# Why is my HPX so loud?



## Scott.Barrett (Oct 26, 2008)

27" riser, medium Excel limbs, 36#, 28.5" carbon one 660's.

Bare shaft and fletched hit together in the middle, bow shoots great, but it is so loud!!!

Tried brace height from 7.75 to 9". Anywhere below 9" creates a loud sound on release. Tried lowering the weight to six turns out to full in and positive and negative tiller, 4 different strins and large and small groove nocks, same results!

Latest theory is that these arrows are just too light as my buddy had a similar issue with ACG's that went away when he switched to X10s....

Anyone have a similar experience?

Scott


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## >--gt--> (Jul 1, 2002)

Without information about string material and strand count, as well as stabilizers, your question cannot be properly addressed. My (easily and well) tuned HPX is dead quiet. Stabilizers are the first thing to look at.


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## Scott.Barrett (Oct 26, 2008)

Strings are 16 strand 8125 or 20 strand 8190, each type in 67" & 67.25".

Stabs are Doinker Fatty's 33" front bar with 8oz and two 12" side bars with six ounces on each side.

Only thing that reduced the sound was a high brace height. Sound seems to come from the top limb more, until you start changing the tiller, then it moves to the bottom.


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## HikerDave (Jan 1, 2011)

Scott.Barrett said:


> 27" riser, medium Excel limbs, 36#, 28.5" carbon one 660's.
> 
> Bare shaft and fletched hit together in the middle, bow shoots great, but it is so loud!!!
> 
> ...


My Border limbs, medium with 37 pounds on the fingers at 30 inch draw, were very loud on my HPX with light Carbon One 720 arrows but quieted down with heavy Carbon One 550 arrows (cut long to give a reasonable spine.)

Just as you are experiencing, the bow with light arrows was much quieter at a higher brace height. I haven't yet figured out whether the stiffer spine or heavier weight on the 550 arrows was the solution -- one of these days I'm going to cut the 720s down to 29.5 inches, point just clearing the button, and see how these arrows fly.

I'm using an el-cheapo Cartel stabilizer with Easton Aluminum v-bars, which means very little damping, other than the layer of some kind of fantastic plastic elastomer on the Easton side rods.

You could buy a few Carbon One 600s or 550s and see how they do. You'll probably gain the speed lost from the heavier weight from a reduction in brace height if your bow quiets down. Brace height on the HPX is supposed to be lower -- with my Borders I'm running 7 inch brace height.

By the way, my bow quieted down quite a bit when I shaved down the grip on the thumb side to accommodate the fleshy base of the thumb. Then the bow didn't twist so much in my hand. There's also a shim under the grip of your HPX which you can move from one side to the other to change the torque balance of the bow. I think that it is supposed to be opposite the sight window side but this is an item that Hoyt forgot to mention in their instruction manual for the bow. If the shim is on the wrong side your bow might be twisting a bit in you hand as you draw, and then rapidly unwinding the twist as the limbs approach vertical, like a figure skater pulling in her arms. I figured this out when I watched my stabilizer as I shot and saw a temporary wicked bend appear right after release. Now that I've customized the grip (see McKinney's book) the bow is quieter.


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## Scott.Barrett (Oct 26, 2008)

HikerDave said:


> My Border limbs, medium with 37 pounds on the fingers at 30 inch draw, were very loud on my HPX with light Carbon One 720 arrows but quieted down with heavy Carbon One 550 arrows (cut long to give a reasonable spine.)
> 
> Just as you are experiencing, the bow with light arrows was much quieter at a higher brace height. I haven't yet figured out whether the stiffer spine or heavier weight on the 550 arrows was the solution -- one of these days I'm going to cut the 720s down to 29.5 inches, point just clearing the button, and see how these arrows fly.
> 
> ...


Ive got some C1 600's I can try tomorrow and some X10's after Christmas....will let you know how it goes....

interesting about the grip and shim. Can you post a pic of your modified grip? I'll go check where the shim is on mine.....


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## limbwalker (Sep 26, 2003)

Most likely the Excel limbs contributing to the noise. George, you're shooting F7's I'm sure. 

In almost every case, premium limbs are going to be quieter than entry level limbs. But of course, there could well be many sources of the noise.


