Jump to content

DeltaWave null-testing audio comparator (beta)


Recommended Posts

26 minutes ago, TomCapraro said:
120/5000
 
 
 
Don't worry ... how is the software for multitone measurements?
Have you completed the program?

Yes, the software was designed to measure devices using multi-tone signals. It's functional, but not ready for others to use, quite yet. At some point I may publish it, when I have a little more spare time. Here's an example result using a 20k multi-tone :) Blue is the full test signal, white is the distortion with the test signal notched-out:

 

image.thumb.png.51edd73d5801ac2bd4cf49c09ca17f7e.png

 

The program computes clock drift, frequency response, and TD+N for any number of multi-tone signals, from 3 to thousands. I was also planning on computing phase response, but didn't get to it yet.

Link to post
Share on other sites
9 minutes ago, pkane2001 said:

Yes, the software was designed to measure devices using multi-tone signals. It's functional, but not ready for others to use, quite yet. At some point I may publish it, when I have a little more spare time. Here's an example result using a 20k multi-tone :) Blue is the full test signal, white is the distortion with the test signal notched-out:

 

image.thumb.png.51edd73d5801ac2bd4cf49c09ca17f7e.png

 

The program computes clock drift, frequency response, and TD+N for any number of multi-tone signals, from 3 to thousands. I was also planning on computing phase response, but didn't get to it yet.

😃😃😃

Link to post
Share on other sites
6 hours ago, TomCapraro said:

In case you decide to send it to me please create two, one with 20,000 tones at 32bit / 44.1khz and another with 20,000 tones at 32bit / 96khz.

 

Here are the files, Tom:

 

https://www.dropbox.com/sh/ieyurbgbndvjwkz/AADlqUEdxceasMJC3Q2MEYUNa?dl=0

 

60 seconds each, 44.1k and 96k @ 32bits.

 

44.1k one contains 4178 tones, and 96k file contains 5459 tones. That's because my software automatically removes any tones that are too close to each other (within a few Hz). This gives the notch algorithm enough space between tones to remove the original ones. Oh, and the start frequency is 14Hz.

 

Let me know if you find something interesting to do with these :)

 

Link to post
Share on other sites
8 hours ago, pkane2001 said:

 

Here are the files, Tom:

 

https://www.dropbox.com/sh/ieyurbgbndvjwkz/AADlqUEdxceasMJC3Q2MEYUNa?dl=0

 

60 seconds each, 44.1k and 96k @ 32bits.

 

44.1k one contains 4178 tones, and 96k file contains 5459 tones. That's because my software automatically removes any tones that are too close to each other (within a few Hz). This gives the notch algorithm enough space between tones to remove the original ones. Oh, and the start frequency is 14Hz.

 

Let me know if you find something interesting to do with these :)

 

I will definitely keep you updated.
Thanks a lot for the files.

Link to post
Share on other sites
5 hours ago, TomCapraro said:

If you send me two more files of 1 minute with the same frequencies (32 / 44.1khz and 32 / 96khz) but this time with 32 tones I will do some interesting tests.

 

Alright. Added two more files. These are named mtone32_...

 

https://www.dropbox.com/sh/ieyurbgbndvjwkz/AADlqUEdxceasMJC3Q2MEYUNa?dl=0

 

Looking forward to more interesting tests :)

 

Link to post
Share on other sites
5 hours ago, TomCapraro said:

Is it normal that the spectral lines are 27 rather than 32?

 

That's because my software is trying to space out all the tones for easier removal after the capture. All the tones that are rejected are between 14Hz and 22Hz, so you're not missing much. If you want, I'll post the files with exactly 32 tones. 

Link to post
Share on other sites

Paul, in your opinion: why doesn't deltawave totally cancel the tones?
According to a certain logic, the cause should concern the alteration of the analog tone compared to the original tone? ... so that the residue of an altered analog tone would remain?

111.jpg

222.jpg

Link to post
Share on other sites
2 hours ago, pkane2001 said:

 

What do you mean 'periodic multitones'? What did you do to make them subtract perfectly?

Hi Paul, to create a periodic multitone signal (whose visualization on FFT does not require weight windows, so to use with a rectangular or dirichlet) you have two solutions:

1) use the REW multitone signal generator, then set to 64k and at least 40 periods on 44.1khz.
Eventually the file will be 59.443 seconds long.

2) or take your multitone signal, load it into a good editing software, then cut a piece with 65536 samples and paste them so that 40 frames are formed.
Also in this case the files will be 59.443 seconds long.

This is your signal transformed into a periodic multitone.
Deltawave, as discussed in the past, works excellently with periodic signals, facilitating their alignment and accuracy.
Under normal conditions, the tones will have to cancel out ... but not down to background noise levels.
A small part will have to "emerge" but ... it will have to have an amplitude equal to about the same amplitude as the harmonic distortion with narrow band signals (such as a fundamental at 0dBFS)
In practice the residual of the multitones will correspond to approximately the level of the harmonics of the THD.
If, on the other hand, the residual is too high ... there is an error.

32 TONI periodici.wav

Link to post
Share on other sites

Here, in my opinion, is the area that ... being non-linear (in addition to undergoing continuous variations as it is very close to the thermal agitation of the noise), it cannot be canceled.
It also seems normal to me as the base of each tone can also contain phase jitter.
At this point, the more the tones are canceled ... the more precise the D / A - A / D acquisition system.

pkane2.jpg

pkane3.jpg

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×
×
  • Create New...