Blog Posts | PURIFI

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SPK16 Reference Design

PURIFI ApS, Lars Risbo

SPK16 Reference Design

Note: SPK16 is now released as a kit with build description SPK16 is a passive 2 way speaker system with a 6.5X-NAA alu cone woofer assisted by two passive radiators on the sides of the box combined w...

Ushindi

May 9, 2023

0 58428

Tech Notes

Low Distortion Filter for PTT6.5X04-NAA

Low Distortion Filter for PTT6.5X04-NAA

In the following, we show that not all methods of equalization are created equal. In particular, using a series notch reduces distortion, which does not happen with alternative methods. The proposed circuit results in an extremely clean low-pass response combined with low distortion...

Ushindi

Nov 16, 2022

0 24619

App Notes

Some Speaker Problems That Needed Solving

Some Speaker Problems That Needed Solving

Some time ago we posted on our website a pair of sound demos that we thought were quite instructive. One showed that Doppler distortion was much less audible than an equivalent amount of amplitude modulation, thereby sinking a lot of “masking theory” based audio discourse...

Ushindi

Oct 14, 2021

0 12870

Tech Notes

This Thing We Have About Hysteresis Distortion

This Thing We Have About Hysteresis Distortion

*Read any Purifi interview and someone is sure to mention hysteresis distortion (or iron distortion, same thing). What is it about and how serious is it?* Hysteresis happens in any coil that has a ma...

Eigentakt Ushindi

Apr 28, 2020

0 14629

Low frequency harmonic distortion is almost inaudible. So what’s the point of low distortion drivers?

Low frequency harmonic distortion is almost inaudible. So what’s the point of low distortion drivers?

Decades of research has shown that we’re not very sensitive to distortion at bass frequencies. I doubt if anything has happened to our species recently that would change that. Consider the science set...

Ushindi

Dec 12, 2019

0 11915

Tech Notes

Distortion, The Sound That Dare Not Speak Its Name

PURIFI ApS, Bruno Putzeys

Distortion, The Sound That Dare Not Speak Its Name

Read any discussion about loudspeakers and you get the impression that distortion as a topic is eagerly avoided. If it is mentioned, it is done sotto voce, implicitly. For instance: “you can’t get goo...

Ushindi

May 2, 2019

0 13113

Tech Notes