Damn it

@wmwatkins,
mrdon here, i want to thank you for taking the time to post your reaction/correction. I do not recall if it was you I spoke to on the phone as a follow up to my message although it may have been. None the less I was impressed with the call back despite being two days later, all the more impressive. It is actions like the call back and the posting here in audiogon to better explain your speaker dynamics that will resonate with this community. And, again, should the S400's not stand up to all their hype I have a 30 day trial. And, it just so happens i know the area code to Tennessee where some very fine speakers are made to audiophile specs.    

Gentlemen, I would like to add a few things to this thread if you don't mind. First I would like to thank mrdon for considering our loudspeaker,
and again apologize for being closed due to a illness and returning his call late. And again we hope that the S400s work out for him.
Second, in regards to the comments made by mzkmxcv. The Gen4s 
have excellent imaging through the crossover region due to drivers characteristics, the crossover device, time alignment, and our modifications. The phase response through this range is smooth and averages 8 degrees. We have learned a lot over the past 50 years there are sonic drawbacks to 12,18, & 24 dB/octave crossovers and found that choosing the best timbre matched drivers, modifying them, and then using the simplest crossover is the best way to go. Why use inferior sounding and complex crossovers to make up for something not right to begin with. The advances in woofer technology can allow for a naturally smooth ~6 dB/octave upper end roll off especially if you modify it to your purpose. Our Gen4's tweeter with modifications integrate seamlessly with our modified woofer's extremely smooth roll off. No drawbacks here.
Also concerning your reference to a tweeters 2000 HZ 1st order crossover -12 dB point being an issue, power wise, if the speaker is powered with 100 watts at 500 Hz the tweeter sees only 6.5 watts. Not a  problem for a quality tweeter. 
I'm sure that your comments apply to many speakers, just not ours.

Thank you,
Bill Jr....

@mrdon 
 
Yeah, nothing inherently wrong with 1st order crossovers, but it does require that both drivers can easily play past the crossover region, so it’s usually more appropriate for speakers that are 3-way or greater. Because, if you cross over a tweeter at 2000Hz with a 1st order, it means it’s only 12dB down when at 500Hz, no way do you want a tweeter playing that deep (and that means the 6.5” woofer is down 12dB at 8000Hz, you also don’t want such a large driver playing such high frequencies). If you have a hard time grasping what a 12dB difference sound like, being 3ft from a riding lawnmower is 12dB louder than 50ft from a jackhammer. So yeah, you don’t want your tweeter playing that loudly at that low of a frequency.

@mzkmxcv, (@CD318)
Thanks for the feedback back on the Watkins Gen 4. I would never had known anything about the 1st order crossover and challenges it present to the music quality. The Gen 4's were very close in the running but I went ahead and pre-ordered the S400's and feel it was a pretty damn good choice. I will not know for sure until after they arrive and are unpacked and connected to my new PS 700 monos.   

I would consider the S400 or the Gen 4.  
  
The Gen 4’s gives a lot of info regarding specs, more than most any other company I’ve seen. However, they are using a 1st order crossover between a 1” tweeter and  6.5” woofer, which I can likely assume that it will have poor imaging around the crossover region. The S400 uses a large waveguide to help with it’s crossover integration, and they provide a good amount of measurements to show that it performs very well (of course, they don’t give you everything, like distortion and the transient response nor decay).

It's always interesting to read other peoples views on loudspeaker strengths and weaknesses. However we know that no loudspeaker is capable of sounding entirely life-like so it can be useful to know where the sound shortcomings fall. Resolution, frequency range, dynamics, imagery, tonal and timbral accuracy, timing etc. As far as I'm aware the only sound issue with the Harbeth 30.1s might be the low bass. If you can live with that..

Then there are the practical aspects - how loud can they play, how much power do they require, what are the grilles like, are the tweeters protected, how much space do they require, and lastly but certainly not least (esp for larger designs) - what do they look like? In all these areas the 30.1s seem fine. I love the classic look of Harbeth speakers, especially in the lighter colours.. 

Ultimately though I'd strongly recommend a listen first, nothing can beat that.

Bear in mind also that Harbeth's do tend to have a  high resale value if things don't work out, but again, a listen first could help to avoid that.