“The purpose of this filter is to provide you with the best quality sound that matches what you would hear naturally when not wearing ear tips. Hearing differs significantly from one person to another, and unlike standard earphones, Audéo PFE allows you to select the filter that works best for you.” (Italics are mine).
Skeptics might at first think the filters are little more than sonic gimmicks designed to give undiscerning listeners the acoustic equivalent of “gongs and whistles” to play with, but that isn’t the case at all. The design thinking that has gone into the filter is much more serious and sophisticated than that, as this deeper explanation form Phonak makes clear:
“When wearing Audéo PFE the ear canal is blocked and the function of the ear is changed. The amplification of the pinna disappears.
1. The natural resonance of the ear canal disappears.
2. That has to be compensated by the earphone, so the target curve is theoretically the open ear transfer function, which corresponds to a flat curve in the free field and diffuse field:
The earphones must recreate these phenomena for the user to perceive a natural sound. Since each person has a different ear, the compensation curves should be different from one person to the other. Standard earphones do not take these factors into account, which makes Audéo PFE unique.
Internal studies at Phonak have shown that most people are not comfortable with a sound from an earphone that reproduces exactly the curve of a standard open ear. The curves of Audéo PFE are a compromise between a frequency response that includes the full open ear gain compensation as well as one that has bass and treble predominance.”
Accordingly, Phonak offers three color-coded types of passive audio filters:
• Black filters, which are said to “provide stronger bass and treble” (and that, on paper, offer what may be the most accurate tonal balance overall).
• Gray filters, which are said to “provide stronger middle tones” (and that vie with the Black filters for most accurate sound overall).
• Green filters, which are said to “provide stronger bass while still maintaining high-quality midrange.”
The PFE 232 ships with one set of Gray filters installed and comes with a filter changing tool and a filter pack that includes a spare set of Black and Green filters so that listeners can experiment with all three filter types to see which ones work best for them.
The theme of flexibility also carries over into more functional and practical day-to-day aspects of the earphone.
• The PFE 232 can be configured as an earphone/headset, complete with an included iPhone-compatible three-button mic/remote. The PFE 232 is fitted with this cable when it first arrives.
• However, with the needs and interests of sonic purists in mind, the PFE 232 can also be set up as a pure earphone (sans the inline mic/remote module) via an included straight-line signal cable.
• To address the fact that the PFE 232 comes with an extensive set of accessories, the earphone/headset comes with cleverly designed two-chamber, zipper-closure carrying pouch with one section for accessories and a separate section for the earphones themselves. This isn’t an entirely new idea, but Phonak has executed it beautifully; it’s great to have a secure place to keep all the “goodies” while still having easy access to the ‘phones.
Sound Quality: Here we see the area where the PFE 232 differs most sharply from the PFE 122. The PFE 232 features:
• A two-way design featuring dual balanced armature-type drivers, which are said to help improve overall sonic resolution, balance, nuance and detail.
• A choice of two high quality, detachable, user-replaceable signals cables—one fitted with a made-for-iPhone remote/mic module, and the other without. To be clear, the train of thought is that, under some circumstances, the presence of the mic/remote module might in some small ways negatively impact sonic clarity and purity, and that it therefore makes sense to give listeners a straight-line cable option.
The PFE 232 is similar in sonic character to already very good PFE 122, but not identical, as we’ll discuss below. As with the PFE 122 it is important to bear in mind that the PFE 232 doesn’t have just one set of voicing characteristics, but rather has three distinctly different characters—depending on which sets of passive audio filters are installed. I found that the PFE 232 responds to the various Phonak filter types in much the same way the PFE 122 did, though the 232’s underlying “core sound” is just enough different from the 122’s that it is worth doing a re-evaluation.