The Klaus Blum Interview - 47 years beyerdynamic experience
Peter: Hello Mr. Blum. Great that you were able to make some time today to answer some questions from our beyerdynamic fans. But first of all a question for my part. With only a few days left until you will retire after 47 years and 2 months employment at beyerdynamic. What kind of feeling is that?
Mr. Blum: Well, the feeling is fifty-fifty. On the one side I can hardly wait and I am really looking forward to it. On the other side, I will definitely miss all the people around me and especially the communication with them. Maybe not after 4 weeks, but surely after 3 or 6 months. I can’t talk to my neighbour continuously (laughing). So, there is definitely a melancholic feeling, I can’t ignore that.
Peter: During all the years at beyerdynamic you have experienced a lot. When you look back, what was the greatest project you worked on and what is your favourite beyerdynamic product?
Mr. Blum: The most exciting project is very easy to point out: it was the introduction of Headzone®. We produced everything ourselves, e.g. the basestation, the headphones, headtracker... So, that was the most exciting thing. Of course, the first projects after my training were also very exciting. The DT 100, was my first project, where I had to manufacture a DT 100 housing out of wood! I was employed in the Sample-Workshop, to manufacture wooden samples, but was also responsible for the correction of the plastic samples. The first models were shown at the Hannover exhibition in the spring of 1968. That was a pretty interesting project for me.
Peter: You have worked on many different workstations / workplaces during your time in the company. Can you tell us a bit more about your career at beyerdynamic and about the different positions you have managed? And which was you favourite?
Mr. Blum: Yeah, at first, like I already said, I was in the sample-workshop after my training in 1967. I really liked that job. I was working closely together with our developers and engineering department. I had the opportunity to bring in my own ideas. That was a fairly interesting job, which I did for about 20 years. In 1990 I then switched to the production department, the headphone production to be exact, where we also assembled OEM products for well-known brands. Shortly after, the Cable Production was added, although that doesn’t exist anymore nowadays. We used to assemble all cables, from the smallest wire to complete headset cords ourselves. The wires were cut and tin-coated during home-work. No cable was purchased externally - except for the raw material.
Over the years, the production, of course, changed a lot. The end of 1996 saw the dynamic microphone production being added to our department. In 2008 the microphone production was extended by the production of electret microphones. Due to these changes also my area of operations changed and expanded, just like the number of employees.
Peter: Ok Mr. Blum, thanks for the interesting answers to start with. Let’s have a closer look at the questions of our beyerdynamic users. First we will start with a question of Noel Pee. He asked “Long hours of music with headphone or earphone really cause damage to our eardrums? What if I listen music long hours with very soft volume? Would it still be harmful to my ears?
Mr. Blum: No, continuous listening at normal volume doesn’t damage your ears. You have to monitor the volume though. Listening to loud music for long periods of time damages the hearing and that’s why we developed the build-in limiter a short while ago (laughing).
Peter: Ok, next question from facebook user Andreas Theel: “Why did Beyerdynamic stop to develop electrostatic headphones? Obviously BD believes in the strength of the dynamic principle. Why is that so and what are the advantages over the electrostatic principle?”
Mr. Blum: We only manufactured one electrostatic headphone, the ET 1000. It was a great headphone, which was also well received within the market. Admittedly it was pretty expensive and therefore not sold a lot. So, on the one hand a drawback was its high price due to the fact that the assembly of electrostatic headphones is more complex than the assembly of dynamic headphones, and on the other hand a drawback was the fact that those headphones need an additional power-supply, which is not needed for the use of dynamic headphones. By the way, I assembled the first sample of the ET 1000. The injection parts were all made in-house, which is still the same nowadays – we produce many production parts ourselves. I can’t say anything about the reason why the production was stopped.
Peter: Nomen Estomen likes to know: “Is there any difference in quality of sound transmission on headphones during some time of their using?”
