Focal Stellia
Type: circumaural, closed-back, moving coil
Test sample supplied by: SCV Distribution, UK distributor
Reviewed in: Hi-Fi News, May 2019
Test Results
The test sample of this headphone was
Results Table
Uncorrected Responses - Confidence Limits, Left - Confidence Limits, Right
Corrected Responses
Leakage Responses, Left - Leakage Responses, Right
Log Impulse Response, Left - Log Impulse Response, Right
CSD Waterfall, Left - CSD Waterfall, Right
Impedance - Impedance Attenuation
Isolation, Left - Isolation, Right
Acoustical Crosstalk
Commentary
Just as with the Elegia, the early production sample of the Stellia we tested was polarity inverting due to incorrect wiring. Whether this error was corrected in subsequent production I'm unable to say as there was no feedback from Focal when the Hi-Fi News review was published, nor was a second sample provided to allow me to verify that the issue had been addressed.
As the costlier sibling of the Elegia, equipped with a beryllium driver diaphragm, the Stellia should deliver a more impressive measured performance – but actually the two sets of results are very similar. Beginning with the voltage sensitivity, which we recorded as a high 119.6dB SPL for 1V at 1kHz for both models.
Uncorrected frequency responses are similar too but the Stellia has a more obvious hump in its LF response, centred on 100Hz, and a little more energy in the treble. The corrected responses reflect these features in the form of a little upper-bass excess and a recessed treble, but the Harman PPR figures are lower than the Elegia's at 50/36 ≡ 44%/31% (L/R). Like the Elegia, the Stellia loses LF output when the earpad seal is compromised, the PPR scores improving to 59/47 ≡ 51%/41% and 53/38 ≡ 46%/33% in the spectacles and 'hair' leakage tests - similar figures to those posted by the Elegia.
The two headphones also have very similar time domain behaviour, with little evidence of the Stellia's beryllium dome providing any advantage in respect of diaphragm breakup. Like the Elegia, the Stellia's CSD waterfalls show treble modes at around 2kHz, 3.5kHz, 4.6kHz and 6.5kHz, and both suggest the presence of resonance below the 200Hz lower limit, which the acoustical crosstalk trace indicates is due to structural resonances either side of 100Hz. These resonances extend the -40dB decay times to 4.8ms and 4.7ms (L/R) – again very similar to the Elegia's results – with decay to lower levels quite protracted.
Similar impedance range also means that the two models are subject to equivalent modifications of frequency response when used with signal sources having finite output impedance, the figures for the Stellia being 0.38dB with a 3 ohms source and 1.10dB and 2.35dB for series impedances of 10 ohms and 30 ohms respectively.
Provided that the earpad seal is good, the Stellia offers useful attenuation of external sounds – again, broadly in line with its stablemate.