Good combo of software/hardware for doing audio measurements

[davorin]

I'm looking for a Software/Hardware solution to do audio measurements with either a PC running Win81 or Ubuntu.

For Software I've checked the ARTA and the RMAA packages, which could do spectrum and THD stuff...
Or someone knows of other Software?

RMAA: http://audio.rightmark.org/products/rmaa.shtml
Arta: http://www.artalabs.hr/


For the Hardware, which external USB soundcard would be a good choice for that and does not cost a fortune?

[quantalume]

I recommend ARTA as it has always worked well for me, and the user interface is pretty reasonable, unlike some other offerings in this category. I really want to like Daqarta (http://www.daqarta.com/index.htm), but I just can't get used to the UI. There is also Visual Analyzer (http://www.sillanumsoft.org/) and TrueRTA (https://www.trueaudio.com/rta_abt1.htm).

Here is a comparison of USB sound cards, geared towards real-time analysis: http://www.daqarta.com/dw_gguu.htm.  I have the Behringer UCA202, and it works really well for audio performance measurements. I don't remember what the noise floor on my particular unit is, but the corresponding THD is somewhere around 0.01%. Not bad for $30. It has phono jacks for input and output, another bonus compared to the 3.5 mm TRS jacks on other units.

[Alex Nikitin]

I use AudioTester and a modified RME Digi 96/8 PAD card (however this card would only work on Win XT). There are some samples of AudioTester results on my web site. My hobby is tape recorders and I do lots of various sweep measurements with AudioTester. Here, for example, 104 cassette tapes measured for 3HD v Level at 315Hz.

Cheers

Alex

[davorin]

Think I'll go with the Creative Sound Blaster X-Fi HD Hardware for my PC....

I've downloaded already the ARTA and RMAA Software and tried it out with the UMIK-1...
Now just downloaded the AudioTester Software....

Are there any more professional USB ADC/DAC converters out there in the US$ 200 - US$ 300 range?

[commongrounder]

Check out the QuantAsylum QA400 audio measurement interface with software.  It is a souped up USB audio device optimized for distortion measurements, etc.

https://www.quantasylum.com/content/Products/QA400.aspx

Good bang for the buck.

[DimitriP]

I use AudioTester and a modified RME Digi 96/8 PAD card (however this card would only work on Win XT). There are some samples of AudioTester results on my web site. My hobby is tape recorders and I do lots of various sweep measurements with AudioTester. Here, for example, 104 cassette tapes measured for 3HD v Level at 315Hz.

Cheers

Alex

 
Did you measure the frequency response of these tapes?

[davorin]

Yes I stumbled upon this one today as well (o;

Looks very professional...and what I like the most....BNC connectors...and not cheap RCA or even 3.5mm jack connectors ;-)

Seems though their device won't register as a regular audio device within Windows...so it is fixed to their software only...


Just read in their forum....a QA405 is in the builds...differential inputs and better ADC/DAC

[commongrounder]

The QA405 has been in the works for a while,  and the specs sound promising.  For me, the dedicated Windows driver is not a deal breaker because I would be using it exclusively for measurements and not audio recording/playback.  I do hope they include decent input protection, as any good piece of test equipment should have.

[davorin]

Someone found in the forum the same product with a different name called FP8400....they also sell other audio hardware:

http://www.fpinstrument.com

For me it is also not a killer if it can't be used as a regular audio interface....but definitively being able controlling from other OS would be great if they released the API used for USB control.

[Alex Nikitin]

Did you measure the frequency response of these tapes?

There is no such thing as a frequency response of a tape, only a pair - tape + recorder/playback machine. Tapes differ by their saturation levels, distortion, noise, durability etc etc, however almost any tape can produce a flat response with a correctly aligned recorder. There are recorders which can get a flat response over 20Hz-20kHz on any half-decent tape with help of sophisticated tuning systems. Here is a couple of graphs (taken with AudioTester  ) . One is a family of frequency response curves for a modern Sony HF cassette, another - for a 35-year old Sony cassette. Except for the difference in saturation at high levels and a bit of difference over 20kHz the responses at -20dB are flat +/-1dB from 20Hz to 20kHz and extend well over 20kHz. And that particular deck can do the same with 99% of cassettes.

Cheers

Alex

On the graphs: -10dBFS = 0dB DIN (250nWb/m @315Hz).

Sony 2012:



Sony 1978:

[Berni]

I use the Visual Analyzer software: http://www.sillanumsoft.org/

As for the hardware i made my own ASIO USB sound card with galvanic isolation and the best audio ADC i could get from TI.

[davorin]

How much for your hardware? (o;

I assume it's not an open source project?

[Timur Born]

I use the Visual Analyzer software: http://www.sillanumsoft.org/

It's free for the time being and it brings quite some features. Unfortunately it is using Windows audio (MME Wave it seems), with no options for ASIO (or anything else). It seems to max out at 96 kHz and the Windows mixer messes with sample-rate conversion anyway. Still a nice free program. Interestingly its tone-generator is limited, even though the "Pro" version is not available.

