Bow noise and sweet spot ?

[T Folts]

I've built a 3pc reflex/deflex longbow and I am trying to fine tune it. It is 1/4" positive tiller
and I am trying to find the sweet spot but cant seem to get it quiet. I have gone from 6 1/2" up to 8 1/8 without much difference. I have been using a decibel meter mounted right next to my bow. Comparing the numbers there's not much difference.
I'm wondering if I should set my tiller a little closer to zero? Any thoughts on this?
Thanks
T

[jess stuart]

I usually keep mine about even, but I shoot three fingers under.  Be sure your arrow isn't hitting the sight window etc.  arrow contact can make them sound real loud.  Is your arrow weight enough?  To light of an arrow can cause noise.

Is it a Bingham design or your own.  The reason I ask once I designed and built a r/d longbow guess I the defex in the wrong area that sucker had so much hand shock I finally gave up and ran it trough the bandsaw.

I am pretty sure you are aware of all the things that I mention, just hoping it will get us to thinking.

[T Folts]

I shoot split finger, the plans are from binghams and I have the nock set at 5/8 above center so plenty high. Also my arrows are somewhere in the 10-11gr per lb range.
I made sure there is no arrow contact (slap) on the shelf area.

[kodiakkid]

I'm no expert but 5/8 up seems awful high for split finger

[T Folts]

The 5/8 is a starting point. I wanted to make sure I was not getting the arrow to slap the bow increasing noise. I had it set to low at first and it was hitting off the shelf. This is a twang, I'm looking for the soft thud I'm used to.

[jess stuart]

What kind of string are you using?  Is the limb tiller okay?

[T Folts]

The string is 8 strand D-97 and the tiller is 1/4 inch positive.

[Jason Scott]

I'm not sure decibels alone is a good way to find sweet spots. Maybe tone is just as or more important. Arrow flight should improve when you find it too and that of course requires tuned arrows. The string is going to buzz and create decibels even when brace height it correct but it may be a softer tone and last for a more brief period of time even though decibels are the same.

If the tips of the limbs are soft you may never get the thud sound and feel.

[jess stuart]

Could you post some pics or your bow.  Is this the first one of this design you have made?  It might just be a bit nosier than what you are accustomed to.  Have you tried any string silencers yet?  I am kind of at a loss longbows are just normally pretty quite.  You don't have one of those Walker's Game Ears in by any chance do you? LOL

[T Folts]

The arrows are real close to being tuned.
I have a almost identicle bow that I've spent alot of time getting tuned and it is 3# lighter.
I think you are correct in the tone thing, I get the thud from my other and a twang from this one.
I am thinking it may be either the tips or I may need to get the limbs timed a little better.
I was planning on adding a tip wedge to the next set of limbs anyway. I have a set of limbs that are a little wider at the nock and I dont get the twang and it is a little closer in tiller.
Thanks for the ideas.
Terry

[T Folts]

No game ear (lol) I tested without silencers and then placed them on as to where I thought it was the best without much difference, I think I'm going to go back and check without the meter maybe I'm over testing this thing and missed the tone paying too much attention to db #s

[Jason Scott]

Experiment with more heel pressure and see if it gets quieter. Don't worry about accuracy for this test. If it does get quieter maybe you should lower the tiller to 3/16 or 1/8. Then hopefully it will be quieter and accurate after re-tillering. Of course you will loose a pound or two doing this. How far from true center is the shelf? And where is the deepest part of the grip in relation to the center?

[T Folts]

The bow is cut to center and the deepest part of the grip is set correct, right over the high point of the shelf tapered before and after.

[Jason Scott]

Sorry, I meant center of overall length between the string nocks. Just wondering what size triangulation you have between the center of grip pressure to the shelf to the arrow nocking point. And how that triangle is related to the true center of the bow length between string nocks. You may find that 1/4" tiller is a little high.