JBL 18Ti loudspeaker Measurements

Sidebar 2: Measurements

I measured the frequency response of the JBL speaker in the listening window—spatially averaged to minimize room standing-wave problems—using third-octave pink noise, and measured the near-field low-frequency response with a sinewave sweep to get an idea of the true bass extension. The low-frequency –6dB point, measured nearfield, was 42Hz, but there was a little too much upper-bass energy in the room between 63Hz and 200Hz, suggesting that the woofer could do with a little more damping. Given that this lift will artificially extend the bass extension, the true cutoff point would probably be around 50Hz; this was confirmed by the in-room measurement, which showed the response to be falling rapidly below this frequency.

Fig.1 JBL 18Ti, spatially averaged, 1/3-octave response in JA's listening room.

The in-room response, very flat from 200Hz to 3kHz, met excellent ±1dB limits apart from a slight prominence just above 1kHz (which may correspond to the slight "eee" coloration noted). Above-axis, a slight notch developed in the crossover region, showing that JBL's engineers have optimized the vertical dispersion for the speaker's use on reasonably high stands. There was perhaps a little too much treble energy in the final octave. The measured impedance fell to around 6 ohms in the lower midrange, but the load will present no problems to amplifiers.—John Atkinson

8500 Balboa Blvd.
Northridge, CA 91329
(800) 336-4525

Allen Fant's picture

Excellent review- JA
how can I get a copy of your HFN/RR test disc?
You may send me a PM here- fantja@gmail.com

Thank You!

JohnnyPapa's picture

Hi, John! I am not an audiophile, but a casual music listener...I liked the Soundboks-2 but it is very expensive. Could you please recommend me a loudspeaker under $300 range?

J-B-Lite's picture

Thanks for this review. these speakers have a sentimental value for me, but it's nice to see how they rate with recent sensibilities.