Towards a complete Linn Kaber Aktiv solution using an rPi and AV receiv

[oomzay]

I would go ahead and build my xover filters in Camilla and map to their corresponding channels, then perform individual driver measurements to confirm acoustic vs electric xover points and adjust them as necessary. It's the acoustic xover point that matters not what you put in the DSP filter. 

Going one step at a time... To get the ball rolling I have used the manufacturers nominal x-over specs: 

• Bass (RED) - Lowpass 80Hz LR2
  
• Mid (ORANGE) - Lowpass 2800Hz LR4
  
• Trebble (BLUE) - Highpass 2800Hz LR4
  

Here is the measured response (@1m < 50ms):

   

Many questions! 

Does this response look like a "typical" starting point to you at this stage? They are quite old speakers but L&R give very similar results so any wear and tear has been symmetrical!

Some things caught my attention:

• The trebble is several dB lower than the mid. 
  
• The trebble falls off from 4K, not 2.8K
  
• The combined response (GREEN) at 60Hz is _lower_ than the individual Bass & Mid at 1m on mid-point. (Phase?)
  
• The bass + mid SPL varies by up to 10dB in the 100 to 1000Hz range (Seems a lot)
  
• At 40Hz we are down at least 15dB. Can Linn's claim of 40Hz for their Aktiv Kaber speakers be met?
  

What would you do next?

• Should I revise the 3R8+12uF tweeter protection? (I feel much safer with it there due to the vc4hdmi channel-switching bug and my own mistakes!)
  
• Should I EQ individual drivers and adjust their levels first or adjust the x-overs and then EQ the whole thing?
  
• What is sensible SPL goal for EQ (e.g. 3dB)?
  
• How low should I be aiming with these speakers?
  
• Should I be worrying about phases at the x-over points?
  

(I have played with house curves and EQ on the passive speakers - so I know "how", but not what exactly "what" I should be aiming for to get the best from these speakers!)

Thanks for patient support!

P.S. Linn Passive speakers don't have an 80Hz Highpass on the Mid driver - So I have followed that on DSP - The Bass and Mid drivers are meant to work together below 80Hz.