Venturi size

[Tbarh]

In the hornguys website they state the venturi sizes of different Kanstul Leadpipe but have omitted the 547 pipes for some reason.... What are the typical venturi sizes of 547 bore Leadpipe?

Thanks.

[Matt K]

They probably ran out of stock and since Kanstul went out business can't furnish additional pipes so they removed them from the table.

[Tbarh]

They are still listed in their inventory... Is it usual to state the venturi size? I am looking for a ballpark figure .

[brassmedic]

https://web.archive.org/web/20120625213 ... /parts.php

[Tbarh]

https://web.archive.org/web/20120625213 ... /parts.php

Thank You, Brad... Perfect

[Crazy4Tbone86]

I have a chart with precise measurements for dozens of my leadpipes hidden in my computer somewhere. I cannot seem to find it right now. Most of the leadpipes in my collection are of the .525, .547 and .562 sizes.

If I remember correctly, the range of my .525 bore leadpipes is from .400 - .426, most of my .547 bore leadpipes are in the .448 - .482 range, and my .562 bore leapipes have a venturi in the .485 - .505 range.

A couple of things should be noted:

*In general....the larger the bore, the less impact that (for example) .003 inch will have on the resistance. A change of .003 inch should have a profound impact on a .500 bore and less impact on a .562 bore. This makes sense when we consider that there is a significant difference between a .459 bore and .462 trumpet, yet the offerings in the trombone world have bore sizes much further apart: .500, .508, .525, .547 etc. However, there are many exceptions to this rule.

*There are many things other than the width of a venturi that impact how a leadpipe plays, including: distance from end of mouthpiece to venturi, type of alloy, seamed vs. drawn, shape of leadpipe after the venturi, overall length of leadpipe, etc....

*Every venturi has a personality all of its own. I have owned several "stock" leadpipes that I have pulled from assorted Bach 42 horns. Every leadpipe has played completely differently, even the ones that have identical measurements. I have owned leadpipes with smaller venturies that played very open. I have owned leadpipes with very open venturies that felt small when played.

[Crazy4Tbone86]

Sorry for that endless rant! Maybe I should have just said this....

Don't let your choice of a leadpipe be based on the width of the venturi. It is always best to play on a leadpipe before passing judgement on it. There are SO MANY variables!

[Tbarh]

Sorry for that endless rant! Maybe I should have just said this....

Don't let your choice of a leadpipe be based on the width of the venturi. It is always best to play on a leadpipe before passing judgement on it. There are SO MANY variables!

Absolutely.... I am trying to find a correlation between venturi size and how they sound, but also how they blow... Conn for instance are usyally very open but with a tight venturi... I am really early in this quest so i am not ready yet to disclose what i am looking for exept what i state above..

[elmsandr]

Sorry for that endless rant! Maybe I should have just said this....

Don't let your choice of a leadpipe be based on the width of the venturi. It is always best to play on a leadpipe before passing judgement on it. There are SO MANY variables!

Absolutely.... I am trying to find a correlation between venturi size and how they sound, but also how they blow... Conn for instance are usyally very open but with a tight venturi... I am really early in this quest so i am not ready yet to disclose what i am looking for exept what i state above..

Warning: soapbox post.

We might list Venturi size, like bore or bell size.... because we can, but it isn’t the most useful predictor of sound. Rate of taper will have a larger effect than the measured minimum ID. But that is harder to quantify and can’t be done in a single number. Similarly, a Bach 36 and a Yamaha 354 both have an 8” bell. I do not expect to correlate those values because of a single shared dimension.

Cheers,
Andy

[JohnL]

https://web.archive.org/web/20120625213 ... /parts.php

Ah, the Wayback Machine.

Thank you, Mr. Peabody.

[brassmedic]

Sorry for that endless rant! Maybe I should have just said this....

Don't let your choice of a leadpipe be based on the width of the venturi. It is always best to play on a leadpipe before passing judgement on it. There are SO MANY variables!

Absolutely.... I am trying to find a correlation between venturi size and how they sound, but also how they blow... Conn for instance are usyally very open but with a tight venturi... I am really early in this quest so i am not ready yet to disclose what i am looking for exept what i state above..

The venturi on Conn leadpipes is larger than the venturi on Bach leadpipes. I know it seems to defy common sense, but the open feel on Bachs is due to the oversize slide crook and bell flare, not the leadpipe.

[Tbarh]

Absolutely.... I am trying to find a correlation between venturi size and how they sound, but also how they blow... Conn for instance are usyally very open but with a tight venturi... I am really early in this quest so i am not ready yet to disclose what i am looking for exept what i state above..

The venturi on Conn leadpipes is larger than the venturi on Bach leadpipes. I know it seems to defy common sense, but the open feel on Bachs is due to the oversize slide crook and bell flare, not the leadpipe.

The GR bass trombone Leadpipe has a rather small Leadpipe venturi, but play really open, but with a lot of front"to the tone.. I supposed it is a bit shorter with a fast taper... Conn tenor Leadpipes are as You say more open, and a part of a system... I am a big fan of Leadpipes that allows some "wiggle room" In centering the tone... Makes You hone and shape the sound easier.... This is a reason that i gravitate towards an old Conn rather than say a Shires, which i find lack this quality...