I forwarded a link to this thread over to Brian at Rythmik Audio. If he feels it necessary to respond then he can. ....
I enquired on their website a few weeks ago, and had a couple of emails with someone called Brian Ding. Could be the same Brian. He suggested one HX800 running each 4 16R drivers, but when I realised it is 2x 400W/4R modules, I didn't follow up that amp with him, thinking it is not going to drive a 16R unit beyond 100W. I did ask a follow-up about he HX600, (thinking to myself it would have higher voltage rails), but he didn't answer.
....Rather than trying to DIY a protected design, you would be better served to discuss your issues with Rythmik. You might spur the development of a new amp model that addresses your issues and has the Rythmik servo control.
Well I hadn't thought of that, but it seems a bit speculative, even though ideal. I kept my questions to Rythmik short and businesslike, " ....I am thinking of running 2 amps to 8x SW-12-16FR drivers, which will share 1 amp between 4 drivers. Therefore high power amps are needed to get high excursions from these 16R drivers. ....is there a high-power option coming to replace the (discontinued amps)?" Once that discussion petered out pretty quickly (and I'm not complaining, people are busy), I thought Oh Well, I'm going to have to try and work out a solution myself, but I'm going to need some help. And here we are.
Back to technical. In my wish to get full excursion from the drivers, I have been calculating on the pretty rough-and-ready basis that the 16R, 200W drivers at least
need enough amplifier to get them to 200WRMS, which will require balanced 80V DC rails on the PSU. I would be very, very surprised if the A370 can do this. On the other hand the UcD700 has 90V rails and can do it. The Rythmik HX800 would have been ideal if it was a single module, but if it is 2x400W modules, it can't.
Unless the HX800's two internal modules can be bridged??
(dubious look) Even if possible, it would probably be limited to a minimum load of 8R --yes?-- and unable to run 4 drivers.
If someone has a better technical analysis of what it takes in amplification to deliver full excursion from the SW-12-16FR, then I am all ears. Because my calculation above is, how shall I put it kindly, indirect.