SB 18 Matthias / Upper Palatinate
SB18 - or the difference between "hearing music" and "listening to music"
For years listening to music was limited to my cars, where a good friend - thanks to owning a carhifi shop - regularly installed the appropriate soundsystem. It never needed to be high-priced. It just had to create slightly more "pressure" and play with more precision than the usual substandard equipment available off the peg. Through him the idea gradually formed to sometimes upgrade the system in the flat as well. This means to finally evaluate the loudspeakers integrated with the mobile phone as well as the "sound system" plugged in the computer to render music as unacceptable and to make space for some sound.
It started three months ago with the construction of 2 mono class A power amplifiers. However, their progress was / is still quite slow moving due to lack of appropriate tools for handling aluminium. As you still cannot enjoy music with amplifiers alone, of course speakers to match them had to enter the house. I realised that DIY was the name of the game.
The beautiful internet and various types of research made me stumble upon Loudspeakerbuilding.com - and the virus immediately infected me. I do not know any site that advises in a more informative, friendly and clear way on the construction of speakers. And the research I did was pretty intensive. All the better that they made it possible to order with just a few clicks, and thus the right kit will be delivered to your home in a fast and hassle-free way.
And now I already had the first “problem”: which kit to take after being abstinent for so many years inside the home? I directly had an answer: It had to be the Needle! Cheap, nice to look at and, according to some reports by music lovers who had built the kit, able to even create a relatively strong sound. Unfortunately, all the pictures here have been taken by the mobile phone. Please excuse the slightly inferior quality.
I will not write more about them – I only mention the fact that I have never listened to a tiny wideband speaker with such a linear, clean and strong sound
Now just 3 months after getting infected I yielded to the appeal for more bass foundation and high frequency resolution and started looking again. For days I went through construction report after construction report on this site until I could draw up a shortlist. They responded to my questions really patiently and very quickly so that I was fast able to make a decision. The SB36 seemed to be too powerful for my badly soundproofed flat and in my eyes other construction proposals in the blues class were slightly exaggerated for a reasonable advancement from the needle. (Yes, it means that we have not yet arrived at the finished article yet…). It had to be the SB18!
To cut a long story short: on 2nd I ordered the kit and on 4th I could sit at home in the evening and allow the blues to reach my ears. Really incredible.
I decided on a 20 mm multiplex connector, which a friendly DIY store employee had cut to size for me within a few minutes. I used the wait to look for a possibility to stain it in a matching colour. My furnishing dictated that it had to be something in walnut. After very good results when veneering the Needle that was made of the optically rather not so appealing material MDF I did not simply want to “paste over” the beautiful (and more expensive) multiplex. So I used dark water-based walnut interior protective wood stain in order to give the good piece a hue similar to my furniture.
To glue the seven boards together to achieve a fit was not really a challenge (Udo, I remember your true words that you do not have to spend any, or only a few, words on it), so the corresponding images at this point have been omitted. After glueing the finished housing a rotary sander equipped with sandpaper 120 was used to smooth out the last few bumps and to create a solid base for the varnishing. The milling of the recesses required the skills of my good carhifi friend. He took up the challenge and conjured up an absolutely convincing end result using a router and a homebuilt circular miller.
The picture on the left shows the housing after varnish had already been applied, the picture on the right the raw state. The varnish was slightly more complex to handle than planned. After all brushes and other painting utensils were found to be unsuitable as every single brush stroke could be seen, ga combination of a foam roll and 1-2 minutes did the trick. Allow it to soak in and then use an old T-shirt to pull off the excess varnish in the grain direction. After the first two coats an intermediate grind with grain 400 was done to get a nice smooth surface. The subsequent finish then could be done without T-Shirt. I could not determine why, but this did not diminish the end result, a really beautiful surface.
The construction of the crossover:
The package of Intertechnik contained a perfect circuit diagram, so the construction of the crossover was no obstacle. I chose a space-saving option on the rear of the connection terminal for the bass/midrange and on a small multiplex board for the tweeter. Now, they only had to be put into their place inside the box.
I had to finally only insert two Sonofil mats, electrically connect the very high quality speakers and finally screw them in.
Well, sound descriptions are something individual, very difficult to describe.
After connecting it to a DTA-1 (I had just bought it for a transitional period) supplied with the appropriate signals by a modified Marantz CD 40, no real listening pleasure was possible. I thought of either wiring errors or incorrect polarity at the speakers or the crossover. The music "stuck" on the boxes, three dimensionality was not really present. Switching to other signal sources did hardly change this impression. It was strange, in particular as the DTA-1 was absolutely convincing on the needles. Well, surely the SB18 would require a little bit more or was I too spoiled? :)
Once again my friend had to help out. I dragged the speakers to him in the store and we provided them with a high-priced car-HiFi-amplifier. And behold the blues was there. One CD after the other was put into the hastily connected car radio to make what I could not quite believe more tangible for me: Katie Melua -just to give an example- was clearly standing in front of her musicians and right in the middle. The drummer played accurately and staggered behind her. But this was impossible, it could never came out of these speakers – could it? If one alternately looked directly at the two tweeters there was no sound because it was clearly spatially distributed on a large, gorgeously tiered, and deep, wide stage. The speakers were simply not there. They played everything that was put into them in a very linear manner. Deep sounds as well as precise heights and fundamentals were played in the same scarily perfect manner. Nils Lofgren, too, seemed to give a concert in the car shop around the corner. I was just thrilled - and did not want to stop to listen to the blues - which without a doubt it really was.
Well, to come straight to the point: There are difference between hearing music (with the PC desktop speakers or plastic full set speakers) and listening to music (Needle/SB18) that all those years I never even dared to believe existed. Stereo was never three dimensional. I was wrong - completely wrong..
Many thanks to the team of Loudspeakerbuilding.com and Udo for answering my questions at lightning speed, Intertechnik for the fast dispatch and the, as always, hassle-free shopping and especially my good friend Alex, whose troubles and toosl, as well as premises I was allowed to use once again.
The only thing left to say for me is: what's next? :)
Matthias from Upper Palatinate
If you want to build this assembly kit yourself too, you can order it from Intertechnik.