Port tuning help needed
I have just set up my M2 wannabe’s (from the Compact Monitor thread) and started measuring. The cabinets are about 70 liter with two 69mm ports on the back side. They are flared on one side so far.
Woofer is LE1400H with:
Fs = 28,8 Hz
VAS = 171 L
QTS = 0,22
When measuring :
Dual 69mm ports about 24cm length gives a system Fs = 30 Hz
No ports, just two open holes of 75mm gives a system Fs = 52HZ
What would be a god frequency to aim for when tuning the ports?
Historically I have always set the port tuning to the FS of the woofer but there is very little info below 30Hz in ordinary music so maybe it should be higher. Or lower....
Original M2 uses 2216Nd with a mechanical Fs = 36Hz and a measured of Fs = 39Hz. The system seem to be tuned to 27Hz which is way lower. Is it the fact that the cabinet is much larger and QTS high that makes that possible.
2216Nd:
Fs = 36 Hz
QTS = 0,44
VAS = 140 L
Kind regards
//RoB