I'm trying to monitor some audio input to my desktop pc with a vu meter. I've connected to the line in, and it's just a bog standard on-the-motherboard sound card. I'm having a problem understanding the various signal levels. I haven't actually bought the meter yet as I need two antique ones at some cost, so at this stage I'm looking at the feasibility and risks involved.
From Wiki, consumer grade kit is designed for a nominal -10dB line level. Recording via Audacity, it appears that my sound card line input actually clips at -6dB so there is very little headroom. The typical analogue (it must be analogue) vu meter is calibrated -20dB to +3dB. The -10 mark is only approximately 1/7th of the way up the scale. To avoid the risk of clipping, I'd need to run at a level less than – 10dB. That doesn't seem a very efficient use of the meter real estate. I'm assuming that vu metering is for absolute readings and not arbitrary scales. I only have rudimentary knowledge of this area, but have I miss understood something?