You are here

Which audio cable?

Customising, building or repairing your own gear? Need help with acoustic treatment or soundproofing? Ask away…

Which audio cable?

Postby alicegoody » Sat Jan 25, 2020 5:46 pm

Hi sorry I'm a complete amateur with these things! I've recently taken over a room which has speakers in the roof. However, I do not currently have any cable to go into a socket in the wall to connect to something like my laptop. I'm assuming that I have to connect a cable into the red and black sockets and that the cable has to have a headphone jack at the other end to connect to my laptop... but I've no idea which cable I need to buy for this?

I'd really appreciate any help with this - thank you so much in advance :)
Ally

IMG_8728.JPG

IMG_8601.JPG
alicegoody
Posts: 1
Joined: Sat Jan 25, 2020 4:53 pm

Re: Which audio cable?

Postby ef37a » Sat Jan 25, 2020 6:49 pm

Those red and black sockets are almost certainly 4mm connectors (aka "banana" sockets) and are feeding two 'passive' loudspeakers meaning you will need a power amplifier to drive them.

You can make very sure with Digital Multi-Meter, £10 or less at Halfords and probably Lidl.
Select the 'Ohms' range on the meter and stick the red and black probes in the sockets. Each pair should read very low resistance os about 6 to 10 Ohms depending on the speakers. They might read even lower, sub 5 Ohms in which case they will probably not be of 'hi fi' quality.

If you can prove they are functioning speakers your saga has just begun! You now need a stereo amplifier and a means to connected to the speakers and the amp to the laptop.

That collection of connectors looks like a pretty professional AV setup. Any chance you can find out more?

Dave.
ef37a
Jedi Poster
Posts: 11167
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

Re: Which audio cable?

Postby Wonks » Sat Jan 25, 2020 9:06 pm

Dave, the speakers may be of the 100v line type. No idea what the ohm reading(s) are likely to be then, but if that is the case, a standard hi-fi amp on its own won't work.

If the speakers are mounted on ceiling tiles, then taking one down and taking some photos would help to confirm either way.
User avatar
Wonks
Jedi Poster
Posts: 10552
Joined: Thu May 29, 2003 12:00 am
Location: Reading, UK
Correcting mistakes on the internet since 1853

Re: Which audio cable?

Postby ef37a » Sun Jan 26, 2020 12:34 am

Wonks wrote:Dave, the speakers may be of the 100v line type. No idea what the ohm reading(s) are likely to be then, but if that is the case, a standard hi-fi amp on its own won't work.

If the speakers are mounted on ceiling tiles, then taking one down and taking some photos would help to confirm either way.

Yes, that had occurred to me too Wonks but I did not want to throw too much at the OP at this stage!

If they are 100V live traffs of about 20W rating I would expect a resistance of 80-100 Ohms but I can check an old traff in the morning.

In any event, connecting a decent amplifier to them will do not harm, he will just get a very weak signal. IMHO he needs to get a meter, give us the numbers then we can all move on.

Dave.
ef37a
Jedi Poster
Posts: 11167
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

Re: Which audio cable?

Postby Martin Walker » Sun Jan 26, 2020 12:40 am

ef37a wrote:In any event, connecting a decent amplifier to them will do not harm, he will just get a very weak signal. IMHO he needs to get a meter, give us the numbers then we can all move on.

All useful information Dave, but put your specs on ;)

Welcome to the SOS Forums alicegoody! 8-)


Martin
User avatar
Martin Walker
Moderator
Posts: 14975
Joined: Wed Jan 13, 2010 9:44 am
Location: Cornwall, UK

Re: Which audio cable?

Postby ef37a » Sun Jan 26, 2020 1:02 am

Martin Walker wrote:
ef37a wrote:In any event, connecting a decent amplifier to them will do not harm, he will just get a very weak signal. IMHO he needs to get a meter, give us the numbers then we can all move on.

All useful information Dave, but put your specs on ;)

Welcome to the SOS Forums alicegoody! 8-)


Martin

Could be a bloke? Alice Cooper is!

Dave.
ef37a
Jedi Poster
Posts: 11167
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

Re: Which audio cable?

Postby Sam Spoons » Sun Jan 26, 2020 1:12 am

True but his real name's Vincent.......
User avatar
Sam Spoons
Jedi Poster
Posts: 11142
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........