Speaker Craft

Since 2025

Super magnets significantly boost the sonic performance of every wide band / full range speaker driver used in the Blumenstein Audio product line.

Neodymium super magnets super charge the stock ferrite magnetic circuit giving slightly greater power and clearer tonality. And before you go trying to add random magnets to whichever speaker drivers you have at home - know that the size / type of the additional magnet chosen matters immensely to the final sonic result.

The end goal is only to nudge ferrite magnets in the direction of sounding more like alnico, but not too far otherwise the sound can become brittle. It’s like mixing paints / optical sources to achieve the desired result, a better representation of nature. The goal is to achieve more of a “daylight” type magnetic source. But not so much additional magnetism that it begins to push the sound into “Flourescent” territory, or tilted too far towards Neodymium’s sonic signature. It took several iterations to arrive at the ideal balance of size vs grade of each booster magnet for each driver model that remained neutral in sound quality.

Since 2025

Solid wood interlocking internal braces - dried and milled from solid lumber for maximum axis of strength. Interlocked joinery like inside a guitar. Much like a guitar shop, our internal bracing structure is an ongoing and slowly iterative process, adjusted across years and various production runs. There were major revisions to bracing sizes and layouts in 2011, 2014, 2018, 2022, 2025. The development platforms for the formula we now use for internal bracing were the Orca and Triton.

Since 2022

Tuned Thickness cabinet walls - thickness of cabinet walls varies based on its size and position in the speaker cabinet. Meaning, some cabinet walls are deliberately thicker than others. This actually reduces weak points in the enclosure from the standpoint of acoustics. Plus, varying cabinet wall thickness relative to the span of each wall spreads the resonance more evenly throughout the enclosure. Together with the solid wood interlocking internal braces, Tuned Thickness means lower intensity resonant spikes than if the entire cabinet had been built in a uniform material thickness.

Since 2022

Flush mounted speaker drivers minimizes diffraction losses / irregularities in the frequency response.

Since 2022

Modular subwoofer shape allows freedom of placement around the room - on a shelf - on stands, subwoofers serving as stands, Inside the Ikea Kallax shelves, pretty much wherever you can dream up!

Narrow monitor / narrow floorstander: Triton II, Abby II, and Active Barnacle are all the same exact size, giving easier choice between Triton or Abby drivers, also allowing use as either monitors, traditional floor standers (one barnacle per side), or tall floor standers (two barnacles per side).

Wide monitor / wide floor stander Vinyl Shelf Tritons, Vinyl Shelf Abby, and Vinyl Shelf 10” Infrasub are all designed around the Ikea Kallax shelves, but aren’t necessarily limited to being used in those shelves… Just like the Triton II/Abby II plus Active Barnacle subwoofers-as-stands turns those monitors into floorstanders, the Vinyl Shelf Infrasubs can also serve as subwoofer-speaker-stands for the VS Triton or VS Abby.

Since 2022

Subwoofer driver choice - hifi home theater / hifi car audio type long throw subwoofer drivers chosen for industry leading dynamics, accuracy, and fun factor in compact, subwoofer cabinets. Subwoofer drivers with a greater potential performance envelope can also scale down to produce normal neighborhood levels of bass just fine. But the sheer amount of bass potentially on tap puts the rest of the bass made into a wider space. Smaller subwoofer enclosures actually have thicker walls per span than large enclosures, making them inherently stronger. For instance, a smaller enclosure made out of 3/4” plywood is going to be less resonant than a larger enclosure made out of the same 3/4” material . Not only are the smaller enclosure resonances lower intensity, but they are higher frequency in nature, which are easier to dampen out inside the cabinet.

Compact high power subs means there’s more energy coming from a smaller physical source. Easy power in the bass range is crucial for the system’s ability to disappear into a few distinct point sources of sound in the midband and upper ranges.

A parallel goal to sufficient headroom in the system is the flexibility of subwoofer / room placement along side or underneath the wide band drivers. Proximity of subwoofers and full range drivers produces tighter imaging, less phase interactions, and greater 3-D realism for subwoofer supported wide-band speakers. The same is true even in more real world/compromised acoustic spaces. Past clients have let us know that having more cone travel on tap than strictly needed is actually appropriate for pairing a subwoofer to our speakers. The subs aren’t ever stressed so you can hear the full range driver’s rich delivery of micro-dynamics.

A subwoofer that can scale up for dynamically challenging passages without perspiring can also scale back down to normal and lower listening levels and somehow everything else remains natural and in scale because power that never needs to be used still shapes the rest of the power being delivered.

Since 2022

Noise Reduction: Quartz pebbles strapped to or placed near audio connections. Quartz is one of several diamagnetic materials that could potentially function as a diamagnetic meta surface near the audio connections. Quartz, however, is inexpensive, readily available, and durable. Placing quartz near audio connections slightly bends a few of the stray magnetic field lines back into the leaky connector, slightly reducing magnetic field losses at connection sites. It turns out it’s actually a universally beneficial, cumulative sound quality enhancing technique for basically any and all audio systems as well as any AC connection (even wall power or digital) feeding the audio system. It sounds unlikely and perhaps a bit esoteric, but many people have tried this technique and kept it in their system. The sonic benefit in terms of three dimensionality and musicality from strapping quartz to the audio system connections is undeniable, as well as the basic science behind it.

