Revised MBOW1 3-Way

Revised Crossover for the Best Buy Insignia

Revised Crossover for the BR-1 Kit

Mod for Morel 403.5 3-Way


Revised Crossover for the Norh 9.0 Marble

The New Vifa Tower

Fixing the Polk RTi28

The MB20

The MB27

The Plop-in-the-Box

The Usher Two-Way

Revised Crossover for the Radio Shack LX550

Alternative Crossover for the Dynaudio Gemini

Crossover for the Revelator-RT1 Mini Monitor

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The Acoustic Research AR4x

A Tale of Two Cabinets

Tweeter Comparison

The RadioShack Minimus 7

JMLab Mezzo Utopia,
Tannoy Westminster,

Measurements for the Radio Shack LX550

Proac Super Tablette

Acoustic Research AR3a

Sound Dynamics RTS-3

Stock vs Modified Gemini

NHT Super One

A Tale of Two Cabinets

Conventional wisdom holds that tweeter diffraction effects cannot be reduced significantly with modest cabinet edge roundovers on the order of 3/4 inch.  This has not been my experience, at least not with the MBOW1.  This design, featuring the GR Research M130 woofer and the Hiquphon OW1 tweeter with 2nd order acoustic slopes, was developed using a cabinet with no roundover.  When I finally built myself a pair for demonstration purposes, I used a cabinet that had 3/4" roundovers on the top, bottom, and sides.  I kept the same crossover boards and drivers that I had used in the prototype.  I fully expected the new speakers to measure pretty much like the prototypes, which suffered from a diffraction peak at 4 kHz and a dip at 7 kHz.  But they didn't.  The diffraction problem was virtually eliminated, and the overall response was perhaps the smoothest I have seen.  Here is the response on axis and 15 degrees off axis with the original cabinet:

And here is the response at the same mic positions using the cabinets with 3/4" roundovers: