- Written by Jason Victor Serinus
- Published on 25 July 2012
Design of the Eficion F300 Speaker
The F300 comes in two versions, single-wire and bi-wire. The single-wire version, which is the subject of this review, is equipped with a single set of speaker cable jacks on the lower woofer module; these accept both spade and banana terminations. The speaker also has two more identical jacks, one on the lower module, the other on the upper, that are reserved for jumpers. For the modules to work as a team, it is necessary to connect them with a single set of supplied or user-choice spade or banana-terminated jumpers.
The bi-wire version requires bi-wire speaker cables, attached to both the lower and upper modules. It also uses a single set of supplied or user-choice jumpers between the lower and upper modules. For audiophiles who own this model but lack bi-wire speaker cables, single-wire speaker cables can be attached to the lower module, and two sets of jumpers used to connect the lower and upper modules.
While I have heard the bi-wire version of the F300 at shows and in the home of a nearby BAAS member, I have not auditioned it alongside the single-wire version. Hence, while Peigen says that there is basically no difference in the sound between the two models, I cannot confirm that claim.
Unique to this speaker is its unusually large Heil Air Motion Transformer (AMT) tweeter. The advantage of Heils is their extraordinary detail, presence, and air. Their positive attributes come to the fore when the speaker is driven by a fast amp.
The dispersion pattern of AMTs, however, is shorter in height and width than a standard cone tweeter. Hence, the speakers must be placed closer together than other designs – Eficion recommends 7-9 feet – in order to image optimally. This produces a somewhat smaller soundstage than do cone tweeter speakers.
I ended up placing the loudspeakers close to 9 feet apart. This not only produced a coherent soundstage, without any hole in the middle, but also enabled me to enjoy much of the extraordinary detail that the AMT provides.
Both the upper module's woofer/midrange and lower module's subwoofer cabinet are ported. In addition, the upper module has a rear-firing aluminum ribbon super tweeter. Hence, distance from the wall behind the loudspeakers is critical. I ended up placing my pair roughly 3 feet from the rear wall.
It is essential to note that the upper module by itself extends down to 40 Hz, far lower than most bookshelf loudspeakers. It can thus be used independently of the subwoofer, providing near full-range sound in tight quarters. I never had reason to use it as a bookshelf, and didn't have stands around in which to try it in that capacity.
I did experiment countless times with the two rubber plugs that Peigen eventually supplied for the rear ports on the two upper modules. His assertion was that using the plugs provided greater control of lower bass. While this was true – it prevented some bass doubling with the woofer compartment – I believe it also resulted in a bit of a hole in the upper bass / lower midrange. I found myself using the plugs for some selections, and removing them from others. Ultimately, I'd say that I never fully came to terms with this mod.
In addition to the crossover modification mentioned in my July 2011 CAS report – details were never supplied, and new measurement graphs were never taken – Peigen, Bob Walters, and I performed one additional mod to the speaker. As originally supplied, the lower range of the rear-firing aluminum ribbon super tweeter doubled part of the AMT's response, making the sound too bright. I tried putting masking tape over part of the super tweeter, but this diminished air. Eventually, Bob, Peigen, and I found it a snap to insert a high quality resistor on the super tweeter's leads, thereby taming its response. I trust that the speaker now sports this mod as standard; it is definitely an improvement.