NT wrote:
On Jun 21, 11:24 am, Dave Osborne wrote:
The Medway Handyman wrote:
Looking to get some speakers for the decking, so we can have a
little music outside.

I've seen wireless ones which transmit from the hi-fi, but they need
plugging in to the mains, which rather defeats the object - no
power on the deck.

They don't have to look like rocks or anything.

SWMBO has some wireless headphone which plug into the 'phones'
socket on the hi-fi (Sony).

So, question is; Can I just use a speaker extension lead of say 10
metres which will plug into the 'phones' socket and connect the
other end to some outdoor speakers? Like these?

Not really. The phones socket usually has resistors connected to
limit the power delivered to the headphones.

If your hifi doesn't have terminals at the back for a second pair of
speakers, then you should consider getting a speaker switch box.

e.g.http://www.maplin.co.uk/Module.aspx?ModuleNo=97927

This box allows you to switch both pairs of speakers on at once. This
might cause a problem for your amp, but probably won't unless you
turn your hi-fi up to max.

Your existing speakers will most likely be eight ohms and your new
speakers should be likewise.

http://www.maplin.co.uk/Module.aspx?ModuleNo=221776 I could build a
box for them out of deck boards

These would be fine.

Would I lose anything over the cable length,

Not really anything to worry about as long as you use reasonably
thick cable. At least 0.75mm2 (6Amp) 2-core mains flex.

If you buy speaker flex, you can run it under the carpet. 42-strand
would be OK.

http://www.maplin.co.uk/Module.aspx?ModuleNo=115110

Part No N20AP

what ohms do I need

see above

& how would

I connect the cable to the speakers - bearing in mind I am to
electronics what Colonel Custer is to Indian fighting.

You might need to solder the cables to the speakers or you might
need to crimp on a Lucar spade or the speakers might have screw
terminals or clamp terminals


I think bell wire would be better. 0.5mm^2 bell wire has a Vdrop of
88mV/m/A. At 8w rms (8v 1A) thats 1% of the speaker voltage, or a 2%
power reduction at the speaker.

1.5mm^2 is rated to 21A with 70C insulation, so again bell wire would
be more than capable.

I would not use stranded wire (speaker wire) outdoors unless really
needed, as its vastly more vulnerable to corrosion.

Sorry, should have said, they will live indoors & be taken outside only as &
when needed.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk