MartinLogan Grotto [15/24] Solid footing

After living and experimenting with your Grotto, you may

want to use ETC

™ (Energy Transfer Coupler) Spikes (see

figure 16), available from the Xtatic shop at www.martinlo-

gan.com. With the use of these spikes, the Grotto will

become more firmly planted on the floor and, conse-

quently, bass will tighten. It is best not to implement the

spikes, however, until you are secure in the positioning, as

the spikes can damage the floor if the subwoofer is

moved. MartinLogan ETC spikes will fit any common

/4-

inch thread insert that may be found on your other audio

equipment (racks, speakers, etc).

Spike Installation Instructions:

1 Carefully remove the grill cloths from your Grotto.

2 Carefully lay the Grotto on its side to gain access to the

bottom.

3 Remove existing feet or spikes. Thread new spikes into

holes and screw them in all of the way.

4 Tighten jam nut snugly by hand. Do not over tighten

the nut.

5 Right the subwoofer.

Caution: Make sure your hands and any cabling are

clear of the spikes. Do not slide the subwoofer as spikes

are sharp and can damage your floor or carpet.

6 Adjust to level by rotating spikes. Tighten the jam nut

securely when satisfied that the subwoofer is level.

Caution: Walking the Grotto may result in a broken spike.

Room Acoustics 15

Solid Footing

Figure 16. The ETC Spike.