Over the last 15 years I have owned (and in some cases still do) many fine speakers including Legacy Focus, Martin Logan, Magnepan, & Focal. I purchased a pair of Pioneer S-1EX speakers three months ago from Definitive Audio in Bellevue WA at an extremely distressed price. I have had a chance to use them in the dealer's show room and in two locations - my small apartment in Bellevue WA and my ludicrously large loft in Philadelphia.
Overall I am not quite as enthusiastic about the speakers as Kal Rubinson, although they can be teased into some remarkable sound. The S-1EX offers a generally smooth midrange but I find their bass to be overly damped and their treble response too rolled off. I would describe the overall sound as smooth and polite (not the first to say this about this speaker). Apparently Andrew Jones and his female sidekick delivered these speakers to the dealer in hopes that the line would be picked up but Definitive could never get them to perform well in any of their listening rooms. They ended up in the used & demo room at a fire sale price.
When I first heard the Pioneers in the small over treated and dead dealer listening room there was no bass and no treble just a smooth midrange. Given the Stereophile review I knew I wasn’t hearing this speaker at even 20% of its potential. When I got the speakers back to my apartment, and with virtually no effort, I was able to greatly improve the sound. My room was fairly small 18'x15' and a bit on the lively side. The speakers were only 2 ft from the rear wall and about 3' from side walls. I found the boundary reinforcement created by this setup made the bass much more natural. Also by adjusting the rake angle, with the rear pikes, I tipped the treble up. That with this lively room acoustics produced some very pleasing sound.
When I brought the speakers to my loft I was confronted with the sound I first heard at the dealer. My 3rd floor listening room is 20’x20’ with 9ft ceilings and is open to the 2nd floor of my loft below, which extends back another 60ft. There is only a half wall behind by couch so sound can reverberate from 2nd floor below but it really has no direct impact on the sound of the speakers. The listening room is dedicated to sound and sparsely furnished with medium weight carpet. The room itself is pretty acoustically dead.
I have the speakers set up 4 ft from the rear wall and 4 ft from the side walls. Overall the bass between 50 Hz-100 Hz is paired down as is the treble. I have done some testing with a pink noise generator, calibrated microphone and my Behringer Digital EQ and found that adjusting the rake angle only effects the treble response between 9K-15K, not quite wide enough to overcome the downward trend. Luckily I have virtually no room modes due to the fact there is only a 3.5’ ft wooden wall behind me so I am able to use my digital EQ and small ERA Sub 10 to obtain a much flatter response. In an A/B comparison between eq’d/non eq’d - it is obvious that the speakers treble in my loft is tilted down a bit too much. I think the most can be had from this speaker in livelier rooms and with some boundary reinforcement.