JBL 4349 Loudspeaker Lab Report

Lab Report

Where you sit may prove vital in getting the very best from JBL's 4349. Avoid the temptation to 'look' directly into the throat of the horn for there's a substantial –14dB notch at the ~1.4kHz crossover [dashed trace, Graph 1]. The midrange output is better integrated at a distance, but the most uniform forward response, and reduced exposure to the horn resonances [see waterfall, Graph 2], is achieved listening between the horn and woofer [Graph 1] even though the response errors are still high at ±4.2dB and ±4.5dB (but a far 'flatter' ±0.9dB from 2kHz-10kHz). The HF trim operates above 2kHz and the UHF above 4kHz, the compound effect of the +1dB and –1dB settings illustrated by the two grey responses [Graph 1]. The influence of the snugfitting bass grille is not substantive [blue trace] while the 300mm pulp-cone woofer delivers reliably low distortion bass (just 0.2%/90dB SPL/1m) whether exposed or hidden. The reflex alignment is slighty 'peaky' [green shaded area, Graph 1] with a steep roll-off below 100Hz, augmented by ports tuned to 35Hz, yielding a diffraction-corrected –6dB extension of 45Hz (re. 200Hz).

With that mid/treble horn on show there's hope of high sensitivity and JBL's 4349 does not disappoint, achieving 89dB/1kHz/1m and 90dB from 500-8kHz, despite the switchback in response. JBL's nominal 8ohm impedance is accurate, the 4349 presenting a very 'easy' minimum of 7.5ohm/118Hz, well away from the highest (though not especially 'high') phase angles of +47°/371Hz and –49°/74Hz. There's a 6ohm dip at an ultrasonic 30kHz, but this will not be troublesome – so the 4349 is an easy enough load for triode tube aficionados! PM

421jbl.lab1

Response inc. nearfield summed driver/port [green], freefield corrected to 1m at 2.83V [yellow], ultrasonic [pink]. Left, black; right, red; w. grille, blue

421jbl.lab2

Horn resonances are present at ~4-8kHz while the strong 1.4kHz mode occurs at the crossover point

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 89.1dB / 89.5dB / 87.4dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 7.5ohm @ 118Hz, 47ohm @ 60Hz
Impedance phase: minimum & maximum (20Hz–20kHz) –49° @ 74Hz, +47° @ 371Hz
Pair matching/Resp. error (200Hz–20kHz) 1.45dB/ ±4.9dB/±4.2dB
LF/HF extension (–6dB ref 200Hz/10kHz) 45Hz / 27.5kHz/26.2kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.2% / 0.3% / 0.9%
Dimensions (HWD) / Weight (each) 737x445x343mm / 38kg
Price £6995 (£320 for JS-120 stands)

COMPANY INFO
Harman International Industries
CA, USA
Supplied by: Harman Luxury Audio Group, Cambs
01223 203200
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