Very low signal level on measured during SC Calibration

MegaG

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I didn't want to hijack Tooms REW but I am having an issue with my input level being extremely low during the sound card calibration

I have double and tripled checked all my settings so I am not seeing the issue.

I am using a USB SC - Sound Blaster Play 3

Starting with level settings at 80% I come in at -72 dBFS and once I increase level to 100% on mic I only get to -62 dBFS

I ended up dropping the sweep level to -60 dBFS just to meet the "gap" requirement and ran a calibration, looks like a mess, but I am totally new to this (if that wasn't already obvious)

I'm on v5.19 with runtime Java available from the REW site, I haven't figured out which beta version has the Java runtime built into the download, the first one I tried was looking for Java.

Any history on this sound card? I didn't find anything in my searches on this specific sound card. Hopefully I didn't just make a bad decision on the sound card I bought?
 
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MegaG

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Just for kicks, I decided to try t& run the calibration on my laptop's built in sound card (Realtek) and basically got the same results. Using the onboard SC, there was an extra option in the levels tab to boost the microphone. If its set to 0 dB, I get the -70's plus reading I was getting with the Sound Blaster. I can boost it to 30 dB and get it in the -40's range.

So if I drop the sweep level to match the input level of the 30 dB boosted mic. Is the subsequent calibration file legit to use? So I know this graph would not make sense for an actual system RTA but I really don't know about a calibration result though it doesn't make sense to me but I have no reference. If it is legit, what is it telling me?
 

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John Mulcahy

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The Windows beta downloads no longer include a Java runtime, if REW doesn't find one it will ask permission to download a runtime from the REW site for its own use only.

The cal efforts sound more like crosstalk pickup, are you definitely using the correct channel and a stereo cable for the loopback feeding a line input? Looks like the play 3 needs a 4-pole connector for the output side, not clear whether the input is mic/line or mic only.

Mic boost is for condenser mics, not line level connections.
 

MegaG

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Ok thanks, the cables I have and unfortunately the ones on the way are all 3 poles as I wasn't thinking about the loop back when I ordered them, rather connecting laptop or FLAC player to aux inputs, but a 4 pole connector makes sense for the mic connection point. Thanks again!
 
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