Rerurn to Romy the Cat's Site


In the Forum: Audio Discussions
In the Thread: Measuring reality: empirical mode decomposition
Post Subject: IntermodulationPosted by el`Ol on: 3/5/2008
I don´t know whether the audio industry`s products are so sophisticatet that they need mathematical steam hammers to improve them. In a German forum there is a discussion about a diploma work from the TU Berlin where the student found out in psychoacoustic tests that the subtraction frequency of the intermodulation products is the non-linearity that interferes most with the perceived sound quality, and built a valve anplifier that is optimized in this respect.

Quote:

"Der "BLACK CAT 2" hat einen Dfferenztonfaktor von 0,002% und einen Klirrfaktor von 0,033 %, während der Telefunken HA990, als Beispiel eines handelsüblichen HiFi-Transistorverstärkers, einen Differenztonfaktor von 0,366 ( das 183-fache des BC2 ) und einen Klirrfaktor von 0,0048 hat."

What can be critizised is that he compares his amp with a quite old mass product, but he says it is representative for what average people have in their living rooms. However, finding out that the subtraction frequency factor of this mass product is two orders of magnitude above its THD, where in his amp it is one magnitude below, is quite shocking.

Rerurn to Romy the Cat's Site