Thiel Owners

To clarify for those recently joining the discussion, my observations are based on an unusual room that is effectively large since the listening room has semi-porous walls within a 12Kcubic’ space, in a 30Kcubic’ building without many partitions. I also have modified the speakers for 3 separate inputs rather than a single pair. I listen at approx 90dB peaks.

Under those conditions the pair of bridged AHB-2s never clip.
I had hoped for a configuration with a bridged AHB-2 driving a woofer and another one (adjusted for matching gain) used in stereo mode with one channel driving the midrange and the other the tweeter. Alas, the upper amp clipped regularly in my conditions. But, in less demanding conditions that setup works quite well.

yyzsantabarbara

"The vertical bi-amp will not work with the Thiel CS3.7 since it only has 1 set of speaker inputs."

Check out bettlemania's system on the virtual systems ,
he bi-wired his 2.4's . 
So with a little drilling and soldering you can have bi-wiring
for bi-amping.

@tomthiel, you seem to be referencing your experience with the AHB2's with the Thiel CS 2 2 's but most of the conversation here is in regard to the Thiel 3.7's.
https://www.stereophile.com/content/thiel-cs2-2-loudspeaker-measurements
https://www.stereophile.com/content/thiel-cs37-loudspeaker-measurements
https://benchmarkmedia.com/products/benchmark-ahb2-power-amplifier
We can see that while the 3.7's appear more sensitive than the 2 2's, the 3.7's work at a lower impedance. The 3.7's are also recommended for greater power input, perhaps to compensate. The AHB2's would seem a bit more comfortable providing comparable useable power into higher impedances than comparable useable power into lower impedances. Though not conforming to ideal textbook performance, the AHB2's are spec'd to the 2 2's load. However, I think that the crux of this conversation is in regard to the  impedance and the corresponding specifications of the AHB-2's into the load at hand for the 3.7's, for which they are not. The difference between a 3.5  and a 2.4 minimum impedance load is not insignificant.
Forgive me if I appear jaded, but that  "John is adamant that the AHB-2 has enough power. Engineers can be that way." sounds more like he's wearing his marketing hat, rather than his engineering hat.

I was about to buy a second AHB2 last night on USAudiomart, but my PayPal was not setup the way I wanted. It will be tempting in 2 business days once my account is adjusted. Smarter move maybe be to pay a little more and do a home trial.

One thing that goes in my favor in buying a second AHB2 is that I have an orphaned KEF LS50 that needs some power. I was thinking the NAD M33 for that but I can happily get an AHB2 for that again.

Here is blurb from the AHB2 manual that I read last night. Which should be good for my small room situation where I won’t be blasting it full blast.

"Speaker impedance always varies with frequency. Speaker impedance may be much lower than the rated "nominal" impedance at certain frequencies. The over-current fault detection circuits prevent potential damage that can be caused by driving very high signal levels into very low impedances. In STEREO mode, at full output, the current limit can be reached if the load impedance dips below about 1.3Ohms. In MONO mode, at full output, the current limit can be reached if the load impedance dips below about 2.6Ohms."

So if I do hit these limits then the amp will shutdown. I am assuming that VERY HIGH LEVELS means high volumes.

@vair68robert  That is something to consider since I already have a speaker repair tech available to help me now. 

1) I have to fix the broken thread on the LEFT speaker frame for one of the screws. I have  repair kit being shipped for that. Hopefully I do not mess up that repair.

2) I have to fix the SPL divergence issue between the 2 COAX drivers. I hope it is not a crossover issue and a simple COAX driver replacement, to the 2012 spec'd COAX,  does the job.

3) I want to sand an lacquer the wood since it has some ugly sheen on certain angles. That was a prior DIY job not from the factory.

4) Setup the outriggers that arrived yesterday, though I will do that last.

5) Maybe add this bi-wire ability

Fun times and all I wanted to do was buy a speaker.