on how to create a drum kit that can be played anywhere and will not break, while ensuring that customers will enjoy it for a long time.

Ensuring the sound quality of our musical instruments

Meeting the needs of making a musical instrument with a lightweight and compact chassis yet which offers drum sounds with full-on impact while being comfortable to listen to is an extremely tough job.

That’s because reducing the speaker size typically means that you must make compromises in sound level and quality. With the FGDP, Yamaha’s developers who specialize in audio products eagerly took to the task of solving these problems… and as a result, they’ve brought into reality a product that makes everyone from pro artists to first-time finger drum players say, “how can an instrument so small make such a massive sound?”

Engineer: Kanayama


In developing the FGDP, our goal was to create a product around 30 × 30 cm in size, meaning something that can rest in your lap and be played comfortably with ten fingers. We also looked at it from the perspective of something that’s neither too small nor too large, and something that you can easily pick up and carry with you.

FGDP product planner: Miura


Given that, what we wanted to prioritize most of all was to ensure this product’s quality as a musical instrument. There were things we didn’t want to skimp on despite the product’s size. These included the punchiness and impact of the sound when you play it as you would play a drum, as well as whether the instrument could produce enough volume to make you feel good when you play it, despite its compact size. If we couldn’t realize these two things, there would be no reason to make the instrument.

Engineer: Tabata


To achieve powerful sound and sufficient volume, we decided to increase the size of the built-in speaker and the speaker enclosure as much as possible, given that the product’s size had already been determined.

That said, trying to secure enough space for the speaker enclosure inside the chassis was like battling with the other components. In addition to the speaker enclosure, but the motherboard and the other components, as well as the bosses (the cylindrical pillars that support the top and bottom of the unit) required to ensure the unit’s durability had to all be packed inside.

It's normal for a product’s body and internal structure to evolve as development progresses, and we used a 3-D printer to create and optimize the speaker enclosure amidst these repeated changes of specifications. Specifically, we created a bass reflex port so that we could comfortably and powerfully achieve a strong low end that’s typical of bass drum sounds. Also, to have a clear sound without wind noise or standing waves that are prone to occur, we made repeated alterations such as changing the shape of the speaker enclosure so that the sounds within the speaker reflect randomly, and amending the placement of absorption materials.

After finalizing the specifications of the speaker enclosure, we fine-tuned the sound using digital processing.

A solid, durable product

Owing to its nature, we designed the FGDP to withstand tens and hundreds of thousands of pad strikes, and considered that the product might be dropped accidentally when placed on the user’s lap while they’re sitting and playing on a sofa. Further, we acknowledged that the instrument might be subjected to harsher environmental conditions than most other musical instruments, due to how easily it can be taken outside to play. Even though the FGDP is compact like analog instruments such as ukuleles or recorders, it’s still a digital musical instrument, which means that it’s packed with precision electronics on the inside. Given these factors, we naturally knew that ensuring the solidity and durability of the instrument should be our top priority.

Kimizuka and Kanayama


How tough does the instrument need to be in order to withstand situations that would normally break it? We imagined that with a chassis like this that’s small enough to fit on your lap and be played, users might drop it while they’re playing, handle it a bit roughly, put it on their sofa and accidentally drop it on the floor and so forth. We tested the product with these criteria in mind.

Aside from the number of screws, we could greatly improve the overall solidity of the instrument just by increasing thickness of the bosses and the height of the ribs (which are attached to the inside of the instrument to strengthen the chassis) by a few tenths of a millimeter, and we actually dropped the unit many times to check the durability.

Engineer: Kimizuka


Aside from the chassis, we conducted durability testing on the pads. These tests involved resistance to dust, heat, cold, and high and low humidity.

For these tests, we prepared extremely cold and extremely hot rooms, where we took turns going inside to pound away at the units. We knew that doing so for long periods of time would be dangerous, so we did this with multiple people and worked to ensure everyone’s safety. As a result, we confirmed that the instrument could withstand the rigors of all sorts of environments, so that people living in all kinds of places around the world would be able to enjoy playing it.

What’s expected from a “mobile instrument”

When you think of something you carry around with you every day, the first thing that comes to mind is likely your smartphone. Smartphones are convenient in that you can use them whenever you need, even while they are recharging. On the other hand, if you always had to replace the batteries every time they were depleted, most people would agree that the device wasn’t very usable.

When we were doing product planning for the FGDP, two of our developers were dead set on using built-in rechargeable batteries for the product, no matter what. Against that, the problem with the rechargeable batteries in smartphones is that they degrade after a few years of use and become unable to fully recharge. We want our customers to be able to use the instruments they purchase for as long as possible, so what kind of batteries should we use? A possible solution we came up with was the lithium iron phosphate battery.

With this, we began researching the use of iron phosphate batteries, a new type of rechargeable battery, with the intent of making the user’s life playing music as comfortable as possible.

Engineer: Hayafuchi


We thought that the unit had to be rechargeable so that users could take it along and play whenever they liked, which is why we stipulated in our planned specs this time that the unit should be able to be powered through recharging.

At that time, we had our eyes set on a type of lithium-ion battery using lithium-iron Phosphate, which hadn’t really proliferated in the market when we started developing this model. This was because although lithium iron phosphate batteries are not quite as good as other common lithium ion batteries used in smartphones and electric vehicles in terms of energy density (capacity), they last longer and are safer by far. Lithium iron phosphate batteries are excellent from a safety perspective, considering that these batteries won’t ignite when players are mashing the pads countless times while they’re playing or when the player happens to drop the unit and subjects it to impact.

When we consider the user’s convenience and safety, lithium iron phosphate batteries have a clear advantage. However, when we started developing the FGDP there were few lithium iron phosphate batteries available on the market that suited our products, so we tried various approaches in our efforts to finalize the specifications, including searching for ICs to monitor remaining battery capacity that were appropriate for use with our products.


As far as battery capacity and overall longevity goes, after studying the issue at length we set our targets at three hours of battery life under continuous play at maximum volume. It’s been a real challenge, creating an instrument that checks all the boxes in terms of product convenience, safety, and longevity.