Maybe some other folks here can answer the question if they hear the signal sound from doors with HK (AUD). I simply don't remember. If they do but you cannot hear, there might be some issue with the Flashing or the software.
The capacitator should not cut out the signal's (MID) sounds. It's for filtering the low freq. sound and keeping the voltage flat. However, B&W MID speakers has higher impendence than HK or HP speakers. This means, you will need to volume up for B&W speakers in order to get same db output as HK / HP speakers when using HK AUD with B&W speakers.
The capacitator should not cut out the signal's (MID) sounds. It's for filtering the low freq. sound and keeping the voltage flat. However, B&W MID speakers has higher impendence than HK or HP speakers. This means, you will need to volume up for B&W speakers in order to get same db output as HK / HP speakers when using HK AUD with B&W speakers.