I have been googling but not really found what I'm looking for.
We see many curves on here. Many are audible responses that have been measured with a microphone. I can do this and understand the process.
However I dont know how I would measure the response of say a crossover, active or passive, or an input signal trafo. For instance I am building a NP 6-24 Active crossover and maybe I'd like to 'see' the response before hooking it up.
I have REW, laptop, DATS, scope.
I need to feed a signal sweep into the DUT, understood. But my what means do I 'record' what comes out the other end.
And is using REW, and considering a passive XO over an Active, one being line level one being speaker level, do the signal amplitudes matter.?
Thanks in advance
We see many curves on here. Many are audible responses that have been measured with a microphone. I can do this and understand the process.
However I dont know how I would measure the response of say a crossover, active or passive, or an input signal trafo. For instance I am building a NP 6-24 Active crossover and maybe I'd like to 'see' the response before hooking it up.
I have REW, laptop, DATS, scope.
I need to feed a signal sweep into the DUT, understood. But my what means do I 'record' what comes out the other end.
And is using REW, and considering a passive XO over an Active, one being line level one being speaker level, do the signal amplitudes matter.?
Thanks in advance
to measure electrical resp, just leave out mic/mic preamp.
start by doing a physical loopback, you should have a flat freq and phase resp, then put in the active filter.
start by doing a physical loopback, you should have a flat freq and phase resp, then put in the active filter.
In place of your measurement microphone, connect the output of your crossover to your sound card. Use REW in the same way.
One thing to look out for, though, is to not overload the input of your sound card. You can prevent that by using a voltage divider if the output from your test device is more than about 1V RMS. A good signal attenuator circuit can be found here: https://www.akitika.com/documents/BuildingTheAttenuatorRev4.pdf
One thing to look out for, though, is to not overload the input of your sound card. You can prevent that by using a voltage divider if the output from your test device is more than about 1V RMS. A good signal attenuator circuit can be found here: https://www.akitika.com/documents/BuildingTheAttenuatorRev4.pdf
What would the input of the soundcard be labelled as. I use the headphone output (stereo 1.5mm jack splits to 2 x RCA) for the output. So I would then take the out from the DUT back into the sound card on the laptop...what would that port be? Microphone in?
Do you a line input on your card? This is generally for higher level inputs than microphone. Otherwise, check to see what input levels the microphone input is able to handle.
The attenuator from the Akitika site uses LEDs to clip the input signal to limit the maximum voltage. That would be around 2 volts.
The attenuator from the Akitika site uses LEDs to clip the input signal to limit the maximum voltage. That would be around 2 volts.
During the design, most Bode plots are done with simulations, expecting the real product to differ with the component accuracy only (~5%).
During production, pre and post measurements are done very swift and (or?) 'in general conformation' mode. ((if at all))
Designing and taking real measurements during that iteration process would take ages, and is not profitable.
During production, pre and post measurements are done very swift and (or?) 'in general conformation' mode. ((if at all))
Designing and taking real measurements during that iteration process would take ages, and is not profitable.