#1
I don't know if this is pointless or not but just try to be understanding. Okay Randall RG3003. 300 watts. RG412. 200 watts. Can I run these in a half stack or do I have to go with the RG1503 150 watts? Meaning can a 300 watt head run a 200 watt cab or is that bad. I have a feeling it's bad but it's so hard to get a straight answer anymore. I'm new to all of this so just try not to feel I live under a rock and don't have any knowledge! I'm familiar with impedance and ohms so don't bother with that. Thanks.
#2
Speaker cab should be greater than or equal to the amp in power or you risk blowing up the speakers if you start turning the amp up.
However, that being said, impedance comes into play too, especially with SS amps. The higher the impedance of the speakers, the lower the output from the amp. The manual should tell you what power the amp is into what impedance loads.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
Last edited by Cathbard at Jul 6, 2014,
#4
Tell me about speaker cables too. Is there a specific brand for certain amps or just as long as it says "speaker cable"?
#5
Read my edit about impedance.

As long as it's a speaker cable you should be fine.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#8
Quote by Cathbard
Speaker cab should be greater than or equal to the amp in power or you risk blowing up the speakers if you start turning the amp up.
However, that being said, impedance comes into play too, especially with SS amps. The higher the impedance of the speakers, the lower the output from the amp. The manual should tell you what power the amp is into what impedance loads.


The operating manual does little more than label the knobs.

If the power were rated (what the hell are the "high gain FET" watts that the advertising copy on Thomans talks about? That's just silliness), we'd know more. Assuming that it's RMS watts, you'd expect that you'd see about half that power available to an 8 ohm cabinet, and perhaps a quarter to a third of that power available to a 16 ohm cabinet.

In other words, if you have an 8 ohm cabinet with speakers that would support a total of 150W, you should be just fine.
#9
Oh, really? That's sad. Usually manuals will list it off in the specs section.

Rule o' thumb is add 10%. So if it's a 100W into 4 ohm then it will be about 55W into 8. Allow 20% (so 60W) and you're playing it pretty safe.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#10
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