The LT/350 & LT/550 are pretty unregulated designs. This is the way we've always done it in 12v and pro applications. As we are finding there are certain applications and certain people who prefer to have a regulated design. You lose a lot of headroom power but in the end that's what some people may prefer.
In the given enclosures w/ said power the suspension / movement of the speaker in a A5-350 for example won't be near it's breaking point. The amp is going to run out of capacity first and the speaker has ample clearance and suspension to absorb it at full power. It's a very resilient design.
The LT/350 & LT/550 platforms being unregulated really allow you to pull A LOT more power out of them than they are spec'd at. When you overdrive that it's designed to kick off and just flip right back on. Similar to a pro amp.
Basically the other way to do it is to limit performance. Put a stiff regulation on performance and force people to get less than they could have. If the amp turns off it's likely just being over driven or at it's limits. There's nothing wrong with that it's just at a point where it can't make more power and it's going to shut off. At that point it's normally operating so far outside it's spec'd power (Ie. 600,700,800w from a LT/550) that it's expected.
If your running your equipment at a large margin over it's rated power to a point where your repeatedly shutting the poor thing down. It's time to turn down the level (The amp can't make more power. It's giving all it's got).
LT/550's kick off normally at about 700-800 watts using a clean input signal non boosted. If you push the PS to try and get more it's going to turn off
There's no governor or limit. It lets you push it right to the threshold and just kicks off.
There isn't a protection that is turning it off at that point. It's turning off and gasping for air. Energy flow in electronics is a lot like breathing to you and me. When something is run hard enough to throw the entire system out of wack when it's pushed considerably past it's limits it WILL NOT operate correctly.
There has to be a limitation somewhere. A unregulated design just allows you to find the limit but requires you to back off it once you've found the limit.
Kind of like a car with no governor that is designed to go 120mph. If you drive it 140mph something might break and there's a point where it's not going to go any faster. The effect of this might be your car just turning off. Same thing here.
Here there is no governor in the amplifier. No inherent limitation that forces users to have less. If you want us to limit your amplifier or get you into something a little more custom that has a amplifier in it that has a built in governor so to speak. It can be done but in the end it will decrease performance. It'll do every watt it's spec'd for but not a watt more.
I'm personally a big fan of a headroom which is why the amp is like that. To get the most amount of power possible. That's always been one of my major gripes with a lot of mass produced HT subwoofers. We can limit electronics so that you'll have no headroom and just put a stop on it essentially so once it hits x amount of power it will just dissipate anything else as heat, not voltage.
Using another amplifier (that is a LT amp) will just do the same thing. They all are designed to allow you to push them to their limits. We don't like forcing limiters onto people.
hus why we must solve this protection mode problem
It's out of power. It's not really a problem. If you want more output. You need a bigger amplifier or a bigger subwoofer. There's nothing that can be done to that amplifier with the exception of placing a hard limiter (governer) internally into the amplifier @ X Voltage. This will basically not allow you to push the amplifier to this level. If you back off the level on the amplifier on the unit you'll likely see that stop.
The protection circuit isn't malfunctioning. It's doing precisely what it should. It's turning itself off before it blows up when it's pushed too hard in some way shape or form. When it's turning off at these high output levels that's normally pretty tell tale that this is what is causing it. Just asking too much from it.
If your hitting the output levels it's spec'd at and above your getting out of it what we suggest ideally you could get out of it. If you want more and the equipment can't take it you've found the limitation. In these designs it's power. Which is still far above where they are spec'd at.
I don't mean to repeat myself or sound redundant but the way to force the amp not to do that is basically to install a limiter inside the amp that cuts you short on headroom. If your ok with that please let us know. It can be done. Nothing can be done to that amp or in your settings to make it stop other than turning something down. Your @ the amplifiers limits.