Adding extension speakers to Loanstar

Help someone!!! My names mark and I'm new to this forum, all I wanted to know was, can I add a 2x12 loanstar cab to a Mesa loanstar classic 2x12 I.e. 8 ohm speaker plugged into the combo and from 4 ohms to the loanstar cab which is 8 ohms, both at the same time? Hope that makes sense.

Thanks in advance Mark

The online manual addresses what is possible in terms of adding extension cabs to the lonestar based on the ohmage of the cabs. Its toward the end of the manual, page 25-30 or something.

Just consider your combo cabinet exactly like it was an external cab being fed from a head.

For instance, if you have (2) 8 ohm cabinets, to run them in parallel you plug each one into its own 4 ohm jack on the back of the amp.

Hi Tommy

Thank you for replying! So back of my combo has 4 4 and 8 ohms I use both 4s to run external 2x12 cab and internal 2x12s ?

If so I've been running it wrong by using 8 to internal and 4 to external but still no signs of any problems yet,

Another question, on the back of my fender hot rod deluxe it has 2x 8ohms spker outs
One is in the combo itself and the other is external, can I run my Mesa cab from the 8ohms whilst the single 12inch speaker is still plugged into the fender, giving me 3 x speakers?

Really don't get ohms at all!!

Thanks again. Mark

You probably know more than what you think, but I'll just make a quick checklist just in case.

Ohms are a measure of resistance to the electrical output from the amp.

Probably the best way to understand is to first look inside an individual cabinet. If it has one speaker, the ohm rating of the cabinet is the same as the ohm rating of the speaker.

For two speakers connected in series, the equation is R1+R2=Total resistance of both speakers hooked together = resistance of cabinet. For example, two 8 ohm speakers connected in series is 8+8=16ohms.

For two speakers hooked in parallel, the equation is 1/R1+1/R2=1/Rcabinet

For example, if 2 16 ohm speakers are connected in parallel, the cabinet resistance is 1/16+1/16=2/16, which is 1/Rcabinet=1/8....thus Rcabinet is 8 ohms.

Understanding what is parallel, what is series, and how and why the resistance calculation works are the first steps to understanding this stuff.

BTW, if I make any errors, I sure hope other members correct me!

There are "safe" mismatches on most of boogie equipment, meaning you can hook them up wrong, but its not a big enough mistake to damage the equipment. The user manual also shows safe mismatches. Sometime a mismatch may sound better than a proper match.

Thank for taking the time to answer