Audio Range (10Hz to 4MHz) Network Analyzer

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I just found this mentioned on a mailing list and thought it might be an interesting item for diyaudio folks. The button says "Buy Now for 1590 GBP" which seems high, but it seems this would be really useful for measuring drivers and speaker systems.

Cypher Instruments | C60 Impedance Analyser | Frequency Response Analyser

Is there software to do something like this with a regular PC soundcard interface?
 
I'm still interested in any possible answers to this question:
Is there software to do something like this with a regular PC soundcard interface?

For FFT/spectrum analyzers there's RMAA, ARTA and a huge number of others, free and otherwise, but about an hour of looking finds (almost) nothing that does the "network analyzer" function for audio.

I did find this, and the AudioXpress article it links to shows it getting the amplitude AND phase response of a simple R-C filter as well as a speaker driver. it's built on Matlab/GNU Octave, and I don't know how much effort it takes to install and run, but I'm about to find out. At least I've run a earlier version of Octave.

MATAA (Mat’s Audio Analyzer) | audioroot
 
Member
Joined 2004
Paid Member
The speaker test mode of Arta should give both gain and phase info just looking at an amp, no acoustics in the middle. I think you can also measure impedance with a simple jig. They will all be limited by the soundcard and not useful for feedback analysis of a wideband power amp for example. Also no Smith charts of the reflections etc, but I don't think that's what you are looking for. If up to 100 KHz is enough try ARTA. It is a free download so you should explore what it can do. REW does similar stuff.
 
...built on Matlab/GNU Octave...I'm about to find out.
I look forward to hearing how your experiments go. I made a brief attempt to run MATAA a year or two ago on my Xubuntu Linux box, and failed.

In M. Brennwald's 2007 MATAA article ( audioroot.net/wp-content/uploads/2013/08/MATAA_aX_original.pdf ), he refers to a piece of software, TestTone, that he (Brennwald) wrote to compensate for a failing of both Matlab and Octave - "simultaneous sound input and output, a prerequisite for MATAA, is not well implemented." Additionally, the write-up says that TestTone requires PortAudio.

I suspect that this might have been the source of my problems; I installed Octave from the Ubuntu repositories, but it probably didn't pull down PortAudio as well. At any rate, I never managed to get a peep out of MATAA. I don't remember if I tried manually installing PortAudio or not - I think I did, but still couldn't get MATAA to work.

I hope you do better than I did. Linux is the only operating system I use at home, and it would be nice to get an audio measurement system going on it.


-Gnobuddy
 
Playrec, the octave MEX module MATAA uses, works very good in linux, IME.
Brennwald's paper is from 2007. It may very well be out of date now. (It's nice to see that MATAA's Github repository is showing recent commits, though. Evidently MATAA is still seeing ongoing development.)

If Playrec was developed more recently than than 2007, perhaps MATAA now uses Playrec rather than Brenwald's own hack (TestTone)?

I like the idea of MATAA. It looks like it will be extremely powerful and flexible. Like Gnuplot and Latex, the initial learning curve will be slow and awkward. But once learned, there is so much power available.


-Gnobuddy
 
I Picked an Analog Devices ADALM2000. Took 8 month to get one but for 99USD it was worth the wait. The software and firmware for this is open source.


You have to make you own test jig for it. 100Mbps sampling at 12bits.



I could on about it but you can read about it here. I'm still exploring it. Not ready to publish a review. AD has a wiki page on this and a ton of useful labs to boot. This is intended for EE students and really serious DIYers.


ADALM2000 Evaluation Board | Analog Devices


Google it for more pages.
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.