Software

Wow and flutter analysis application

Nothing to do with World of Warcraft or Betty Boop!

Jim Lesurf has released an application called LP_WowAndFlutter, with which you can examine and measure any “wow and flutter” produced by an LP replay system which, with vinyl apparently coming back into fashion, might be useful when those old turntables are pulled back into service.

Wow and flutter is a variation in pitch that may be caused by flaws either in the equipment or the playback media – though it’s only possible to use an application such as Jim’s to analyse the equipment itself, such as the rotation rate not being perfectly steady. Such flaws result in the stylus not be moving as it should, with the extra movement result in those pitch variations.

To use the software, you need to (get hold of and) play a “test LP” and record a suitable test tone – the standard recommended tone bing a 3,150 Hz sine wave, though Jim says the program should work for a range of test tone frequencies from around 1kHz to over 5kHz, as well as for square or other periodic wave shapes.

That recording needs to find its way onto your computer – and into the application – as an LPCM wave file. LP_WowAndFlutter will then analyse the file, and from that provide you with the relevant figures. The results, which Jim explains are produced in a way defined by the Audio Engineering Society, will tell you just how far out of kilter your equipment is.