How good is the crossover in your loudspeakers?

The crossover can be used to modify flaws in the drivers’ response curves, or tailor the sound to the room/individual’s taste and so can be better than having no crossover at all.  It all depends on the drivers chosen to do the job and what is expected of them.

And, different caps can/do sound different from other caps, even the conjugate caps.

"JBL measured the frequency response of my speakers @ 1 watt @ 10 watts and @ 100 watts and they have <1 dB compression of SPL output. See speaker specifications here last page. 

Mike"

I don’t think this means what you think it means.

I think what is referred to is the power linearity over the frequency response and they show plots of the response for the three power levels and look at the response to see that it does not so as to throw the curve off by more than 1 dB.   Otherwise, why are the three curves not 10 dB apart for the three power levels?

OTOH, I would think that depending on the "compatibility" of the components, lesser speakers would show far more "areas" of compression because some components just can't "keep up" with others when the going gets tough.

They say they are 10 dB apart, but that would infer NO compression and that’s just not the case.

BTW, JBL does note the dynamic compression for a 2226H at 1.5 dB between 1 watt and 100 watts.  The 2226H uses the vented gap technology, same as my 2241H, and JBL notes that this measure was instituted to reduce the power compression.

"JBL introduced the VGC products in an effort to reduce dynamic compression to even lower degrees and increase general power handling in the process. Figure 7 shows 1 watt and 100 watt superimposed compression curves for the JBL 2226H The curves show compression on the order of 1.5 dB over the range from 100 Hz to about 2 kHz, with virtually no compression at lower frequencies." 

Based on this, one would expect the 2234/2235 to exhibit more compression than the 2226H, though none of the literature states what it is.

If one wanted to compare factory bi-amped speakers to the same speakers with passive crossovers, one need look no further than Altec.

Just one example:

How good are my crossovers?  There are probably no others in the world that function as these do using these components and the parts selection has taken years of tweaking.

Caps were mixed for there "particular sound" and multiple values were mixed to as to produce the most common value (e.g., the higher of the two was always mixed with the lower of the two other caps when used in parallel).

On an Lpad, there are two floating wipers, but only one is shown in the schematics.  We are using the other and it goes from ~11 to ~36 ohms before it opens completely.  The circuit works best above ~18 ohms, hence R2, with ~20 ohms being near optimal.

If you saw the frequency response of the JBL 2251J, the circuit would make more sense.

I want to roll it off at about 2,500 Hz but that peak at ~3kHz makes this near impossible to do cleanly.  I had to come up with some very imaginative thinking and a bit of luck from experimentation to make this work!

What I do is to roll it off a bit earlier by "over capacitating" it.  If you use too much capacitance in a second order low pass filter, you will greatly increase the slope but also  create a hump just below the roll off point.  The more capacitance, the bigger and lower the hump.  The shape of the rising hump is obvious with the Lpad is turned full up (open).

But I also let some of the signal pass through R1 or R2/VR1.  This portion of the signal is NOT IN PHASE with the hump and the more you let through, the lower the hump becomes until you have a fairly smooth response up to the ~2,500 Hz roll off point.  VR1 lets you selectively tune the hump.