Is anyone aware of any tweaks/rework of the System 030 (D130;075). Yes, the N2600 crossover was reconfigured in the N2400 with a few resistors to reduce the possibility of overdriving the 075. Without changing the cabinet or drivers, is there any experience with different crossover designs, shelf-filters or zobel networks.
I found this suggestion on another forum and found it very interesting.
"...However, the low bass of a D130 in a vented box can be assisted somewhat, by using a "shelf filter" on the woofer, between the crossover and woofer... something like a 10mh choke and a 6 ohm high-wattage resistor (50 watts, use two 25 watt 12 ohm resistors in parallel) in parallel, wired in series with the woofer should make the power balance more palatable. Depending on the box baffle dimensions and such, some experimentation may be required, to tune this in for optimal balance and response flatness... but the above values, should be a good starting ballpark. If you do this, you may also have to add some padding to the tweeter... about a 3 ohm resistor in series, followed by a 25 ohm resistor to ground, between the crossover and tweeter, should re-balance things. Worth trying, might also be about a .33uf cap, in PARALLEL with the 3 ohm resistor... this will 'ramp up" the falling response response of the 075 above 15kHz, a couple dB, which will help the "air" of the tweeter. The shelving will reduce the system sensitivity from 100 to about 97 dB... but it'll give usable, full bass down to around 40 Hz."