Filter Difference… MEASURED!

While we have said time and time again the Vibro Veritas is not the most accurate of measuring tools, what it is great at is picking out the differences a tuning system can make on an IEM, in this department it is accurate!

Lets start by combining all filters on one graph to see how it all stacks up! The Black lines will be bass, silver reference and orange(y) treble. Just like the filters IRL!

16T20 Filters Correct

Now looking at the bass you may feel as though there is variance but that is all channel imbalance, in reality the bass is identical in frequency response on every filter. Unlike what RHA are claiming with their on site measurements. In fact the following graph makes out that there is one curve for the reference filter, then treble has a boost throughout the treble. Then it shows bass have a small boost throughout the bass. Wrong and misleading.

Screen Shot 2016-07-29 at 12.29.52

The real answer to the filter system is between 2 and 5kHz, with there being roughly 3 decibels of gain difference from bass to reference and then again from reference to treble. Seems like a silly naming scheme when they all have the same amount of bass….

Lets quickly break them down so you can see them all separately. Starting with the bass measurements.

16T20 Bass

Now reference…

16T20 ref

and lastly treble!


As you can see on all of them the bass grows about 8dB from 1kHz to 100Hz but there is also a small variance between left and right for everything under 1kHz. Things are much more in tune above that! Again in all filters, just to a different degree there is a jump up towards 2kHz and then a hold there until 5kHz, before things calm down a bit!

Josh Coleby
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