Andrew Quint Reviews the Unique BACCH-SP Stereo Purifier

[STC]

Yes. It measures from the in ear microphones. That does make it a little bit different of a measurement.

Thanks. are you referring to the charts previously posted here?

 

[Justdafactsmaam]

Thanks. are you referring to the charts previously posted here?

No. I have the BACCH4Mac. Referring to the measurements taken when I launch a new filter

 

[STC]

No. I have the BACCH4Mac. Referring to the measurements taken when I launch a new filter

I think someone else posted those measurements here but aren’t they simulated and not the actual response? I will add the link here ….

Edit:-
Post in thread 'BACCH and other XTC'
https://audiosciencereview.com/forum/index.php?threads/bacch-and-other-xtc.47755/post-1711395

 

[Justdafactsmaam]

I think someone else posted those measurements here but aren’t they simulated and not the actual response? I will add the link here ….

Edit:-
Post in thread 'BACCH and other XTC'
https://audiosciencereview.com/forum/index.php?threads/bacch-and-other-xtc.47755/post-1711395

That’s the actual response

 

[Gwreck]

That’s the actual response

That’s my measurements and it’s the simulated result. I was just shown how to make a measurement of the BACCH filter and the program graphically compares the results in the same format as the screenshot.

 

[Justdafactsmaam]

Here’s an example of an actual set of measurements from the BACCH4Mac

 

[STC]

Here’s an example of an actual set of measurements from the BACCH4Mac

In the chart, the solid lines represent simulated values. The dashed lines which supposed to represent the measured values are not there. This is white noise and actual measurement at ears cannot be flat.

 

[Justdafactsmaam]

In the chart, the solid lines represent simulated values. The dashed lines which supposed to represent the measured values are not there. This is white noise and actual measurement at ears cannot be flat.

What makes you think they are simulated? How would the BACCH simulate a frequency response? I know memory is unreliable but Edgar talked at some length about that measurement and made no mention of it not being an actual measurement. And the measurements are pretty far from flat

 

[STC]

What makes you think they are simulated? How would the BACCH simulate a frequency response? I know memory is unreliable but Edgar talked at some length about that measurement and made no mention of it not being an actual measurement. And the measurements are pretty far from flat

 

[Justdafactsmaam]

That’s for the XTC and I don’t think that’s a simulated measurement either. I suspect this is a leftover from previous versions. If I launch a new filter with another listener the frequency response changes. It’s got to be measuring the affect of different ears. But next time I talk to Edgar I will ask him.

 

[onion]

Interesting. For me, the process is to put the microphones in my ears and click the button that starts the measurement process. If the volume is turned all the way down, this is reflected in the measurement so I'm certain that the frequency response is not simulated. Maybe in relation to XTC, it is a mathematical calculation based on the frequency response at each microphone position and their interaction so is not directly measured. I think the calculations can be viewed in this paper

 

[STC]

What makes you think they are simulated? How would the BACCH simulate a frequency response? I know memory is unreliable but Edgar talked at some length about that measurement and made no mention of it not being an actual measurement. And the measurements are pretty far from flat

The top portion is actual measurement but the bottom one is what I am interested. Ears as such that frequency at ear canal cannot be flat due to pinna. So what are those lines? Why it is flat?

 

[Justdafactsmaam]

The top portion is actual measurement but the bottom one is what I am interested. Ears as such that frequency at ear canal cannot be flat due to pinna. So what are those lines? Why it is flat?

Maybe the numbers are deceptive. It’s not flat. It turns into a roller coaster at around 2khz

 

[STC]

Maybe the numbers are deceptive. It’s not flat. It turns into a roller coaster at around 2khz

Without pinna, if the source is flat response the response measured in ear will be flat. A flat response will not be flat with pinna. It changes depends where the source is coming from and will look more like the response at the top.

The sweep is said to be white noise. Depending on the speakers position the response of cancellation should look exactly like how the response is measured without cancellation for a perfect colourless cancellation. The charts looks nice but what are you interpreting from them? Even if is a roller coaster chart it is still cannot be what the actual measurement at ears supposed to look like unless BACCH filter removes the frequency shaping of the pinna completely. If that’s the case, then it will not sound identical to the non XTC sound as the original response will be altered.

 

[Gwreck]

There is a way for BACCH to measure the actual XTC of the BACCH filter. As long as your head has not moved the XTC simulated vs measured are very similar. I will try to do this tonight after work and post my results.

 

[goat76]

I just downloaded the VST-plugin, do any of you have suggestions of tracks that you find sound particularly well with uBacch?

 

[Cbdb2]

He's a classic Dunning-Kruger. He doesn't understand what BACCH does, thinks it is some kind of sound effect. If anybody is interested, there are a few write-ups on BACCH technology in Archimago's blog here and here, and more info on Theoretica's website about how it works. There is also an easy to digest wikipedia article. Plenty of resources to look at. There is real science involved, this is not some mere effects plugin.

As an EE and 30 years as a recording engineer I understand exactly how it works. Crosstalk cancellation is nothing new. Its an effect, like EQ or compression or artificial reverb. It CHANGES the sound. How can you deny that, Dunning.

Google Search

 

[Dialectic]

Here’s an example of an actual set of measurements from the BACCH4Mac

Very impressive numbers.

What speakers are you using? Room treatments?

 

[STC]

As an EE and 30 years as a recording engineer I understand exactly how it works. Crosstalk cancellation is nothing new. Its an effect, like EQ or compression or artificial reverb. It CHANGES the sound. How can you deny that, Dunning.

Google Search

You are not the first EE or recording engineer to say so. There was another Grammy winner audio engineer had the same opinion but thankfully he was in Spatial Audio forum where he was corrected by an eminent member of the topic. Sound effect is what you do to the signal before coming out the speakers. Crosstalk cancellation deals with the sound after coming out from the speakers. There were many AES papers on this topic. The was an institute which was part of AES technical tour.

 

[Justdafactsmaam]

As an EE and 30 years as a recording engineer I understand exactly how it works. Crosstalk cancellation is nothing new. Its an effect, like EQ or compression or artificial reverb. It CHANGES the sound. How can you deny that, Dunning.

Google Search

It doesn’t “change” the sound. It prevents the cross talk from damaging the sound. It is objectively more accurate.