PROS / The midrange and high-range frequency accuracy is excellent.
CONS / It was the quietest speaker in our comparative loudness tests.
VERDICT / The Infinity Reference X car speakers produce very accurate frequencies, but their loudness, compared to the top car speakers, is poor.
Each car speaker in the Infinity Reference X series features the Plus One woofer cone, which has 30 percent more radiating surface area designed to provide greater bass and louder volumes. Unfortunately, our tests showed that the bass was merely average while the mids and highs were excellent and the loudness wasn't loud at all. The series has car speakers in every available size, so it won't be difficult to find a size to fit your vehicle. For the purpose of this review, we tested and evaluated the series' 6 x 9-inch car speaker – Reference 9602IX.
To find the top car speakers, we evaluated audio quality and power handling with three tests. We tested the frequency accuracy by recording it play a 20Hz to 20kHz tone, which was followed by a close analysis of the frequency signature. Then we had listeners rate the speaker as they listened to it play several songs. Finally, we tested power handling by measuring how loud it was at 1 meter in comparison with other car speakers when the amplifier was set at the same volume output.
In the frequency accuracy test, it received a B for the low frequencies, 20Hz to 470Hz. This was average. We found that it emphasized bass frequencies too much, causing it to overpower the mids and highs when playing a full mix. The midrange and high frequencies receive As, which made it one of the most accurate speakers for frequencies ranging from 470Hz to 20kHz. You can also adjust the tweeters. The bracket pivots, allowing you to aim the treble. You can also boost treble by 3 dB, which can allow it to cut through the boosted bass.
In the subjective ear tests, this 6 x 9-inch car speaker received average marks. Like similar car speakers with emphasized bass, listeners gave it high ratings on the first listen, but the quality fell on subsequent listens as the ears adjusted and listeners realized that the bass was muddying the midrange and treble. In addition, when considering user reviews, it also received average grades.
The biggest downside to the Infinity Reference 9602IX was the comparative loudness, which was the lowest in our tests. The speaker's sensitivity rating, provided by the manufacturer, is an impressive 94 dB, the highest in our review. However, this rating was determined using the 2.83 method for measuring sensitivity instead of the 1-watt method used by most of the other manufacturers. When you consider the impedance is a low 3 ohm, this sensitivity rating means it used over 2 watts of power (a 4-ohm speaker draw 2 watts of power from a 2.83-volt current). This inefficiency was clear in the comparative loudness tests where it was measured at 7 dB less than the loudest speaker's average loudness, which makes it over three times as inefficient.
The inefficient loudness isn't made better with average power-handling ratings – the continuous rating is 100 RMS watts and the peak is 300 watts. If the speaker were more efficient at converting electricity to volume, then the average power-handling ratings wouldn't be a significant downside. However, since it requires much more power to produce a volume comparable to the best car speakers, you won't find it difficult to push this speaker past its capabilities, which eventually leads to clipping, distortion and, ultimately, damage.
The Infinity Reference X speakers are high-end car speakers with very accurate midrange and high frequencies and overly emphasized bass. However, the overall audio quality is just average. The sensitivity rating is very high at 94 dB, but don't let that fool you, as it was the quietest speaker in our comparative loudness tests. This series has speakers of all sizes, so it won't be difficult to find a speaker to fit your car.