Crispin's magic mix


Crispin Murray
Crispin's magic mix
Wednesday, March 13, 2013

In February loudspeaker manufacturer PMC, in cooperation with its Dutch distributor Stage Acoustics, organized four workshops at PMC dealers with guest speaker Crispin Murray. Crispin, formerly Technical Manager at Metropolis Studios in London, is a freelance pro audio consultant and this instructive event was all about the complete production process from recording to mixing and mastering, up to the final music release. It’s not surprising to see PMC taking a lead in this area, they have sturdy relations with recording studios all over the world, they supplied loudspeakers to Metropolis Studios and they maintain a good relationship with musicians and music lovers alike.

After a short introductory speech from the Dutch distributor, Mike Picanza from PMC introduced Crispin Murray to the audience. Crispin explained who he is and where he comes from. "I have been active for over 30 years in music, recording and mastering. I started at the BBC as a recording technician, to record programs or live events with pop, jazz or classical music. One of the highlights was recording the Glastonbury Festival, which I enjoyed so much that I have been involved with the festival for over 25 years now. After eight years at the BBC I changed jobs to Virgin’s Townhouse Mastering studio and The Manor Mobile, first as a recording technician, moving on to mastering engineer after a few years. During the years that CD replaced vinyl I had a chance to work with people like Whitney Houston, Carlos Santana and Cab Calloway. In 1992 I got involved with Metropolis Studios and was employed in London up until 2012. I had a lot to do, I was and still am (today as a consultant) involved with recording, mixing, mastering and overall technical jobs. Together with my colleague Miles Showell we reintroduced half-speed cutting of vinyl masters. In my first years at Metropolis I was also responsible for furnishing the stereo and multi-channel mastering rooms (with PMC speakers all over the place), the design of our own electronics and the promotion of SACD. I had a lot to do with bands like Queen, Kraftwerk, the Rolling Stones and the Beatles.



“My main personal interest is the mastering process. The starting point is the rough mix of the recording. It is the mastering engineer’s job to make a coherent sounding CD or LP from all those takes. Musicians do not even have to see each other during the recording sessions that might take place anywhere on this planet. For the final result all tracks need to have the same volume level, give the same impression and it must be possible to play the album on any device. Big studio monitors, small speakers at home, headphones or as a broadcast. These demands often conflict and besides these considerations we have to listen to our clients, the record companies, who have their own agendas. They want to hear no dynamics at all; every album should be on Metallica level. We have to be careful that space, positions, voices, timbre, volume and everything else is in order before the band, the producer and the record company look happy. I will let you listen to some examples to make clear what we do and what is possible these days."

Now the time has came for the first piece of music, which was recorded at the Dorian Grey Studio in Munich. The band consists of a female singer with a ribbon microphone, a drummer in a separate room surrounded by twelve microphones. Again in another room are the piano and bass, each with an array of microphones. The original recording sounds very incoherent, too much bass guitar and too much bass drum, the piano playing in between, while the singer sometimes gets smothered by the band. Then we heard the same part of the recoding, but with a better mix, at once the band and the singer no longer battle for space, they play like a team in an easy way that fits the character of the song. Next came the mastering. Bass is a lot tighter, very nice for small speakers that cannot handle too much energy, there is more air surrounding the instruments, more open space, and a more smooth sound. We would call it audiophile. The public chose the mix before mastering as their favourite, because it has more to do with the performance itself. However, we should remind ourselves that most of us do not have PMC IB2i or a speaker of similar quality at home, able to handle all the bass energy presented here. Crispin points out that volume control is done by hand, any well trained mastering engineer never leaves this part to limiters and compressors. Once in the past Crispin had to record a pipe organ in the Royal Albert Hall with a dynamic range of 125 dB. For broadcasting purposes the range should only be 26 dB and on a CD 70 dB. Hard work, he says, and following this he explains why he chose PMC for Metropolis in the first place. "A studio monitor has to be able to play at the same volume level as the recorded instrument. We must be able to hear everything in the recording, even a loose screw in the drum kit. We don’t want the public to hear that. So this monstrous speaker needs to be able to sound like a small speaker at other times, to recreate the impression of one for the recording engineer. Just a handful of brands can deliver such speakers and PMC is one of them. Apart from that you need to be able to listen to these speakers for hours without getting tired and they should be completely neutral at high but also low volume levels".



The next piece of music was from an Eleanor McEvoy CD that is expected in the stores by May 2013. First we heard the CD master version, next the SACD master, although the SACD file was converted back to PCM format for CD. It showed us the advantages of SACD recordings, even if we go from the SACD layer to the CD layer on a hybrid disc. Less noise, more air and an expanded frequency range are positive elements we can preserve this way. For that reason Crispin likes to produce a SACD master even if the recording is just for CD in the end. As he says: "The Irish voice of Eleanor is just more Irish after the use of SACD techniques". He also points out that the unprocessed recording would cause bass problems at home. The mix is already far more coherent with tight bass, a clearer voice and almost the sound as we expect it to be at home. Next he demonstrates the final version for CD production. Beautifully balanced, fast guitar, an organ appears out of nowhere, voice and drums no longer in each other's way. If the CD sounds like this I will be running to the record store in May (if it’s still there, Ed).

