Speaker Level Test & Measurement Interfacing - Correct Method

[Off Axis]

Hello All-

First time caller to a great resource- I've tried to find the answer to this question but I'm drawing a blank, I'm afraid.

I've just repaired an old 45W Pioneer receiver and would like to take some measurements on an analyser... and I hope not to destroy the thing!
I have an aging Neutrik A2-D test set that I use for various line level measurements of audio devices but never fed Speaker OPs directly into it- is this OK and if so does the impedance mismatch skew results for THD & Frequency response?

The specs for the A2 show the Input stage has a max. 300V peak / 200Vrms so should be fine there. Once a signal goes above a certain level p-p the lowest A2 input Impedances are deactivated and 100K applied.

I'd love to know if I can safely connect the two devices or whether an intermediary voltage divider needs to be made.

Many thanks for any assistance!

 

[MaxwellsEq]

Hello All-

First time caller to a great resource- I've tried to find the answer to this question but I'm drawing a blank, I'm afraid.

I've just repaired an old 45W Pioneer receiver and would like to take some measurements on an analyser... and I hope not to destroy the thing!
I have an aging Neutrik A2-D test set that I use for various line level measurements of audio devices but never fed Speaker OPs directly into it- is this OK and if so does the impedance mismatch skew results for THD & Frequency response?

The specs for the A2 show the Input stage has a max. 300V peak / 200Vrms so should be fine there. Once a signal goes above a certain level p-p the lowest A2 input Impedances are deactivated and 100K applied.

I'd love to know if I can safely connect the two devices or whether an intermediary voltage divider needs to be made.

Many thanks for any assistance!

What load will you be using?

 

[Off Axis]

Ah, thank you Maxwells- that's clearly what I've left off the list... I've got a couple of 4.7ohm 100w strapped to a heatsink per channel.

I'm assuming the method would be to parrallel the test set from the load?

 

[MaxwellsEq]

Ah, thank you Maxwells- that's clearly what I've left off the list... I've got a couple of 4.7ohm 100w strapped to a heatsink per channel.

I'm assuming the method would be to parrallel the test set from the load?

The input impedance of the test set is high, so won't affect the loading at all. Effectively you can measure the voltage change across the load. You should expect volts to be in the 10 to 50 range. Start by checking with an AC voltmeter.

 

[Off Axis]

That's understood- thank you!

 

[MaxwellsEq]

Check if the test set probe is at ground or not, and if so check the power amplifier can handle ground on its output.