You can’t plan for the success or failure of a loudspeaker box – something that upsets more than a few retailers who want to plan their purchases in advance based on what is popular with their customers. Always having enough products in stock guarantees satisfied customers who can listen to music just a few days after ordering their new boxes. At this juncture, the Development Department would like to warmly thank our readers; their enthusiasm for the assembly kits presented here shows that we haven’t been tinkering at cross-purposes recently. In large part, our information about what people might like to see comes from the close customer contact with the makers of this magazine. In daily conversations, it is easy to discover what is still missing from our product range. Sure, a glance at our assembly-kit range would have told us that the metal-head faction is strongly underrepresented, while other manufacturers serve this group almost without exception all the way up to the high-price offerings. But it was only the immense success of the FirstTime 8 that showed us the unmet need in this area. That’s why we developed the Dayton 17 AL, a handy free-standing box in the proven 17/ 25 format.
Dayton DA 175-8
Measurements as Zip-file
With the Dayton DA 175-8, we now have a chassis in the product catalogue that certainly makes a good visual impression with its pure aluminum membrane. The black steel basket is sturdy, and it has room for five screws to attach it firmly to the box. The surround material is made of rubber, which contrasts nicely with the large dust cap made of fiber-reinforced paperboard and the shiny silver membrane. The voice coil diameter is 35 mm, and the magnet has a generous hole drilled in it. The chassis does not have any other ventilation openings. Since the DA 175-8 has not yet been reviewed in an individual test, we do have to subject would-be builders to the technical data this time – we owe it to the measurement collectors.
|Membrane:||Aluminium||Air gap height:||6 mm|
|Surround material:||rubber||Winding height.||13 mm|
|Basket:||stamped steel||Magnet diameter:||100 mm|
|Polke-piece hole:||yes||Mounting holes:||5|
|Centering:||raised flat spider||Outside diameter:||176 mm|
|Shielded:||no||Installation openening:||144 mm|
|Voice coil:||35||Milling depth:||3 mm|
|Voice coil former:||Aluminium||Installation depth:||82 mm|
For the tweeter we chose the DC 28 F-8, which made its debut in the March issue’s chassis test.
We calculated the necessary volume at just under 32 liters. For a low-reaching bass, according to our calculations, the reflex balancing should take place at 32 Hz, which we thought was too low for the intended use. A shorter reflex tube (HP 70, full length) created a slight exaggeration at 60 Hz, which completely matched our intent of building a box for people who like to hear a little more bass. The experienced reader will see from the construction drawing that this project has been in the supply closet for a while, since the drawing was created before SketchUp.
Milling depth bass / Milling depth tweeter: 3mm
Wood list in 19 mm MDF per box:
Sides:2x 100 x 24,2cm
Lid and floor: 2x 18,0 x 24,2cm
Front and rear wall: 2x 18,0 x 26,2cm
Reinforcement boards: 3x 18,0 x 10,0cm
Each box is filled with three bags of Sonofil, which is distributed throughout the entire interior. Rubber feet hold the boxes up off the floor, which will make the rest of the family happy when the offspring decide to listen to a little hip-hop in the next room. But the benefit of interrupting the bass transmission through the floor works both ways, for instance when Dad is seized by the urge to hear his old rock albums. The construction process is documented with the obligatory photos.
Smooth assembly depends largely on the mood of the person cutting your wood at the hardware store, since that will determine the quality of the cuts. At my local Praktiker store, I met a saw operator who knew exactly how to cut boards to size. First he calculated how many sections he needed in the 24.2 and 18.0 cm widths; then he cut off the appropriate number of strips from his board without changing the settings, before cutting the second dimension. It’s rare to find a specialist like that at the saw; usually the measuring slide is moved at least twice for every board.
Now it was up to me to continue his good work. Joint glue is applied to the cut edge; the board is set up in its later position and is wiggled back and forth a little to create a film,
then we set the first board on it. The second board creates the right angle and the third one creates the shape,
which is completed by the floor piece. For the reinforcements, we draw on markings with a pencil,
so that they end up in the right spots. Before gluing the last side, we draw an “O” for oben (top) on the front; an “X” would work too, of coursen.
After about an hour of drying time, we were able to put the boxes in the cellar, where we did the dustier part of the work. Thanks to the good pre-cutting, there were hardly any edges to sand off. But since all traces of glue need to be removed completely by the sander, don’t get too excited about the small amount of work just yet. It’s helpful to have a band sander or an orbital sander for this step. A sanding block, on the other hand, is good for bodybuilding.
We will devote a separate chapter to the routing process soon. We are always answering questions submitted by email that could not be sufficiently explained during the assembly-kit presentation. So for now, just the short version: use the router template to cut the outer ring for the chassis cutout first, then the hole. Be careful at the point where the router loses its guide, at the latest when the cutout is finished. It’s also fine to cut the inner hole with a jigsaw – it doesn’t look as nice, but it has fewer tonal disadvantages than measurement-related ones. We need one more hole for the connection lines to the tweeter, which can be cut quickly using a rasp or jigsaw..
