INTRODUCTION:
Neither do I have a university electronic engineering background. Nor am I a speaker designer employed by ML. Therefore to answer your question I would have to extrapolate. Good practice is to answer questions with relevant facts rather than extrapolation. Possibility of other person searching for accurate answer being misled is reduced. I have not recently read relevant technical data of ML center channel.
PART 1.
1.
Human dialogue frequency range seems narrow and therefore inaccurate to me. If you refer to ordinary speech this range may apply. If I am not mistaken male and female opera artists go lower and higher respectively than are indicated by this range.
2.
Greater the panel size the more capable panel is in recreating lower low frequency sound. Due to very small electrostatic panel size speaker unable to recreate very low, low or mid bass frequency sound. Hence the inclusion of mid bass woofer. When we slowly increase the frequency of sound signal. Then there is output transfer from mid bass driver to electrostatic panel.
3.
Your assertion seems plausible, namely, folded Motion tweeter augments the overall high frequency response by improving vertical dispersion and ambience. Whether included for any other reason, I do not know, I would again be forced to extrapolate.
PART 2.
1.
In reality not the case however assume ML assembles only one product and outsources all parts of hybrid loudspeaker. Assume outsourced contract specify 10% increase in panel size at10% increase in former panel price. Since new larger parts are required to maintain balance in design or to accurately increase in scale. Hence assume all related hybrid part price will increase by same 10%. For instance, larger cabinet, larger woofer, higher rating crossover component, larger grille cost etc. Assume for variable cost activity base measurement is in output unit. Assume D.L.H.U and D.L.C.U does not change. Assume total variable material cost per unit after addition of all individual variable material unit cost result in total 10 percent increase.
When management decides to increase electrostatic panel size by 10 percent. Immediately production may not be able to start due to long term lock in nature of committed capacity cost and short-term lock in nature of discretionary cost. For instance, factory building, specialized machinery, warehouse may be disposed of in short term however this action will harm the long-term profitability and continuity of firm. Discretionary fixed cost for example maintenance, insurance, advertising have duration of single budget period. These cost result from contractual obligation and are in the short-term fixed. Management unable to change without providing legal remedy. When increase in panel size is implemented then assume total fixed cost include 10% increase in shape of capitalized plant additions.
Annual Production level 0 units.
After 10% increase in panel size and based on assumptions. Total product cost if production level 0 is equal to current annual dep. cost, 850,000.
Total V.M.C and total V.DL.C both are equal to zero.
Annual production level 400 units.
When output is 400 units total fixed cost remains static at value after capitalized additions equal to 8,500,000. At 10% straight line dep. annual dep. is 850,000.
When production level is 400 units.
Then total V.M.C is equal to
activity level x 1.1 x prior total V.M.C.U
Activity level x 1.1 x 2500 = 1,100,000
400 x 1.1 x 2500= 1,100,000
When production level is 400 units.
Then total V.DL.C is equal to
activity level x 1 x prior total V.DL.C.U.
400 x 1 x 3000= 1,200,000
New total production cost 3,150,000.
Prior year production cost 3,000,000.
Increase in production cost 150,000 or 5 %.
In this case increase in production cost percentage could be any number.
2.
Panels are 10% different in size but cost increase is 66%. Inaccurate or wrong to say cost increase. Say market price increase. Price comprises cost plus profit. Difference in panel size will add 10% to variable panel cost. Price is set at the discretion of management. Management decides low C.M.U or high C.M.U. Cost not the only factor to be considered when setting price.
3.
Cost difference between two is further linked to cabinet wall breadth, strength of material, accompanying type and quantity of feet, size quantity and quality of transformer, quality and type of speaker terminal, reinforcement or bracing if any, internal wire material and gauge, natural wood veneer and related polish and last inside enclosure rear wave dampening material since the ELS 9 front woofer is in sealed enclosure unlike ELS X front woofer.
4.
I extrapolate since listened extensively to ELS 9 and some years prior briefly auditioned Electromotion ELS. Not audition ELS X. After separately listening to both I can confidently assert clear difference in sound. I like and prefer the sound of ELS 9. In my opinion, audible difference may be heard attributable to the following reasons. First, due to paper or pulp woofer material compared to aluminum woofer. Second, less resonating heavier frame. Allow resolving of fine detail. Third, slightly larger area of panel. Fourth woofer type mix - combination versus only bass reflex. Difference in frequency to impedance profile. Assuming for both speakers all other sound variance factors do not vary.