Amateur orchestra recording/post-processing

Question

I play in an amateur university orchestra, and I just recorded our last concert this weekend. This was a very simple setup: just a Sony PCM-D50 recorder, set to record at 96/24 through its internal mics, on a tripod a couple of meters away from the orchestra.

I set the recording level low enough that the internal limiter never triggered, while getting peaks at around -3 dB when the orchestra was really loud (and 0 dB during applause, of course).

Now with an orchestral program (especially in this case where we played movie soundtracks, so you get a solo violin in Schindler's List, a small woodwind ensemble in Harry Potter (Nimbus 2000 theme), and full-tilt brass/percussion in Star Wars) there is an enormous dynamic range to cover. It seems that modern productions use heavy dynamic range compression to "lift" the soft passages, and while I'm quite happy with the sound quality of the recording as-is, I'd still like to try and "equalize" it a bit so it's more in line with other CDs.

My problem is that when I use the pre-set Dynamic range compression settings in Sound Forge Audio Studio (for example 2:1 compression from -18 dB, or 3:1 from -15 dB) and then add gain (say, +6 dB), I find that the recording starts sounding quite muddy.

I don't think that that's because of a bad algorithm (I find the same problem in Audacity) but probably because I'm using a sledgehammer instead of a fine screwdriver to adjust the sound. Do you have any tips on how to lift low volumes without muddying the middle dynamic and high peaks?

Answer 1

The real answer: make sure your input level is OK every time you record something. Make sure that the loudest passages are just hitting the head (I try getting to > -1dB FS while not clipping.) , so the soft passages have enough detail. Also remember that dynamic range is a musical ingredient in classical music, even between different pieces. If things are soft in the hall, you don't want them as loud in your recording as things that are loud in the hall, you will lose a bit of musicality.

So: never ever compress classical music to solve your dynamic range problems, unless you use it for professional broadcasting purposes only. (And even then, don't compress the master, but use compression in the broadcasting chain.)

Instead, if you still want to fix things because you are turning the volume up and down between the pieces: slightly adjusting the overall levels of the pieces a bit is in many occasions the right thing to do. To do this, edit all pieces so that they fade in and out on the beginning and the end. (With a piece, I mean, if you record a Beethoven symphony, those 4 movements are related, so only fade the beginning of the first movement in, and the applause at the end of the last movement out. Don't fade in between the movements and don't adjust the volume for the individual movements!) If you do this, you can make slight adjustments to the overall level of the pieces. Don't normalize to 0dB FS though, and don't make the changes too big. A few (e.g. 3) dB could just be enough to solve your problem.

If you want to go this path, make sure you always record in 24 bits so you have more detail in your audio if you increase the volume in the master. (Sample rate is of less importance, but to record in 96KHz or in 88.2KHz is always good.)

My personal tips:

• Adjusting the volume of a classical mix changes the accoustics of the hall; all sustaining noise from e.g. the audience is louder as well as the reverb it creates.
• Adjusting the volume of a classical mix/master is almost always an excuse for having too much headroom on your recording and will result in dynamic detail getting lost. Therefore, always record in 24 bits if you decide to increase it.
• As mentioned: dynamic range in classical music is a piece of the music itself, even between the different pieces. Getting rid of it is destroying part of the musical contents.
• As a rule of thumb: never touch the volume of a part of a classical recording if the difference in dynamics is so bad that you can't listen to the recording in the living room without touching the volume button.

Answer 2

If it sounds good, don't change it. You could try to change it to 44.1kHz-16bit and see if it's really that off from a CD. Otherwise leave it as it is. The whole loudness war is lame anyway. http://productionadvice.co.uk/dynamic-range-day/