Short bass horn - impedance vs distortion

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
As i got into fixing one old turbosound based soundsystem, I have made a couple of measurements and what stroke me was that the horn has quite a drop in impedance just around 115 Hz. Out of curiosity I made a hd test and there is quite a rise of hd in that region.

Just to be more specific, the speaker is a closed FLH with precision devices pd 186, the inner structure is i guess pretty much similar to this construction -http://speakerplans.com/index.php?id=hd15horn
attached is a detail on the impedance plot and the fr with hd curves

could someone please enlighten me why this is happening?
 

Attachments

  • impedance3vbednedetail.png
    impedance3vbednedetail.png
    70.5 KB · Views: 85
  • 3-hd.png
    3-hd.png
    57.3 KB · Views: 89
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.