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UHF Speakers

Posted: Sun Jan 30, 2005 3:53 pm
by lowndsie
what the best way to run two speakers off a uhf???

I'm going to run the two front stereo speakers from the uhf because i have installed bigger speakers into the doors.

There is a small plug slot at the back of the uhf which fits plugs from a set of earphones from a walkman. Is there an adapter that divides this one hole into two so i can run two cables from external speakers in to the existing stero speakers?

Sorry if this doesn't make any sense, let me know and i'll try to clarify.

Posted: Sun Jan 30, 2005 5:21 pm
by mickyd555
Tandy or Dick smith electronics is the place to go, i think yuo would probably have to get a stero jack to RCA i think........something like that. and you may need to put RCA plugs onto the speaker wires too, thats gonna be a bit bulky, it might not fit behing the UHF, and if it does, id tape it all up so it doesnt come apart. :D good luck

Posted: Sun Jan 30, 2005 7:38 pm
by Tas_Dean
You would need to buy a MONO(yes, your stereo 3.5mm headphone jack will go in, but you would find that there is only one of the headphone speakers working) 3.5mm Jack, as the output of the UHF is only a mono plug. All you would have to do is solder both speaker wires into the mono jack, quite easy to do. If the speaker wires are too hard to get to where your UHF is mounted, just run new wire to the speakers. You do not need to stuff around with RCA's or anything of the type. What you may find, however, is that the output of the UHF may not be powerful enough to drive stereo speakers to any decent volume. If the speakers are the standard factory speakers, they may only be about 8-10Watts, and the UHF may drive them okay. A typical UHF has about 4-5watts of audio output.

if, however, I have misread what you are trying to do, and you are trying to use the SAME speakers that your stereo is using, then it is a totally different method to input your UHF to the speakers, and what I have said is useless to you!

If you buy good quality (eg GME) Extension speaker they are very loud, and some are quite compact. They are loud due to the speaker being matched to the output of the UHF.

Cheers, Dean

Posted: Sun Jan 30, 2005 11:21 pm
by gqswb
What he sad. ^

Posted: Sun Jan 30, 2005 11:30 pm
by Woop
You'll need to find a 3.5mm 'Y' split jack. This will parallel the output of the existing jack. If you cant find one, you will have to make up a Y Cord--1 3.5mm mono plug and 2 3.5mm mono sockets

Nick

Posted: Sun Jan 30, 2005 11:49 pm
by Tas_Dean
Woop wrote:You'll need to find a 3.5mm 'Y' split jack. This will parallel the output of the existing jack. If you cant find one, you will have to make up a Y Cord--1 3.5mm mono plug and 2 3.5mm mono sockets

Nick


Why? Why not just solder the two cables into the one 3.5mm mono jack?
Or else solder the second cable into the one that is soldered into the jack? We're not talking about high quality stereo gear! and if its all soldered, there is only one jack to vibrate loose and not three!

Cheers, Dean

Posted: Mon Jan 31, 2005 7:12 am
by Tiny
Just buy an external speaker....I have a cheap tricky dicky's one and it is more than loud enough for me with the stereo turned up. you can mount under the dach if you want to :D

Posted: Wed Feb 02, 2005 1:20 am
by Woop
Yes that would work fine as well--wasn't sure if he had access to a soldering iron though

Nick

Why? Why not just solder the two cables into the one 3.5mm mono jack?
Or else solder the second cable into the one that is soldered into the jack? We're not talking about high quality stereo gear! and if its all soldered, there is only one jack to vibrate loose and not three!

Cheers, Dean[/quote]

Posted: Wed Feb 02, 2005 7:17 am
by Tiny
Woop wrote:Why? Why not just solder the two cables into the one 3.5mm mono jack?
Or else solder the second cable into the one that is soldered into the jack? We're not talking about high quality stereo gear! and if its all soldered, there is only one jack to vibrate loose and not three!

