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May 24, 2021

Back in January, Robin Maconie, a composer, writer and Stockhausen scholar from New Zealand contacted me with technical questions concerning Catherine Christer Hennix’ 1974 recordings of Karlheinz Stockhausen’s Unbegrenzt which I have restored and mastered for a vinyl and digital release on Blank Forms. Below are my email replies from January 29 and February 24 respectively.

 January 29, 2021 

Hi Robin,

the original reels have been transferred at 96kHz/32-Bit float through a Lavry Gold AD-122-96 converter, no noise reduction was used during the transfer.


The restoration was made with Cedar Audio tools, some light noise reduction and spectral repair. The tape was in rather good shape, no baking necessary, the recording turned out to be in M/S like the remaining reels I've been working on for the other two editions on Blank Forms.


The M/S decoding was done with an analog matrix by Roger Schult, EQing in the digital domain with DMG Equilibrium and an analog Fairman TMEQ for the finish. No dynamic processing was used, Christer‘s wish was to stay as true as possible to what's on tape.

Let me know if you have more questions,


 February 24, 2021 


I spoke with Catherine Christer Hennix and also heard back from the transfer engineer in the meantime concerning the technical aspects for the recordings of Unbegrenzt and can give you more of an in-depth background info now. Let me address your questions one by one below.

Best regards and thanks for the patience,


The piece was recorded in Mrs. Hennix’ studio in Stockholm in 1974 on 1/4" tape by artist Ria Knox, using a portable Nagra IV–S and a Schoeps M/S microphone kit, items on loan from the local broadcast station. There was no Dolby noise reduction involved since the Nagra didn't offer such a feature.


The setup comprised various speakers surrounding the players, some of them self build. The instruments used for the performance were miked with “toy like“ Sony microphones fed into a battery powered consumer grade 6-channel mixing board, a Sony MX-12, introduced by the company in 1973. This console only has unbalance inputs and was known to be prone to noise, distortion and catching interferences, the output was sent to the speaker array to be amplified at high levels. As you may know, Mrs. Hennix was impressed by bands she saw live in the States, ie. MC5, which performed their music at extraordinary, maxed out levels.



If no noise reduction was used during the transfer, did you listen to the tape played back on an analogue speaker system prior to remastering? Did you keep any notes? What state was the tape? 


The transfers were made in 2018 at Calyx Mastering Berlin by Andreas Lubich, a seasoned mastering engineer himself, a friend and colleague with whom I have collaborated for 27 years now. The reels were in good condition, no baking required. The transfers of roughly 13 hours material in total were made during a series of sessions with Hennix in attendance.


The full resolution files I have received are of highest integrity and allow me to hear an exact copy of the reel's content in my own room. My studio‘s acoustics are optimized for mastering and I didn’t compromise when it came to the level of accuracy and transparence of my monitoring and processing chain. My aim is to hear exactly what the source has to offer and then take it from there. I'm working on a wide range of material, some of it brilliantly produced, others less so. To me this makes no difference, I'm trying to get the best possible results from the material I receive, but I do not twist audio to make it fit within certain standards or meet specific expectations except for creating a correct master. I cherish authenticity and I'm certainly not afraid of noise. Working with historic reels, opposed to working from a digital production has a special layer involved. To me the tape, 78, wax cylinder or acetate becomes part of the performance and I want to present it in the best possible light, ideally by applying only as little adjustments as necessary to make it enjoyable. My goal is to work out an optimized copy of the medium that represents a recording as the artifact it is.




I was surprised to hear an almost continuous hiss throughout. The most obvious explanation would be that Dolby expansion was used in the original tape which not de-Dolbyed in the remastering.


Dolby would have been used during the transfer if it had been applied during recording. Since the noise level in the flat transfer of the reels is far from identical in the mono and difference channel it is safe to say that it is part of the performance, the band's unique sound. Broadband noise contains much of the spatial information, pull it down and the sound will become dull. The tape hiss present was average, the amount of noise was introduced by the gear used and the high level of amplification of the instruments. This is what I hear from the flat transfers of the tapes and it was crucial to me to preserve this sonic signature with integrity in the reproduction masters.



The audio panorama was also strange and appeared skewed to the listener's right when played back on speakers, though for some reason the effect on headphones was less prominent.


