# Calculate Total System Impedance

#### Aleph_Null

Hi all,

Long story short, I have a couple of new sub cabinets which I wanna set together with another two-way speaker in my living room (for the time being I will only set 1 sub and 1 two-way top). Anyways, I was doing some calculation to see if my amplifier is up to the task but I'm worrying the overall impedance comes out to be 2.66 Ω, while my amp can only support 4-8Ω.

What confuses me is the role the passive crossovers play in the calculations. I feel like this is all in parallel right? is there any way I can sort this out without aving to get a second amp?

The amp I'm using is a digital Kam KXDR 1600.

here is a simplified schematic of the connection (Mind I'm only using one output channel on the amp set in mono).

#### Galu

I'm worrying the overall impedance comes out to be 2.66 Ω, while my amp can only support 4-8Ω.

The crossover ensures that the drivers are not in parallel as you are thinking.

The division of the signal into two frequency ranges ensures that the amplifier sees only the impedance of the woofer at the low frequencies and only the impedance of the top cabinet combination at high frequencies.

#### Aleph_Null

The crossover ensures that the drivers are not in parallel as you are thinking.

The division of the signal into two frequency ranges ensures that the amplifier sees only the impedance of the woofer at the low frequencies and only the impedance of the top cabinet combination at high frequencies.

The overall impedance will actually be close to that of the woofer, as that is to where most of the music power is delivered.
Thanks a lot, that is weight off my mind.

I always had some troubles wrapping my mind around how impedance is affected by frequency division. I guess I have some more reading to do..

So would what would you say the overall impedance would be in this system? closer to 8 or 4?

#### Galu

You must have missed my edit - nominally 8 ohm.

The top cabinet is 8 ohm overall, the sub is 8 ohm and the entire system impedance 8 ohm (nominally).