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## Fury90flier (Jun 27, 2012)

Sounds like your bow just likes a BH around 9". Personally, I wouldn't question it.

Are you using med-long limbs?


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## HikerDave (Jan 1, 2011)

Scott.Barrett said:


> Ive got some C1 600's I can try tomorrow and some X10's after Christmas....will let you know how it goes....
> 
> interesting about the grip and shim. Can you post a pic of your modified grip? I'll go check where the shim is on mine.....


I'm not quite finished modifying the grip. I'll probably add a small amount of putty on the finger side near the throat. But basically, I left the finger side alone and sloped the grip to the left, mainly under my thumb. I just kept pressing the bow against my hand with the grip in shooting position and rasping away material until it fit. Then I shot, and rasped some more, and sanded. Applied a bit of mineral oil to darken the finish and job done.


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## Scott.Barrett (Oct 26, 2008)

limbwalker said:


> Most likely the Excel limbs contributing to the noise. George, you're shooting F7's I'm sure.
> 
> In almost every case, premium limbs are going to be quieter than entry level limbs. But of course, there could well be many sources of the noise.


Will be ordering some new limbs in the new year....

Sound is a loud crack like the a arrow is contacting, but it is not....smeared lipstick all over with no marks left. Definitely sounds more like the top limb until the tiller gets equal...then you hear it more from the bottom do the bow. Hopefully some heavier arrows will sort it out.....


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## Scott.Barrett (Oct 26, 2008)

Fury90flier said:


> Sounds like your bow just likes a BH around 9". Personally, I wouldn't question it.
> 
> Are you using med-long limbs?


Mediums....and I know where Katy is....:wink:


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## Scott.Barrett (Oct 26, 2008)

HikerDave said:


> View attachment 1550816
> View attachment 1550817
> 
> 
> I'm not quite finished modifying the grip. I'll probably add a small amount of putty on the finger side near the throat. But basically, I left the finger side alone and sloped the grip to the left, mainly under my thumb. I just kept pressing the bow against my hand with the grip in shooting position and rasping away material until it fit. Then I shot, and rasped some more, and sanded. Applied a bit of mineral oil to darken the finish and job done.


Threw me off there for a sec....you're a lefty!


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## HikerDave (Jan 1, 2011)

Yes, I shoot left-handed because I'm left-eye dominant and possibly naturally left-handed. I write with my right hand and eat and drink with both hands


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## Fury90flier (Jun 27, 2012)

Scott.Barrett said:


> Mediums....and I know where Katy is....:wink:


on a 70" bow, 9" sounds about right...around 8.5-9.25ish. I'd say keep it in the 9" range if that's where it's quiet.

So how do you know about Katy?


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## Scott.Barrett (Oct 26, 2008)

Fury90flier said:


> on a 70" bow, 9" sounds about right...around 8.5-9.25ish. I'd say keep it in the 9" range if that's where it's quiet.
> 
> So how do you know about Katy?


that is out of the recommended range, but a buddy of mine shoots his setup about there....will try it....

Used to live off of Blalock Road near the archery shop when I was a kid!


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## chrstphr (Nov 23, 2005)

None of my gear matches your gear, but I have always had a brace height of 9.1 to 9.4 inches on my aerotec riser. From G3s to Samick limbs at 68 inch bow and 70 inch bow. The recommended brace height for my MK limbs is also 22cm to 24cm (9.2 to 9.4 inches). 

I think you should try going over 9 inches and see if it quietens down. 

My hoyt recurve manual recommended 8.75 to 9.25 inches. 

Chris


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## Fury90flier (Jun 27, 2012)

Scott.Barrett said:


> that is out of the recommended range, but a buddy of mine shoots his setup about there....will try it....
> 
> Used to live off of Blalock Road near the archery shop when I was a kid!


Hilcrest Archery, right? That's where I got my first bow.

The BH I was quoting was taken from a few sources as an average. From all I've read, the suggested specs are just that "suggested"...all bows are different, so yours might be just slightly outside of spec.

if you want to know more about BH tuning, do some research on the user Nuts & Bolts. he does a great job of describing a step by step process of getting properly tuned.

do you happen to have any hunting weight arrows...maybe even from a different bow? If so, try them out to see how it sounds. I know my heavier hunting arrows made another recurve I had almost silent.


