View Full Version : Clipped audio levels.

09-06-2005, 09:18 AM
I'm using this M-Audio device to record from my stereo to my Mac. One cant adjust the input levels as its set (with accuracy) to the amplifiers line level output.

What I'm seeing is alot of clipped levels (see attached jpg).

Whats wrong? Does my amp need to be checked out? Or is it quite standar for musicians to master their records so the peaks are clipped (distort?).

Bearing in mind that this is a cross-section of Crazy Titch's "Singalong" ;)

Grievous Angel
09-06-2005, 11:01 AM
Does it sound distorted?

The clipping doesn't look that bad to me but it might still sound a bit raspy.

Have you tried recording in 24 bit (still at 44.1k)? This may give you more headroom.

But if the record-out from the amp is running too hot for the M-audio's inputs, you may want to see if there's some control software for the M-audio to turn the gain down...

09-06-2005, 12:38 PM
I read an article about this on the web recently (give me a minute to try to find it again); basically this guy compared the levels for loads of tracks from the last few decades and found that yes, CDs are getting mastered louder and louder to the point where now, some things you buy are almost entirely clipped. Which is a minor tragedy since that's musical information that can never be reclaimed. The weird thing he noticed was that the amount of clipping seemed to depend on which world region the CD was sold to - US/Europe was definitely worse.

09-06-2005, 12:54 PM
The page I'm talking about is down due to bandwidth problems, but you can read it (without images) at http://web.archive.org/web/20041011215457/www.mindspring.com/~mrichter/dynamics/dynamics.htm

Grievous Angel
09-06-2005, 02:11 PM
There's always been a bit of controversy about compression, Rambler, but I wouldn't be completely against it. One can (and should) distinguish between clipping, distortion and compression. Certainly there's a lot of compression now, and the perceived loudness is greater now than it was in say the 50s, principally because of multi-band compression and digital look-ahead techniques. That doesn't mean that the clipping of the waveform is much different to what you'd get on a Frank Sinatra or Beatles record. What is compressed via Waves or a hardware unit from GML or Focusrite would have been just as compressed in the fifties due to overloading of valve stages in microphones, mixing desks and tape decks. Of course that sound is much sought after now... It's not so damning to say "compression can never be taken out" -- neither can many of the other artefacts that have affected the last few decades of recording.

Matt, you might also want to check what voltage the line inputs on your M-Audio is running at -- there's pro and there's semi-pro levels (I think pro is +10v but I;m not sure). Should be a switch to change it -- might be worth trying.

09-06-2005, 02:21 PM
Bearing in mind that this is a cross-section of Crazy Titch's "Singalong" ;)

singalong is distorted to high heaven - that's exactly how I would have expected it to look as a waveform just from hearing it

09-06-2005, 02:24 PM
Yikes - I'm quickly getting out of my depth :)

09-06-2005, 03:55 PM
Yeah - Matt, if you are using an M-Audio quattro, there should be a button on it to switch the level in which it comes in. I have found with it open that either playing out (to mixing desk) or in (to soundforge) that there is a noticable amount of clipping. If you switch it, you get none, but typically have to normalise the file to actually get any volume comparison to other recordings. I can post my rip of singalong in a bit (am at the office at the mo) but I am sure it didn't clip.

10-06-2005, 08:33 AM
thanks for that info Rambler. may have inadvertantly started an interesting topic ;)

thanks too 3underscore and 2stepfan. annoyingly though there isnt a am/pro switch like on the quatro. lest you think i'm bugging you without having followed up other avenues beforehand heres what technical support told me:

"Thank you for contacting M-Audio Tech Support.

Using the Line Inputs – Connect the line level output of your external audio device to
the FireWire Audiophile’s rear panel Line Inputs.

The signal level that you receive at the Line Inputs will be the signal level that you
record. Any adjustments to that signal level must be made at the source. If you have an
output level control on the device that you’ve connected to the FireWire Audiophile’s line
inputs, adjust that output level control to change the recording level. Most recording
software will allow you to add gain to a recording that is made at a level that is initially
too low, but be careful that the recording level is not reaching digital clipping (going into
the red) while recording.

You will then want to route the input signal to your DAW’s inputs. Refer to the section
below on monitoring your inputs, and your software’s documentation for more information."

So basically I can turn it up (i always normalize to 100% anyway) but cant turn it down. afraid that hint may have the answer here (that singalong is pumped up really high) ;)

10-06-2005, 09:32 AM
So basically I can turn it up (i always normalize to 100% anyway) but cant turn it down. afraid that hint may have the answer here (that singalong is pumped up really high) ;)

the waveform you posted above is what went in through your interface, so looking at that section you can see that there are plenty of sections where the waveform is "squared off", even when several dB under the clipping point.

this will be down to the source - either you are pushing your mixer / amp so hard into the red that it's distorting the signal, or the original recording is itself distorted - either through a bad pressing, over eager mastering or (most likely) crazy titch shouting into the mic and overloading the mic itself or the preamp ;)