The trial-version of DFFS3 offers a tone-generator that can be used for unlimited time. I once (years ago) compared its noise-generator to various freeware ones and found it superior.

http://www.ymec.com/products/dssf3e/index.htm

[Berni]

It's free for the time being and it brings quite some features. Unfortunately it is using Windows audio (MME Wave it seems), with no options for ASIO (or anything else). It seems to max out at 96 kHz and the Windows mixer messes with sample-rate conversion anyway. Still a nice free program. Interestingly its tone-generator is limited, even though the "Pro" version is not available.

The trial-version of DFFS3 offers a tone-generator that can be used for unlimited time. I once (years ago) compared its noise-generator to various freeware ones and found it superior.

http://www.ymec.com/products/dssf3e/index.htm

Yes you need to tweak the windows sound settings a bit in order to make it work correctly. It does not need to have support for ASIO, just set the default settings in windows and in the software the same and it should not resample. Also it does work at 192k if you manually type it in and hit enter.

How much for your hardware? (o;

I assume it's not an open source project?

I never totaled up all the parts on it but it certainly was not cost optimized. I have a few left over bare PCBs(4 layer) for it but it might take you a while to get all the parts together and a lot of them are QFNs with head pads under them so not the most friendly thing to solder.

[davorin]

Well...soldering I could do with VPS as I have few kilograms of Galden LS-230 left....

The PCB looks really professional....never though if going commercial?

[Timur Born]

Room EQ Wizard can measure various things and is free:

http://www.roomeqwizard.com/features.html

[alexanderbrevig]

I use Audiolense which can output a FIR filter for room correction. Not a complete 'suite' but I like it for what it is

[Timur Born]

This one may be useful for test-tones. Didn't test myself yet, though.

http://www.wavtones.com/functiongenerator.php

[Berni]

Well...soldering I could do with VPS as I have few kilograms of Galden LS-230 left....

The PCB looks really professional....never though if going commercial?

I use solderpaste applied with a toothpick and hot air to solder down the QFNs

Its not commercial, just a tool i developed for testing audio equipment during development. So far it can test distortion down to 0.0003% THD.

[davorin]

Do you mind to share the schematics?

[Timur Born]

As for the hardware i made my own ASIO USB sound card with galvanic isolation and the best audio ADC i could get from TI.

I want that!  Is it purely USB powered so that you can use a laptop on battery to have a floating measurement system? And did you write the drivers yourself or got a chip + generic drivers?

[Berni]

Sorry not sure if i can post the full schematics on the internet but i can share details about it.

The isolated side is designed to run from batteries or external power. There is a isolated DC/DC to charge them from USB power but that was not fully implemented. I designed it to do floating measurements using a regular desktop PC that cannot be easily floated.

[Timur Born]

Is (desktop PC components) noise traveling down the USB ground line a problem? Especially when you playback (test-tones) via XLR cables (pin 1/shield connected) to equipment that uses 3-prong power-plugs (earth)?

Usually this kind of noise is very low in level, but it can be pushed by certain PC load states (and sometimes CPU c-states). Incidentally I would use an interface like yours (connected to a floating laptop running on battery power) exactly to measure this kind of noise coming from desktop PCs. That being said, a bus-powered RME Fireface 400 works quite well for me, too. It's rated 110 dB RMS dynamic range usually are good enough.

[Berni]

Is (desktop PC components) noise traveling down the USB ground line a problem? Especially when you playback (test-tones) via XLR cables (pin 1/shield connected) to equipment that uses 3-prong power-plugs (earth)?

Usually this kind of noise is very low in level, but it can be pushed by certain PC load states (and sometimes CPU c-states). Incidentally I would use an interface like yours (connected to a floating laptop running on battery power) exactly to measure this kind of noise coming from desktop PCs. That being said, a bus-powered RME Fireface 400 works quite well for me, too. It's rated 110 dB RMS dynamic range usually are good enough.

Power coming from USB will always be noisy but if you have good input filtering and regulation it should not be too big of a problem. Its worse when you try connecting stuff inside the PC. I built a home theater PC for the living room with a 5.1 amplifier built in to the same case and had at first a noise problem where i could hear CPU load in the speakers. Some rewiring to get the grounds sorted out fixed that.(I was using a PCIe sound card with single ended outputs)

As for ground loop noise, it should be taken care of XLRs differential nature but nothing has an infinite common mode rejection. It depends a lot on the power supplies in the equipment and how they are plunged in (Especially bad if they are plugged in to two different wall outlets rather than a power strip) and other equipment near by that might be pushing currents in to the earth wire. So i just play it safe and float my instrument to be sure. When you are looking at -140dB signals you can pick up all sorts of noise(Even radiated noise from CCFL lamps if they are near by).

[Alex Nikitin]

Here is the FFT at -10dBFS of one of my two RME cards (internal PCI, BTW), single-ended input from the (external) Amber 3501 generator (the internal RME DAC produces about 0.0004% THD at 1kHz) . No question, one can do better, however for me it is good enough  .

Cheers

Alex