Since 2021

Sanding with the grain. (no orbital sanders).

A technique adapted from the scrape finish of luthiers, sanding with the grain maintains the axial strength of the wood at the surface layer - which is crucial for controlling the way the enclosure resonance couples to the air in the room. It sounds unlikely but it turns out that the surface finish / not just the speaker enclosure material is actually where the “rubber meets the road” in a speaker enclosure’s resonant character.

Since 2019

Urethane feet - low durometer means minimal vibration transfer to surrounding objects. Grippy to the surface it’s sitting on for safety. While many materials were tried, urethane rose to the top of the list for its sound quality. Urethane is also, unsurprisingly, the best material for soaking up road vibrations as longboard wheels.

Since 2019

Upgraded to solid wood terminal plates as well as heavier duty, but still low mass binding posts. Three way binding posts accept bare wire, banana plugs, And now more readily accept spades and solid copper pin connections than the prior thru hole posts.

Binding posts since day zero of this company have been low mass, low distortion. At home, years before I started this business, I tested this experiment and almost every time, larger posts (any brand) will physically distort / diffuse the magnetic field of the signal versus smaller binding posts. My theory is that smaller binding posts look more like the actual 13ga speaker wire from the standpoint of the electrical signal. Now yes, there are far more esoteric / high concept binding posts than the relatively basic ones I have chosen. But I’m looking at one final factor - ease of user serviceability.

Since 2014

13 ga. internal wire - Waterline Cables (Blumenstein Audio’s in-house cable brand) primarily uses Gotham cable which is Swiss manufactured. Gotham makes traditional European studio monitor and microphone wire from the 1960’s, slightly modernized to the needs of today’s consumers.

Since 2013

Speaker gasket - A combination seal / damping compound to control the metallic resonances inherent in the speaker driver frame. Combines with the stacked rubber washers to damp out all unwanted vibrations from the speaker driver frame.

Since 2013

Screw torque. Along with damped washers, carefully seated driver screw torque creates a balanced contact between driver and cabinet. Driver frames themselves are instruments, and there is a specific range of contact pressure that is ideal.

Since 2012

Stacked rubber washers on driver mounting screws - combining urethane as well as rubber washers yields tuned decoupling between driver frame and cabinet.

Since 2009

Special editions in Bamboo ply - similar acoustics to Baltic Birch plywood and now offers an aesthetic choice - Caramelized color

Since 2005

Linseed oil Recommended by mentors Terry & Leslie Cain. They insisted that I only use non toxic finish products because they’d both dealt with the health horrors of using typical spray finishes over the course of their woodworking careers.

As it turns out, violins and other fine musical instruments are also traditionally finished in linseed oil. I work with a prior apprentice of Blumenstein Audio who went on to develop a variety of violin finishing products. Over the years, we have worked together to refine the acoustic recipe of what I do here with finishing the surfaces of the speakers…as well as the longboards.

Since 2004

Soldered internal connections. Terry Cain and Feastrex also used soldered internal connections to give themselves a slight sonic edge over the competition. Industry standard is cheap female disconnects for connecting internal wires to the speaker drivers and binding posts. Soldered connections take a little longer but do sound slightly better.

Since 2004

Baltic Birch plywood - The type with interior grade (non toxic) glue, the glue layers are clear. However, the “Outdoor” or “marine” grade stuff actually doesn’t sound quite as good for music and can be identified by the black glue layers. “Outdoor” or “marine” grade Birch has toxins in the black glue that spreads around the shop in the form of dust and eventually off gasses in the customer’s home. Authentic Baltic / Russian birch (with the clear glue layers) that comes in 5’ x 5’ sheets is also the first choice of music industry professionals for loudspeaker material.

Since 2004

Stacked plywood bass reflex ports. The strongest part of the enclosure should be the one subject to the greatest differentials in air pressure. Stacked and drilled plywood layers are stiffer and less resonant than industry standard plastic bass reflex ports.

Since 2004

All parts made by humans.

All patterns and parts made in house, without the assistance of a CNC machine. Unnecessary woodworking detail is avoided to keep the focus on just the sound quality.

Since 2004

Full range speaker drivers:

While there always seems to be something new on the scene, I somehow keep coming back full circle to working with the original Fostex and Pioneer type wide band drivers chosen by my original mentors Terry & Leslie Cain of Cain & Cain Audio. Terry had built many DIY audio systems dating back to the 70’s and carefully chose his favorites by the time he formally launched Cain & Cain Audio in 2001. At that point already, he’d chosen barely updated vintage drivers to launch his company with.

It’s important to bear in mind with full range drivers is that it’s already a 100+ year old technology, and the engineering behind them is basically mature and has been for quite some time. That’s not to say that progress isn’t being made at the cutting edge of the home built and high end full range driver scene like Voxativ and Feastrex, but the best drivers in my opinion (for the rest of us) are still a few tried and true standby models that have been consistently produced by the hundreds of thousands since the 1970’s, and gradually evolved into the top modern day performers we now have.

Sticking with basically the same full range speaker drivers for 20+ years of cabinet experimentations is a decision based on decades of further feedback and wisdom from thousands of additional Blumenstein customers from all over the globe. There’s always going to be the next level of musical performance possible from these original roots - and this is partly because the driver companies we’ve chosen to stick with have also thankfully chosen to slowly refine their construction and evolve the sound of their products as well.