The cross over network
Looking at the aluminum of my DA 175-8, with its volume dropping below the angle even at 1.5 kHz and its subsequent resonances at 8 kHz, I never thought I would be reporting on a completely simple second-order crossover here. But even the first measurements showed me not to be so hasty about throwing around my own prejudices. Despite the separation frequency of 3 kHz, which is relatively high by today’s standards, the peaks completely vanish after filtering. Even the tweeter was satisfied with two components and a voltage divider, and by adding the branches I ended up with a very balanced curve in the wide overlap between 1 and 4 kHz.
Now all I had to do was distribute the parts nicely on a circuit board and weld them on, again using the circuitry plan without component values. As you know, the one with the values only comes with the complete assembly kit.
The crossover was assembled on a preprinted LP-S1 2W circuit board. The connection to the chassis and the terminal comes from the color-coded cable set parts. Both are optional, so you can also glue the parts to a board and connect them by the legs (of the components, naturally, connecting them to your own would be a bad idea).
By now I’m well qualified to state that buying my Yamaha AV receiver was worthwhile, even though I’ve never watched a movie on it. Recently, we have been making more affordable assembly kits, which don’t necessarily need to be heard on the highest-quality equipment. It wasn’t a pure coincidence – the kits filled in gaps that other sets didn’t necessarily provide. If we take a look at the apparently very similar FT 8, FT 10, Elip 2 and Quickly 36 models, each box fulfilled a different task in the low-price sector. FT 8 is the perfect home theater when supplemented by the FT 8 Top, while Elip 2 has an advantage on the musical level – we even had to give it an impedance correction for tubes, which wasn’t for nothing. FT 10 charms you with its unassuming nature, a real wolf in sheep’s clothing that doesn’t conflict with the Female Factor, and Quickly 36 is an all-around talent that makes great music even with compact systems and that can be supplemented by the Quickly HK, 14 or 18 for a home theater. All that’s missing is a place for the Dayton 17 AL. On a purely visual level, it’s wider than the FT 10, but much shallower, making it the smallest of the boxes named here. Many people consider its silver-colored membrane attractive, which is confirmed by the sales figures for the FT 8. It is delicate compared to the FT8, Elip 2 and Quickly 36 the 17 AL, which is also a good argument for installing it in the living room.
Still, since boxes can’t be judged merely on outward appearance, I naturally also did my usual listening test with the Daytons. The reference to the amplifier earlier was a hint. Even in the radio playback, I was surprised by the newscaster and the reproduction of his “S” sounds, which was unusual for a metal chassis. There was no sharpness, which to be honest I had expected to hear; even at a low volume, his voice didn’t turn into an unclear hiss. So I dared to turn on the CD player and have the laser read a couple of zeros and ones. My Bravo hits came first, because I thought that would be the hardest test. Very compressed music, where everything is the same volume, quickly becomes torturous; but I still listened to Madonna’s song all the way to the end and even understood every word she sang. The bass emphasized her performance in a powerful and amazingly deep way without ever devolving into a droning sound. Moving in a completely different musical direction, Johnny Lee Hooker’s “The Healer” offered slightly less underlying warmth than with the Elip 2, but in exchange, Carlos Santana’s guitar was able to play slightly more in the front. I was very taken with the relaxed, nicely dissolving play of the low-cost tweeter, which offered more fine resolution – without any hardness – than I had expected from it. There was still time for a little good old rock music: “Smoke on the Water.” A cocky electrical guitar, clean bass scales and a taut drumhead on the snare, good room reproduction and offset in depth – what more do you want? Volume? You can have that too!
We haven’t talked yet about the money that changes hands when the loudspeaker is purchased. If you count up all the individual component prices, it comes out to just under 100 euros per box. To facilitate entry into the do-it-yourself world, Intertechnik is offering this more than reasonable set for just 90 euros each. That will make more than just your ears happy.
Dayton 17 AL
|Chassis||Dayton DA 175-8||Wood list in 19 mm MDF|
|Dayton ND 28 F-8||per box (dimension in cm):|
|Sales||Intertechnik||Sides: 100,0 x 24,2 (2x)|
|Construction||Udo Wohlgemuth||Lid/floor: 18,0 x 24,2 (2x)|
|Front/ Rear wall: 18,0 x 96,2 (2x)|
|Principle||Bass-reflex||Reinforcement boards: 18,0 x 10,0 (3x)|
|Insulation:||3 bags Sonofil|
|Reflex port:||HP 70/BR unshortened|
|Cost assembly kit|
|without wood approx.:||60 USD||Wood cut: approx. 10 USD|
The Dayton 17 AL assembly kit can be ordered from Intertechnik