The shelf that plays music: a Visaton exciter

Guide no. 69

A Visaton EX 45 S glued under a panel and the DFR0720 Bluetooth board: a speaker you can't see.

By Ada Intelisano · informaticait.it technical team

Download the PDF (A4, 3 pages) Free to print and share, without changes — CC BY-ND 4.0

In short

The exciter vibrates the surface: the surface is the speaker.
EX 45 S, 8 Ω and 10 W, on channel L of the DFR0720.
Stiff, light, non-metallic panel.
Slightly off-centre, tried first with double-sided tape.

Time: one hourLevel: some solderingBefore: guide no. 66

An exciter is a speaker without a cone: a magnet and its coil that you glue behind a surface to make it vibrate. The shelf, panel or cabinet door becomes the speaker, and from outside you see nothing. We drive it with the Bluetooth board from guide no. 66.

1The parts

Visaton EX 45 S, 8 Ω: 10 W, 46 mm square plate, glued or screwed on;
DFRobot DFR0720 (Bluetooth and amplifier, takes speakers from 2 to 8 Ω) with the USB battery holder;
the panel to bring to life, double-sided tape for testing and glue for the final fixing.

New word: exciterIn a normal speaker the coil moves a paper cone. In an exciter it moves the surface it is glued to: the surface pushes the air. That is why Visaton gives no frequency response: it depends on the panel.

2Wiring

The exciter + is the wider tab (4.8 mm; the − is 2.8 mm). A single exciter goes on channel L; with two exciters you get stereo, L and R, as in guide no. 66. The same rules apply: power from the USB cable, never join the two −.

3Choose the surface

It must be stiff and light: thin wood, thin HDF or MDF, acrylic, glass, plasterboard, ceiling tiles.
Non-metallic: the magnet would be attracted and the suspension would be damaged.
The bigger it is, the more bass it reproduces; the heavier, the quieter the sound. For the EX 60 S Visaton tests HDF panels of 690 × 660 × 4 mm.

4Find the right spot, then glue

Clean the surface: it must be flat, with the whole plate resting on it.
Fix the exciter with ordinary double-sided tape, a little off-centre. Play a track you know and move the exciter until you like the bass and the voices.
Once you have the spot, glue it for good: two-part adhesive, silicone or a double-sided tape that lasts (Visaton also sells its own adhesive pad).

✓ What you should seeThe whole shelf plays, even though the exciter is hidden.

If it doesn't work

Buzzing and rattles: a cable is vibrating against the panel. Fix it with a cable tie.
Something resting on top “rustles”: it vibrates too. Move it.
Little bass: the panel is close to the wall, or too small.
It plays quietly: that's normal, an exciter is less efficient than a speaker. Turn the volume up on the phone.

5Challenge yourself

Try it yourself

Two exciters under the same shelf, left and right: invisible stereo.
Try a sheet of acrylic and a plasterboard panel: hear the difference.
For large panels there is the Visaton EX 60 S, 4 Ω and 25 W.

✓ What you learned

the exciter makes the surface it is glued to play;
the panel matters: stiff, light, non-metallic;
you find the right spot by ear, with tape first;
cables held still and nothing resting on top.

Sources: Visaton, EX 45 S – 8 Ohm (art. 4501), datasheet; Pad EX 45 S (art. 4555) · Visaton, Basic principles of exciter-technology · DFRobot, DFR0720, product page · informaticait guide no. 66