Changing a Goliath jr III from 8 ohms to 4 ohms

[catalinalaolla]

Hi,

I have a goliath jr III speaker cabinet (8 ohms). Can I change it to a 4 ohms speaker cabinet by replacing the speakers with two 8 ohms speakers wired in paralel? Or I need to replace the crossover plate too.

Angel

 

[steveksux]

Yes you can. That's the only way to do it, replace the existing speakers. No amount of rewiring the original speakers would do it.

Not sure about the crossover.

Randy

 

[catalinalaolla]

Thanks for your response.
Angel

 

[B-string]

Yes the crossover also needs to be changed for the new load (impedance).

 

[Tim1]

I am not sure that B-string is correct there. As far as I am aware the crossover and horn does not affect the overall impedance of the cabinet, and I am also fairly certain that the crossover in my 4 ohm Goliath Junior is identical to that in my 8 ohm Goliath 410. I would be inclined to use the existing crossover.

 

[BassmanPaul]

If the crossover is a high pass only you can ignore it when changing speakers. If it has a low pass as well it will need to be replaced just as BString opines.

Paul

 

[Tim1]

Bassman Paul is corect, and from memory the crossover in the Goliath is highpass only so you should be fine.

 

[DukeLeJeune]

If the original woofers are 16-ohm units and the replacements are 8-ohm versions of the same model, then be aware that a typical constant-voltage-approximating solid state amp will put out twice the wattage into a 4-ohm load as into an 8-ohm load for a given input level setting. In English, this means that the new woofers would be 3 dB louder, relative to the horn, than was previously the case - so the tonal balance would be different.

If this is the situation, possible solutions include modifying the crossover (assuming it incorporates padding of the horn), changing the crossover and adding a second horn or adding a second identical crossover and horn in parallel (if a single horn isn't efficient enough to keep up), using an equalizer, or just not worrying about it.

Duke

 

[anderbass]

I was kinda wondering if you have positively confirmed what ohm speakers are currently in this cab? For all we know someone could have already swapped speakers or even have factory mis-labeled cab ohm info and it might just already be a 4 ohm cab. I try not to assume anything and I'd sure be double checking this before spending any money...


ps:
If your (origanal?) speakers are indeed not 8 ohm models, you could probably have them reconed to 8 ohm (and wired in parallel) instead of purchasing replacements that may or may not preform as well in this cab.

 

[Bluesbob]

I have a Fender-SWR Goliath III Jr. that was originally 8 ohms and after one of the 16 ohm 10-inch drivers caught fire (!) I replaced both of them with Madison Knight 10-inch 8-ohm speakers. My now 4-ohm Madison-SWR 2X10 sounds great with my Eden WT400, but I usually only turn the horn up to about 9:00.