Cheers, Dean
[/quote]

If you do this you need to put some resistors on each positive line to prevent power "blowback" into the other units ie stereo when the UHF is working and vice versa.

If you don't do this you will end up frying the UHF and posably the stereo.

Why put the UHF int the speakers as this will not work real well with the stereo going, as you hasve a very low output in copmarison.

Just get a cheap external, it the cheapest and easiest way to get out of trouble.

Tiny

Posted: Wed Feb 02, 2005 8:30 am
by stu
computer shops sell pc speakers really cheap that are about 5 watt output. ive been thinking about doing this too with my uniden.

Posted: Wed Feb 02, 2005 10:47 am
by Tas_Dean
[quote="#Tiny] If you do this you need to put some resistors on each positive line to prevent power "blowback" into the other units ie stereo when the UHF is working and vice versa.

If you don't do this you will end up frying the UHF and posably the stereo.


Tiny[/quote]

He said he was using the now UNUSED stereo speakers as he'd put new stereo speakers in the door !!!!

Cheers, Dean[/quote]

Posted: Wed Feb 02, 2005 11:15 am
by Tiny
Tas_Dean wrote:[quote="#Tiny] If you do this you need to put some resistors on each positive line to prevent power "blowback" into the other units ie stereo when the UHF is working and vice versa.

If you don't do this you will end up frying the UHF and posably the stereo.


Tiny


He said he was using the now UNUSED stereo speakers as he'd put new stereo speakers in the door !!!!

Cheers, Dean[/quote][/quote]

Ooops, me thinks I should read better :oops:

Posted: Wed Feb 02, 2005 10:19 pm
by Tas_Dean
Hey Tiny, Don't feel too bad about it. I had a nice big long reply drawn up before I reread the question and figured out what Lowndsie was really saying!!

Cheers, Dean

Posted: Thu Feb 03, 2005 8:58 pm
by -Scott-
(Just because I'm bored - I know I'm nit-picking.)

Once you put two speakers in parallel you effectively halve the impedance the radio is driving into. If the now-halved impedance (probably 5 or 10 ohms) is significantly less than the impedance the radio is designed to drive (unlikely - probably designed for 8 ohms) then you may have trouble getting much a lot of volume out of your speakers.

If you've got a nice quiet vehicle this is unlikely to be an issue. If you've got a noisy old soft top running swampers, you may have a problem hearing your UHF at highway speeds. :D

Cheers,

Scott

PS The preceding is based on a lot of "if" statements - you'll be fine! :D

Posted: Sat Feb 05, 2005 4:09 pm
by bilby
$ 20 smackers from stoopidcheap and it works cool !!

sits on the dash of the GQ just nice in front of ya !!!!!!!!!

Posted: Thu Mar 03, 2005 11:38 pm
by hefty_merv
NJ SWB is on the right track, ohms is the problem since most stereo speakers run at 4 ohms, and your UHF will be running at 8 ohms. To solve this get a mono headphone plug,
Wiring as follows

phone jack(+) to speaker 1(+), then speaker 1(-) to speaker 2(+).
finally speaker 2(-) to phone jack(-).

This makes your 4ohms speakers act as 1 8ohms speaker....

Posted: Fri Mar 04, 2005 3:37 pm
by Scrapper
Hefy Merv is correct. This will give best power transfer and least risk to equipment.

Please use heat shrink over joined wires - electrical tape has a nasty habit of giving up under hot 4WD dashboards.

"Series" the speakers (as Merv described) and see how you go. It may pay to try and put just one speaker on the plug (3.5mm or 1/8" mono - effectively the same thing) and see how it works. It may drive one speaker with a 'lower impedance' better than two speakers with the correct impedance. If you are like me and have two radios, I have one speaker per head unit, so you can have say CB one side and UHF on the other. Just a suggestion.

Some of the best things in modern electrical - heat shrink, nylon ties and hot melt glue...