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## fader (May 17, 2010)

Mine sounded like a gunshot when I first shot my HPX (25" riser, 40# F7 mediums, 18 strand 8125). Increased my BH just short of 9" to get a good sound. Later I added limbsavers and properly aligned my bow. My BH is currently just under 8.5" and sounding great.


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## gpb (Feb 14, 2009)

Scott.Barrett said:


> Strings are 16 strand 8125 or 20 strand 8190, each type in 67" & 67.25".
> 
> 
> Scott The noise might be coming from your tiller being off. You noticed the sound changing as you changed tiller. Start at 0 tiller and increase it 1/8 turn of the top and bottom limb bolts at a time. Shoot after each adjustment and listen and watch the end of your long rod. If the tiller is off the limbs will close at slightly differently times causing the long rod to jump on the shot and the bow to be noisy. Another noise maker are limbs slightly twisted. Sight down the string of each limb tip to be sure the limb tips are centered. If not use your limb adjustment system for your riser to straighten them. Hope that helps.
> ...



Scott The noise might be coming from your tiller being off. You noticed the sound changing as you changed tiller. Start at 0 tiller and increase it 1/8 turn of the top and bottom limb bolts at a time. Shoot after each adjustment and listen and watch the end of your long rod. If the tiller is off the limbs will close at slightly differently times causing the long rod to jump on the shot and the bow to be noisy. Another noise maker are limbs slightly twisted. Sight down the string of each limb tip to be sure the limb tips are centered. If not use your limb adjustment system for your riser to straighten them. Hope that helps.


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## gonehuntin (Dec 2, 2004)

I'm pretty confident it can very well be a combination of the string weight, and brace height... the HPX really shoots dead quite when string weight is correct...

If you start by first going to a heavier string, then slightly modify your brace height, I bet it will quiet right down.


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## Scott.Barrett (Oct 26, 2008)

Could you recommend a good string size? I would probably build it in 8190 and my current strings are 20 strands of that. Perhaps take it to 22 or 24?

SB


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## Bob Furman (May 16, 2012)

Don't forget that the Hoyt HPX/RX recommended Brace Height is different than the standard Hoyt ILF Brace Height. If you are going off a Hoyt manual, make sure you have the correct one, especially if you downloaded it.


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## st8arrow (Apr 25, 2005)

I had the exact experience with my hpx plus f7. I talked to several on UK post about hpx and many said around 9 is the sweet spot. I shoot 9 and it shoots great and very quiet.


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## Greysides (Jun 10, 2009)

I have Border limbs set up around 37-39# and 28" Carbon One 600's. I shoot barebow so not a direct match. I had a loud crack too despite playing with BH and tiller.

I tried some Jazz arrows I'd around........... much quieter! 

If the noise still is there after you've done all the more sensible suggestions above.....

I put on compound limbsavers at the fade-outs, rubber washers between the limb butt and underneath of the tiller bolt head and a bit of velcro on the limb tips just where the string is leaving the recurve.

This has helped at lot. My limbs are fast and my arrows light and it's this combo I blame for the 'crack'.


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## Scott.Barrett (Oct 26, 2008)

Greysides said:


> I have Border limbs set up around 37-39# and 28" Carbon One 600's. I shoot barebow so not a direct match. I had a loud crack too despite playing with BH and tiller.
> 
> I tried some Jazz arrows I'd around........... much quieter!
> 
> ...


You are correct.... shot a heavier arrow and it was stone cold quiet.... 

Sent from my DROID RAZR using Tapatalk 2


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## rookcaca (Oct 10, 2002)

Mine is very quiet. I will measure the BH when I get home but I am pretty sure it is around 8 inches. 25inch riser with med F7 limbs.


