Hi all
Hopefully you can suggest some help for me please. I'm new to REW and wish to use it for impedance measurements. I have a set up problem that I can't find any advice on how to solve this.
I have a Soundblaster SBX ProStudio and Windows 10.
I have set up the Soundblaster in the preferences and when I do a loop-back test for SPL I get a very sensible looking pair of curves that match well with other Soundblaster curves I've seen on here.
I have built the Rsense measurement jig according to the diagrams and with a non-inductive resistor of 100 Ohms using the sound card's headphone output and mic input. For the impedance tests I have a heathly -11dB level set and no input from my laptop's microphone.
I have run the impedence calibration test (Rsense shorted) and I get a reading of 102.3 ohms for my resistor. Then, when I short out the load connections (Rsense no longer shorted) I get a very high resistance measure - in the 3 to 6 MOhms range. But using a multimeter I get sub 0.1 ohm measurements on on the cables and connections. So the -ve output from sound card to -ve input or -ve speaker gives me sub 0.1 ohm measurements, as do the connections from output to Rsense and input to Rsense.
Of course, this MOhm measurement on the cables gives me very silly measurements on speakers too.
Any help you can offer please?
Hopefully you can suggest some help for me please. I'm new to REW and wish to use it for impedance measurements. I have a set up problem that I can't find any advice on how to solve this.
I have a Soundblaster SBX ProStudio and Windows 10.
I have set up the Soundblaster in the preferences and when I do a loop-back test for SPL I get a very sensible looking pair of curves that match well with other Soundblaster curves I've seen on here.
I have built the Rsense measurement jig according to the diagrams and with a non-inductive resistor of 100 Ohms using the sound card's headphone output and mic input. For the impedance tests I have a heathly -11dB level set and no input from my laptop's microphone.
I have run the impedence calibration test (Rsense shorted) and I get a reading of 102.3 ohms for my resistor. Then, when I short out the load connections (Rsense no longer shorted) I get a very high resistance measure - in the 3 to 6 MOhms range. But using a multimeter I get sub 0.1 ohm measurements on on the cables and connections. So the -ve output from sound card to -ve input or -ve speaker gives me sub 0.1 ohm measurements, as do the connections from output to Rsense and input to Rsense.
Of course, this MOhm measurement on the cables gives me very silly measurements on speakers too.
Any help you can offer please?