What’s the advantage if any of the ‘H’ style bass drone end like on Paddy Keenan’s old set as opposed to the u-bend? I’d have thought the H would impede airflow.
Cheers,
DavidG
Ausdag, this is in the same vein as the other thread you posted on about chanter top connections. The issue is not about air flow, it is about ease of sound/pressure waves passing through. In each case, there are those who swear they can hear a difference in the quality of the sound of a straight path versus a broken one.
Any sharp angles in the path of the sound waves can set up small interference patterns that can modify parts of the frequency spectrum of the original sound. These can cancel out certain parts of the spectrum of the original sound. Can you hear a notable difference?
I think this may have more to do with what each individual has the ability to hear versus what they were expecting to hear, so it becomes very subjective.
djm
Yeah…I’ve never been able to tell the difference, not that I’ve really tried too. But I was looking at pics of Keenan’s Williams set and wondered why makers began making them like that.
Cheers,
DG
You really need to have a pipemaker close to hand to see what the differences are. I have sat with Joe Kennedy and listened to different designs he has worked on for things such as chanter top - side entry versus top gooseneck versus top straight in, bass drone straight versus curled versus H, bass drone puck resonator versus plain, etc. Sometimes you can discern tiny changes if you listen to one type then immediately another type, but these changes are really small. You would have to have memorized a certain sound to have expectations where you could say that one was better than another.
djm
sonically there are no differences bet. the H and bend. i have sets with each style… structural stability (i.e. the solder points) may be more of an issue.
i have seem many a froment with the H with chipped or broken plastic inserts on the ends… and have sen many a bent drone return with dents on the bottom (including one of mine)…
It seems to me that this H design came about because of different metals used in the bass drone “bend” area. Brass and sterling silver tubing may be easier to bend than nickel silver or steel. Can any pipe makers out there confirm this?
-Dirk
The ladder end provides a couple of nice areas to place little ivory ornaments 
Wheh wheh wheh…
PD.
i was told by a well known american pipe maker (sort of tongue in cheek, but not really i think) that he thought the H design was for makers too afraid to bend metal.
If you have ever used a lathe you should know that all pipemakers are fearless.
Patrick.
From one who has worked with metal and lathes, as well as having had loads of physics classes in college (about 20 years ago). I can think of good points for both methods.
Personally I think the “H” looks really cool when done well, like Patrick’s pic. That is my esthetic preference. But we all have different tastes.
I use both types
Bending the metal is no problem so long as a sensible diameter is chosen. Woods metal is used to fill the tube which on my instruments is either seamless brass tube or hard soldered nickel silver tube rolled from 22g sheet.
The “H” bend with its ivory plugs is less prone to damage - the “U” bend is vunerable to denting.
Chris
Square corners are used in the tunnel business to break wind. In every 90 deg. corner lies stagnant air. In every wind tunnel, the air current along the wall moves in a reverse flow. The U bend, or sweep, helps keeps stagnant air from returning to the primary source. Assuming that the air flow is aligned to the plane of return, pressure irregularities are minimized. Thus, the sweep system (U-bend) is preferred by pipers, plumbers, heat duct installers, and people in the pathological profession.
Notice in Patrick’s illustration above, the tube extention in the H dead-ends. This is the same principle that is used in natural gas piping for heating systems and hot water tanks–per Uniform Building Code. The pipe is required to run past the outlet valve. The reason given, according to the UBC, is to absorb pressure differences.
And anyone who believes that is full of hot air as well
[quote=“Lorenzo”]Square corners are used in the tunnel business to break wind.
My large intestine has loads of U-bends and I produce a nice steady tone when I break wind
RORY
Its important to keep your body in tune. 
djm