I know that JBL produced many drivers that were actually 10 ohm in spite of being labled 8 ohm or 16 ohm.

I have not run into that situation with Altec products until now. I bought (4) Altec 421A's and measured the DCR of all of them and they were all really close to 4 ohm.

I then ran a impdedance curve (WT2) and discovered they were roughly 5 ohms and rose slowly as frequency increased. They were only 7.5 ohms at 1khz.

Is this something anyone else has run into before?

I'm also making a crossover for a pair of 421A's in Altec 815A dual 15" horns with Altec 288's on 203B multi-cell horns. So I'm thinking of running the 421A's in series for 10 - 12 ohms.

This is for a good friend of mine.

Thanks in advance for any and all comments/info on this subject!

Also, this is my 1st post on the forum.

Regards, Ron

PS: I know some of you know me from other forums.