<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html> <body bgcolor="#FFFFFF"> David Love wrote: <blockquote TYPE=CITE> No, I don't think it does.  The action regulates purely as a function of action ratio, with some wiggle room.  The SW zone has nothing to do with it. In the context of our discussion it sure does. Because the action ratio is being changed around to deal with higher SW zones. And this is what you are on about. Your whole point seems to be that higher (defined as anything above mid mediums)  SW zones demand lower ratios, which causes regulation problems and yeilds no tonal benifit. You can vary the aftertouch but you have more room on the deeper side.  You need a minimum amount.  Tastes vary somewhat, but not generally to the degree that it requires a wholesale change in the targeted ratio. You draw up a very narrow set of parameters indeed David. Mine are quite a bit wider, tho as I have stated not so wide as force the use of whippen assist springs to or go over the maximum FW standards. You state that tastes do no vary largely enough to justify any ratio outside 5.85 - 5.75 range. What evidence do you have that this is true ? Where is your research that confirms this assertion ? So let's do the math.  Let's take note 18 in high strike weight zone. After re-inclusion of the qualifier to my above statement, I find this example out of the scope which I drew up. Indeed, I stated right out that when one reaches this highest level (and you picked the absolute highest) one runs into problems. We could just as easily do the same for the absolute lowest. But the issue doesn't exist at the lowest level in the same way.  There are no concerns about exceeding front weight maximums.  Anyway, my point in this was "why heavy hammers".  The example I gave of a high zone hammer is something I recently saw on a Stanwood project.  (One that I was asked to undo, BTW)  No it doesnt, you are correct. There are concerns however about problems with regulating within the specs you give and still maintaining a good balance..... or perhaps you take issue with that as well. This would be an interesting turn worth persuing me thinks ? Your point was "why heavy hammers ? ". You justify your point by <blockquote>1: a subjective opinion on the tone benifits of heavier hammers. 2: a claim that outside the 5.85 - 5.75 ratio range the action regulates poorly. 3: an assertion that the velocity of light hammers compensates for lower mass, even to the degree of providing better pppp control.</blockquote> These are the centerpins to your argumenation so far as I can see. So since you decided on an extreme heavy SW example, I took the opposite extreme which as far as my understanding goes requires a higher ratio to balance well. A higher ratio increases hammer velocity relative to key travel, where as a lower one appropriate for heavier hammers does the opposite.  In fact at least one major manufacturer has moved in this direction, opting for a key deep of a bit under 10mm as part of the configuration. Fits the bill so to speak... unless the whole bill is wrong to begin with. It's a bit jumbled.  But in short, I think that regulation rules in terms of decision making on actions.  The rest must fall within the area where regulation requirements can be met.  I don't think I said anything about restricting weights to low mediums.  I think the ideal regulation happens with an action ratio of 5.75 - 5.85.  You can do the math from there to figure out the highest strike weight zone that will keep you in the ballpark when you factor in desired balance weight and front weight.  Pushing up the strike weights to high zones for the sake of aleged tonal benefits creates other problems that, in my opinion, are not adequately solved by the currently employed protocols.   By restricting the ratio to a range of 5.75 - 5.85, limiting yourself to maxium FW's at 80% or below of the maximums Stanwood gives, and not employing an assist spring, you infer a SW zone that does not exceed the middle part of the mid SW zone. Which aggrees nicely with your stated preferences for SW's. Take your example note 18. Mid medium is about 10.6 grams SW. 80% of the max FW comes out to 29.6 grams. A 5.75 ratio and 9 gram WBW yeilds a BW of 40.35 here. Fine enough... but you cant add much SW without needing to change things... hence the infered SW restriction to mid mediums or below. Increase this SW to just 11.7 and leave all else the same and you have a BW of 46.7 But by accepting a 5.6 ratio and FW's at 90 % you can achieve the same BW with this increase in SW. There is no way a 5.6 ratio is difficult to regulate, even within the 10mm dip 45 - 48 mm blow you parameters you give. And there is no evidence given to support the claim that this small increase in key inertia creates a "problem". I still maintain that SW zones up to the mid highs do not cause any of the regulation problems you claim. For your note 18 that would be 12.4 grams. A 5.6 ratio here yeilds max FWs and thats it. Same BW, same key dip, virtually same everything else. Wheres the problem ?  Pianists tastes in touch and sound do vary, but not as largely as you think in terms of what is needed as far as design.  You can achieve a wide enough range of touch and tone within the parameters that I've outlined to accomodate 99% of the pianists.  Similarly with tone.  The designs I see that incorporate high strike weight zone hammers, I believe, have a more limited range of who they will accomodate and so I would not advocate them as a standard approach. I beg to differ, but I am willing to look at any documentation or research done that would support this claim. My own experience tells me different, and the only large information base compiled on the matter would also seem to point in this direction. In any case, none of this last paragraph can serve as a basis for condemnations of configurations which employ ratios moderatly outside the range you give. Tho I will aggree that any  "standard" approach concept would be best to approximate an "on average" representation of measured preferences. David Love</blockquote>  Cheers David. And thanks for the interesting exchange. This is what the list is all about eh ?   Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway <A HREF="mailto:rbrekne@broadpark.no">mailto:rbrekne@broadpark.no</A> <A HREF="http://home.broadpark.no/~rbrekne/ricmain.html">http://home.broadpark.no/~rbrekne/ricmain.html</A>   </body> </html>