Is anyone familiar with Infinity Slope brand speakers?

All correct...

Richard Moddaferi, of McIntosh fame, patented the Infinite Slope crossover back in the late 80s.  John Solecito championed the design with his JSE Infinite Slope Line.  JSE went under in the early 90s.  The aforementioned Jeff Joseph appears to be the lone wolf implementing it these days.  For what it's worth, Ray Kimber also has a unique and interesting (Bud Fried, the cable hater, of all people, was sort of an inspiration to Ray) patented crossover for license, but I don't know if anyone's employing it.

Sounds like you either have the JSE Model 2 or 4. If you send me a picture, I could perhaps remember.  The entire line was a very nice / good sounding lot, and different than you encounter today.  It hearkens back to the 80s (and 70s?).  Definitely on the relaxed and luxurious sounding, if blunting the transients and detail in the absolute.  That's a reflection of the crossover, which points to another current thread where I mentioned the importance of same, but got little traction out of it.  People don't realize to what extent sonics reflect the crossover; it's easy to get lost in the sexiness of drivers and cabinetry.  Keeping your loudspeakers on the casters, or installing spikes, as opposed to removing them, and siting them directly on the floor, will keep them as sharply focused as they can, and mitigate their flaws to the greatest degree.  At this point, the value they provide sonically far outstrips their monetary value in the market.  If you like them, hold on to them for a long time

When looking at your speakers from the front, if the cabinet is rectangle and the front side edge are sharp corners, it is the Model 2. If the front side edges are beveled, it is the 2A.
If from the front from side to side , the bottom of the cabinets are obviously wider than the top, (sloping inward like the letter "A"), you have the Model 4...and I'm jealous.

I have a JSE story....In 1987, after 2 years of searching for the best speaker/amp combo I could afford, I bought a set of JSE Model 2's and a Soundstream DA-1 amp (before it was THX certified). It's all personal taste, but for the truer amplification, I chose the DA-1 over the Adcom GFA-555, which I thought had a boosted bass. Fun Fact 1: The salesman at Harvey Electronics in Paramus NJ that sold me the JSE speakers and demo'd the DA-1 was Jeff Joseph, who years later, after John Sollecito closed JSE, licensed the Infinite Slope technology and started Joseph Audio. I preferred the extended bass range of the JSE Model 4, but couldn't justify the increased cost. Fun Fact 2: The List Price of the JSE speaker line coincided with the model numbers. therefore, the Model 4 was priced at $4,000.

In 1992, the oak veneer of the Model 2's began to lift/bubble. I called JSE and spoke directly with John Sollecito. He was extremely supportive! However, instead of fixing the Model 2 cabinets I had, he offered a more expedient solution that I happily accepted. He sent 2 technicians in a van to my house with an upgrade replacement to Model 2A's in gloss black. The 2A had the upgraded super tweeter and rounded cabinet edge for smoother high end dispersion. The 2A grille covers the full front, not like the slanted cover of the 2.

In 2003, I called John Sollicito again and talked briefly about Source Technologies and the old JSE line. I mentioned how happy I was with the Model 2A and mentioned that originally, I thought the bass of the Model 4 was noticeably better, but I didn't think they were $1,500 better. Fun Fact 3: John laughed and agreed. He said when originally designed, he needed to price the Model 2 performance competitively, so he didn't use the best woofers available at the time. The Model 4 was the no compromise speaker with a larger volume cabinet. To enhance my system bass, I went with his suggestion of what would best match/compliment my 2A's. At the time, it was the Source Technology XLS 12" 450 watt amplified passive radiator subwoofer. It has a very sold bass and extends the frequency response down to 18hz. He gave me a great deal and I'm very pleased with this unit.

In 2012, the 2A woofer foam surrounds were disintegrating, so I gave John a call. He remembered me. We discussed the options and he suggested upgrading the woofers and replacing the aging capacitors of the crossovers. I and a friend who has the Model 2 each bought an upgrade kit. It came will detailed instructions and was easy to install. The only small issue was that the new woofers protruded just a bit more from the cabinet surface, so I shimmed the cloth cover frame a bit. Again, I'm very pleased and haven't had any issues since.

Hello everyone. This post is a bit old but perhaps some of you are still monitoring it. I acquired a pair of Infinite Slope speakers yesterday that are a totally unknown model from what I can tell. They are not .6s, not Model 1 or Model 2 and in fact are about a third the size of the .6 speakers (I have owned or still own all those models).  These speakers are 18" high and 11" across.

The drivers are definitely Infinite Slope issue, the cabinet construction and rounding of the corners matches my Model 2A speakers. Other than the badge on the front no other identifying marks. I will try to post a picture of two, and if anyone has any thoughts on it that would be appreciated. I understand that JSE did some one-off speakers from time to time that were not well documented.

http://spuddls.com/slopes/

John Sollecito from JSE infinite Slope fame is known as JS Speaker Technology and a Partner in Next Level Acoustics where all current speakers are being engineered and produced. www.NextLevelAcoustics.com