The Mandolin 2 Loudspeaker kit by Jeff Bagby

The Crossover

Jeff optimized the crossover in both the frequency and phase domains at the same time. The frequency response is exceptionally flat from 45 Hz up. The two drivers track each other in the relative acoustic phase. They track together in the crossover region and over a very wide bandwidth. The crossover point is at 1.8kHz. The response on-axis measures flat. The Mandolin would compare to many of the premium commercial designs available today.

How Does it Sound?

The speaker offers a wonderful sense of scale and weight, and bass extension that seems to defy its size. Not many speakers this size can reach into the 30 Hz band with low distortion. Sitting on a pair of quality stands, a pair of these small speakers will provide near-full range performance for the majority of music lovers on most of the music they play, without the need for a subwoofer.  However, if a subwoofer is used, these will blend gracefully, and allow a fairly low crossover point to the sub, which helps the subwoofer disappear, and provide a greater sense of realism.

Only a small tweak to the crossover was necessary to bring the “2” version up to date and a slight change to the box tuning.  I hadn’t listened to the Mandolin for some time, but it was a pleasure to reacquaint myself with them.  This tweeter was the first offering from SB and I am still surprised at the detail that emits from it.  The updated woofer still has that low-end punch but the mids are now more present and open.

The woofer cabinet is .53 cu ft or about 17L and measures 8.5″ wide, 15″ High and 11.5″ deep (3/4″ material)  You can download the cabinet drawing below.

Sensitivity is rated at 85dB  Easy 8 ohm load.

When you buy the Mandolin 2, here’s what you get:

Included in this kit are the full build plans.  You can purchase is in two forms, depending on your resources:

The Bare Bones Version:

• 2 x SB Acoustics, SB29RDAC-C000-4  Ring Dome Tweeters
• 2 x SB Acoustics, SB17NRX2C35-8 Woofers
• 2 x Crossover components featuring a choice of capacitors, choice of resistors, and Jeff’s specified Air and steel Core Inductors. (Audyn and Lynk pictured)

Need all the goodies?

The Full Kit Package:

• 2 x Choice of the Input Terminals
• 2 x Flared Port Tubes
• All mounting hard hardware (screws) 2 types
• Internal damping material
• Color-coded hookup wire
• Optional push-on connectors
• Gasket sealing tape
• MDF boards for mounting the crossover parts.

Have trouble soldering or reading a crossover diagram?  We can assemble them for you at a nominal charge.

Upgrades – Have another favorite input terminal or preferred capacitor brand?  Feel free to call or email with your request.  We are happy to accommodate you.

Mandolin Write Up

Mandolin 2 Cabinet Drawing

“Listen to the Mandolin Rain

Listen to the music on the lake

Listen to my heart break every time she runs away”

Bruce Hornsby