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Mark J.
10-05-11, 06:25 PM
I used to of the belief that you need'nt worry about your stocks, as they do nothing for the overall sound.

Now I appreciate that reeds need an good quality column of air beneath & around them to function properly.

Question:
Instead of using two bags for two sets of pipes, or swapping stocks every time I wish to play my different pipes, I use my Henderson stocks to house both my Henderson drones (2009) and MacDougall drones (1890).

Is there any (noticeable) effect using different stocks, from that the maker intended, for the drones?

I can't notice any, but my ear is less trained than some, and maybe someone here knows of any research that's been done on the subject?

Cheers
MJ

phyx
10-05-11, 10:36 PM
If you really want some fun...search conical bored stocks...or rounded edged stocks on the 'net. There's some debate on this subject that is quite interesting...well...to me at least. :beer:

Mark J.
10-05-11, 10:38 PM
Will do, thanks very much

EarlyE
11-05-11, 02:05 PM
Interesting question.

I really don't know the answer but I would think that there would be no difference to the sound. My reason is that once the air hits the reeds the vibration, and therefore the sound, travels up the drone and is projected from the hole at the top.

Of course this assumes that both sets of stocks have a parallell bore. If the bore were conical as phyx has been reading about on one set and parallel on the other then I would (again without any research or knowing the answer) think that the conical set would make the drone sound sharper assuming that the thinner end of the cone is where the reed is. I would guess this because the narrowing of the stock should increase the pressure of the air where it meets the reed

So there you have my largely un-informed rambling on the subject. Well I say uninformed, does having Higher Physics count?

StuartR
11-05-11, 04:10 PM
Interesting question.

I would guess this because the narrowing of the stock should increase the pressure of the air where it meets the reed

So there you have my largely un-informed rambling on the subject. Well I say uninformed, does having Higher Physics count?

Will just add some input here as I have a limited scope of knowledge on fluid dynamics and frequencies, but fairly high knowledge on mechanical engineering principles.

I can however tell you that the pressure will remain unchanged no matter what you do to the bore (this is because once a chamber is created the pressure in this chamber is constant throughout it).

What will change is the flow area and therefore the achievable flowrate. However, in most drones the governing factor of flow will not be that of the flowrate in the stock it shall be the flowrate allowed by the reed and the area of the bore of the drone.

I do however believe that there will be a change in sound by changing the stocks (be it possibly a small change). This is because the angles at which the air flows through the reed will change by changing the bore size. Also by altering bore and wall thickness of the stock will also change the resonating frequency of the stock (this will have a knock on effect on the overall sound of the drone).

Hope this helps,

Mark, You going to be at Dumbarton? you can buy me a pint!

Heed
11-05-11, 05:29 PM
Only thinking out loud here, but I suspect the argument re the Sheepskin bag having more "resonance" than the synthetic might be similar to the different stocks Q.

If we were to be really elitist, we could say that for the authentic Macdougall sound, the original stocks should be used.

I'm just totally jealous that you've got a set like that. I reckon if I had them I'd be keeping 2 sets going, just to show them off properly.

I'm on Hendersons too btw, I believe about 2006, and they are going really well. I would love a second, old, quality set like you have, as the amount of playing I'm doing, I could keep two sets going no bother.

So, if you ever get fed up with either, send them down to Stirling for a while.

Incidentally, despite the above, I don't think I could tell any difference in sound between old or new stocks. If we were to take things to extremes, ye'd need to source 1890s drone reeds.

Have fun, lucky man!

Mark J.
11-05-11, 07:47 PM
So there you have my largely un-informed rambling on the subject. Well I say uninformed, does having Higher Physics count?

Thanks for the rambling haha ;)
The physics is about as far as I've gotten in my thoughts with it, but I kind of felt without any woodturning practical handsmanship behind and a (relatively) small amount of experience with older pipes, it'd be worth asking!
I might get some vernier calipers out if I can find any & take some comparison measurements...though I'll probably make an arse of them!!

What will change is the flow area and therefore the achievable flowrate. However, in most drones the governing factor of flow will not be that of the flowrate in the stock it shall be the flowrate allowed by the reed and the area of the bore of the drone.

I do however believe that there will be a change in sound by changing the stocks (be it possibly a small change). This is because the angles at which the air flows through the reed will change by changing the bore size. Also by altering bore and wall thickness of the stock will also change the resonating frequency of the stock (this will have a knock on effect on the overall sound of the drone).

Mark, You going to be at Dumbarton? you can buy me a pint!

