Wiring a twin horn setup. Series or parralel?

The standard horn on the GSXR1000 has just failed. I tried it direct
onto the battery and all I get now is a feeble tick noise. Five days
after it's new MOT too.

So, I just bought some of those Motrax twin horns, claims to be 130db
compared to the claimed 105db of the original horn. (Cue another
series of arguments over how to measure sound...). I now have two
cable connections hanging down on the bike and four terminals to
connect to. So, should I connect in series, ie positive from bike to
horn, across to other horn, back to earth on bike or split so that
there are now two positives and two earths, parallel.

I tend towards the latter, but I'm no electrician so I want to check
before I blow up a bit of wiring loom.

Thanks all.

 

Using the patented Mavis Beacon "Hunt&Peck" Technique, Mike Barnard

Almost certainly parallel (is there no diagram with the horns?

You're very likely to need a relay too, because the new horns will pull
much more current than the standard one, in which case you use the
existing wire to switch the relay, and run wiring back to the battery
(via a fuse) to power the horns.

--
Wicked Uncle Nigel - Podium Placed Ducati Race Engineer as featured in
Performance Bikes and Fast Bikes

WS* GHPOTHUF#24 APOSTLE#14 DLC#1 COFF#20 BOTAFOT#150 HYPO#0(KoTL) IbW#41
SBS#39 OMF#6 Enfield 500 Curry House Racer "The Basmati Rice Burner",
Honda GL1000K2 (Falling apart) Kawasaki ZN1300 Voyager "Oh, Oh, It's so big"
Suzuki TS250 "The Africa Single" Honda ST1100 wiv trailer

 

Parallel, definitely. Just wire to the + and - terminals as before,
but make up bridging wires to connect to the second horn from the
first. Wot 'e said about a relay. It will protect the switch from
the heavier current the new horns will almost certainly draw.

 

Mike Barnard fumbled, fiddled and fingered:

Have you tried readjusting it? There's usually a small crosshead screw
with a locknut on it that can be tweaked to adjust. I've had previously
"failed" horns working this way.

HTH?


--
Steve Parry
K100RS SE & F650
and a 520i SE Touring for comfort

(not forgetting the SK90PY)

http://www.gwynfryn.co.uk

 

'It it wiv a nammer often works, too.

 

The latter.

 

No relay used. See below, but thanks for taking the time to reply.

 

Hi.

I've looked for stuff like this, stripped it, wirebrushed it, hit
it... not a whimper.

No, but thanks anyway.

 

Ow it was done. See below.

 

I phoned Motrax. Got a techie [1] who said they were designed
electriclly to replace a standard horn without needing extra relays
added. So I've found a space under the fairing and bunged them in,
wired in parrallel. Quite loud and effective, but where they are a
lot of the sound comes back up through the fairing and seems aimed at
me. Oh well, I'll move them sometime, but for now I have a legal bike
and a noise to use.

[1] I love the idea of these footnotes! Had to wait ages on the phone
with 'music' that would have been at home in an old ZX spectrum. Sort
of a xylaphone sound with no noticable tune. I'll bet the 'techie'
was really a cleaner who had nothing better to do at the time.

 

Glad you got them fitted OK. Ready for the argument on sound levels now?
130dB 'just like that' is pretty meaningless. Linear or 'A' weighted ?
Sound Pressure Level at a stated distance or Sound Power Level?

I would guess that the claimed figure is for a linear SPL measurement
very close to the horns (possibly 100mm). Still respectably loud though.

--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

I had a similar problem wiring speakers so I did a little spreadsheet.
www.molly.org.uk/ohmcalc.xls

 

Thanks for the input Molly, all help is always apprecieated.