Bob Ludwig, while technically needing no introduction, will still get one here. Why? Because the man deserves it for all the amazing work he’s done in the field of mastering. As one of the top mastering engineers in the world, his skills have been in demand for decades, starting with his work at Sterling Sound, then Masterdisk and later with his own company, Gateway Mastering in Portland, Maine. Even if his name isn’t familiar to you (and as a musician, you should be embarrassed if this is the case), just flip open the liner notes to some of your favorite albums. Ludwig has mastered countless classics from independent bands to superstars, including Jimi Hendrix, Megadeth, Metallica, Nirvana, The Strokes, Queen, U2, Guns N’ Roses, Tool, Bryan Ferry, Tori Amos, Bonnie Raitt, Paul McCartney, Bruce Springsteen, Madonna, Radiohead, Steely Dan and more.
He has also occasionally undertaken long projects, such as remastering the entire back catalogues of Rush, Dire Straits, Creedence Clearwater Revival and The Rolling Stones.
We recently had the pleasure to speak with Ludwig about the current state of mastering, the loudness wars, how musicians should approach the process, and where the art form is headed as it relates to digital releases.
Can you give us a brief background on your career?
Well, I graduated from the Eastman School of Music in Rochester, NY. I have a bachelor’s and a master’s degree and I used to be the principal trumpet player with the Utica Symphony Orchestra when I was there. I went to work recording with Phil Ramone, who got me into the industry. He was my mentor and I learned the art of mastering there, and then went on to be the first employee for Sterling Sound when they opened their doors. I worked there for seven years and then made a lateral move to Masterdisk in New York. At one time Sterling and Masterdisk were owned by the same public company, so I just switched tabs there at one point. I spent a long time there and then in ’92 I decided I was going to start my own place, which was Gateway Mastering Studios up here in Portland. We opened our studios in January of 1993.
Can you explain what exactly mastering adds to the process after the tracks are mixed and recorded?
Mastering is the final creative step in the record making process. You do the recording, you do the mix down – sometimes using the best mixers in the world, sometimes using your friend who just bought Pro Tools because you don’t have any budget. The purpose of mastering is to maximize the amount musicality that’s kind of inherent in the tape that’s been mixed. We work with some of the greatest mixers on the planet, guys like Kevin Killen, Michael Brauer, the list goes on and on – who are already really great and fortunately for us, when a mix is so finely honed, if we do even just the smallest amount to it, it sounds like we’ve done a lot because the mix is so finely balanced that just doing a little thing really can be the icing on the cake. But a lot of DIY people who are just getting into this – mixing is a very, very difficult thing to do right, which is why there are only a handful of mixers on the planet that actually get a percentage of royalties for it. When someone is doing that at home, sometimes a good mastering studio can really make the difference between a record that sounds like you did it in your basement, and something that sounds commercially viable. We can usually turn a piece of dog meat into something that’s at least OK sounding.
Let’s use that example. What specific things do you add to a poorly mixed home recording project or even a well-mixed DIY project in the mastering stage?
Well, having heard tens of thousands of recordings and having mastered them, I have a great wealth of knowledge as to what constitutes a good-sounding record. When I hear a raw tape, in my head I can envision how it ought to sound and then I know what knobs to move in my studio to make it sound like it does in my head. We have many different kinds of equalizers, some in the analog domain, some of which are solid state, some of which are tube, some of which are used for very broad strokes, some of which are extremely transparent-sounding and are used for more surgical touch ups. And we have a whole plethora of digital domain equalizers that also have a lot of characteristics, some of them try to emulate tube gear and some of them try to be as absolutely perfect as possible. They all have their different sound and they all have their different uses. And we have compressors – both analog domain compressors and digital domain compressors – they all sound different from one another. There are very few pieces of gear that sound exactly like another piece of gear. A good mastering engineer knows what all these different tools sound like, so when I hear something in my head – it might even be a piece of gear I haven’t even used in a year – and I’ll say, ‘Well, this thing is going to be just right for this. I just know it.’ And I’ll dig it out of the closet and hook it up and put it on. Nine times out of ten, I’m right.
Would you say that EQ and compression are the two most common tools that you are applying to a record at that stage in the game?
And level adjustment, definitely level adjustment as well. There are so many other things that we do now, you know. There’s reverb, which is not used very often, but the times you do need it, it’s pretty essential. There’s adding spaciousness or narrowing the sound stage, there’s tape simulators now. Some people feel that going to tape doesn’t buy you anything anymore so you can just put up a tape simulator now. Which may or may not be true depending on what it is [laughs].
I’ve heard some good ones. Universal Audio makes a pretty nice tape simulator.
Yep. And then a lot of producers still do mix actual tape. We have many different kinds of tape playback machines and different kinds of heads, all of which have different sounds to them – solid state playback, tube playback, quarter inch, half inch, one inch stereo, 8-channel analog, 8-track or 2-inch tape – we can cover it all.
Speaking of formats, are there any different steps in your mastering process when it comes to a band releasing a 12-inch version of their album compared to releasing a CD of their album?
If the guys who are mixing it have given us high-resolution digital, which is anything more than 44 kHz, 16-bit – we usually like to master in as high as resolution as possible.
So are you talking like 24-bit, 96 kHz?
Yeah, that’s very common, or on rare occasions 192 kHz. If we master in that high resolution format, then when it comes to doing vinyl, we like to supply that 96k, 24-bit file to cut from because the vinyl has another octave that the CD doesn’t have, let alone the download [laughs], and a well-cut and well-replicated vinyl disc can truly sound better than the CD version of the same material.
