MONITOR 890 MK II / TL

Exploded drawing

Assembly

This octagonal cabinet looks more complicated than it really is. All the chamfers are cut at 22.5° except two (at 45°). When you set up the saw, it is best to cut fractionally over 22.5° to ensure that, on the outside, all the chamfers are really airtight. First cut the required cut-outs in the boards, which have already been cut to size. The two circular ones for the bass loudspeakers, the square opening for the tunnel and the two for the level controller.
Next, build the main body without the base and top. You will need plenty of sticky tape to hold the joints together when gluing the side panels. The parts for the tunnel, the four stiffeners on the side panels and the vertical stiffeners (50 mm wide) on the front baffle then need to be shaped to an exact fit. The base then has to be shaped to fit exactly in the completed main body, since it is hardly possible to build the body with millimetre accuracy. Next, glue the vertical stiffeners to the base and the stiffener between the baffle and the rear panel. The top with its cut-out for the terminals for the high- to mid-range is then shaped to fit and glued in position. The two crossover circuit boards are attached to the rear panel opposite the lower bass speaker drivers. The wiring to the horns need not be heavier than 1.5 mm2. From the terminals to the circuit boards and to the woofers, use wires with a cross-section of 2.5 mm2.
The twin terminal unit for connecting the mid- to high-range horns is fitted in the square cut-out in the top. The two gold-coloured jumpers have to be removed to do this.

Cabinet parts list for 1 box

Parts
Size (mm)
Quantity
Material: 19 mm chipboard or MDF
Top and bottom panel
688 x 508
2
Front panel
782 x 380
1
Rear panel
782 x 280
1
Rear side panel
782 x 283
2
Middle side panel
782 x 150
2
Front side panel
782 x 212
2
Sides bass-reflex channel
91 x 79
2
Top bass-reflex channel
91 x 342
1
Brace
80 x 294
4
Brace
105 x 444
1
Brace
100 x 782
Strip
50 x 782
2
Base
630 x 450
1

Crossover

Sketch (top plate / base)

Position of horns

Press

Extract from Klang & Ton

Provided you have enough space and a very tolerant partner, we can warmly recommend this major contribution to the art of building speakers to every aficionado of lively guitar-based rock through to subtle and sophisticated rhythm & blues. Although the Monitor set-up is perfectly capable of reproducing classical musical and can cope with lower volume ranges, its strength is definitely in the excellent representation of live-sounding events, full of temperament and dynamism.

Auszug aus Selbst ist der Mann 10/2003

Den benötigten Platz und einen toleranten Lebenspartner vorausgesetzt, können wir dieses Kleinod großer Boxenbaukunst jedem Liebhaber fetzigen Gitarrenrocks bis hin zu einfühlsamen Rythm & Blues wärmstens ans Herz legen. Obwohl der Monitor auch bei klassischer Musik und kleinem Pegel nicht versagte, liegt seine große Stärke eindeutig in der exzellenten Darstellung live-haftiger Ereignisse, temperamentvoll, dynamisch, gut.