What Class D amps will drive a 2 ohm load

Bahahahaaaaa...
You's are funny, got me laughing.
House is still standing. 

What happened...
The wife called me saying the boxes arrived.
She then asked me, there's amps in these two boxes?
So, had to explain what they were, why they were so small and why they weighed next to nothing.
All I got was an ok.

Removed the WOPL 700's and hooked up the SX-1000's.
I let the amps play on a repeat cd at a low level with the Kappa's in the "Normal" switched position starting early in the morning. Let that roll until 3:00 in the afternoon.
Time to start listening...

At half volume I listened for about an hour. All was ok so, time to crank it up. Turned up the volume to 3/4 on the Oppo (the 105D is driving the amps directly). Listened for another 30 minutes and all is still ok.
Time to get down to amp-busting' Kappa 9's, lowered the volume to 1/4 and switched the speakers into "Extended" mode. I've put many of my amps into protection mode with the Kappa's in "Extended" mode.
Being a little leery of these tiny amps I started out at 1/4 volume listening to various CD's, SACD's and DVD-A discs.
All is well after 30 minutes so, time to crank it up a bit.
At 1/2 volume now, stayed at this level for an hour while checking if the amps were getting warm. This is the point of no return for many amps I've tried. Half volume and up with the 9's in "Extended" mode is a brutal test for any amplifier.

Ok, I'm starting to get curious. I'm getting up and down, feeling the amps to see if there's any sign of temperature increase. Feeling the sides, the top, the front & back... no temp increase.
In comes the wife from running around town.
I haven't given my assessment of the sound for a reason. It will come later.
I'm listening, the wife walks in and is looking at the speakers with a puzzled look on her face. She turns to me and says... what's wrong with speakers? Something's missing, I don't like it.
That's the extent of her ability to evaluate what she hears. 
More on this later...

Time to turn the volume up to 3/4 and listen.
Put in some dynamic music... John Lee Hooker's "BOOM BOMM" 24/96 DAD.
The SX-1000's are still pushing the Kappa 9's in "Extended" mode.
Many amps have shut down at this point and, only a few have passed the next level test.
Volume up to 100% and let's have a go.
After 2 minutes I get some very loud snaps coming out of my EMIT K & SEMIT K drivers on the left channel speaker. Right channel speaker ok.
Wife comes running in from the kitchen asking what was that? I got to the volume control as quick as possible and turned the system down.
CRAP!!!

Not sure what happened. I have the protection on my crossovers by-passed. Have never had this happen.
I looked at the EMIT & SEMIT drivers on the left speaker to see if there was any arcing visible on the membranes. Nope, all looked normal.
Let everything rest for a half hour and then started bringing up the volume. Wanting to make sure I didn't fry something.
Music came back as before. Whew... hoping I dodged a bullet.

I want all to know that I'm in no way a qualified listener/evaluator of equipment and/or speakers.
I also can't give any measurements of what this listening session produced... to/for ME.
What I am is a person who enjoys his system and the music that's played on that system.
I do know what my system sounds like and feel I can give an accurate blah blah of what I heard.

Now let's get to the sound produced. 
And also to what the wife had observed.
At lower levels the music seemed to have lost weight/slam/punch. This loss was in the lower frequencies.
This is exactly what my wife had heard. She's not sure what was missing but, she knew something was missing. I didn't prod her or guide her for an explanation but what she said was "Where's the bass"?
As the volume went up the bottom seemed to increase but, the Kappa 9's sounded anemic. These Infinity's are everything but anemic!

I also found the same thing when driving the amps with my DV-AX10.
Just to make sure it wasn't the Oppo producing what I was hearing.

I'm gonna be the first to say I didn't think these amps had a chance.
I was surprised my Infinity speakers didn't throw the amps into protection mode... I did try.
In no way did I think they could drive one of the most difficult speaker loads ever produced... they did.
When I heard those loud snaps... I'm not gonna say that the amps started clipping at full volume. 
I do know what other amps sound like when clipping, I don't know what a Class D amp sounds like when clipping.

I want to add something to the Class D monos driving my Infinity’s...