Do you even want to comment on mastering for MP3 or is that a touchy subject? Because let’s face it: a lot of our bands are probably going to be sending digital tracks to their fans on the email list or posting them online. And those have to sound good as well.
Yeah, and Apple has a new initiative out right now called “Mastering for iTunes.” And that’s a new process that Apple has, that instead of ripping from a 16-bit CD, you use the high-resolution digital file as your source. Apple has a sample rate converter built into the OS X that if you know how to get to it, it’s a very high quality sample rate converter. And you can take the 96k file and make a 44.1 file of it and the act of making the finals from the 24-bit source creates a much better sounding source than the 16-bit rips do. And then there’s the second thing they have – it turns out that the AAC encoder that Apple uses is a 32-bit floating point encoder so it can use those bits 17-24. And then there’s another step in the process when you are mastering especially for iTunes that looks at any clipping that was created in the act of making the AAC encode.
So will that actually look for distortion?
Yeah. If you have a PCM 96/24 file that has no digital overs on it or clips where it’s exceeding digital zero, the active AAC encoding can actually create some clips where none existed before if that thing is at a very high level, which most pop [records] are. This piece of software they have will let you know – you can take that 24-bit master you’re using for the encode and you can lower the levels, say half a dB or 7/10 of a dB, and you can re-measure it and you can actually get rid of all those clips. And the difference between a hot pop record that’s just ripped from the CD vs. one that’s gone through this extra care – the difference is audible even on laptop speakers.
I know there’s been a lot made against the “loudness wars,” and you had a very interesting process with the last Guns N’ Roses record. Would you mind recapping a little bit of what happened there?
Yeah, that was great. You know most producers are just totally paranoid about their record not being loud enough or if somebody put something on shuffle mode that theirs won’t be as loud as anything else. The really delusional people think that a louder record sounds louder on the radio, which is absolutely not true. But anyway, a lot of producers feel that way. But Axl Rose was mixing the record with Caram Costanzo, so they did these really good mixes, in my opinion, and Axl had taken it to five different mastering engineers before he got to me. All those people just wanted to make it like other loud records and I was totally willing to have it contain all the dynamics of his mix. So we mastered it that way – I mean there was plenty to do as far as level balancing and EQ and bringing out certain lines that were lost in the mixes. But it creates a record where you can have all these layered guitars and you can hear the differences between them all. And then the vocals can come in and sit on top of all layering and there is still plenty of room for them. What a concept!
Well, music is all about dynamics and I think a lot of that is lost in modern recording. We’ve heard a lot of complaints about recent CDs carrying that “remastered” tag, when all that means is they’ve made it louder.
Yeah, it’s true and it’s really a shame. It tends to squeeze out the dynamics already in the music.
Do you have any tips for the home recorder or independent bands during the tracking phase or the mixing phase? Something that can help them best prepare their tracks for when they deliver it to a mastering studio?
When you’re mixing, one of the most difficult things to do and get right is the vocal. Most engineers don’t pay quite enough attention to the vocal, where some lines are easily heard and then other words will get lost here or there. It’s really important to get that right, since the vocal for most pop records sells the record. So it’s always helpful once you’ve created that vocal line to print another one with the vocal up a half or even maybe 1 dB, so that when it gets to mastering, if the act of mastering needs more vocals still you’ll have the mix right there with it. Another big thing for young engineers who are starting out is…you know they’ll get a magazine probably like Performer or one of these review magazines, where every week it seems like there’s a hundred new plug-ins – a new engineer can get really overwhelmed by that. My suggestion is buy just a few well-recognized plug-ins to start, like some of the Universal Audio ones or the Manley Massive Passive EQ, or the Massenburg EQ or the Sonnox Oxford EQ – you know, some really well-respected plug-ins, and just spend a long time learning those really well.
So, learn fewer plug-ins well as opposed to being overwhelmed with all the different options out there?
Instead of trying to keep up with all the latest and greatest. Believe me, I can tell you hardly ever is there a ‘latest and greatest’ that came out that week [laughs]. There might be a different or cheaper one – it’s not the latest and greatest. For instance, get to know the difference between a linear phase equalizer and IIR [filters and equalizers]. And as I said, they’re all not built the same. It’s very difficult to make a very good sounding digital equalizer. If you stick with the ones that are really well-regarded and learn them very well, that will go a long way towards making a better mix.
You’ve mastered countless records – you said in the thousands. Could you name some of your favorites?
Certainly anything Bruce Springsteen has ever done [laughs]. I’ve done pretty much his whole catalog. All the Rush records that I did. I see that they are going through another round remastering the Rolling Stones records…
Again? Didn’t they just do high-res DSD remasters of those not too long ago?
They did Exile and also Some Girls, or something like that.
Okay, so those are the later Virgin years, I guess.
Right. I’m very proud of the ones I did and apparently a lot of people believe that those are still worth having. And you know all those Rolling Stones ones I did for ABKCO are on Super Audio CD. Both the versions that I did in the ’90s and ABKCO – I’m very proud of all those.
The Black And Blue CD, in particular, sounds amazing.
Yeah, it’s so hard – when I first started as a kid I mastered Led Zeppelin 2 and Houses of the Holy. I never dreamt that all these years later they’d still be keeping young bands off the radio!
Photos courtesy of Gateway Mastering