My pair of 938s came with "bars" with the screw spikes and black plastic covers which I happen to find ugly and inconveniently wide. I called Albert who referred me to the CA office who were kind enough to send me a set of the brass spikes - the kind you see in the pic.
These made a definite positive difference in tightening the bass focus, but - they are not full carpet-piercing spikes. They terminate in a screw hole to which you screw a flat disc if you're putting them on hardwood (I'm not).
Is anybody using any type of carpet-piercing spike they could recommend?
Anybody using any sort of granite slabs or similar under the speaker that's been found to pay dividends?
Paul
