brombo wrote:
https://www.roomeqwizard.com/
You will need a calibrated microphone
https://www.amazon.com/gp/product/B00N4 ... d31c8d59a9Note that this is a usb microphone, you won't need a sound card.
Depending on the measurements you will be taking a direct input mic may not work. For example if you are testing frequency response of a speaker you have to not only need an input device but also an output device. I'm attaching a PDF showing one type of connection. Generally for the greatest flexibility in testing you have to have an interface device that has both inputs and outputs. Also if you are doing electrical tests you need a protective device between the DUT like an amplifier and the sound card to keep it from frying if you make a mistake. I built and wrote up such a device for "Speaker Builder" magazine and can supply you with the info.
Tom