Support
Looper's Delight
|
Support |
|
|
Well, I just received my Alesis Masterlink ML-9600 and I absolutely love this unit. It is a dream come true for live recording and archiving...especially so because I can burn CDs of my performance right there on stage from the unit's hard drive. The recording quality is immaculate and I really like the DSP, non-destructive editing features. Anyway, I'd like some feedback from some of the other sound engineers out there. I understand compression and limiting reasonably well (the mathematics of compression, ratios, etc) and use it frequently in both live and recording/sound engineering contexts. However, this Mastelink has a "look-ahead peak limiting" function, which as the manual says, is "designed to give you the ability to limit the highest peaks in a Track and simultaneously bring up the gain of the Track in order to maximize its level before creating a CD." After messing around with this, I am very pleased with the results, but I'd like some thoughts what others are using for output and threshold levels. First of all, I'm targeting -3db or -4db as my max. output level, which is pretty much industry standard these days for CDs, 16 bit, and 44.1K. Right now, I have the output of the look-ahead peak limiter set to -4db and my threshold is set to -3db. This seems to work well. Based on some guidelines I've seen for limiters, threshold is typically set at the max. desired output, and output perhaps just a sliver below this max. output, which is what I've done here. I could have set both the same as well. What are some of you, who do your own mastering, using for limiting setting guidelines? Better yet, if you are using a look-ahead limiter, what setting guidelines or rules of thumb are you using for that? For you techies, I've copied the manual description of this function below, so you can how it works differently than a traditional limiter or compressor. It's almost like a limiter, expander, and compressor all wrapped up into one function. I can't seem to fine any good guidelines on the web either, regarding look ahead peak limiting. This functions seems quite a bit more sophisticated than standard compression or limiting. ************************************************************************ ************** Krispen Hartung http://www.krispenhartung.com info@krispenhartung.com View improvisational / real-time looping videos: http://www.myweb.cableone.net/chagstrom2/music/kris-hartung/catalogue.ht m#videos Interactive tour of my gear: http://www.boisemusicians.com/gear.htm 5.4C DSP3:LOOK-AHEAD PEAK LIMITER The Look-Ahead Peak Limiter is designed to give you the ability to limit the highest peaks in a Track and simultaneously bring up the gain of the Track in order to maximize its level before creating a CD. This allows you to "squeeze" that extra couple of decibels out of the dynamic range, without squashing your audio by hard compression or traditional limiting. The limiter in the ML-9600 is very different than a traditional limiter, which is typically thought of as a compressor with a high ratio setting. By virtue of all-digital processing, the limiter is able to "look ahead" in time to see audio level peaks. This allows the limiter to begin smoothly reducing the gain of the audio so that when the peak does occur, it is limited to the desired value. In essence, the limiter becomes a "perfect" limiter or one capable of attaining an infinity-to-one gain reduction ratio. Another difference from a traditional limiter is that the "make-up" gain is automatically applied as a function of the threshold level. This allows the limiter to act as a "maximizer", enabling you to bring your Tracks very close to the maximum level allowed without clipping. The final difference in this limiter is that the final output level can be fixed as a function of full-scale; i.e. the limiter has infinity-to-one compression ratio with an extra gain stage at its output. This allows you to decide what the peak output value of the audio will be (-0.2dBFS, for instance). The Look-ahead peak limiter is perhaps best thought of as three discrete gain blocks: . The first gain block is dynamically adjusted so that its output level never exceeds the threshold level (the "perfect" limiter). . The second gain block adds make-up gain to the signal equal and opposite to the threshold value (a threshold value of -10dBFS would have 10dB of make-up gain applied). . The third gain block is a "scaling" gain block; it allows you to select the exact maximum output level (as a function of full-scale). If this gain block were not there, the automatic make-up gain would cause all signals that reached the threshold to equal 0dBFS. There are only three parameters in the limiter DSP block, so it is extremely easy to set up and use. A detailed look at each of the parameters follows. Threshold The Threshold parameter of the limiter sets the maximum output level from the first gain stage. No gain reduction is applied as the signal level approaches the threshold, but once it does, the limiter holds the output of that stage to the threshold value. Make-up gain is applied to the audio after it has been limited to the threshold value, so if audio is playing while the threshold parameter is adjusted downward, the output audio will appear to get louder. The threshold parameter is adjustable from - 0dBFS to -65dBFS in 0.5dB increments. Output Level The Output Level parameter sets the absolute maximum output level from the limiter, as a function of full-scale. A value of -0.1dB will limit the output audio to no greater than -0.1dBFS, regardless of input level or threshold setting. The output level parameter is adjustable from 0dBFS to -65dBFS in 0.1dB increments. Release The release parameter functions exactly like its counterpart in the compressor; it controls how long gain reduction is applied to the audio after the input signal drops below the threshold. Release is adjustable from 0 microseconds to 9.9 seconds.