The decoding of the M/S signal was made with great care. What you hear in the masters is the point where the decoding to stereo sounded best to me and revealed the most details. As you can tell, the noise level is pretty much stereo now, that's because I used it as one of my guides during the decoding.




If indeed the original tape was recorded with a coincident pair, the stereo imaging should be adequate, providing the players were correctly positioned originally.


M/S is a fact. The flat transfers have one channel with the mono signal while the second channel mainly contains room information. From the decoded stereo you can tell that the instruments were not distributed evenly across the stage, also the multi-speaker setup added a level of phase mix-ups which had to be addressed during mastering. 




However, that still does not account for the inserted tape segments featuring Japanese drumming which recur from time to time. These prerecorded elements would have to be reproduced from equipment of some sort, and balanced with the live players. It is unclear to the listener where the prerecorded elements are located in the stereo panorama.


There are no pre-recorded or sampled percussion instruments present in the recordings, what you hear is a set of temple blocks and a tabla played by Hennix, along with various playing techniques used on the tam-tam by Hans Isgren. Those instruments can be heard either dry or processed through a tape delay or ring modulator. Pre-recorded audio used during this performance contains material created by Hennix at the Royal Institute of Technology in Stockholm, experiments with speech synthesis conducted with a mainframe computer system.

The choice of the tam-tam, temple blocks, tabla and ring modulation for this performance was made in reminiscence to Stockhausen’s work.




Since no technical notes relating to the original recording are included in the sleeve notes, did any original notes survive along with the tape?


The tapes came without specific notes apart from title, date and tape speed, please see below.




Are you perhaps familiar with the Stockhausen recording on DG and the Shandar recording of the same piece? Whatever one might think of the sounds made, the quality of recording is amazingly clean and sharp, and essential technical information is provided.


I know the DG 7LP set well. You are comparing the high Westdeutscher Rundfunk standard for Stockhausen versus a room recording from a rehearsal space, made with modest equipment by the players themselves. Unbegrenzt is a private recording of an ensemble which Hennix herself has described as “the most rejected band ever formed in Sweden”, a band which looked to perform live for an audience, the context in which Hennix wants her music to be experienced. The recordings were made so the group could listen back to them, to see how they sound from the perspective of an audience. Back then there was no intention to have those recordings released by a label, let alone by Deutsche Grammophon. Today a lot of people feel blessed by the fact that the archival recordings are available in editions made with great enthusiasm and a great level of care. The music became kind of a holy grail for people like me, and Unbegrenzt has its unique place among the pieces recorded in Stockholm between 1974 and 76.




Ms Hennix may have asked for the recording to stay true to the tape, but that could be because she has forgotten or is uninterested in such matters. 


The masters where prepared in close coordination with two of Hennix' collaborators, partly because at that time she didn't have a good enough system available to monitor the process properly herself. Everybody involved in the process was familiar with the quality of the flat transfers of the tapes, the results were approved by five people in addition to the transfer engineer and myself. What you hear on the LP or from the lossless digital formats is a representation of what is on tape, decoded to stereo, cleaned from excessive tape hiss and gently re-EQ'ed. There is no dynamic processing involved in any of the masters apart from gentle de-essing to get hold of some moments of shrieking bursts.




Or because any technical record has been lost, in which case care would be needed to interpret the original intention. 


The tapes are no Abbey Road, Columbia or WDR recordings where you would see notes concerning test tones for calibration, EQ settings, even info on the specific EQ models used, noise reduction etc. The notes on the slipcases don’t go beyond recording date, title and tape speed. That's all it takes for them to be played back correctly from a well serviced 1/4“ machine. 




This is a nontrivial matter because Stockhausen's text pieces are intended above all to convey the reality of a musical event taking place spontaneously in the moment, which is a musical phenomenon at the opposite extreme from the theory and practice of digital music in 1968 - and even in 1974, as represented by Max Mathews's music composing package (which eventually became MaxMSP). 


