Wiring 2 identical drivers series-parallel?

[sadams]

Hello folks. New here on diyaudio. I am combining a 4 ohm tweeter with two 4ohm midbases in a pair of MTM satelites. Already had the midbases or would have bought 8ohm and wired them parallel. Anyway, I want to wire the 4ohm midbases for a final impedance of 4ohms to match the 4ohm tweeter. I have read about series-parallel of 4 identical drivers to give a final impedance matching that of each driver (ex.: 4x4=4). Can I do this with 2 speakers? The other option would be to wire the midbases parallel and place a 2 ohm resistor in line, right? Thanks

[sadams]

OK, now I realize my original was a dumb question. You cannot wire 2 drivers series-parallel. So then, my question becomes...with a 4ohm tweeter and 2 4ohm midbase drivers (wired together) in an MTM configuration, am I better off wiring the midbases in parallel and incorporating a 2 ohm resistor, or wiring the midbases in series and putting an l-pad on the tweeter? Thanks

[planet10]

If you have a voltage source amplifier it will not matter if the woofers are wired in series for 8 ohms nominal and the 4 ohm tweeter. Wiring then in parallel would only be suitable if your amplifier is 2 ohm capablt (not many are). You do not want to add a series R to a woofer.

dave

[AdamThorne]

You cannot wire 2 drivers series-parallel.

Ok, good...

So then, my question becomes...with a 4ohm tweeter and 2 4ohm midbase drivers (wired together) in an MTM configuration, am I better off wiring the midbases in parallel and incorporating a 2 ohm resistor,

This would result in a 2-ohm speaker load plus an equal 2-ohm resistor load. Each load would burn half of the amp output power. So you'd waste a lot of power on that resistor, and you'd need a big macho resistor to avoid smoking it. So don't do this.

or wiring the midbases in series

This is what you should do.

and putting an l-pad on the tweeter?

I'm a little confused by this statement... You'd likely need some sort of l-pad either way to match your tweeter's acoustical output to that of your woofers. Are you worried about making the tweeter act like an 8 ohm load? You don't need to worry too much about matching the impedance of your tweeter to that of your woofer, just design the tweeter section of your XO for a 4 ohm load and the woofer section for an 8 ohm load.

At least, that's according to my understanding.



... oops, co-temporal w/ Dave...