Hi everyone!
I have a dilema:
Why the shamisen loses clear sound in high octaves? Depends with skin tightness? Maybe the material of the skin (natural, synthetic)
Recently I’ve replaced a broken skin, and is very tight, and clear sound is produced. But if I compare the sound with other shamisens, is not so clear.
What is the reason for it?
Thank u!
Cheers,
Rod
Could be playing technique as well. Maybe you could take some videos or photos while playing. For example in your profile picture you seem to use left hand in 90° angle to the Sao. Try playing especially the high notes with your fingernail by putting it on the string in a right angle. (nail facing towards the dou)
This can also improve sound quality in lower registers.
This could illustrate Martina ´s answer : https://www.youtube.com/watch?v=SaXQvKPrlG4&list=PL2C102890E243094C&index=12
Wooo… I guess it´s because I’ve been just a guitarist so many years…, I will practice to change it!
Thanks Martina, thanks Patrick! 
But I have another question:
I cannot do ‘Hajiki’ techinique correctly 'cos my nagauta has a neck so thin… what do u think about?
Hugs from Chile
:3
In your profile pic I guess it is not a nagauta ! My tip : practice !
hahahaha I don’t have these shamisen enymore… (Homemade, sold) I have a nagauta now… 
I haven’t watched the video link above but I will have to agree. Using the fingernail has a lot to do with getting a clear sound especially in high registers. You might also check the sawari because the resonance of the shamisen extends to the high registers when applied properly.
Wow that really works. I should re-watch the bachido videos on all this stuff with more attention :S Now I just need to break the habit of biting my nails.
So Patrick in your video link, X doesn’t mark the spot
Fingernail… interesting. My nails are too short… LOL (when I was a kid I used to bite my nails, so now I have them weak fingernails…
But something I gonna invent!
thnx 4 the tricks!
^o^/