While most soundboards are traditionally graded by visual and tactile inspection (grain, colour, figure, and stiffness by feel), our Sonically Graded Soundboards go a step further.

We use BING (Beam Identification for Non‑destructive Grading) technology to measure key acoustic properties: density, stiffness, and damping (Q value). These measurements help us steer the high-Q wood into our sonic sort, and from there, we put it into three different density buckets: low, medium, and high density sonic grades. This allows luthiers to choose the right wood for the right guitar.

The sonic grades reflect the measured density of the soundboard after it has already passed tests for stiffness and damping (Q value). Once a board qualifies for sonic grading, it is sorted into:

• Low Density (350–400 kg/m3): Lighter boards, often selected by builders who value quick responsiveness and warmth.
• Medium Density (400–435 kg/m3): Balanced weight and stiffness, an excellent all-purpose range for most guitar designs.
• High Density (435–500 kg/m3): Heavier boards with strong projection, ideal for larger bodies or players seeking headroom and clarity.

Yes, it’s completely non-destructive. In simple terms, we place the soundboard blank across a beam fixture and drop a small steel ball from a consistent height. Sensitive microphones capture the board’s vibration response. From this data, we calculate stiffness (modulus of elasticity), density, and damping. The board is never damaged, and no material is removed. You receive it exactly as tested.

Not entirely. While sonic grading gives highly useful quantitative data, we still evaluate each top for grain uniformity, cosmetic quality, colour consistency, and defects. The focus of our sonically graded tops is performance, but we ensure every piece meets a strong visual standard as well. You might see a range of visual grades within the sonic sort, but every top is clean, buildable, and selected to sound exceptional.

Yes, our sonically graded tops are listed by grade, and you can shop accordingly. If you're looking for a specific density or Q value, the Vault is the best place to start. You should be able to see 2-piece and 4-piece tops. There, you can filter available tops by stiffness, damping (Q), and density to find the right match for your build style.

Sonic grading adds a level of predictability that many luthiers find valuable, especially for repeatable builds. For production runs or builders dialing in consistent tonal targets across multiple guitars, the measured data allows for more precise material selection. It also helps newer builders better understand how material properties correlate to final tone.

Currently, our sonic grading program focuses on spruce species, specifically Sitka and Lutz. These are among the most widely used soundboard species for their stiffness-to-weight characteristics and their versatility in guitar making. They benefit greatly from this level of testing. If we expand sonic grading to additional species in the future, we’ll update our catalogue accordingly.

Sonically graded tops offer a higher degree of repeatability. Traditional grading relies on visual cues and tactile experience, which are valuable but subjective. By contrast, sonic grading allows multiple tops to be compared against objective measurements like stiffness-to-weight ratio and damping. 

This means that luthiers gain the ability to select tops that fall within a highly consistent acoustic property range, making it possible to build multiple guitars with nearly identical sonic starting points. This is particularly helpful for production runs or builders fine-tuning a specific tonal target across many instruments.