Here are some measurements of the Infinity Primus 150 Bookshelf speaker.
The MSRP was $198/pair back in 2003.
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Specifications:
Frequency range: 58Hz - 20000Hz (+/- 3dB)
Recommended Power: 10 - 100W
Sensitivity: 88 dB
Nominal impedance: 8 ohms
Crossover frequency: 3300 Hz; 24dB/octave
Low-frequency driver: 5-1/4" (130mm) MMD
High-frequency driver: 3/4" (19mm) MMD
Weight: 13.5 lb (6kg)
My measurements are quasi-anechoic, with near-field port+woofer, corrected for baffle edge diffraction, combined with gated measurements at 1m distance.
I have attached a 1m vs 2m comparison, pair matching and measurement axis comparison for those who are interested. I used the speaker with the smoothest response for the spin.
Recommended listening height is with the tweeter "approximately at ear level" according to the user manual. I got the flattest response ~40 mm below tweeter axis, so that's what I used for the spin.
Here's the CTA-2034 data:
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It looks surprisingly good considering how inexpensive this speaker was. Most of the response errors should be fixable with EQ thanks to the smooth directivity.
Early reflections:
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Horizontal, and total early reflections:
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Estimated in-room response:
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Quasi-anechoic response:
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Horizontal directivity:
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0-90 deg compared to measurement by John Atkinson:
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Sidebar 3: Measurements
www.stereophile.com
Vertical directivity:
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Near-field response:
Steep roll-off thanks to the 24dB/octave crossover, but there are clear port and/or cabinet resonances, and a woofer resonance at ~8 kHz.
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Distortion:
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< 1% THD from 75 Hz and up. Very low tweeter distortion (less than 0.1%).
Comparison with Stereophile, 30 deg horizontal listening window:
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Overall, I'm quite impressed by this speaker. It sounds better than most of the budget speakers I have measured so far. Sure, it's not perfect, but frequency response is ok, horizontal directivity is excellent, and distortion is quite low as well.
There's no deep bass though. A subwoofer is definitely needed.