WMcD

I took another look at the Symposium bass horn and see the throat is 50.27 in^2; the mouth is 3,600 in^2; the length is 131.76 inches (approx). From those I calculate the Fc to be 34.83 Hz. Thanks to John A for the graphic. Good Night All, WMcD

Since I've been writing about US Patents . . . Please consider the bass horn shown in the Klipsch Papers i.e. Bell Labs' Symposium. I shows up in US Patent 1,970, 926 titled "Sound radiator" to E.C. Wente and assigned to Bell Labs. (It is likely the same IMHO) It seems best charactized as a giant re-entrant horn (like a bull horn) in a box. It does not seem adaptable to home construction. But take a look. It claims 300 to40 Hz with a 5 square foot mouth and 3' 8" depth. Stackable. 'Good Night, WMcD

It is instructive to look at US Patent 4,210,223 (Note this is corrected)which concers the big MCM bass horn woofer. The Length to double area is 23.3 inches which gives an Fc of 31.95 Hz. You can find the document at USPTO.GOV or Google Patents. There is in that patent document some design information. And Klipsch and Gillim use the 18.1 figure (so I was correct!) Many thanks toJames and also to John A for helping me through this stroke time. WMcD

Typically horn flare rates (areas)are described by the term "cut-off" frequency aka "Fc"; at freques below this this the horn just about stops working. You put Fc into the exponential equation however, PWK often used the term "lamedh" (I'll use "Ld") to describe the horn area expansion; It is the lengh of travel down the horn in which the area doubles (or halves). Therefor the expansion works like animals / bacterium doubling every time period. If my math is correct, the cuttoff wavelength (I'll call it "Lc) is 18.1 times the length to double. We can examine the LaScala's two paths (combined) and notice the area at the throat is 0.5 ft^2; then the paths go across the back to the interior corners where the area is 1 ft^2; then toward the front for a foot to where the area is 2 ft^2; then another foot to the mouth where the combined area is 4 ft^2. Therefore we see the Ld is 1 foot or 12 inches. The Lc is thus 18.1 * 12 and we dived the velocity of sound 15,00 in/sec by that wavelength to get an Fc of 62 Hz. We can check the PWK article on the K400 horn and notice that the length to double is given as 2.75 inches. The math like the above shows that it's Fc is 270 Hz. PWK was really getting it to go as low as possible to where the bass bin on the Khorn is running out of steam! Good night all, WMcD

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The ussual response to a question like this is to try different things and see what you like. But I think that is a cop-out (unless you'asking an aesthetic question -- like what color to paint the spare room. Rather,you are asking a technical question in view of conflicting instructions. IMHO your likely best starting point is to use the output tap with the lowest ohms rating. *Very generally this will have the least hum and noise. (if those are a problem) *Very Generally using a light load (16 ohm load on an 8 ohm tap) will result in lower distortion. WMcD

It looks like Im wrong about hair spray. https://en.wikipedia.org/wiki/Hair_spray

The attached cut-sheet provides some info. It appears to me that the LS (at least that year) was available in unfinished, clear lacquer, or black lacquer. I can only think that Raw is unfinished rather than clear lacquer. It is my understanding, and small experience that lacquer is used on furature because it can be sprayed and cures very quickly. I think hair spray is lacquer. Otherwise it is poor finish because it can be damaged by water. White Rain can be washed out. Clear lacquer causes very little change in the grain of birch. I would try veneer first. WMcD LaScala and Belle Cut Sheet (blue grid) (1).pdf

In a similar situation I used foam weather stripping. Getting the right angle bend worried me even though I thought that under compression the bevelled edges (like a picture frame) will mush together. I did not investige further. Then I tried using the foam sheet which HD sells as a liner for tool drawers. It was too gummy and would not allow the hatch to open . You know the cable saws HD sells to cut PVC? I had to get the cable in the gap but it was a messy job. Next time I may cut the gasket from a yoga mat . WMcD 1. fo

I think Klipsch will sell you a new woofer, though not a Jensen, but might ask for the serial number of the speaker. If it is not available I don't know. I would get two. WMcD

Lye as in Murphys is the major ingredient in Easy Off oven cleaner. I have not checked for its use on wood. smile.

https://www.popularwoodworking.com/woodworking-blogs/murphys-oil-soap-a-most-unusual-story/ This gives you a solution of lye and water.

It is possibly okay as long as neither the water nor the soap reach the wood. WMcD

One of our members found that it ruined speakers. DO NOT USE!!!!