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## Harperman (Sep 3, 2006)

My 27" FRX, with "Short" wood/glass limbs, and 16 strand Fast Flight string, 37# on my fingers, at 27" draw length, and 310 grain Carbon One arrows shoots very quiet, and feels nice at the shot, with 8 1/4" brace height...I run either a single Barebow weight mounted in the stab. bushing, or a 21" Doinker stab., with 4 oz. out front...Nothing else mounted on the riser, no Limbsavers on the limbs...Everything that I've read about the Formula system is that once set up properly, they are very quiet...Mine is pleasantly quiet also.....Jim


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## Scott.Barrett (Oct 26, 2008)

Harperman said:


> My 27" FRX, with "Short" wood/glass limbs, and 16 strand Fast Flight string, 37# on my fingers, at 27" draw length, and 310 grain Carbon One arrows shoots very quiet, and feels nice at the shot, with 8 1/4" brace height...I run either a single Barebow weight mounted in the stab. bushing, or a 21" Doinker stab., with 4 oz. out front...Nothing else mounted on the riser, no Limbsavers on the limbs...Everything that I've read about the Formula system is that once set up properly, they are very quiet...Mine is pleasantly quiet also.....Jim



I have even tried the same string and my arrows are the same weight....that loud sound stays until I get up to about 9" of BH. If someone puts their hand around the top limb pocket, or I shoot a much heavier arrow, it is completely quiet.


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## MartinOttosson (May 31, 2011)

I would second the posters above that give you the tips of trying different tillers. It can be the limbs that have a balance that is slightly out, so one limb is stronger than the other, even if the static tiller looks ok. I shot a HPX that was a bit off in the tiller, and also tried it with barebow (stringwalking), which basically makes the bow behave like the tiller is wrong, and that bow was by far the loudest bow I have ever tried. It was so loud so my ears made piiiiiiip after the first shot. Really like a gunshot, and I thought that the bow broke. I put plugs in my ears just to be able to analyze the problem and filmed the bow in a high speed camera. 

What I found was that the limbs were moving on the limb bolts in the shot, so the limb was actually jumping off the surfare of the limb bolt, and when it hits back, the sounds that is created is a crazy loud, metallic, aggressive PANG. I think it is caused by the fact that the force that keeps the limb tight to the bolt is around the half of the force in the Formula compared to a ILF system. As long as you set the bow correctly, and don't use a short bow for stringwalking, this fact doesnt create any problem. 

A lot of stringwalkers use soft plastic spacers between the aluminium surface on the bolts and the upper surface of the limb. That takes away a lot of noise on the short targets. For you, I would suggest the following things to try: 

1. Try to measure the dynamic tiller. Make a exactly 90 degree cross on a wall (one vertical line and one horizontal line). Ask a friend to stand 5m away from you while you stand about 2m from the wall. Stand with your chest aligned with the vertical line. Draw the bow and slowly bring the sight up from low in the target. Have your friend tell you when the arrow is aligned with the horizontal line and check where you sight is at that height. Keep aiming there and then your friend should move around slightly so that he can see how much the limbs are bending in relation to the vertical line. If the dynamic tiller is set correctly, the limb tips should be somewhere near the same position. If they are not, try to adjust the tiller until you are within one inch or something like that. 

2. Play around with the static tiller from -10 to +20mm and see if you notice any difference. 

3. Try a thicker string. Add 2 or even 4 strands to your normal thickness and try. 

4. Add limbsavers. 

5. Add soft plastic spacers on the limb bolts. 

6. Add a rubber sheet under the grip and make sure the grip cant move. 

The goal should be to have a VERY quiet bow. It is definately possible with the HPX, even if I am not sure about the Excel limbs.


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## Scott.Barrett (Oct 26, 2008)

A couple of more tests.....

Tried shooting a ACE 430 at 28" with the BH at 8.5". Much quieter, but this arrow is obviously way too stiff at my 40# DW. I added some Doinkers with weights on both of the limbs and it is now super quiet no matter what arrow I shoot, but it is certainly much heavier than before! 

My next testing steps are...

1. Try some X10 550's at the correct size and see how they work.
2. Build another set of strings. With 8190, I am going to go as high as 24 strands and see how that works.
3. Add some Limb Savers top and bottom.


