wiring advice


First, I am a speaker newbie so please allow me to apologize for asking what might be stupid questions. :-)

I am looking for advice on the best way to connect 8 transducers to an amp for a haptic setup.  Each transducer has an impedance of 8 ohm, and a power rating of 5W RMS / 10W peak. The amp impedance range is either 2-8 ohm (specs) or 3-8 ohm (printed on the amp itself), and can output 100W.

How best to combine the transducers in series and parallel to match the amp?

Using an online impedance calculator (https://geoffthegreygeek.com/speakers-in-series-parallel-calculator/), I came up with the following options so far:

Option A: Connect 3 in series, 3 in series, and 2 in series. Then connect the 3 sets in parallel. Total impedance: 6.86 ohm. Some transducers receive 8.3W and others receive 18.7W. Max power is 87W.
Option B: Connect pairs in series. Then connect the 4 pairs in parallel. Total impedance: 4 ohm. All transducers receive 18.7W. Max power is 150W, which might damage the amp or distort sound.

1. Is Option A or B better, or even another combination?
2. What are the considerations for choosing the overall impedance? Is it best to aim for 2 ohm, 8 ohm, or somewhere in the middle?
3. I already have the transducers and amp, and I would like to come up with something appropriate for this equipment without buying something else.

Much obliged for any suggestions and advice!

jbudman

Each transducer has an impedance of 8 ohm, and a power rating of 5W RMS / 10W peak.

The total power requirement of 8 transducer = 8 X 5W = 40W RMS

The amp impedance range is either 2-8 ohm (specs) or 3-8 ohm (printed on the amp itself), and can output 100W.

Although the amp impedance specs is 2-8 ohm, if you connect a 16 ohm load to this amp, instead of 100W output it will provide up to 50W of output power and that still has enough power to drive those transducers. 

So my suggestion is parallel 2 sets of 4 transducers in series = 16 ohm.

Usually amplifier prefer higher impedance load, it will run cooler with lower distortion.

 

 

2 in series = 16 Ohms each.

For of these in parallel = 4 Ohms total.

 

Easy.

Thanks @raysmtb1 . The diagram on the bottom of the page has 4 speakers in series/parallel. How would that be modified for 8 speakers?