10-15 dB lower input audio level on audio interface than output level on source

0

I am trying to record audio from a Philips VR 948 S-VHS Videorecorder with my Apogee Duet 2 audio interface. Somehow the input signal is at -10 dB (or about 10-15 dB lower) on the audio interface (Analoge Level set to -10 dBV), while on the video recorder the level is shown as 0 to 3 dB.

The cinch audio output from the VR is connected through a cinch-xlr cable with the breakout cable of the Apogee Duet.

The Apogee has 4 different input settings (1. Line in +4 dBu, Line in -10 dBV, Mic and Inst), but only the two line in settings go right to the A/D, while Mic and Inst goes through an amp first.

I guess that my setting is right, but I do not understand why there is such a huge signal discrepancy between the output level on the VR and the input level on the Duet? Could it be the cable (2-3m) or is something broken?

What is going on?

I am currently recording 96kHz/24bit at minus 10-12 dB and normalizing everything in Sound Forge after I recorded. Would that be ok?

Thanks in advance!

VCR audio levels with peak 0 dB

Audio Levels on the VCR

Input levels in Maestro 2 with peak -15/20 dB

Maestro 2 input levels

Recording level in Sound Forge with peak -12 dB

Sound Forge Input levels

SEJU

Posted 2019-09-18T13:12:17.370

Reputation: 166

1Could be a difference in references. Does the Philips specify dBu/dBV etc? – Hobbes – 2019-09-18T15:50:07.040

The Philips VCR has typical cinch audio in and out. To my understanding all consumer/prosumer level equipment are -10 dBV. +4 dBu has an even lower volume level and is used mostly in pro equipment. – SEJU – 2019-09-18T15:52:55.127

1If your Apoge metering is a peak meter and the Philips metering is an rms meter, your -12 db peak is not inconsistent with a 0 rms. – audionuma – 2019-09-18T19:51:01.437

1@SEJU : as can be seen on the pictures provided, the maximum level on the VCR is actually at +13 whereas it is at 0 on the AD card. So a 0 level on the VCR is around -12 on the AD card. Nothing to worry. Sample peaks around -12 dB on an audio signal is not uncommon. You shouldn't even normalize because that leads to other issues, besides a very high level compared to other programs. – audionuma – 2019-09-19T06:39:10.453

@audionuma you mean that the level meters on all my audio gear such as on the PioneerDJ 900NXS2 mixer or the Philips VCR use RMS style meters, while my DAW and the Apogee Maestro 2 software uses peak meters? With RMS showing head above 0, while peak ends at 0? Infact the 900NXS2 has clipping at +12 dB, while in the DAW at 0 ... But is that peak vs rms or just a difference in how the level scale is displayed? Thanks in advance ... – SEJU – 2019-09-19T06:43:46.287

@audionuma. Thanks! You were faster than me ;0). In case you wrote a short answer, I would be happy to upvote it! I had a similar problem when I recorded my vinyl, where I opted for setting the preamp of my turntable higher and used +4 dBu in Maestro to have in VinylStudio a recording volume around 0 ... – SEJU – 2019-09-19T06:48:28.893

Answers

1

One meter is displaying dBV and the other is showing dBFS. which is what was suspected by Hobbes. Typical line level for dBFS is going to be between -18 and -12. So no big deal like audionuma said. It doesn’t have anything to do with peak or rms differences it is the difference between dBV and dBFS.

Timinycricket

Posted 2019-09-18T13:12:17.370

Reputation: 678