Where do classical vinyl records get their rumble from?
Recently converted back to vinyl from silver disks, I am struck by how much rumble seems to be inherent in the new and used vinyl I am buying.
A case in point, is a recent Deutsche Grammophon (DG) recording (487 7484) of Mahler’s Second Symphony made at a live performance at the Sydney Opera House (I was there). The first set I bought was amongst the dirtiest pressings I have ever had, but the second set was much improved. However, there is a persistent rumble whether played on my Holbo Mk2 air bearing system or my venerable Garrard 301 (new bearing from Classic Turntable Company).
Mahler typically has huge dynamic range, from muted off-stage performers to hundreds of musicians going hell-for-leather.
The rumble could be partly caused by the venue’s air conditioning system, but I hear similar background on a Telarc recording (Stereo 10051) of Saint Saens Organ Symphony made in Philadelphia. Telarc even arranged to have local roads shut down for the recording sessions.
Similar efforts were made by DG when recording the organ at Notre Dame in Paris, where recording was done late at night to reduce traffic noise. My copy includes Dolby Atmos on Pure-Audio Bly-ray (DG 486 1466).
I was beginning to think the rumble was inherent in my tables, but then I played a German Direct Metal Mastered (DMM) set from In-Akustik for Clearaudio’s 40th anniversary (INAK 78051 2LP). It includes some Telarc tracks. This set has the quietest background I’ve never heard. There is virtually no rumble, exonerating my tables.
So apart from the recoding venue’s air conditioning and traffic noise, why do so many classical records seem to have built-in rumble? Could it be from the mastering lathe?
I am really only thinking about classical recordings where the dynamic range approximates the signal to noise ratio of vinyl, meaning that very low-level signals are musically important, while simultaneously bumping against the noise floor.
