Infinity Primus P-362 (sold)

Product Highlights:

video-shielded
- 3-way, bass-reflex design
- frequency response 38-20,000 Hz (±3dB)
- 8-ohm impedance
- sensitivity 93 dB
- handles up to 200 watts
- 3/4" MMD tweeter
- 4" MMD midrange
- dual 6-1/2" MMD woofers
- black wood grain vinyl finish
- 5-way binding posts
- 9 1/8"W x 40-5/16"H x 13"D



Audio Performance

A great floor standing speaker can’t be judged solely on the basis of specifications, but one pair of numbers that is always critical to understand is the frequency response. Ultimately, it’s the figure that tells how much of the human hearing spectrum can be reproduced by a speaker system.

The Infinity Primus P362 boasts an impressive 38Hz to 20kHz range. That covers most of the audible sounds that humans can typically hear but leaves some room for improvement. While most sonic information is contained in the mid-ranges, it tends to be the extremes that really define the character of a speaker. Being able to reproduce the low 38Hz frequencies covers all but the lowest musical extremes. To put the figure in perspective, it’s helpful to know that the low E, the lowest note produced by a bass guitar or double bass is 41Hz so these speakers have that covered, but with little room to spare. Sonic information that is of lower frequency than that will have to rely on the addition of a subwoofer, though it’s not an absolute requirement with these speakers.

On the high end, the 20kHz corresponds with the typical upper end of the human ear’s ability to hear. It will accommodate the highest pitches that any musical instrument will produce accurately and clearly. Missing, however, is the ability to reproduce overtones. An overtone is sound material that exists beyond the 20kHz mark. It isn’t actually audible to the ear but the brain perceives it as that almost indefinable space and ambiance that makes live music so entrancing. Both the highly rated Klipsch Reference Series RF-52 and the Polk Audio TSi400 speaker systems feature tweeters that produce these very high frequencies.


Power Handling

The P362 is a very efficient floor standing speaker with a 93dB sensitivity rating. That puts them squarely between the 91dB achieved by the Polk Audio TSi400 and the remarkable 96dB rating of the Klipsch Reference Series RF-52.

There are a number of advantages to having speakers that are this efficient. Most notably, perhaps, is that it takes rather little amplifier or receiver wattage to drive them effectively. Many people react to that with the presumption that they can be played very loudly. While that’s true, it misses the real point. High volume levels are easy to reproduce but reproducing high volume with exceptional clarity is a challenge. The high efficiency of the speakers is the characteristic that makes the clarity achievable.

The 93dB sensitivity rating has other positive results. When not being driven, the P362s will be virtually silent, devoid of the annoying hiss that can be heard with lesser speakers. The sensitivity is also the characteristic that allows the manufacturer to recommend as little as 10W of input power. On the other hand, they can handle maximum average input up to 200W.



Speaker Design

Being able to reproduce a very wide range of sounds depends on the various drivers that are housed within the floor standing speaker enclosure and how they’re interconnected. Infinity states that their proprietary Metal Matrix Diaphragm (MMD) is the key to the drivers’ performance. It’s based on an aluminum core that is somewhat stiffer than most speaker material and therefore makes for unusually clear, precise performance at any volume.

We were impressed with the bass response produced by the twin 6.5-inch woofers within the Primus P362s. Ultimately, great bass depends on moving a lot of air pressure in a very controlled manner. The two dedicated woofers do a somewhat better job of that than either the Klipsch or Polk Audio models mentioned above. The stiffness of the cones tends to keep the bass very tight even though there’s a lot of it.

There’s a crossover that directs frequencies higher than 350Hz to the 4-inch mid-range driver. It capably reproduces the majority of audio information including vocals. Another crossover set at 3300Hz directs the highest frequencies to the ¾-inch dome tweeter. The MMD material tends to offer better damping than more traditional dome material, resulting in a smoother, less "tinny" or "crunchy" sound at the higher frequencies




Summary

We’re particularly fond of the warm, lifelike bass response that is provided by the Infinity Primus P362 speakers. Similarly rated speakers have good bass response, but Infinity’s dual woofers produce tones that are overall more pleasing. They’re terrific as the main speakers in a surround sound home theater system, but are remarkably good audio speakers as well for enjoying great stereo music.