Speaker ohms

[weeo]

I hope some of the technically gifted members can help me here:
I have a pair of bass bins rated at 8ohms and a pair of tops rated at 4ohms. which i want to use together.
They are both made by Peavey,so i sent an e-mail to Peavey asking if i could change the baskets on the tops to 8ohms, to make them usable with the 8ohm bins.
Peavey,s answer was that because the bass bins were rated at 8ohms,whatever i used after that didn't matter because the amp will only recognise the 8ohms from the bass bins.
I was always lead to believe if you have a speaker with 8ohms and you added a speaker with 4ohms, it would make the overall rating less than 4ohms and therefore would not be safe to operate.
Can any of you technical minded guys throw some light on this?
I don't for a second disbelieve Peavey, i just want some reassurance .
Thanks ,
Eddie

[frank]

Here you are.You can wire in series or parrallel.
www.sengpielaudio.com/calculator-paralresist.htm
2.6 ohms in parrallel.
12 ohms in series.
Invest in a multi meter and a soldering iron they are part of a muscos gear.

[kenja]

Frank's calculation is right but the water is perhaps muddy in this situation. Your signal will presumably go to the bass bin first and then the mid and high signals will pass through the internal crossover to the tops. Surely this is not quite the same as a simple parallel or series connection so perhaps Peavey are right in this instance. Only sure way to check is with a meter at the end.

[weeo]

Thanks Guys.
Frank, your calculation is exactly what i thought initially,but the engineer at Peavey is telling me different.It's all peavey gear that i'm using,so i tend to think he'll be right.
Ken, i think your observations are closer to the mark and i'll check out with my meter in the next day or so and let you know my findings.
Regards
Eddie

[doricvision]

Hi Eddie , try to think of the speaker set up as one bassbin and one top speaker as you would a normal speaker with a crossover unit inside . Peavey are correct as only the connection to the bass bin is matched to the output of the amp ie 8ohms .After that the signal after the crossover is fed to the top speaker.
Frank is also right if you are using normal speakers and either adding to them in series or in parrallel
But stick with Peaveys solution if you are using matching units
Bigmike

[weeo]

Thanks Mike,I should've known you'd have the solution.
Regards
Eddie

[frank]

Sorry I thought you were trying to wire 2 speaker bins together with only one speaker in each .I did not realise you already had a cross over system.