Arm resonance - the anal way
- Thread starter borchee
- Start date
OK, I'm nearing the end....you wish!
The effective mass of an object (arm + counterweight + cartridge) is the sum of effective masses of the parts.
I did throw some other numbers around.
Fequency:
- SME-Ortofon with cartridge calculated as point mass is 8,11 Hz, with mass moment of inertia to paralell axis 8,56 Hz.
- Revox linatrack arm 9,80 Hz and 10,84 Hz.
I estimated the center of cartridge's mass, took arm's effective mass as stated by manufacturers (counterweight at unknown position) and didn't (yet) estimated and took into account the mass moment of inertia around the axis through the mass center of cartridge - will do so to end this ordeal. Oh well, at least now I'm rather certain that I could calculate the frequency with data provided.
BTW, J!m,
I like the idea with different screws and gave it some thought. How about just adding nuts to the screws instead of changing them - it may be more convinient.
The effective mass of an object (arm + counterweight + cartridge) is the sum of effective masses of the parts.
I did throw some other numbers around.
Fequency:
- SME-Ortofon with cartridge calculated as point mass is 8,11 Hz, with mass moment of inertia to paralell axis 8,56 Hz.
- Revox linatrack arm 9,80 Hz and 10,84 Hz.
I estimated the center of cartridge's mass, took arm's effective mass as stated by manufacturers (counterweight at unknown position) and didn't (yet) estimated and took into account the mass moment of inertia around the axis through the mass center of cartridge - will do so to end this ordeal. Oh well, at least now I'm rather certain that I could calculate the frequency with data provided.
BTW, J!m,
I like the idea with different screws and gave it some thought. How about just adding nuts to the screws instead of changing them - it may be more convinient.
When Mike was here (best ears in our group) we were using the Feikert to set up his ZYX Yatra on the Audiomods. Noticed it was off by about 0.5mm. He said it made a significant difference.
I don't sit in the spot when friends come over so I don't know. I was doing the adjustment and setting up the listening.
This just means you do need to be careful when changing one mounting bolt at a time to keep the nail exactly where it was before the loosening the bolts.
I don't sit in the spot when friends come over so I don't know. I was doing the adjustment and setting up the listening.
This just means you do need to be careful when changing one mounting bolt at a time to keep the nail exactly where it was before the loosening the bolts.
