Audibility of low frequency distortion in speakers

[restorer-john]

@March Audio Will you continue using and MP4 container and the AAC codec for the youtube links, when things get busy with music samples? I am thinking you should perhaps move to PCM (.wav) attached files because AAC has telltale indicators of it's own which could mask aberrations?

 

[richard12511]

Don't have salties around here. The big salties up north get a few tourists every now and then when they take a dip at a creek crossing and ignore the signs. They are pretty well fed in general and leave humans alone mostly.

I feel like Australia has all of the worlds deadliest creatures . I used to watch a bunch of those "top 10 deadliest creatures" shows on National Geographic as a kid, and it always seemed like half of the creatures in the list were from Australia.

I've never been outside the USA, but Australia is a place I've always wanted to visit. New Zealand, too.

 

[restorer-john]

I've never been outside the USA, but Australia is a place I've always wanted to visit. New Zealand, too.

You should do it once this Covid thing is done and dusted. Buy/hire a camper van, take six months and drive around the country. @March Audio is nearly 4300km away from me on the other side of the country. I've never been to Western Australia (where he lives) and it's huge, even bigger than our state.

New Zealand is a beautiful country and you'd love it too. Much easier to see, you could do it from end to end around each island and have a nice holiday in say 3 weeks. The beauty of NZ is the scenery and self drive is the way to go, stopping wherever you want. It's only 870km from Queenstown to Nelson (south island) and an awesome drive around lakes and glaciers, the ocean and up into the marlborough sounds. Lots of wineries, good food and insane scenery. Do it in winter and get all the log fires etc.

Then take the inter island ferry from Picton for sure and do the north island.

 

[Doodski]

I feel like Australia has all of the worlds deadliest creatures . I used to watch a bunch of those "top 10 deadliest creatures" shows on National Geographic as a kid, and it always seemed like half of the creatures in the list were from Australia.

I've never been outside the USA, but Australia is a place I've always wanted to visit. New Zealand, too.

Yes, Australia is a hotbed of venom and biting creatures. Not my cup'O joe that's for sure. I used to be a outdoorsman but I stopped all that stuff. Too many bears freaking me out. Kept running into black bears and grizzlies. Can't shoot 'em and they are known to attack especially attacking human females. I read a gov <.pdf> that stated ~94% of attacks are on females and ~94% of those attacks are very serious due to females being more easily injured. A scary and easily remembered statistic. We have rattlers in the south of the province au plenty and some nasty spiders but overall we have it pretty easy with the wildlife.

 

[March Audio]

@March Audio Will you continue using and MP4 container and the AAC codec for the youtube links, when things get busy with music samples? I am thinking you should perhaps move to PCM (.wav) attached files because AAC has telltale indicators of it's own which could mask aberrations?

Oh absolutely. The videos are simply for demonstration and to allow others who wont want to do the whole Foobar ABX test to understand whats going on. The foobar tests will be wav/flac.

 

[BillG]

New Zealand, too.

I'm an expat American that's been living in Aotearoa (New Zealand) since '96.

Culturally it's much more friendly, relaxed and polite than the US, not to mention far less violent, less religious, and less racist, at least in the urbanized areas anyway. However, cities globally tend to be more liberal and diverse. Its politics aren't as crazy, either.

I've done a bit of traveling throughout the country but mostly to its cities. I live in Auckland, by the way, and am a confirmed urbanite for life now - I grew up in rural Virginia and countryside does little for me after ~20 years of being surrounded by it.

An interesting fact about Auckland, it's situated on a field of ~53 volcanoes - all dormant, fortunately. I happen to live within a few miles of 4 of them and I've climbed a few. They're not particularly tall or rugged making it easy to do.

 

[March Audio]

I feel like Australia has all of the worlds deadliest creatures . I used to watch a bunch of those "top 10 deadliest creatures" shows on National Geographic as a kid, and it always seemed like half of the creatures in the list were from Australia.

I've never been outside the USA, but Australia is a place I've always wanted to visit. New Zealand, too.

Whilst true they are not all terrifying..then again even roos can kick you to death.

Currently outside the office mom and baby roo.

