Parts-Express Samba MT

The Below is an excerpt from the Parts-Express product page for the Samba (this link takes you to a full kit available for purchase from Parts-Express, which simplifies the build process significantly, Highly Suggested):

Designed by the engineers at Dayton Audio, the Samba speaker kit is a compact 2-way bookshelf speaker that provides a reference quality sound without the usual high price. The Sambas produce an extremely detailed and accurate sound while still delivering a natural and non-fatiguing quality that is perfect for long listening sessions. Both the woofer and tweeter use low distortion motors and non-resonant diaphragms to deliver accurate sound that allows the speakers seemingly disappear into your listening environment. The Samba speaker kit will be right at home in everything from a high-end recording studio to any audiophile's living room.

The Parts Express Samba MT is a notable two-way bookshelf speaker design, leveraging high-quality components and advanced acoustic engineering to deliver reference-quality sound. This overview serves as a comprehensive repository of information about the Samba MT design, detailing the enclosure, crossover, woofer, tweeter, and port characteristics. It provides technical insights and practical advice for audio enthusiasts and DIY builders looking to understand or replicate this sophisticated audio system.

Enclosure

The enclosure’s external dimensions are about 15″ H × 8.5″ W × 11.75″ D, yielding roughly 0.5 cu ft of internal volume (after accounting for bracing and driver displacement)​. This relatively compact, bookshelf-friendly size still provides enough volume to support bass extension into the 40 Hz range, as we’ll discuss in the Port section.

Internally, the Samba MT cabinet should feature horizontal braces tying together the front, back, and side walls. This bracing, combined with thick panels, controls resonance.

Damping material is suggested to absorb internal reflections and midrange energy, preventing “boxy” coloration. Some hobbyists even experiment with adding a bit of polyfill or additional foam, but the stock damping of lining the walls with 1/2" acoustic foam is suggested for the intended bass response.

The design fully accounts for baffle step compensation (BSC) in the crossover – meaning the baffle width (8.5″) and resulting bass dispersion loss are compensated by boosting the speaker’s lower frequencies about 6 dB. In practice, this means the Samba MT is voiced for free-space placement, and you can place it on stands or away from walls without the bass thinning out. If you do place the speakers near boundaries (wall or shelf), expect strong bass; some builders in tight spaces have opted to slightly adjust port tuning or add stuffing to tame potential boominess, but in most rooms the stock tuning yields a pleasing balance.

Crossover

The crossover point is approximately in the 2 kHz range (where the woofer’s and tweeter’s outputs overlap and sum). This frequency was chosen to balance the dispersion and power handling – it’s low enough to avoid the woofer beaming too much, yet high enough to keep the tweeter comfortable and out of distortion. Both drivers’ “low distortion motors” and smooth roll-offs help in this regard.

The Samba MT uses a second-order filter topology (12 dB/octave slopes) on both the woofer and tweeter, combined with some response-shaping elements. From the included parts we can infer the network: the woofer circuit employs a 1.2 mH air-core inductor in series to low-pass the woofer, and a 7.5 µF capacitor (with a resistor) likely in parallel to shape the upper mids. Indeed, the crossover implements the full BSC by bleeding off midrange through a shunt network (a 7.5 µF cap in series with a 4.7 Ω resistor across the woofer) – this attenuates the woofer’s output above a certain frequency, effectively shelving down the mid and treble by ~6 dB to match the baffle loss​.

The tweeter’s high-pass uses the other 7.5 µF capacitor in series, paired with the 0.25 mH inductor to ground, forming a 2nd-order high-pass filter. The tweeter level is adjusted with an L-pad: the 1 Ω and 4.7 Ω resistors are used to pad down the tweeter’s higher sensitivity and ensure the combined system is around 87 dB/2.83V@1m​.

The exact configuration (whether 1 Ω series + 4.7 Ω parallel or vice versa) yields a few dB of attenuation so that the tweeter’s output integrates smoothly without overpowering the woofer. This also helps the Samba achieve its “natural high frequency response”, avoiding any harsh brightness​.

Modifications

For tweakers, the Samba MT’s crossover provides a great platform to experiment. Some advanced builders have tried replacing the passive network with an active crossover/DSP, essentially bi-amping the woofer and tweeter and using something like a miniDSP to dial in their own target curve​.

On the passive side, hobbyists have swapped resistor values to slightly brighten or soften the treble to taste, or experimented with higher-end capacitors, etc. The general consensus, however, is that no major changes are needed – the included components are well-chosen, and any significant rework would essentially be redesigning the speaker. If you do want to tinker, you can take comfort that the community has measured data (Erin provided raw driver measurements included in the Design Snapshot) so you can simulate crossover alterations before heating up your soldering iron​. For example, reducing the tweeter’s padding resistors could add some sparkle, or adjusting the woofer’s R+C shunt could bring the mid forward – but any such changes should be done with careful listening and possibly measurement, as they can affect more than just one aspect of the sound.