Hi Stuart

I once worked with a lad who thought a pump wasn't making the desired discharge pressure because it wasn't getting the required suction pressure because (he reasoned) there were too many bends in the pipe preceeding the pump! I couldn't move for laughing!!

So, you think unless there's a reasonable difference in bore size (in all dimensions), I should be safe enough with having a reasonably authentic sound?

Yes, will be at Dumbarton. Just around the corner & can't wait!! Have you gone up the road to Peter-Napper or elsewhere? ...sure it's your round anyway!! I'm on at 12:05 with Badenoch so I'll probably beat you (and most people) to the beer tent anyway!!

Only thinking out loud here, but I suspect the argument re the Sheepskin bag having more "resonance" than the synthetic might be similar to the different stocks Q.

If we were to be really elitist, we could say that for the authentic Macdougall sound, the original stocks should be used.

I'm on Hendersons too btw, I believe about 2006, and they are going really well. I would love a second, old, quality set like you have, as the amount of playing I'm doing, I could keep two sets going no bother.

So, if you ever get fed up with either, send them down to Stirling for a while.

If we were to take things to extremes, ye'd need to source 1890s drone reeds!

...and a sheepskin bag from the 1890's, for the real thing!!

To be honest, I have been debating putting a sheep onto the MacD's. It wasn't that long ago I changed back to synthetic and I much preferred the feel of the skin bag.

I find the Henderson's superb for most everything. They're perfectly suited for a band environment (IMO) with an ace bass sound! I think the auld yin's would be wasted in the band; got to be heard to be properly appreciated.


Cheers for all the replies - got food for thought now

phyx
11-05-11, 10:52 PM
example with pics of what I mean...

http://www.mv.com/ipusers/lsg/Bagpipes/KiddWork.htm

Another search would be for John Kidd and bagpipe stocks...interesting reading

StuartR
12-05-11, 02:28 PM
Thanks for the rambling haha ;)

Hi Stuart

I once worked with a lad who thought a pump wasn't making the desired discharge pressure because it wasn't getting the required suction pressure because (he reasoned) there were too many bends in the pipe preceeding the pump! I couldn't move for laughing!!

So, you think unless there's a reasonable difference in bore size (in all dimensions), I should be safe enough with having a reasonably authentic sound?

Yes, will be at Dumbarton. Just around the corner & can't wait!! Have you gone up the road to Peter-Napper or elsewhere? ...sure it's your round anyway!! I'm on at 12:05 with Badenoch so I'll probably beat you (and most people) to the beer tent anyway!!



I would think so.

When the band went under last year, I did go up to Buchan, got busy with work etc though so was planning on taking the year out. Spoke to DC just over a month ago and have since went down to Denny. So Davie, Johnny and I are trying to make it down to practice as often as possible from up here in sunny aberdeen.

Mark J.
12-05-11, 03:36 PM
Few (rough) measurements today - the orginal stocks are wider (internally), thinner (from OD to ID) and longer.

Hardgoing that mate - that's some amount of travelling. But I dare say it's no worse than what I was doing going down to Dundee. I couldn't handle that again to be honest!

Good medley from what I was hearing on youtube! Were you at Gourock?

Sunny aberdeen? Is there an Aberdeen somewhere sunny, is there?

StuartR
12-05-11, 04:09 PM
2 and a bit hours there just under two hours back. 250 mile round trip. Guess it's all about what you want to get out of going to band and what there is available locally..

Yeah I was there, run could have went a little better, tighten up and corps the fingerwork etc. but good to get out, there are a lot of players that haven't played together before, just looking for improvement all the time.

Haha, no it's that dull place that you know of, somethmes I hope that if I say sunny Aberdeen often enough it will become so.

Mark J.
12-05-11, 05:23 PM
250 miles...that is pretty rough! Think I was nearer the 300 mark tho so you've a bit to go to have me beat :P ...maybe try a few laps around Stirling or Raplock haha! I felt like I lived on the A9 then!!

For Badenoch's practise, I'm about a 75 mile round trip plus it's a Sunday afternoon practise (nae use for Saturday night sessions but anyway) so I'm getting plenty of free time. The folk in the band are good crack too so it should be a good summer.

Well I guess we'll see how it all goes next Saturday then - it'll be a good day I'm sure, regardless of results!

More chance of the World's being sunny for the day than Aberdeen being sunny

redneck
13-05-11, 05:42 PM
Tell Katie 'n John Moneagle Redneck's looking forward dae 'is birthday pint lol.
See ya in the swallie tent pal.