B&W Preference P6 - question concerning crossover

[sarsagoth]

Short disclaimer, I’m rather new to (audio) electronics, I hope the approach and my questions are not too basic.

I recently acquired said speakers. Initially the sound was truly underwhelming. After some research and maintenance of tweeters with new ferrofluid it improved, but overall, the sound is still very unpleasant. So I hoped changing the caps might improve things.
Before I swapped them, I did a very basic frequency response measurement using a HP 3325A and a HP 3478A. The meter should measure validly until 300kHz. Now the result is somewhat puzzling to me: Why are both lower channels employing the same response. Why is there no cutoff for higher frequencies?



I did simulate the crossover in LTSpice by using this schematic as reference. Am I assuming correctly, that the deviation between sim and measurements is stemming from using ideal elements in the simulation?


Here is a picture of the crossover, there are some unpopulated holes in it, under some components are more.



So my final question, is this a faulty design? The most expensive part seems to be in place just for the looks.
Any input is very welcome, also concerning the approach itself

Thanks
Nik

 

[tiefbassuebe]

I don't understand the conditions for your very basic frequency response measurement using a HP 3325A and a HP 3478A, but I think, this measurements are not helpful.
If you want helpful measurements you need the frequency response from all drivers alone and separately bass-midrange response and tweeter response include the crossover low pass resp. high pass filter. I use still my vintage audio measurement system DAAS3NT from 1993 (from ADM Nordhorn) but currently only very rarely. In post #3 under

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