Mr. Blum: No, the sound doesn’t change. Only if the ear pads are worn out, they become flat and therefore also the sound changes, because the drivers are closer to your ears. The sound becomes dull. The drivers themselves don’t change, which can be measured. Normally, the drivers do not wear out.
Peter: Mr. Blum, Christian McIntire is a fan of the DT 880 and he wants to ask the following question: “Does design follow function, or is design entirely secondary and nondependent (outside of the need to fit over the ears and produce sound, obviously) upon the internal workings of your headphones? Love my DT-880s, not only for sound quality and design aesthetic, but also because they are the best-fitting and most comfortable headphones I have ever owned.”
Mr. Blum: Yes of course, design is in close relation to the function of the headphone. The space behind the driver must be aligned, the volume must be balanced. The housing is either open or closed, which is also important for the design. You can’t take any housing-design, put a driver inside of it and say: „So, that’s it...“. The first thing is the acoustics, but of course the optics are also very important. When you have a great device, but nobody likes the look of it, it’s not optimal either. But, the most important thing for us is the sound.
Peter: We have many fans of the DT 48 among our Facebook users and they have some questions about it. Here is one from user Eugen Beyer, the name already sounds as he is a big fan of beyerdynamic: “Dr Blum... Another big fan of the DT48 here. The only headphone ever made that will probably survive us all. Would you happen to know how the frequency response design goal of the DT48 was tuned: i.e to match a free field sound field HRTF or was it based on experiments and listening only... Oh, and by the way, what is your favorite Beyer headphone?” Our Head-fi-forum user Deep Funk also would like to know what your favourite headphone is and why it is you favourite one.
Mr. Blum: Dr. Blum, that would be nice (laughing). The title only would be useless, the cash behind it should also be right (laughs again).
So, the development of the DT 48 was back in 1936, which was before I came to beyerdynamic. The DT 48 was developed while beyerdynamic was still in Berlin. What was the goal? I guess to get a frequency response as linear as possible. Only small things changed, like the head bow and ear pads, but the actual construction with ring magnet and aluminium diaphragm never changed. Unfortunately, most likely due to the war, there is no documentation anymore. After the war Eugen Beyer came to Heilbronn, back in those days in a different building, a formal (former?) army-officer casino.
By the way, my favourite headphone is the DT 880 Pro. I bought mine in the beginning of the 90’s. I like the sound very much. On second spot is the DT 770 PRO for me. I like the low end of this headphone.
Peter: And one more question to the DT 48 from Dale Thorn: “Here's my sensitive question Mr. Blum: In extensive listening to the Sennheiser HD-800, the new Beyerdynamic DT-48E and the DT-1350, I find the DT-48E comparable in clarity and overall balance to the HD-800, whereas the DT-1350 sounds muted in the range from approximately 3 to 8 khz, resulting in an unsatisfactory sound for music listening. Since the DT-48E would seem to be a great bargain at the B&H price of $379 U.S., do you know of any plans to make something that sounds as good as the DT-48E in the $500 or under range, that is also comfortable and does not require a "perfect seal" to get the right bass response?”
Mr. Blum: That’s right, the highs and lows are slightly accentuated on the DT 1350, at least that’s how I hear it. The DT 48 E sound relatively balanced and the highs and lows are not as much as on the 770. Concerning the plans for new headphones, I can’t say anything. That is not my decision (laughing).
Peter: Again a question to the DT 48 from user Beyerdynamic DT 48, and we think he is really a big fan of the DT 48 because he owned a lot of DT 48 models: “Mr Blum… I have owned 14 DT48 models from the 50's to 08.. I notice, for the most part, they sound a bit different.. Were different minerals used in the early models that are no longer being used in the later edition DT48 models? Was there ever a 600ohm DT48“
Mr. Blum: The diaphragms are still being produced out of the same aluminium as back in 1936 and also the form of the diaphragm hasn’t changed. The used aluminium still has the same trade name, but of course there are tolerances. Also the suppliers changed a couple of times over the years, although the chemical composition always stayed the same. There might be a slight change in tolerance due to the change of suppliers, but I am not sure. The form and other inner parts haven’t changed. A 600 ohms version is not known to me.
