i was needing to know what i can use for an extended cab from my amp ?
are there limitations ? can you not use certain type of speakers like
stereo speakers ? any advice is appreciated

the amp is a peavey delta blues .
Any guitar speaker cab should work. I believe that the delta blues has a 16 ohm speaker with 16 and 8 ohm speaker jacks. So you would want a 16ohm guitar cab if your planning on running it along with the stock speaker, or either a 16 or 8 ohm cab if your going to run your amp as a head (without the stock speaker).

I hope that helps!
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