What wattage and ohms are my speakers?

[toejam]

I've got an old Marshall Valvestate 8240 combo with two 12" Celestion speakers. All the speakers say on the label is Celestion G12T. How do I tell exactly how many watts and ohms they are? Here's a description of the amp.

"8240 - 40x40 Watt, 2x12 Stereo Chorus Combo. Very similar to the 8080 except with the addition of Stereo Chorus and Reverb for a truly panoramic spread. The 8240 also features stereo Line Out jacks and a stereo, parallel Effects Loop (mono Send, left & right Returns) complete with a Loop Level switch (-20dB or 0dB)."

[Cleveland Metal]

Re: What wattage and ohms are my speakers?

AFAIK, Most are 75 watt although some 100s are out there. As for impedance, you'd have to meter them to see whether they're 8 or 16 ohm.

[toejam]

Re: What wattage and ohms are my speakers?

Thanks, John.

[Cleveland Metal]

Re: What wattage and ohms are my speakers?

Not much help, I know... But, I'm often master of the obvious, hahaha...

At least close in wattage. If they are wired in parallel, the impedance you get at the plug is the actual impedance of each speaker. If they are wired in series, divide that by 2. If you get "roughly" 16 ohms at the plug, they are 8 ohm speakers.

[toejam]

Re: What wattage and ohms are my speakers?

Guess I should get a meter. I knew there was a reason I wanted/needed one anyway. [img]/images/graemlins/idea2.gif[/img]

[Tashtego]

Re: What wattage and ohms are my speakers?

I think it works the other way when figuring out the resistance (Ohms). Parallel wiring should always have less resistance than series wiring for a pair of resistors.

[Cleveland Metal]

Re: What wattage and ohms are my speakers?

Umm, yes. That is what I said...

So, maybe you shoud read what I wrote again then...

[Tashtego]

Re: What wattage and ohms are my speakers?

[img]/images/graemlins/scratchhead.gif[/img] Is it? Maybe you should read what you wrote again before you jump all over me. I'm sure you meant series is R1 + R2 and parallel is (R1 * R2) / (R1 + R2) but I think you reversed it by mistake in your post.

"If they are wired in parallel, the impedance you get at the plug is the actual impedance of each speaker. If they are wired in series, divide that by 2. "

[Zerberus]

Re: What wattage and ohms are my speakers?

[ QUOTE ]
Not much help, I know... But, I'm often master of the obvious, hahaha...

At least close in wattage. If they are wired in parallel, the impedance you get at the plug is the actual impedance of each speaker. If they are wired in series, divide that by 2. If you get "roughly" 16 ohms at the plug, they are 8 ohm speakers.

[/ QUOTE ]

Actually, if they´re wired parallel the impedance at the plug will be HALF the impedance of each single sdriver [img]/images/graemlins/wink.gif[/img]

Possible setups and Plug measurement.

2x8 Ohms = in series 16 ohms, parallel 4 Ohms
2x16 Ohms= 8 ohms in parallel, series wiring uncommon (32 Ohms)

Likely are 2x8 Ohms in series or 2x16 in parallel [img]/images/graemlins/wink.gif[/img]