The kind of mastering depends on the final medium. Pop CDs need to be used not only at home but also for broadcasting. SACD offers new possibilities. MP3 is important on this side of the ocean as are the high resolution files in the USA. If we consider vinyl we have to cut back high frequencies and remember that we have to deal with more background noise. About ten years ago things were different. The mastering engineer did his utmost just for CD. Should it become a SACD, well, just convert the CD master. Preferably this converting was done by someone who never was involved with the original recording in the first place. It all lead to SACDs of a lesser quality compared to the original CD or they sounded totally different from the original. Also a lot of record companies tried to make a lot of money from reissues. Using old, noisy master tapes that had been played too often. Luckily Crispin often found multichannel tapes beside the stereo ones in the archives, they were in a far better shape because no one used to play them. They were just waiting for someone to come by and were the reason why a lot of the popular 5.1 channel SACDs were released. Music by Genesis is a good example: Crispin played us first the bad stereo recording, followed by the far better multichannel SACD track converted back to stereo PCM for the demo. It’s not only the tape that’s a limiting factor, but also the electronics in the studio are far better today. An old Beatles reissue from 1994 can be remastered today in a far better sound quality, even from old tapes. Today’s tracks sound far more open, faster, less compressed, no longer dull, with clear voices etcetera. Although a purist may say that the remastered ‘new’ CDs sound ‘unrealistic’.

A short detour, Crispin not only works for the music industry but for film and TV as well. These industries present completely different demands, mainly due to the current flat screen TV sets with their small speakers, located mainly on the backside. We listen to the title track of the popular TV series The Killing (original mix). Next we hear the remastered version Crispin made, which gives far more space, more dynamic impact and suddenly it sounds much more sinister. He explains how little needed to be done to obtain this result, only a little bit more high frequency gain around 6 kHz. He tells us the art of mastering is not turning all the knobs. It is the other way round, keep as much of the original as possible. Never change too much.



Crispin’s continues to cherish his old flame as a craftsman and audiophile: vinyl. He treats us to an original Sheffield Lab recording from the seventies, a direct-to-disc recording of Thelma Houston and her Pressure Cooker band. Direct-to-disc means a microphone is connected to a mixing desk and from that connected straight to the vinyl cutting lathe to make the masters, without recording on tape first. The music almost explodes from the speaker cones when played on an Avid record player with Ortofon cartridge, connected to a Cary Audio tube amplifier via a Pro-Ject phono preamp. A nice counterpart to Crispin’s laptop and his Prism Sound Orpheus A/D-D/A converter. Crispin tells us: "I am rather jealous of how they managed to capture this sound quality in the seventies. With the stuff they had in those days. Such an enormous sound quality is even nowadays not possible with a digital recording. To prove it we made a recording in Metropolis with a band well known to us. We recorded a seven inch direct-to-disc, as well as a tape and a digital file at the same time. The conclusion at the end was obvious. Third place was for the tape results, second came the digital recording and the absolute winner was vinyl, as long as we consider only sound quality. One of the band members started crying spontaneously while listening to the record, because this was the first time he heard himself playing live, as he said at the time. On all other occasions he was listening to a "recording of him playing". Of course vinyl no longer rules, only for a niche market. Even though we experiment in Metropolis Studios with half-speed lathe cutting. Which is very tricky, because you can’t just cut the speed in half. Adjusting the speed by hand is a job for a very experienced cutter. Mobile Fidelity did this in the seventies almost the same way. A 20kHz tone needs 20dB gain according to the RIAA standard, so a huge amount of energy is fed into the cutter head which makes it incredibly hot. A big advantage of half-speed cutting lies in the fact that at 10 kHz only half the energy is needed. Less heat is developed, the distortion level drops and the cutting process is far more linear. This way we made reissues with seven LP boxes, with a generous low end, a wide open stereo soundstage, air and ease. We only used digital tools to enhance the master tapes".



It was time to listen to a half-speed cut example, pressed from the original master and therefore limited to just 100 copies. This too is music from Eleanor McEvoy, this time taken from one of her SACDs. Crispin tells us this LP contains the best results in recording/playback ever attained on any kind of medium (lucky me: I own a copy and I have to agree). At the end of Crispin’s demonstration questions are asked by the public like: mastering a mix, is this done in the digital or analogue domain? Crispin answers that today every recording is done on a digital storage medium, but converted back to analogue for mastering and at the end converted back to digital in order to make a CD-ready file. The explanation is simple; in the analogue domain more can be done and in a more subtle way. A fine example is the technique of a compressor, a device used in all studios all over the planet. A compressor has an almost linear gain up to the maximum setting and above that the volume increase is cut off fast. Year after year designers worked on analogue compressors to make that ‘kink’ inaudible. In the digital domain this is very easily done through software, although even the company who made a prototype admitted that the compressor sounds horrible. The same happened with equalizers and limiters, but even Crispin has to admit that today's electronics have improved and some ‘digital only’ studios do exist. Some more questions like these followed, until this fascinating and informative event came to an end. The attendees were all very pleased and applauded spontaneously to show their appreciation. Applause not only for our host, Crispin Murray, but just as well for PMC, its Dutch distributor and his dealer, who in association organized these workshops.

This translated report was previously published in the Dutch magazine Music Emotion