Andrew Jones MoFi SourcePoint 8 Concentric Speaker, Compact Form Factor

Loudspeaker designer Andrew Jones reportedly spent over 18 months developing the SourcePoint 10, his first effort for MoFi Electronics. Jones said the SourcePoint 10 was designed like a cost-no-object loudspeaker — completely custom-tooled, and packed with proprietary technology. It was also Jones’s first two-way concentric design (he has favored three-way speakers for most of his career) and his first to use a 10-inch concentric driver. With the R&D groundwork laid and the SourcePoint 10 out in the world, Jones was quicker to release his second MoFi speaker, the new SourcePoint 8 ($2,750/pair), which was introduced at the Axpona audio show. As its name would suggest, the SourcePoint 8 is a smaller version of the SourcePoint 10, with an 8-inch concentric driver instead of a 10-inch. In fact, the SourcePoint 8 looks so similar to its larger sibling that it’s hard to know which one you’re looking at in a photo. But place them side-by-side, and the difference is clear. The SourcePoint 8’s cabinet measures 18 by 11.4 by 13.2 inches, giving it about half the cabinet volume of the SourcePoint 10. Jones explains that since the new driver’s diameter is 80% that of the original, it made sense to shrink each cabinet dimension accordingly. The new speaker is therefore about 80% as tall, 80% as wide, and 80% as deep as the original. The result of this mathematical reduction is a Mini-Me speaker that can fit into more rooms than the SourcePoint 10 (which, though it’s a stand-mount design, looks surprisingly big when you see it in person).

We always had the intention of releasing a smaller SourcePoint, but our first priority was demonstrating just how good a large diameter 2-way concentric speaker could sound when we were not so much size constrained. Everyone who hears and loves the sound of the 10-inch, but can’t fit them in their room, now has that sonic quality available in a much smaller package.

 — Andrew Jones, Chief Loudspeaker Designer at MoFi Electronics

Like most of Jones’s designs, the SourcePoint 8 is built around a custom-made concentric driver, in this case an 8-inch “paper pulp mix” cone with a new corrugated surround, combined with a 1.25-inch soft dome tweeter with a large-diameter voice coil and a surprisingly wide surround for a high-frequency driver. At work behind the scenes is MoFi’s innovative Twin-Drive high-flux magnet structure, which “creates a fully symmetrical magnetic field, eliminating flux modulation for extremely low intermodulation distortion (IMD),” according to MoFi. The magnets of the woofer and tweeter motor “deliberately couple together so that each aids the other in driving flux across both the woofer and tweeter gaps.” The result is said to be greater flux density than either motor would be able to achieve on its own. The shape of the 8-inch cone is optimized both for resonant behavior and for tweeter waveguide duty, increasing the tweeter’s low-end efficiency and helping it work properly down to the unusually low 1.6kHz crossover frequency. The woofer’s waveguide function also helps match the directivity of the two drivers.

We didn't just optimize the woofer and tweeter's frequency response, we also prioritized reducing distortion in the motor structure of the drive unit. By designing the motor to minimize distortions, we've ensured that the system generates minimal additional frequencies beyond the original signal. The Twin-Drive system creates a fully symmetrical magnetic field, resulting in extremely low intermodulation distortion and a pure, accurate sound.

— Andrew Jones

The cabinet of the SourcePoint 8 is made of 3/4-inch-thick MDF panels, except for the sculpted, multi-faceted front baffle, which is made from 1.5-inch-thick MDF. This chunky cabinet, the interior of which is further strengthened by two braces, contributes to the speaker’s 27.9-pound weight. But the SourcePoint8 is still a lightweight compared to the 46.2-pound SourcePoint 10, which is nearly 2 feet tall and 14.5 inches wide. Owing to the smaller cabinet and driver sizes, the SourcePoint 8 can’t match its larger sibling’s 91dB sensitivity or 42Hz bass response. Nevertheless, the SourcePoint 8 digs down to a respectable 47Hz, and has a sensitivity rating of 87dB. Considering the speaker’s eight-ohm nominal impedance and minimum impedance of 6.4 ohms, the SourcePoint 8 should still be fairly easy to drive and well-suited to a wide range of amplification. MoFi recommends anything between 30 watts and 150 watts. (Given the SourcePoint10’s reputation for being ever-so-slightly bright in the high-frequencies, plus Andrew Jones’s established reputation for delivering holographic imaging, I’d be tempted to try a tubed integrated amplifier, such as the PrimaLuna EVO 300 Integrated or the Rogue Audio Cronus Magnum III.)

I wanted to retain the character of (the SourcePoint 10). I looked to retain as many of the parts from the 10-inch driver as I could. It’s exactly the same motor structure, exactly the same tweeter, the same cone, but I just trimmed about half an inch off of the radius to reduce the size of the cone, to shrink it to the size for an 8-inch driver. By shrinking down the cone, I had to use a new surround and change the chassis… but all the other parts are the same. And the measured performance is near identical. And it turns out that… the strength of that motor structure, combined with the smaller diameter cone, is still the correct ratio of area, mass, and BL for it to tune right in this cabinet. (BL equals the flux density of the magnet multiplied by the length of voice coil wire in the magnetic gap.)

— Andrew Jones, via Audiophile Junkie

The MoFi SourcePoint 8 is offered in a real wood veneer of satin walnut or black ash, as well as in a satin white painted finish. Though not cheap at $2,750 per pair ($2,999 per pair with stands), the SourcePoint 8 costs $1,000 less than the SourcePoint10, and should be considerably easier to accommodate in a room. A five-year warranty (parts & labor) is included when purchasing from an authorized MoFi Electronics dealer, like our friends at Audio Advice. 

Would you rather go big with the SourcePoint 10, or stick with the scaled-down SourcePoint 8? Share your thoughts in the related forum thread below.

More information: MoFi Electronics

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