Help needed with parallel wiring

> > > Help needed with parallel wiring

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Member Since: Mar 15, 2009

Edit: Sorry, I think I have posted this in the wrong section.

Hi all
I am new on here and I'm looking for some help.

Here goes, please bear with me...

The guy who owned my guitar amp (randall warhead 2x12) put in new speakers but bought 2 x 16 ohm speakers instead of 2 x 4 ohm. The amp puts out an 8 ohm load so I gather the speakers now have to be wired in parallel instead of series.

The guy has wired it as follows:

+ output wire to speaker 1 + connection
- output wire to speaker 2 - connection

then the speakers are linked as follows:

+ speaker 1 to + speaker 2
- speaker 1 to - speaker 2

I have done some reading and a couple of websites say it just a matter of connecting the +s from the amp output to the +s on the speakers and the same with the -s, so technically that is what he has done.

My issue is the pictures on the sites show it wired slightly different, as in the speakers not being linked together, if you know what I mean.

I'm getting there...

I have two speaker outputs on the back of the amp so I thinking the best thing is to run two speaker cables from the amp and then connect them + to +, and - to -.

like this

output1 output2
+ - + -
\ \ / /
/ / \ \
\ \ / /
+ - + -
Speaker1 Speaker2

The reason I am asking this question is that I cranked up the amp the other day and it didn't sound that loud considering the output is rated at 150 watts. I was thinking that if it was wired wrong it might only be putting out half the output because of the wrong resistance/impedance, or something.

Any help would be greatly appreciated, even if it is "dude, take it an amp repair shop..."

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The Czar of BS
Member
Since: Dec 31, 2007

Mar 15, 2009 04:59 pm

From what I am reading, you have it correct. Keeping all of the Positives on the positive side of the amp is correct for parallel.

And when ever you wire in parallel, you divide the ohm load.

The reason that the amp did not get any louder, is the fact that 16 ohm load speaker takes more voltage and wattage to get moving.

You need to take a look at the RMS values of the speakers that you bought. They mey require more then the amp can deliver.

Czar of Midi
Administrator
Since: Apr 04, 2002

Mar 15, 2009 06:47 pm

Agree with Rob here.

Although the Randall head is 150 watts it does not get nearly as loud as many other high wattage heads. I just sold an old Traynor bass head which was used for guitar more often then bass by most who owned one. It is rated at 120 watts, and compared to the warhead it is much louder, and it runs a 16 ohm load.

My little Dpi Valve Jr. runs 5 watts of class A single ended tube power through a single 12" eminence 16 ohm and it is loud as hell.

I am guessing maybe he did not buy speakers designed for guitar possibly.

> > > Help needed with parallel wiring

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