Line level subwoofer out voltage?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
What is a normal voltage to expect on a line level subwoofer output? I was just plugging in a cheap computer sub to my receiver to test it and nothing but silence. I checked the subwoofer output of my receiver with my trusty 300mhz Tektronics O-Scope and it is telling me only 70mv peak to peak... this seems very low to me I would have expected in the 1-5V range. The frequencies comming out look good but the voltage is really low.
 
Ok well I took maters into my own hands and made a little opp amp circuit (gain = 14) to boost the signal high enough that the amp in my subwoofer picks it up and now everything seems fine... well its not perfect since there is a lot of noise in the circuit due to the fact that it is on a bread board and I had no shielded cable to make an RCA so I just used speaker wire... but since its just driving low signals on a sub it seems to be ok.
 
Schematic
 

Attachments

  • subfilter.jpg
    subfilter.jpg
    54.2 KB · Views: 80
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.