50 years of progress
A couple of weeks ago, I was checking out a musician 2nd hand site. And I noticed something extremely unusual for a site like that, a vintage Bruel and Kjaer type 2209 sound level analyzer. There is something very appealing with the design of vintage measurement equipment. Everything from the big knobs and clunky switches to the choice of text font just oozes with hand made quality. I thought that this would make an excellent addition to our Umeå office. As a conversation starter, it doesn’t get much better than a professional sound level meter from five decades ago.
I had some issues getting hold of the 2209 though, as the ad clearly stated, “will not ship, pickup only”. But I thought I would give it a shot anyway, because the market of potential buyers of ancient measurement equipment is probably quite a small niche. I even offered the seller a price premium on his asking price, if he could only ship it to me but it was to no avail. But then I had an idea and called Musikbörsen in Norrköping and asked them if they could help me out as a favor from one musician to another, and ship the unit for me. “Of course we will help you mate” was their instant reply. I know that music stores have a ton of packaging material from all their instruments and they are used to shipping instruments around. And the 2209 comes with a solid hard case so it would be super easy to ship. Now everything was sorted, I just payed the seller and he dropped the unit off at Musikbörsen and less than 24h later it was on a truck heading for Umeå. Thank you Musikbörsen, that was some quality service right there.
A couple of days later the delivery truck arrived with my package. Honestly, I felt like a kid on the night before Christmas eve, eager to open my Christmas present. Until now, I hadn’t cared much whether the unit worked or not as I was primarily going to put it up for show. But during the week I started to wonder what it must have been like for yesterday’s engineers who used devices like the 2209 in their daily business. I realized that if the device would be indeed operational, it would open up the possibility to some very interesting possibilities. Like conducting a real field measurement with both my state-of-the-art Norsonic 150 and the ancient 2209 and compare the experience. A fair comparison would be a classic American muscle car like the Stingray vs the latest and greatest Tesla model S. Both are two powerful cars, but the Stingray can create emotions that the Tesla simply cannot. Even though I know which one I’d rather use as a daily driver. To do a field measurement with a 2209 would be the acousticians equivalent to taking the Stingray for a cruise. I am smiling when writing this, realizing how extremely nerdy this is.
Old acousticians that I have worked together with have often said things in the line of “if you only knew how complicated a measurement was back in the 1970s/1980s”. A modern analyzer can do one single measurement and grab almost all information you need simultaneously. With the retro device the process is very different. You can only measure one parameter at a time, with a dynamic range of only 10 dB (!). This means that an octave band measurement must be repeated once for each octave band – in every measurement position. A sound insulation measurement in two rooms – even in 1/1 octave bands – would require seven measurements in each microphone position, in both rooms. We are quickly closing in on 100 measurements here, that I will do in just two (2) with the modern Norsonic! And the measurements should preferably be done in 1/3 octave bands, which would triple the number of measurements with the 2209. However, I only have a 1/1 octave band filter so I can’t do the full method. The bottom line is that you really need to know your stuff when using a 2209. You can’t afford to make mistakes with that huge number of measurements. And you really need to work the device. There will be a lot of switching and turning dials and buttons during the measurements.
Anyway, when I opened the hardcase and saw the 2209 for the first time my jaw dropped. I could hardly believe the shear size of it. It was HUGE! And it was just as heavy. I even struggled to just pick it up. The filter module is a separate box that is attached to the sound level meter “mothership”. A common comment regarding the Norsonic 150 is that it is a big device that can be problematic to use with only one hand, and that is a correct observation. However, compared to the 2209 the Norsonic 150 is tiny and looks like a little toy. I will probably never refer to it as large ever again, with my new reference point from 50 years ago. I opened the battery lid and found that the batteries had expired 22 years ago. I had to get to the store as soon as possible and grab a fresh set of batteries to find out if it still worked. Apparently, my device had spent its days in a music studio, and I would say it is mint condition. Compared to the condition of the ones I have seen on Ebay I have made a jackpot. Even if these things are built like a tank and can take a beating, it was extraordinary to find one in such magnificent condition. And of course, when I popped a fresh set of batteries in and flicked the switch it awoke instantly. The reference sound source showed it was only 0,5 dB off the mark. I will calibrate it next time I use it.
I haven’t felt so happy in a long time as when I saw the VU meter starting to move according to my voice. This device will bring me so much joy and when I conduct my first measurement with it, I will gain a special kind of understanding that cannot be acquired any other way. You can’t experience the screaming roar of the Stingrays V8 in a Model S. Even though the Model S if a lot faster, the experience in the Stingray is much more visceral and you feel more alive. Probably because you are only one mistake away from game over when you launch a classic muscle car. I cannot describe in words how much I look forward to “launching my new Stingray” after driving a top spec model S my whole career. I think it could be a quite interesting video to demonstrate and conduct a field measurement with both the 2209 and the Norsonic 150 and present my findings and describe the experience.
It is truly unbelievably how much progress we have made in the past 50 years.