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## cana1709 (Jun 6, 2012)

here is my experience- it could be strings


Hpx 27", med 30lbs f4's foam- fingers 40lbs
Brace height 8 1/8
2212 with 180 grain points
strings 8190 20 strand loud
strings 8190 22 strand loud
strings 8190 24 strand perfect

Hpx 27", med 32lbs f7's wood- fingers 42lbs
Brace height 8 1/8
2212 with 180 grain points
Dyna 97 16 strand perfect


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## gonehuntin (Dec 2, 2004)

Scott.Barrett said:


> Could you recommend a good string size? I would probably build it in 8190 and my current strings are 20 strands of that. Perhaps take it to 22 or 24?
> 
> SB


I would recommend 24 strands of 8190


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## Scott.Barrett (Oct 26, 2008)

Got it fixed!!!!

Here is where I am at....

41# and slightly positive tiller, 8.5" BH, 29.5" draw....

Now using the following:
Easton X10 550's cut to end of clicker plate
Put Limbsavers on the fade outs on back of limbs
Donut Limbsavers in the bolt holes on the limbs
24 strand 8190 string

All of this together has the bow almost silent! The biggest difference of change was that my plunger required a much higher tension on it that I had used on previous bows. Fixing this and resetting the center shot almost fixed the problem completely. Thanks Matty!!!!

Bow is shooting great!!! I did a little "angling" on the grip and the bow sits very well in the hand and now I need to refletch a bunch of arrows after shooting single spot for too long last night!

Thanks to all!

Scott


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## lksseven (Mar 21, 2010)

Scott,

FWIW, I'm shooting X10-550's at 28" out of my Formula RX with 42lb limbs, and it's extremely quiet. Two weeks ago the noise was bright (tuned a little too stiff). So I set centershot dead on; raised BH from 8-1/8" to 8-1/2"; and increased plunger cushion tension to 6.5 from 8.5 (medium spring) ... and the bow is whisper quiet and harmonic.


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## lksseven (Mar 21, 2010)

Oops, just saw that our last posts crossed paths - looks like we both found the bone! Congrats.


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## Scott.Barrett (Oct 26, 2008)

lksseven said:


> Scott,
> 
> FWIW, I'm shooting X10-550's at 28" out of my Formula RX with 42lb limbs, and it's extremely quiet.


I think my issue was related to the spring tension. I had a medium spring in my Beiter and had it set directly in the middle. This has always been a good starting point for me, but was very weak with my set up. Two turns in and it was very quiet! We did some walk back tuning, adjusting pressure and center shot and had it shooting quietly at all distances. 

Going from 20 to 24 strands and a few LimbSavers and I can shoot this in a quiet range without anyone noticing.


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## Scott.Barrett (Oct 26, 2008)

lksseven said:


> Oops, just saw that our last posts crossed paths - looks like we both found the bone! Congrats.


I double crossed ya!!!


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## thac0 (Jul 26, 2012)

Scott,

I had the same issue with my HPX/F7 Wood setup when I changed over from F2's. (I am 30.5" DL and weight at full draw is ~42 lbs, 8.75 bh). For me it had a lot to do with the arrows. I'm shooting indoor now, so I switched to a Fatboy 400 @ approx 386 grain and that did a ton for the noise reduction. I have tried X7 2311/12 as well, and they are quiet to. (I was using Velocity XT before). After this I did exactly what you did and added 2 Fuse limb blades. This reduced the noise quite a bit more. I have not put on limbsavers or limbjax.

I am using the string that the shop made for me which is 452x. I am looking to build a new string, but I haven't decided between Angel Majesty or 8125G. I am gathering opinions and any relevant data from folks as they are willing to share. The Angel Majesty, from what little I have read, is louder. I am not sure by how much.


mike


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## Scott.Barrett (Oct 26, 2008)

I've found mine to be very quiet at 8.75"BH....seems like the magic spot and outside the range given in the manual....


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## HikerDave (Jan 1, 2011)

cana1709 said:


> here is my experience- it could be strings
> 
> 
> Hpx 27", med 30lbs f4's foam- fingers 40lbs
> ...


My HPX / Border Hex6 BB2 bow was quiet only with heavy arrows when used with 18 strand 8190 string. Today I tried a 16 strand D97 string, served with .014 Halo to fit small-groove nocks. The bow was relatively quiet even with my light (270 grain) arrows and a low brace height where with a previous 14 strands of D97 the bow was also noisy.


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