The Gen1 Ultras were introduced in 2015 and had a run for like 5 years, during which time the Ultra 9 was the quietest 9" can, or amongst the quietest (towards the end of that period). We revised them in November 2020 (a year ago) to squeeze out more dB's and more ounces. These are 1.5" diameter format cans. I don't think you can find a 1.5x7" or 1.5x9" suppressor quieter than the Ultra 7 and 9 Gen2 respectively, and everyone who wants a small format can will get the best performance from one of these.
Anyway, during that time, we always pointed people at the 338 Ultra as the quietest option.. which is a 1.8" diameter can. Given a similar level of baffle refinement, you can't argue with volume ("No replacement for displacement.") Ray just posted the "Large OD 30 cal suppressor" a couple months ago. Compared to the Ultra 9 Gen2, these had like about 28% to maybe 43% more volume. So it proves that a large diameter format can "can" be quieter than a smaller diameter one of the same length. Not a big shocker to anyone.
Last year when I was looking at cans on my guns, I saw the 7" Dominus-SR and the 11-inch 338 Ultra SR (both of which are 1.8 diameter format) and it was pretty obvious that there was a slot in the middle that could be filled. Let's just say that we aren't worried about lacking a fat format 9" can that gives best in class performance..
The 1.5" Ultra Gen2's aren't going anywhere. We had time in 2021 to do R&D to fill some slots in our lineup and you'll be pleased with what we bring to SHOT (and one of them should be pretty unexpected)