With the noticeable lack of bass at lower volumes I must pose a thought I’m having.
Is the lack of bass/bottom caused by the crazy impedance load of the Kappa 9’s when being driven by these amps?

I have a pair of Legacy-Audio Focus speakers tucked away.
They do not lack any bottom end with any amps I’ve driven them with... maybe because they’re a much more efficient speaker than the 9’s might that bottom return with these Class D amps?
I don’t know.

Y'alls thoughts regarding the impedance of the Kappa 9's...

Maybe one of these days I can wrestle those heavy bastards out and hook up the SX’s.
Kinda doubting that will happen as I’m not getting any younger or less broken.

I was really hoping the Class D amps would provide this.
I’m gonna start reducing the amount of gear I have and would have loved amps the size and weight of these Class D’s. I could have moved them around easily.
But, the Infinity’s are staying... the rest are going bye-bye.

So, I now have to carry those heavy/awkward Phase Linear Clair Bros WOPL amps back up the stairs and re-configure...
Damn!

One more thing, about my cables in the system that was tested...
Cardas Golden Reference power cables, Monster Sigma Interconnects with Monster Sigma Speaker cables (ME2’s).
Not junk cabling for sure.

I don't know what a Class D amp sounds like when clipping.

That depends very much on how the amp is designed. Some soft clip and some don't- some 'snap' when they clip. You really don't want to do that with a powerful amp- the tweeters are at risk!

Rather than saying from an earlier post, I'll just paste it in again (from the spec sheet):

Overload Protection - In case of high-amplitude continuous low frequency signals in loads lower than 4 ohms the power supply may not be able to deliver the required amount of power to the amplifier and the supply voltage will drop. The overload protection circuit will then lower the threshold of the input soft clipping circuit until the output power has been reduced to an acceptable level. As a result the amplifier will not shut down because of under voltage and the music will still be playing but with a softly shaped audio signal.

Pretty much what I expected. Your experience is basically the same as my except I was using the IcePower 1200AS/2 modules (2.7 ohm rated) with Wilson Watt/Puppy's. I believe you were using the 1200ASP modules (2 ohm rated). Not just the bass, but I noticed it in the midrange as well. It became very sterile to the point I couldn't listen anymore. Stereophile also uses the word 'Anemic' to describe this behavior when an amp is under powered for a given pair of speakers - which I think is a good descriptive. I tried using subwoofers to 'fill-in' more musicality, but it really didn't help that much either. 

One thing you can say about the B&O Icepower modules, and I give them credit, they really do try hard to keep things going even in Overload Protection (no blown fuse). 

joysjane
At lower levels the music seemed to have lost weight/slam/punch. This loss was in the lower frequencies.
As the volume went up the bottom seemed to increase but, the Kappa 9’s sounded anemic.
After 2 minutes I get some very loud snaps coming out of my EMIT K & SEMIT K drivers on the left channel speaker.

I rest my case.

At 625W!! into 8 ohms, and 1225W!! into 4ohms and "said to be stable into 2ohms". They didn’t wattage clip, they have no drive into 2ohms.

It wouldn’t have mattered if these Kappas had the 3000w Behringer on them, same thing would have happened "no current, no 2ohm drive, no music".

They didn’t wattage clip or soft clip as atmasphere would have you believe, they just can’t handle the load and current that they were asked to give, and it’s what I’ve been saying all along.

Even a $199 1980’s NAD 3020 integrated "is stable into 2ohms", there’s more than just that, it needs to "almost double" or "greatly increase" it’s clipped" 4ohm wattage into 2ohms also (not just from 8ohms to 4ohms), and that why that spec need to be independently tested "if" ever given.

This is why a pair of old Mark Levinson ML2 monoblocks which are only 25w!!!! into 8ohms!! would have been able to drive these Kappa’s beautifully full range to a certain volume level, as they are only 25w, but they can close to double all the way down to 1ohm it’s said.
8ohm 25w
4ohm 50w
2ohm 100w
1ohm 200w

https://img.canuckaudiomart.com/uploads/large/2229206-mark-levinson-ml2.jpg


Cheers George