On 28/01/2014 10:24, Chris J Dixon wrote:
John Williamson wrote:

On 27/01/2014 16:41, Chris J Dixon wrote:
I boxed up an L-pad
http://cpc.farnell.com/_/lp-200-8/speaker-l-pad-stereo/dp/LS00544?Ntt=LS00544
and installed it a while ago, but it doesn't really seem to have
sufficient adjustment.

I find that odd, as if it's wired correctly, an L-pad should give an
adjustment range from 0- 100% of full power.

Well, AFAUK I have done it right, but I suppose that is a bit of
a circular argument. ;-)

There are only three terminals on a potentiometer.

The amplifier should go to the outer pair and see 8R load. The speaker
should go to the centre tap and one end (the low end). If you choose the
correct end then you will get a logarithmic adjustment and if you choose
the wrong end you will get a sort of all or nothing behaviour.

Rotation 0 1 2 3 4 5
r (correct) 0 0.5 1 2 4 8 (correct)
r'(wrong) 0 4 6 7 7.5 8

Swap the end you connect the speaker to and you might be surprised.

You still lose some bass damping this way but it may not bother you.

--
Regards,
Martin Brown