Ohmage for 1964 & 1966 Twin Reverb External Cab Altec 417's ??? HELP!!!

[rcboals]

I have a 1964 Twin Reverb and a 1966 Twin Reverb. I am real ignorant about technical stuff. Thanks for the Gear Page forum where I can ask people that know the answers for help. The last thing I want to do is damage these amps by doing something stupid.

1. Both amps have 2 Altec 417 8ohm speakers wired in parallel which I understand is 4 ohm for my main speakers.

2. The cabinet I want to use also has 2 8ohm Altec 417 speakers wired in parallel for 4 ohm.

My little brain says that would make everything a 2 ohm load. Am I wrong? I just don't want to hurt anything. I want to be sure I'm ok plugging the 4ohm extension cab in to my amps. Let me know if I'm ok to do this or not.

[tmac]

Yep it would load the amp at 2 ohms.
IMHO you're ok to run a Twin Reverb at 2 ohms (no lower though as that's the generally accepted limit).

[rcboals]

Fender tech suppport said it is actually better to plug in a 4ohm extension cab into the extension jack. They said matching the ohms of the extension speakers to the ones in the amp was better than mismatching the ohms. They expect it handle a 2ohm load just fine.

[walterw]

fenders are reputedly ok with impedance mismatches, while marshalls supposedly are not. (i still don't really understand why.)