Thanks tls, so are we thinking that even if the amp was not clipping and was suitable or I "cheated" and picked up one the new crown Xls drivecores-the f12s would still frustrate me at loud volumes because their limited frequency response and limited output? It sounds like I should have gone with the Jbl studio 590s I was also looking at? Do you have an idea why the f12s were designed for only 52 hz, like you said, similar to the frequency response of a bookshelf speaker?
Edit: clarity
There are fundamentals you have to understand about loudspeakers. Your speakers are quite sensitive. Now there is always an inverse relationship between sensitivity and bass extension.
Now whether a speaker will work well for you depends a lot on the type of music you listen to. For quite a bit of music there is not a lot below 52 Hz. For most classical music a response to around 30 to 35 Hz is fine.
The next issue is the average power the music requires. Pop music is inclined to be highly compressed, at least in digital formats. You can't do that with an LP or you have very short playing times! The point is that highly compressed pop music at highish and loud volumes causes a lot of heating in the driver voice coils. This plays havoc with the response. This is especially true of three ways, were as I said one small mid range driver can succumb to severe thermal dynamic compression. Classical music on the other hand has lots of low volume passages as a rule, allowing plenty of time for voice coils to cool.
In addition in your speakers, I see from the pictures the crossovers contain pretty small iron core chokes. These are prone to core saturation at high volume also compounding the problems you note. Small chokes like this also have thermal compression issues.
Now with many music sources in a smaller contained space your speakers almost certainly would sound quite pleasant as they measure pretty well and seem pretty good value for money.
Speakers that would fill a space like yours at high spl, are going to cost a lot more. Drivers with motors systems then can dissipate a lot of heat, and perform well at high spl are costly. In addition they would have more drivers, and certainly larger bass drivers. In addition the crossover would have much larger and more costly inductors.
Speakers are hard to choose, and music preference, volume levels and the space to be filled all have to come into consideration.
In your case that room is really working against you. Domestic speakers really work best in confined rooms with a dominant dimension of 20 to 25 feet or so and around 14 feet or so wide.
Large rooms that open to other spaces, because they have no doors get your back to the wall before you start.
A couple of good subs will help you, but not solve all your problems. With that space you will need some hefty subs, as you have to pressurize the whole space. The next issue, is that when you do pressurize the whole space like that in a house you end up pressurizing the whole house which can, and usually does, upset domestic harmony.