My name is Matt Glenn. I am a student of music technlogy and sound engineering at the University of Michigan in Ann Arbor. Outside of class (and sometimes during) I do a ton of thinking about music and audio engineering. This blog is a my attempt at organizing my mental maelstrom.

Matt Glenn

Friday, December 26, 2008

A modern take on the noise wars of popular music

A lot of people who are not familiar with music production do not know about the noise wars, so really briefly: over the past couple decades, a lot of engineers have been mixing and mastering popular music to be louder and louder, and thus are squashing the natural dynamics of the music in order to maintain a more constantly-loud feeling. Metallica was recently humiliated when their new album "Death Magnetic". The album was mixed not only in this fashion but was terribly distorted as a result; of course they are not the first album to have this problem, but even uneducated listeners got a comparison with the guitar hero mixes of certain songs on the album, which were produced with much more clarity. Yeah, they got a lot of shit for that.

Anyway, the noise war trend seems to affect rap and hip-hop more blatantly than it does more acoustic or jazzy pop. I've been listening to a bunch of Sara Bareilles lately, and her stuff is mixed to be pretty loud, but you can still feel the dynamics. When compared to a lot of the pop that comes out nowadays, this is not a bad thing. But when I look at the level meters, the song is still pretty crushed.

My analysis: I think we as listeners have become used to sensing dynamics in popular music from other stimuli besides actual dynamic level range. I mean, when you listen to Queen's "We are the champions", the perceived jump up in dynamic right at the pre-refrain (when the full band comes in on top of the piano and bass) is an *actual* jump up in volume—and a pretty significan jump. Of course, that was the 80s—in the first verse of Sara Bareilles' "Love Song", the full band that enters after "even I know that" doesn't really pump the meters much higher. From my listening, I see a trend of engineers resorting to alternative techniques to create the illusion of dynamics. Some of the things I've noticed...
  • number of instruments - more will inherently sound louder because of association and common sense, but also because of....
  • frequency range - if a recording contains a group of instruments that balance across the full range of frequencies, then it will sound louder than a more frequency restricted group (or a smaller number of instruments). Thank Fletcher and Munson and the perceived loudness phenomenon for that.
  • reverb - there is clearly more reverb when we yell in a church than when we whisper—as such, it's possible to increase the perceived loudness of a recorded part by increasing the amount of added reverb on it
  • bus compression - movies do this all the time: when there is a loud sound effect, the other tracks often "duck" out to make room for it (whether this is done manually or with a ducker varies). In music, if a pop singer belts, for intance, sometimes the bus compression on the whole song will make it seem like the other tracks duck down a bit, making the vocal appear louder than the rest of the tracks temporarily
I'm not knocking this approach—I mean if the song needs to be as loud as possible, at least the artist's dynamic interpretation will come through *somehow*...

Thursday, December 25, 2008

Mic Pre-Amps: What the hell...

Here in California, it is snowing a hell of a lot—3 feet last night. So I have a lot of downtime, and in this time I have read a very high (definitely double-digit) number of articles, forums, and product descriptions about mic preamps. Out of all of this reading I've come to ONE conclusion for *certain*: mic preamp selection and application is very subjective. But I also learned about a bunch of characteristics that I did not know about before.

First of all, look at the naked purpose of a preamp: to boost the level of a microphone to usable line level. Keep that in mind. Now, if that were the *only* purpose of a mic-pre, then there would not be around 3000 models out there—one company would simply design this simple circuit, patent it, and have a monopoly over the design. But each of those 3000 models, aside from achieving its basic purpose, provides something sonically different because each model contains slightly different circuitry. The variations can be as drastic as using tube vs. solid-state circuitry or class-A vs. class-B amplification, or as subtle as using transistors of different brands or materials. How does this affect the sound? Well I have been able to hear myself that different preamps can affect the frequency response of a microphone slightly, but what I didn't know is that preamps actually have a response time. I found it a little hard to believe that this could make a big difference. Sure enough, in most modern equipment it doesn't. It's very nice to scratch one spec off the list of importance.

The supposed "color" of a mic pre seems to determine most engineers' opinions, but I think (as do many others) that adding color to a mic pre defeats the purpose somewhat. If the studio were a kitchen, it would be like trying to get better-tasting cookies by mixing the batter in a bowl of a different brand. I'm sure it makes the slightest.....SLIGHTEST difference, but I would certainly try to focus on the batter itself first. I have no doubt that I could record a very professional-sounding record with talented musicians, good instruments, well-tuned acoustics, and detailed attention to mic placement.This being said, I have heard the difference between mic pres myself. Here is an excellent place to train your ears to the detail of listening required. The engineers at this site had musicians play/sing the same musical passages over and over again through different preamps or mics. It's all done as a very controlled experiment, which is very helpful.

Some of the facts/opinions I have read but have not had to chance to experiment myself:
  • Class-A amplification delivers a clearer, less distorted sound than Class-B or Class-AB. The difference lies in the output stage (read more here). Class A mic preamps tend to produce a significant amount of heat due to their inefficiency
  • You can find a diagram of the color character of well-known preamps here and of well-known mics here (both also from the listening sessions site)
  • All-discrete circuitry (i.e., using individual transistors as opposed to integrated circuits) tends to be more trusted, although is almost always more expensive.
That's pretty much all. I might have learned more, but obviously not well enough to remember it. Please feel free to post angry replies if you disagree with me on anything, but I hope this has been informative!

Welcome to my blog attempt!

Hey everyone,
First of all, I have never blogged before but i just spent the past week or so reading a ton of very interesting stuff on other people's blogs and now I wanna be that cool.

The purpose of this blog is mostly to share my (and listen to your) ideas surrounding music, music technology, sound engineering, and/or sound design for theater and film—but I will also include random things I'm thinking about.

I hope you enjoy!