If you ask me, it doesn't come closer than what we have on tape here. The intention is perfectly realized. From a purely technical aspect, Stockhausen and Hennix in the mid 1970s could not be further apart. To stay only with the DGG version of Aus den sieben Tagen, the 1969 recordings were made at Georg-Moller-Haus in Darmstadt (the location used for the Musik für ein Haus event one year earlier), a specifically selected space where a team of white coat engineers would set up the finest recording gear available, including selected microphones for each of the instruments. Stockhausen’s console, credited as Filters and Potentiometers, was of course custom build for him and if you’re familiar with the level of standards, norms and skills at work in German broadcast stations, this console had to be state of the art.




In other words, a  text piece asks the general question "How do you capture an impression of organic reality though a medium that reduces reality to a string of numbers? 


I'm not sure whether you are questioning the truthfulness of analog tape transferred to digital (a string of numbers)? A well made transfer will represent the content of a tape 1:1. The string of numbers analogy may be true for early digital audio, if you transfer an analog medium to digital today by means of carefully chosen converters etc, say at 96kHz/32 float, you will get an exact copy of –


A/ the sound captured on the tape itself 

B/ the sound and character of the analog playback device, a Studer A812 in this case, which is optimized so it won’t add a sonic footprint at all but rather reproduce the source as faithfully as possible by analog means.


If you’ll capture from a tube based reel to reel machine, say an early generation Telefunken M5, the machine will come with a good portion of its own vibe which will also be captured digitally. The transfer will sound like the tape played back from the valve unit.


If the content of the reel sounds pristine, the digital file will deliver exactly this. The string of numbers is so vast and quick it will recreate analog sound without adding or subtracting in all it’s analog smoothness, detail and character. Digital audio can be very good today as long as it’s done right. It offers much more precision than analog ever had and leaves nothing to be desired even by die-hard analog folks like myself or my teachers. All of the preconceptions from the 80s to the late 00s are simply gone.




You may think such a view as old-fashioned, but Unbegrenzt is a pointed philosophical statement by the composer at a critical point in his life, a kind of Hamlet moment where the composer asks: "To be, or not to be?"



While listening to the DGG 1969 recordings now, I can’t help but think that various of the players involved were not entirely ready for the Intuitive Musik. I admire Stockhausen’s work and his classic ensemble players in general. Hymnen is among the best tape music I know and I saw the premiere of Freitag in 1996 which was quite something. I have performed Spiral several times solo and Kurzwellen as part of an ensemble. However, much of his own recordings of the Intuitive Musik pieces sound weak and undecided to me, and I can’t help but wonder how they would have sounded if Stockhausen had worked with more avid ‚free’ improvisers instead, people from the British (AAM, SME), German (FMP) or Dutch (ICP) scenes for instance. The Scratch Orchestra? I don’t intend to disrespect the players, I only question if all of them were the right choice for this specific pieces. What I hear is good recordings of sometimes rather unsatisfying performances, with many of the cliches in play that can make spontaneous music so uninteresting. This certainly does not affect all the pieces, but Unbegrenzt in my opinion is clearly among them.


The 1974 recordings of Unbegrenzt by Catherine Christer Hennix and Hans Isgren are different in many ways. I imagine the band would not have turned down the opportunity to record their material in a radio station or in a dedicated electronic music studio. What we had available today would sound different, a period high end capture probably. I first heard material from Hennix’ private archives from the mid 70s in 2005, a 96kbps online stream by Dutch VPRO radio. Back then I could only hope that the material will be released at some point. In fact I thought the recordings were made at EMS and was definitely surprised when I finally received the transfers since they sounded so rough and edgy, not like an electronic music studio production at all. Next I fell in love with their unique sound, to me the recordings are outstanding documents.



During our conversation about recording, interpretation and capturing a performance for later playback, Catherine Christer Hennix pointed me to the following paragraphs from Wittgenstein’s Tractatus:



The gramophone record, the musical thought, the score, the

waves of sound, all stand to one another in that pictorial internal relation, which holds between language and the world. To all of them the logical structure is common. (Like the two youths, their two horses and their lilies in the story. They are all in a certain sense one.)



In the fact that there is a general rule by which the musician is able to read the symphony out of the score, and that there is a rule by which one could reconstruct the symphony from the line on a gramophone record and from this again—by means of the first rule—construct the score, herein lies the internal similarity between these things which at first sight seem to be entirely different. And the rule is the law of projection which projects the symphony into the language of the musical score. It is the rule of translation of this language into the language of the gramophone record.


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