Compact Form.
Expansive Sound.
Flow/1 is a folded coaxial tapered quarter-wave-tube 3D-printed loudspeaker system for builders who want more than output, more than specs, and more than another box with a driver in it. It is designed to deliver deeper bass, sharper image focus, and cleaner system coherence from a unique, compact enclosure that fits in real rooms.
Engineered for Presence
Quarter-Wave Tube
The Flow/1 is A 1.7-meter folded, tapered quarter-wave tube loudspeaker that you 3D print yourself. The Flow/1 delivers controlled low-frequency extension while suppressing standing waves through distributed geometry.
Coaxial Point Source
Time-aligned coaxial drivers with FIR crossover produce a coherent wavefront, yielding precise imaging and stable soundstage localization.
Compact, Tuned Enclosure
A 5L enclosure tuned to 48 Hz balances size, bass extension, and efficiency in a form factor suited to real listening spaces.
Most speakers in this size class force a tradeoff. Flow/1 resolves those compromises through geometry and Digital Signal Processing
Designed for the PiBiDiY Maker
Flow/1 was created specifically for the PiBiDiY community: people who print, build, measure, refine, and care deeply about how a system works. This is not a finished consumer product. It is an engineered loudspeaker system you build yourself, understand deeply, and bring to life with your own hands.
Who it is for
- For builders who want a loudspeaker that they cannot buy off the shelf
- For listeners who care how and why it works, not just whether it plays
- For people who see the effort itself as part of the reward
What You Get
Maker’s Guide
A detailed build path covering materials, tolerances, assembly, and construction choices. The value is not just instruction; it is confidence that a physical object is being realized the way the design intended.
Theory of Design
Theory of how the folded coaxial tapered transmission line works.
User’s Guide
Set-up and in-room testing guidance for builders who want the result, not just the build. Includes the workflow around listening, refinement, and tools such as REW, miniDSP, and SigmaStudio.
Design Files
Complete STL and STEP files for all enclosure components, optimized for printability, fit, and acoustic performance.
DSP & Tuning Files
DSP and tuning files make Flow/1 a complete system rather than a loose concept. Geometry, active FIR crossover, and alignment were developed together so the design performs as a coherent system.
Created from First Principles
The Flow/1 is not a conventional small loudspeaker. It is based on the folded coaxial quarter-wave tube principles embodied in U.S. Patent 7,925,036 B2, and combines that patented acoustic architecture with modular construction, active DSP crossover control, and modern additive manufacturing methods. The result is a compact but highly engineered loudspeaker system designed to achieve unusually coherent imaging, strong low-frequency extension, and flexible driver experimentation from a very small form factor, optimization, coaxial point-source behavior, and FIR-based time alignment into a compact, buildable system.
Every dimension, taper, and fold; every internal cubic millimeter is intentional and optimized for accurate sonic reproduction.
Why this design
The folded quarter-wave tube is there to extend and control low-frequency output, while unequal-length segments and the dimpled, pimpled folds help suppress internal resonances that overwhelm a small speaker.
The coaxial driver is there because coherence starts at the source, helping the speaker behave more like one acoustic event than separate elements fighting for position.
Time alignment and FIR crossover are there to reduce crossover compromise and make the system feel connected, resolved, and intentional.
Why Bother Building This Flow/1 Speaker?
Because Flow/1 is not just a box that makes sound. It is a compact, engineered loudspeaker system built to do something most small speakers struggle to do well: disappear into the room and leave you with the music.
Most speakers in this size class force a compromise: you get convenience, but not bass; detail, but not coherence; imaging, but not transparent soundstage.
Flow/1 exists to challenge those tradeoffs through careful geometry, controlled loading, time alignment, and DSP, not brute size. The goal is simple: deeper bass from a smaller footprint, sharper image focus, and a more coherent presentation from a speaker that still suits a real room.
Because building it gives you access to the whole system:
- the acoustic design
- the physical design
- the DSP
- the reasoning behind the choices
This is not generic DIY for its own sake. It is a compact active loudspeaker designed for serious listening, with controlled low-frequency extension, point-source coherence, precise imaging, and a form factor that makes sense in everyday spaces. Because if you are the kind of person drawn to PIY, DIY, or BIY, the effort is part of the reward. You do not just end up with a product. You end up understanding the machine and hearing the difference those decisions make.
And because the cost of building one is not just money and time. It is an exchange. You put in care, attention, and effort, and in return, you get something personal, unusual, and deeply considered. Something that reflects your standards, not a manufacturer’s brief.
So the real answer is this:
- You bother if you want presence instead of mere playback.
- You bother if you want to build something rare.
- You bother if you want to hear what careful geometry, controlled loading, and coherent radiation can do in a compact system.
If that matters to you, then Flow/1 is exactly the kind of project worth building.