Peter: And a final user question from the Head-fi Forum user Crayonhead: “Mr. Blum, in your 47 years in the audio industry, how has the overall "feel" of the audiophile world changed? Do you like this change?”
Mr. Blum: Indeed a lot has changed; the technical development over the years has been tremendous – not only in the audio business. The look of the microphones and headphones back in the days was partly very bad. In relation to nowadays it’s poles apart. It was a very rapid development up to digital signal transmission and digital microphones. I like the development, the quality has changed so much. Microphones used to have pretty much residual noise when you recorded to a reel-to-reel tape recorder. Nowadays there are digital recordings, that’s great! There has always been this enthusiasm for special devices and there have always been people who wanted the best and the newest devices. As soon something had a gold-plated plug, it was something special (laughing).
Peter: Many interesting questions, don’t you think? But to mention it also finally, the last position of your career was in the pro audio sector, from which also microphones are a part and we had no microphone question, yet. Therefore I would like to ask you a question and it’s a microphone question. What was the biggest challenge in the microphone production during your career? And what was the most difficult problem you ever had in the microphone production and how did you solve it with your team? How was it working 47 years at beyerdynamic in Heilbronn, Germany?
Mr. Blum: Biggest challenge? Nothing which belongs to the dynamic microphone production. Those mics are easy to assemble. Electret microphones are far more difficult to assemble. When I joined the electret microphone assembly, they were working on the MCE-72, which had a couple of challenges. There were problems with contact noise – it was really noisy! So, we had to exchange some parts and find solutions, which had cost time and nerves. Finally it did work well. Problems are part of the job though, that’s why we are here - everyday is a new challenge.
Concerning the overall feeling over the years: I always liked working at Beyerdynamic. I worked in the Sample-Workshop for 20 years, which I liked very much and that is surely one of the reasons why I liked working in the company so much. You had to manufacture a complete product from raw material.
Then I was asked if I would like to switch to our production department, which was of course a new challenge, which I’ve never regretted. I had had to communicate with more people than before – there were also more problems than before (laughing). I was very interested in the internal changes. I was responsible for punctuality and quality of the products. That was a real challenge.
Peter: What would you have done differently in the last 47 years at beyerdynamic, personally?
Mr. Blum: Difficult to say. Nothing comes to my mind. What I would like to have done a bit earlier, is changing the design and colours of the microphones and it’s great to see that we’ve done that now.
Peter: What products from beyerdynamic do you have in use at home?
Mr. Blum: As I said before, I use a DT 880 PRO, which I bought in the beginning of the 1990’s, although I changed the ear pads more than once in the meanwhile (laughing). A very good headphone! Concerning microphones, I like the TG-V96, that model simply looks good, even when I do not use microphones myself. I already liked its predecessor, the TG-X 930, since this model already used a different design as the other models.
Peter: To finish this interesting interview, one last question: what will you do when you retire?
Mr. Blum: (laughing) I abrogated a lot of work. I am for instance postponing some renovations in our house for a while now. I do a lot of work by myself, so I at least know who screwed up (laughing). I also like to do some gardening and of course sports: jogging and walking is what I am doing for years now. I will extend that with some bicycling. I will stay active. And when I don’t know what to do anymore – drinking coffee and reading the newspaper is not enough – I will be more active within the club I’ve been a member of for years. You only have to raise your hand slightly and you already have a function (laughing sincere). I also would be very interested in working with young people, they are always looking for somebody to do that and I am a member of the local soccer club for many years. If I would do that, I would have to communicate with a lot of people again, in case I am going miss that.
Peter: Thank you for your willingness to answer our questions! We wish you all the best for the time after your career at beyerdynamic. As well thanks to all users for the great questions! Don’t hesitate to ask further questions if you would like to know something in detail.