 

[March Audio]

OK so to move forward with some further more scientific tests you will need some software to perform ABX testing. Copying some explantory text from elsewhere;

Here's how ABX testing works: The ABX box presents two audio signals, A and B, plus a third, X. X is either A or B; the assignment is random, and it changes (or doesn't change) with every trial. So you listen to A, listen to B, listen to X, and then decide whether X is A or B. Then you or the test administrator activates a function on the ABX box that displays whether X was A or B for each trial.

Random guessing will, after enough trials, result in correct selections 50 percent of the time. So, to prove there's a significant difference between A and B, you'd have to correctly identify X somewhere between 50 and 100 percent of the time. Even someone randomly guessing might get 6 or 7 out of 10 right, so the results aren't meaningful unless you can do even better than that. For a 95 percent confidence level (a typical standard for statistical significance), you'd have to have correct identifications on 23 out of 24 trials.

I will let the statisticians amongst you advise what is most appropriate, but the Foobar ABX software defaults to 16 trials not 24.

So download and install Foobar music player here:
https://www.foobar2000.org/getfile/c50260edf59e3e13d2cb66f34a9a8784/foobar2000_v1.6.2.exe

Also the ABX plugin:
https://www.foobar2000.org/components/view/foo_abx

just dbl click the plugin to install.

To use Foobar watch the following video. Set your sound device then load the 2 A/B sound files. Right click them and select ABX test.

The the order of track A and B always remain the same. You can play them as often as you like comparing them. Then play X / Y and decide if it it is A or B. Click your selction and press next trial.

Once finished you will end up with a result like this showing how many times you got it right.

Just copy and post here.


EDIT:

To increase reliability of the data you can set you playback volume levels to 80 to 85dB(A). You can get an idea of this by playing the "clean" audio file and measuring the sound level with a phone sound level meter app. Without calibration this wont be very accurate, but still it might help.

I use the app iNVH by Bosch. Its available on Android and IOS.

 

[Doodski]

I attempt to install the <ABX Comparator.fb2k-component> by clicking on it and FooBar opened and then crashes. Am I doing something incorrectly?

 

[Doodski]

OK After some extended time it accepted the ABX Comparator.fb2k-component

 

[Doodski]

Using Sennheiser HD 598 headphones and ASUS Z370E motherboard it was reallly close and as one can see it was half and half. I set the EQ to disabled.

 

[March Audio]

@Doodski (and everyone else ) practice using Foobar ABX with this one.

 

[Doodski]

TestA1 - clean and distorted files comparison.

 

[March Audio]

TestA1 - clean and distorted files comparison.
View attachment 98935

Cool . I expected that result, its just an obvious one for people who havent used the foobar ABX previously to gain confidence they are doing the right thing.

 

[q3cpma]

For people on UNIX, there's https://gitlab.xiph.org/xiph/squishyball

 

[March Audio]

I just installed foobar for the first time and the ABX tester for this. First attempt. Headphones AKG-702s on a focusrite 2i2v2. Can't do speakers today- where are in the middle very wild weather, had 400mm of rain in <24 hours and the wind is really loud.

View attachment 98886

Just seen the news. That weather is pretty extreme.

Impressive result there !

 

[March Audio]

Ok first real test (A2)

I will show the distortion levels and plot of the FFT later once some results have come in.

A tip. If the difference is obvious to you then you can speed up the test by just comparing X and Y. The order of A and B remains constant

 

[March Audio]

My results for test A2

16/16

 

[andreasmaaan]

16/16.

EDIT: should have mentioned, I did it using IEMs. Tried also with open-back headphones, but found the background noise a bit disturbing.

 

[ctrl]

I will show the distortion levels and plot of the FFT later once some results have come in.

Without all of us listening to the examples at roughly the same sound pressure level, it doesn't really make sense after all.

At 10dB sound pressure difference, the audibility of the distortion in percent can change by a factor of three.

At the very least, everyone should estimate at what sound pressure level the listening test was performed and include this in the result.

Would it make sense to provide a kind of calibration tone, recorded for example at -80dB or -70dB, and then adjust your speakers or headphones so that the sound is just perceived?
Because then we would have something like a common sensation level.

This calibration tone is then, with a short instruction, simply added to each example.