Monitor W690 Crossover Design

Back to Monitor W690 

Vented 2 way System
HiVi W6 and Focal TC90Tdx

Designed for Dan Marx by BobM9

Option 1

Partial Baffle Step Compensation

XO Topology and Values:

The lowpass is a standard 2nd order electrical yielding a 4th order target response.  The original zobel was found not to be needed. The highpass is a third order electrical filter yielding a 4th order target response. The L pad is used for ease of manual adjustment of tweeter padding. This is a very minimal XO topology for a 4th  order target, however it does yield a good response with these drivers. The XO point was 2200 Hz, however the optimizer raised the XO point slightly.

XO Values:

The component values have been rounded to match readily available component values. R2 and R6 is the DCR of the inductor coil.

Predicted Response Curve Option 1:

Note: 5 dB per division

The option 1 curve above represents about 4 dB of baffle step compensation with the expectation of some room reinforcement on the low end. Over system sensitivity is 86.5 dB. The response curve is +/- 2.5 dB from 200 20k Hz. The reversed polarity null is showing about a 10 dB dip. While we are guessing at the relative offset of the drivers at 20mm, it should be relatively close.

Impedance Phase

As you can see the impedance does not drop below 7 Ohms. This will be an easy load for almost any amplifier. The impedance phase reaches its minimum of 60 degrees at 2k Hz and is otherwise unremarkable...

  Option 2

Complete Baffle Step Compensation 

XO Topolgy and Values:

Same XO topology, values changed to reflect an overall system sensitivity of 85 dB which fully compensates for the baffle step loss. This option can be used if the system sounds light in the low end.

Predicted Response Option 2:

Overall a very good frequency response. I did not compensate for the gentle hump centered at 450 Hz due to the fact that this is modeled data.

Impedance Phase:

Nearly identical to option 1.

Polar response at Crossover:

Typical 4th order LR lobing pattern.

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This page last updated on June 02, 2004.