first of all you guys need to get your nominclature straight. the early 90s reference series spelled out the model number. a "reference six" not reference 6, not RS6. a reference series four is a completely different animal than a reference standard 4.
people have been slow to catch on to how good these early 90s infinity reference series are. a lot of people dismiss them as "oh, those HK infinitys are no good" but they fail to realize arnie stayed on as president of infinity well after HK bought infinity, and he kept infinity independent and continued to push the innovative design philosophy that made his (and infinity's) reputation. these reference series represent the last technological advancements that went into production before arnie left and the bean-counters finally took over (and are probably are the reason they took over).
people also seem to forget that when and arnie finally said "sayonara" and went off to found genisis, the technology he took with him was the emit-r and the graphite (soon to be kevlar) coned drivers that HK deemed too expensive to produce, and they became the foundation of the genisis line.
IMG cones, sealed cabinets, and emit-r tweeters are a hard combo to beat. the emit-r has vastly better vertical dispersion than the ribbon type emit (30º vs 18º). i personally prefer the acoustic suspension sound (and the rounded-edge looks) of the reference series sealed cabinet to that of their cousins, the ported crescendo series (a line which was actually designed more by the circuit city audio chain, where they were exclusively sold, and produced by infinity). the reference series are pure infinity, and have much more accurate bass and none of that ported cabinet boominess.
the reference series are very user friendly compared to other vintage infinities. they don't have to be bi-amped, don't have low impedance issues, don't have poly drivers that become brittle with age, don't have beamy ribbon-style emits prone to diaphragm problems, don't have a boomy ported-cabinet sound, don't have tinsel wire problems, don't have parts so rare you can't easily find replacements, don't need a mandatory cap replacement, yet can be had at bargain prices in an otherwise inflated market. in essence they avoid all the pitfalls of other vintage infinitys without sacrificing superb sound.
some like to claim the cabinet construction is questionable, however construction quality of mine are equal to, or better than any of the other infinity speakers i own (including those from the 70s and 80s). my only issue is they have vinyl veneer. not that anyone has ever noticed they were not real oak, because the veneer looks real enough, but i'd prefer real wood. after 22 years my sixes still look like new.
the reference fours, fives, and sixes are undervalued in today's market. i have a pair of each. given the right amount of power, i prefer the reference six to either the RSIIIa or the RS6000. the five is almost as good as the six. for a small 3-way, to my ear the reference four beats both the Qb and the RSb. the reference one, two, and three have no emits, and are nothing to get excited about. fours are a little light on the bass, but great on mids and highs. the fives and sixes are serious speakers.
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