Qe and Beyond: Infinity Qe
Infinity Qe Speakers on the workbench.
These came home with the NAD 7100 receiver that recently bested my Pioneer SX-1250 and made its way into my main listening system.
They are a bass reflex two way system from the late 1970s, a little on the big side for a bookshelf speaker at 18 x 12 x 10 inches. They feel light for their size however, and probably weigh less than 20 pounds apiece.
The Qes were the entry-level model in the Infinity line of the time, which also released the Qa, Qb, and Quantum line series speakers. All came with a special ribbon tweeter known as the EMIT. The EMIT tweeters use a plastic membrane as a voice coil between two magnets. The sound is touted as detailed and exact. Some folks absolutely love these tweeters ,and Infinity used variations on the design into their later Reference series speakers, which still sell for good money.
Close-up of EMIT tweeter in its housing. The tweeters can rotate 90 degrees in the cabinet for horizontal speaker placement – the limited vertical dispersion of the tweeter sound makes this a requirement.
This example, a two- way with an 8″ woofer, is covered in a luxurious vinyl walnut veneer and come with groovy 1970s brown nylon grilles. Overall the build quality is nothing to write home about, but from a distance they don’t look bad at all. But how do they sound?
Infinity Qe on the stand for demo. note the woofer cone on this one is a little dented.
The tweeter lives up to its reputation. When I set them up for a demo on stands in front of my regular system hooked up to the NAD 7100 it was the tweeters which made themselves known first. They are not shrill or harsh, but detailed. As I had the speakers placed in the room (about 3-4′ from back walls and 8′ from eachother) the treble carried the day, with midrange and low end following. When I gave them more watts and upped the bass control on the amp, things evened out. But I felt that despite the great tweeter, these speakers were getting lost in my bigger basement room.
Infinity Qe on the stand. Future basketball star (and speaker stand hazard) in the background
This all changed when I had them hooked up to my Lepai mini-amp on my workshop desk. Closer to the wall and at lower volume, the lost frequencies returned. The sound was full and fun. And the tweeter kept shining. I realized that these speakers really excel as true bookshelves in more-nearfield applications. They weren’t going to fill a big room. But boy did their character change in a small one!
Infinity Qes on the bench. They sound great in near-field applications and tight spaces
The internet is filled with tales of blown tweeter membranes and advice on how not to cook the EMITs (hint: use lots of clean watts, it seems that clipping is the culprit to many a tweeter-murder). I’ll have to keep that in mind as I enjoy these on my workbench with my little Lepai. But so far I am happy.
silverfacestereo 