OldSpook
I realize what the sound energy differences are for even a 3 dB difference. I am more concerned about what human perception differences are for 3 or 4 dB changes. Considering the extra 2 mm in bore diameter and much larger area increases that go with that, I would expect more than a 4 dB change, based on my impression of your opinion. If I am wrong that the difference between each step in this little experiment will be on the edge of detectable by ear, then I will have learned a valuable lesson.
I used to design printed mufflers for .22 with 7 mm bores. There were a number of clipping complaints, so I increased that to 7.5 mm at the back, and taper stepping up the bore towards the front by 0.5 degree included angle; because the front is where the clipping occurred. During that exercise I designed some .22 mufflers that had 9 mm exit bores and was surprised how little effect it had.
Rather offer anecdotal report reports, I figured that an exercise such as the reason for this thread, would be more valuable. Then it is not an argument about different mufflers, but essentially the same one, with just the bore diameter being varied.
If you feel like this short muffler is cheating, let me know how long it should be, and I will create a longer set.
Another consideration I had for the short length was that I figured people were more likely to participate if the prints were easy and short. An 8" long 1" OD muffler often exposes adhesion problems, and may fail before it is done printing.
If I do a longer muffler version for this test, I think I would add a fourth configuration, with the baffle angle, spacing stepped open bore size I would use, if I was trying to "sell" the design for common use.
I do many free designs for people. Yesterday I worked on 5 different muffler designs. In turn, many of these same people provide me with free test results; even though that is not the primary reason why they make and test my designs. They want them to work well, and so do I. Everything I learn is used to make future designs better. Better means quieter and better sounding, for the size and weight; but without clipping or blowing up grouping ability.
Thank you for adding your audio capture and analysis expertise. It would be great if you would print and test these mufflers too. After all, they are tiny prints and don't use a lot of material.
I realize what the sound energy differences are for even a 3 dB difference. I am more concerned about what human perception differences are for 3 or 4 dB changes. Considering the extra 2 mm in bore diameter and much larger area increases that go with that, I would expect more than a 4 dB change, based on my impression of your opinion. If I am wrong that the difference between each step in this little experiment will be on the edge of detectable by ear, then I will have learned a valuable lesson.
I used to design printed mufflers for .22 with 7 mm bores. There were a number of clipping complaints, so I increased that to 7.5 mm at the back, and taper stepping up the bore towards the front by 0.5 degree included angle; because the front is where the clipping occurred. During that exercise I designed some .22 mufflers that had 9 mm exit bores and was surprised how little effect it had.
Rather offer anecdotal report reports, I figured that an exercise such as the reason for this thread, would be more valuable. Then it is not an argument about different mufflers, but essentially the same one, with just the bore diameter being varied.
If you feel like this short muffler is cheating, let me know how long it should be, and I will create a longer set.
Another consideration I had for the short length was that I figured people were more likely to participate if the prints were easy and short. An 8" long 1" OD muffler often exposes adhesion problems, and may fail before it is done printing.
If I do a longer muffler version for this test, I think I would add a fourth configuration, with the baffle angle, spacing stepped open bore size I would use, if I was trying to "sell" the design for common use.
I do many free designs for people. Yesterday I worked on 5 different muffler designs. In turn, many of these same people provide me with free test results; even though that is not the primary reason why they make and test my designs. They want them to work well, and so do I. Everything I learn is used to make future designs better. Better means quieter and better sounding, for the size and weight; but without clipping or blowing up grouping ability.
Thank you for adding your audio capture and analysis expertise. It would be great if you would print and test these mufflers too. After all, they are tiny prints and don't use a lot of material.
Upvote 0
