what's with this whistling sound i get on a semi-broad reach i've never bothered to really find out but when i started using this sail that has zippers on the boom cut-out there could only be one thing and it could be the fin? only on this fin it happens and if i remember on one thread it's a no good thing..am thinking since i tried this using a normal open boom cut-out sail it could either be the boom too. if you sheet in to windward it stops but when open to a more open broader approach it whistles loud nice to hear but i think something's wrong
am curious if it is how does the sound get produced
Every once in a while I get it with my North 5.4 wave sail. It seems to be coming from the boom cutout.
It's a sweet sound and it only happens in strong winds, not every time.
are you using a select fin?
some of these are notorious for screaming like a banshee
Could also be whistling from the holes in the boom extension
is your boom a single pin, because one of our booms with a single pin whilstes but only in strong winds. and when your really hard up wind or going down wind
could be your extension , one of mine used to whistle all the time , drove me nuts
just a thought
Usually get a whistle when gybing on the inside but it's from the girls on the beach
, but seriously, my old pride extension used to whistle as the apparent wind changes direction.
i could imagine the most possible or likely place for the whistling sound to come from the unused boom extension holes much like a flute i guess but as i said on this particular one the sail had a zippered cutout too..funny i would really sheet in and out or up and downwind to get the most volume..if it came with melody then it gets funky
I've had whistling from my mast extension, and a friend has one of those F2 boards with the air holes in the deck, which I think were whistling once when he passed me like a rocket...
Don't worry about it; it makes you sound faster!
I sometimes get crazy deep humming sounds from the cutout on my Superfreak. I assume it's down to having the sail at the wrong angle to the wind, so more air is going past the leading edge on one side than the other and pushing into the cutout or something...jeez I can't think, what am I talking about, can barely type, was sailing fully powered all day and ...and...dzfgsetystdghdhtrshrthryh
Select fins hey elmo,
I just changed from a drake 40 to select 38 and you can hear me coming a mile away, I thought I must of been rigging something different but its probably the the fin like you say, how can a whistle come from a fin anyway its underwater????
I had a Select Lightning Evo 37 that screamed like a banshee!!
I sanded it all over the place from instructions from top sailors and even the maker. Didnt make a squat of difference. When you started to get wound up it would start around 27 knots and by 30 all my mates could hear me coming from 100 meters away.
I showed Sam at WSS and he discovered the whole fin was slightly warped. Likely explanation was out of the mould like that. Now using a JP 36 and its sweet.
JP747, check your fin VERY closely.
I thought it was vibrations of the trailing edge of the fin.
I used to get it when I raced Lazers, coming from the centre board - but it was a lower pitch.
Sure I read somewhere that you can sand the trailing edge so it's a bit more boxy (and less like a knife) and stops the whistle!
Crash , Thats actually the opposite of what you want to do to stop a fin whistling . It whistles if the trailing edge is too fat . What you need to do is get some 400-600 wet and dry sand paper on a block . Run it down the trailing edge at about a 45 deg angle . Bring it almost to a point ( but no need to make it razor sharp , bad for feet when water starting)
This should solve any whistling .
Had a Torquay fin that used to whistle all the time, When hearing it I always looked and checked how my set up felt, and every time it was spot on, could play the piano on the boom , all felt very balanced. So was using that as a guide for that set up. Dont happin any more though
hmmm 555 says he's got closed cell in the extension arms and mine does too so that erases the boom hole flute theory..ka43 says to check warped fin theory and i did just that from top to bottom and from leading to trailing not much there..since i tried luff cutouts open and with zippered and same thing so 555's explanation on first paragraph seems a bit of a science but does make sense on the guitar body theory..you know i just remembered that i drilled a hole at very end of boom to further close the gap for smaller sails and on that the drill bit ate through the foam could be that
although 43's could be and i just couldn't see well enough the minute warp..should check the angle of the fin to board when attached maybe it's offset
Not 100% sure on this... but u can hear the fin which is underwater because it resonates which is transmitted to the board through forced resonance, which is what u hear. I think...
i'd like to believe that filthy but when at speed and all that noise the board skimming and wind and all the whistle blows just like it was a foot away..oh i'd let it be if it whistles then cool
. here's another what i noticed it only whistles on starboard tack and why not the other sidehere we go again
It's the fin.
My select 37 does this, it goes up in distinct steps, G# means 28 knots, A means 29 knots, Bb means 30 knots, C means 31.5 knots...
My other select fins whistle as well but at different pitches, the 28 weedy only has two pitches that are a good 2 or three tones apart. If you hear the higher pitch then you're going broad and doing more than 30 knots, the lower pitch happens on a beam reach above say 27 knots and gets louder the more the fin is loaded up (so it really screams as you pull out of a speed run).
Haven't had the select 25 wave up to a good enough speed to hear it whistle yet but I'm sure it will....
Simplest explanation is that the trailing edge is too square. This causes vortices that alternate between clockwise and anticlockwise, as the vortex swaps sides it makes the fin 'bang' over the other way, when it happens quickly you get a whistle that gets transferred through the board, up the mast and you think it's coming from the boom/mast.
Chamfer the trailing edge to stop it happening.
hey nebs longtime no hear good results your side ey! okay i'll accept that it sure is loud and as i said from a foot away but for your explanation that is simply amazing..i'll try to chamfer but honestly what do you mean by that
oh by the way this fin is a 34 northshore maui and erect for upwind performance..regards
en.wikipedia.org/wiki/Chamfer
Grab some 600 wet and dry, put it on a sanding block, and make the trailing edge sharper. Stops the whistling... but I kind of like it, it tells me how fast I'm going
Hmmmm... might be able to do "Mary had a little lamb"... would have to be the right conditions though, and getting the sound to stop then start at the one pitch would be tricky. Chop hopping does work, I've done it before, the sound seems to gets louder just as the fin starts to leave the water for some reason then stops when in the air.
Where's my waterproof sound recorder gone?
no doubt you've scared off all the whales and dolphins with your squealing chamfered fins nebs.
chamfering is a non science
block sanding is good.
