27. March 2025
I got the chance to generate correction filters for quite many systems, ranging from desktop to very high end ones. I thought it could be a good idea to share some objective data as information on how neutral loudspeakers and rooms can be for audio enthusiats. The data are based on a little bit more than 200 different systems. I have extracted some important features you will see below. First one is the direct sound from the speakers at listening position. To ease the comparison I have scaled...
04. January 2025
Born in 1973, I mainly listened to CDs and it was only much later that I rediscovered vinyl. I had a negative preconception, as my experience was limited to the family turntable, and I didn't expect to get such a good result: charm outweighs pure fidelity, and listening has a natural, immersive and non-tiring feel. With the improvement of DACs and the advent of computer based hifi, the situation has changed: maintenance, wear, surface noise and the poor quality of certain pressings have taken...
14. September 2024
In this short article, I'd like return to a unique feature of my filter generation service. This is the differentiated management of direct and reverberated sound. As explained in the “Technology” section of my website, it's vital to have both direct and reverberant sound well balanced and consistent between them. Reverberant sound is impacted to first order by the radiation pattern of loudspeakers, and many of them show defects, particularly in the transition zones between different...
23. December 2023
It is quite usual to assess and represent the impact of a room by only plotting its frequency response at listening position (or multiple positions) …. And most of the correction systems or DIY methods are only using this information to generate filters. This is a significant shortcut as any signal is only fully defined by the combination of its frequency (magnitude) and phase response. The same applies to the impulse response, the signal that characterize the room behavior. We can find an...
30. March 2023
The commonly agreed requirements for loudspeakers crossover filters are Flat magnitude of the combined output Sufficiently steep rolloff slopes between the output bands Acceptable polar response Acceptable phase response Increasing the rolloff slopes has a very positive impact on distortion and imaging: each driver operates in its own frequency range and the overlap region is reduced. There are many resonances from woofer or mid range drivers that could be avoided by using crossovers with...
19. June 2022
So far Room Shaper playground was the low and medium range. We have now managed to extent its operational range to higher frequencies. Even if the concept of reverberation time mainly applies to large rooms like concert halls, it can be extended to smaller rooms by looking at the energy decay time and how it evolves depending on frequency range. Large fluctuations of decay time in narrow frequency bands is a fingerprint of small room in the low end where resonances dominate. In the upper range,...
15. February 2022
Although not described in the original stereo proposals, the 60° playback angle has become the standard over years. Sound engineers are using this configuration during the different stages of recording & production process. You might not have this standard 60° configuration at home for different reasons: installation constraints, personal preference, use of acoustic crosstalk reduction (lower span angle improve effect robustness) Any deviation from the standard configuration has an impact...