Bell types accoustical horn comparison

[Mark Horne]

I believe the post you are thinking of was penned by Rick Denney some time ago. If I recall correctly he was comparing bell flares with high frequency speaker horns (for PA speakers). The German bell profile (like Alexander) is more like an exponential horn - designed for long-throw applications (projecting the sound to a distant audience), whereas the American bell profile (like the old Yorks or Conns) was more like a bi-radial horn, where the sound is spread in a much wider pattern over a short distance.

These profile concepts seem to match many of the descriptions used characterize the classic "American" sound (e.g. "enveloping") vs. the classic "German" sound (e.g. "direct" or "column of sound").

[Tom]

Funnel-shaped bells offer fewer highs...Listeners typically describe this as "less focus".

Pancake bells (as long as the pancake is conservative) tend to offer a more "focused" sound, as the expansion of the funnel towards the end of the bell tends to be less severe.

Interesting. I have always thought exactly the opposite.

Funnel-shaped bells = "stovepipe" bells, right? If so, I have always felt tubas with bells of that sort were more focused. I'm thinking of the sorts of bells found on Miraphones, Alexanders, Rudy Meinl (most), and typically other "traditional style" German/European tubas.

Pancake bells always seemed less focused to me, more diffuse, I guess. While it is an extreme example, I thinking of bell shapes along the lines of the Getzen G-50 and tubas built with that "short and fat" look about them: Conn 5xJ tubas, the new Eastman, Kanstul tubas. I suppose these tend to be the instruments that are either American in origin or design and/or have been developed out of the Monster E-flat tubas of the past.

So, I dunno...

[Donn]

We might could use some pictures or diagrams here.

I would have said "funnel" means a wider taper in the more-or-less conical part of the bell, particularly if it appears to be a wider taper than the preceding bows. I don't know, the Kanstul line looks like that to me for example; among "Rick Denny"s horns, the Holton.

"Pancake" on the other hand evokes a wide bell flare, which could happen with any kind of bell, but would be more conspicuous if the bell isn't already very wide.

Tubas with modest bells and wide flares, maybe Conn 21J for example, and RIck Denny's York Master. Or in the extreme, front facing bells and sousaphones. It's an interesting combination, because I think we expect the bell flare to have a diffusing effect, but per above maybe there is also a softening effect in a different way from the wide conical bell's timbre.

I think "exponential" and "bi-radial" are fairly specific geometry terms, but it isn't easy for me to match them to a tuba bell profile. And I'm not sure I read Rick Denny to be doing that, literally - more intution than analysis - but he apparently relates the exponential with the narrower bells.

(And of course there's the effect of a shorter wrap, which makes the bell look fatter without changing its dimensions, cf. King 2340.)

[eupher61]

I THINK, if reading your statements right, you are exactly opposite of the descriptions used above.

Funnel-shaped bells offer fewer highs...Listeners typically describe this as "less focus".

Pancake bells (as long as the pancake is conservative) tend to offer a more "focused" sound, as the expansion of the funnel towards the end of the bell tends to be less severe.

Interesting. I have always thought exactly the opposite.

Funnel-shaped bells = "stovepipe" bells, right? If so, I have always felt tubas with bells of that sort were more focused. I'm thinking of the sorts of bells found on Miraphones, Alexanders, Rudy Meinl (most), and typically other "traditional style" German/European tubas.

Pancake bells always seemed less focused to me, more diffuse, I guess. While it is an extreme example, I thinking of bell shapes along the lines of the Getzen G-50 and tubas built with that "short and fat" look about them: Conn 5xJ tubas, the new Eastman, Kanstul tubas. I suppose these tend to be the instruments that are either American in origin or design and/or have been developed out of the Monster E-flat tubas of the past.

So, I dunno...

[Donn]

I THINK, if reading your statements right, you are exactly opposite of the descriptions used above.

Yes, it seems that funnel shape is a term that admits some ambiguity. After a little legal-in-Washington-State mental refreshment, right away I got on bloke's wavelength and realized that it might be easier to visualize the bloke scheme if you think of it as bell size while hold the bell flare width constant. Considering only one variable, not two. As he says several times.

A smaller bell has relatively straighter sides, and a more extensive "pancake" flare; the larger bell is more widely tapered sides ("funnel") and less flare. Everyone seems to agree on the playing characteristics, only the words change. All that's left is the classification or rating of tubas in this scheme. In that regard, I'm rooting for at least the later big Conns for the pancake category, inasmuch as to my eye the bell is smaller when it starts into the flare, than say a Holton 345. The relatively rare combination of large size, large flare, and not the biggest possible bell.

[Tom]

There are different shapes of funnel shapes, thus the confusion.

The PARTICULAR type of funnel shape to which I refer is the Conn 36J / Rudolph Meinl 5/4 type of funnel shape, where the last linear foot of the bell expansion would hold considerably more liquid (more area inside) than a bell which (rather than gradually expanding outward to a final rim diameter as do the RM and old 6/4 Conn bells) opens out to a fairly large size, and then - at the very end - suddenly "pancakes" out to the same final rim diameter.

Those BIG Conn and BIG RM bells (with LESS pancake) offer a fluffier sound with less definition, whereas same-diameter bells (with MORE pancake) offer a clearer sound with more definition.

Though "fluffy" and "less" may seem to be negative connotation words, I don't mean them in that way...but (while typing this post) I simply cannot come up with any connotation-neutral words to use instead.

Got it. I owned a Ruolph Meinl 5/4 at one time, so I am familiar with the shape you're referring to.

I think the confusion really stems from the use of term "pancake." I was using it to refer to an OVERALL bell shape, whereas you are using it to specifically refer to the flair on ANY overall type [shape] of bell. We're talking about the same thing, actually, but well...the "pancake" got in the way - I actually agree with you now that I understand how it is you're defining it.

[Mark Horne]

Probably a better source for Rick Denney's comparisons of bell flare types can be found on his own web site: http://www.rickdenney.com/york_vs_miraphone.htm" target="_blank" target="_blank

Note that he uses the term "focus" to describe the denser and more directional qualities of the German-style taper; I would also tend to use the term that way. However, I agree that the more American style flare provides more high frequencies - and to the extent that people equate high frequencies with more "clarity" (thus, "focus"), I can see how "focus" can be used to describe American-style tuba sounds.

[Donn]

However, I agree that the more American style flare provides more high frequencies - and to the extent that people equate high frequencies with more "clarity" (thus, "focus"), I can see how "focus" can be used to describe American-style tuba sounds.

What's an example of your American style tuba? From the Rick Denny link, I thought the specific tuba with the high frequencies and more apparent focus was an Alexander. Bloke's funnel shaped tuba with less high frequencies seems to be talking about Holton 345, for example - but that isn't about the flare so much if I read it right, as the shape of the bell below the flare.

[Mark Horne]

Rick's American-style example was a 4/4 York Master - having a relatively small bell throat that expanded to a wide-flat bell in the last few inches of taper. He used a classic Miraphone 186 as his German example - it being the older 16.5" bell diameter that is very Alexander-like in profile. He actually did some spectral analyses comparing the two: http://www.rickdenney.com/the_tuba_sound.htm" target="_blank" target="_blank

Here he demonstrates that the York, although sounding generally deeper in tone, contained more of the higher overtones than the Miraphone. I believe he did these tests before he had the Holton 345 - it would be interesting to see how that horn would measure.