I have tested my three bows and all are so close it is hard to believe. Decibal readings are so close it is hard to measure, like one or two decibals difference. And for the three bows my peak freqs are 21691, 21830 and 21758 HZ. These are all very high. One of these bows is loaded with the latest sound dampeners too.
I am beginning to think atmospheric conditions have a great effect in transmitting the sound to the deer.
I am going to check some recurves and a stick bow next.

I tested a recurve and the decibal level is only 1 and 2 decibals below the compounds. The freq is 10835 HZ which is far less then the compounds.
I then shot my osage orange longbow and the decibal level is almost the same as the recurve and the compounds, the freq is a tiny bit higher at 10877 HZ. Neither of these bows will make any animal react at all. They just never even look.
My conclusion is that it is still the higher frequecies that scare the deer. I just don't know at which point and freq that it starts to happen.
The strangest thing is that the bow that is loaded with the latest sound reducing items is no different then the ones that do not have any. The decibal level is virtually the same for all three bows. Yes, it sounds different to me but deer go nuts at the shot.
If I put the S-Coil stabilizer on this bow, it gets much louder. My mercury stabilizer is much quieter. The special string silencers are not as good as the puffs. Even the stick on Limbsavers have done nothing. I am going to start testing various components on this bow to see if any reduce the peak freqs.
I think we are in a marketing hoopla stage. I will forever say that what we hear is not what scares animals. The bow that sounds dead to you can make a deer turn inside out. Until the freqs are reduced to the recurve and stick bow, the compound will always be a problem in certain outdoor sound and atmospheric conditions. The more wind, and noise outside, the less trouble you will have. Damp air seems to be bad too.

quote:

Originally posted by bfrshooter:
I am beginning to think atmospheric conditions have a great effect in transmitting the sound to the deer.

I'm sure it has some effect. As does ambient background noise as well.

A little bit of wind goes a long way. If you are shooting into the wind the volume of the bowshot is greatly diminished when compared to shooting with the wind. If you can get some results at 15, 20 and 25yds with respect to wind direction and speed it may prove extremely interesting.

I have bit off a lot here and it will take a long time. One thing I do see between bows are that one will have several high freq points in the spectrum while another will only have one. Vibration with different nodes.
The thing that amazes me is the decibal level for all the bows I have shot so far is almost the same. I expected the stick bow to be very low, it is not!
Everyone, even the Limbsaver people tell me it is the level of noise, not freqs. How do you explain deer not running off when a .475 Linebaugh or .44 mag goes off and kills one of them? If it drops or does not run, the rest of the deer stay right there. I have had a herd bed next to a dead one because they thought he bedded.
I need a freq generator to send a series of thumps towards deer while changing freqs. I wish I had some money! I would love to know at what level they are affected. The decibal level would have to stay the same for the whole test.
So far I have seen the freq is 50% higher with the compound.
Someone here must have access to equipment to aid in tests.

I forgot to mention that the highest decibal levels I measured are all at the lowest frequencies. About 484 HZ or so.
We hear from 20 to 18,000 or 20,000 HZ. Most animals go to 100,000 HZ. As we age it goes down so at my age I am lucky to hear above 10,000 to 12,000 HZ.
One reason I can't hear a bow that will frighten deer. All bows sound close to the same to me except I can detect a THONK sound from some and a THUD from others.
It would be interesting to start a post listing the worst offending bows where guys have the most trouble with deer jumping the string along with weather conditions.
I wish I could record everyones bows.