Beautiful Infinity Interlude Series Towers w/ Powered Subs IL50

Arnie Nudell and John Ulrick, aerospace engineers at Litton Industries, left with Cary Christie in 1968 to build speakers, starting in Nudell's garage. Their Servo-Statik combined electrostatic panels with a servo-controlled woofer, an idea from their aerospace work, and sold for $2,000 a pair.

EMIT and the reference years. In the late 1970s the Quantum line and the low-priced Qa, Qb and Qe brought in Infinity's EMIT tweeter, a flat plastic diaphragm with etched conductors, and Stereo Review called the $145 Qa one of the best loudspeaker values on the market. Infinity's flagship reference systems arrived at the end of the 1970s, and in Canada its speakers came in through Gray Acoustics of Markham, Ontario.

Harman. Infinity has been part of Harman International since the mid-1980s, and Samsung has owned Harman since 2017. The Kappa, Reference, Interlude, Primus and Beta lines followed through the 1990s and 2000s. In North America, Infinity now sells mainly car and marine audio.

1970s high end: the Servo-Statik, Monitor and Quantum models.

1970s and 1980s budget: the Qa, Qb and Qe, and the InfiniTesimal mini speakers.

Reference Standard and Kappa (1980s to 1990s): many numbered RS models, and Kappa towers and subwoofers.

Interlude (2000 to 2001): the IL10 bookshelf, the IL30 to IL60 towers, the IL25C and IL36C centres and IL subwoofers, with Infinity's ceramic metal matrix drivers. Infinity lists the IL30 and IL40 as made in the USA.

Primus and Beta (2003 to 2010): such as the Primus 250 and 360 towers, and the Beta bookshelf speakers and subwoofers.

Later lines: Cascade, Classia, TSS and the Reference series of 2014.

Swap channels first. Infinity's own advice: if one speaker of a pair is silent or distorted, swap amplifier channels. If the fault follows the speaker, look for a loose wire, a bad crossover or a bad driver.

Crossovers. Inspect the crossover board for parts that look burnt or bulged.

Tweeters. Check that every tweeter, EMIT tweeters included, plays at low and moderate levels.

Powered models. Test the bass amplifier of any powered subwoofer or tower at volume.

Parts. Infinity lists no replacement parts for models such as the Interlude series, so replacement drivers come from donor speakers.

Everything we list is inspected, tested and serviced as required here, and comes with our warranty.