hello everyone. lately i've been doing a lot of impedance measurements with a 100 ohm resistor in series with the speaker connected to the headphone output of my e-mu sound card. sometimes i have to switch to SPL measurement and therefore i have to change the connections. i would like to use a box that allows you to change the type of measurement with a simple switch. i could build a box like this by buying all the components online and then proceed with the assembly but i would like to know if there is a ready-to-use box that doesn't have an excessively higher price than the diy self-construction. hello and thanks.
Are you looking for a box with a single pole switch that can bypass a 100 ohm resistor in series with the speaker?
https://www.amazon.com/dp/B0C36NP4WK/
https://www.amazon.com/dp/B0C36NP4WK/
I did exactly what you are proposing. I had the resistor divider in a small project box and switches and RCA jacks etc. It worked, but in the end when trying to do precise distortion measurements I found there would be problems. I eventually just made a cable with the 100 ohm resistor, RCA plugs and the TRS plug with hard wired set of clip leads for impedance measurement separate from the attenuator box that I use for amplitude measurements.
I found ARTA-box. For impedance measurement I use the LIMP program that is part of ARTA so this box would be just right for me. I usually use the headphone output of my E-mu USB sound card (and I would like to continue this way because it is more convenient) but it seems that this box uses an external amplifier.
I read the preface very quickly and I looked at the wiring diagram just as quickly so forgive me if I made some errors in my evaluation, surely many people in this forum use it so, if they wish, they can express an opinion that would certainly be appreciated.
here are some links below:
https://www.artalabs.hr/AppNotes/AN1-MeasuringBox-Ver2-Rev2Eng.pdf
https://www.petoindominique.fr/pdf/box_arta.pdf
http://park8.wakwak.com/~hilo/audio/arta/index.html
I read the preface very quickly and I looked at the wiring diagram just as quickly so forgive me if I made some errors in my evaluation, surely many people in this forum use it so, if they wish, they can express an opinion that would certainly be appreciated.
here are some links below:
https://www.artalabs.hr/AppNotes/AN1-MeasuringBox-Ver2-Rev2Eng.pdf
https://www.petoindominique.fr/pdf/box_arta.pdf
http://park8.wakwak.com/~hilo/audio/arta/index.html