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.
Now, I nevercheck in in my system the Tacet testing record but Iown many others and the best for me is the D2D Ortofon test recording,just splendid. We have to remember here that Ortofon not only manufacture cartridges but even cuting heads that speaks of Ortofon first hand experiences with that subject.
Time to time appears on ebay.
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@richardbrandFor your edification, Paul Miller’s technical evaluation I copied from the Nov 4, 2021 Hi Fi News and Record Review. At the bottom are included are his findings of vertical and horizontal compliance as well as trackability which seems to be very much in line with MCs in general as well as the rest of the performance parameters he lists. DS Audio DS 003 Cartridge Lab ReportLab Report Like the DS-E1 [HFN May ’19] and earlier DS 002 [HFN Jun ’17], the DS 003 may employ a basic crimped alloy cantilever but its line-contact stylus has more in common with the former (Shibata) than the latter (elliptical). Its tracking performance beats both, however, not least because the downforce range has been increased from 1.6-1.8g to 2.0-2.2g in the third-generation DS 003 and Grand Master [HFN Feb ’21] ’optical’ pick-ups. Unlike the DS 002, the DS 003 cleared the maximum 80µm groove pitch (75µm on the right channel) and the most severe +18dB modulation (315Hz lateral cut, re. 11.2μm) at 1.7% THD. Says Aki, ’In the 2nd generation vibration system, the distortion rate was consistent regardless of the stylus pressure, but in the 3rd generation, the distortion rate decreased when the stylus pressure was increased.’ In practice distortion is slightly lower at 1.5% (DS 003) vs. 1.7% (DS 002; 1kHz/5cm/sec) but trends higher at 0.55-15% (20Hz-20kHz, –8dB re. 5cm/sec) vs. 0.45-10% for the lateral cut [see Graph 2, below]. The latter is as much a function of the DS 003’s improved HF frequency response where the +7dB/12kHz peak from the DS 002 is traded here for a less aggressive +2dB (left)/+3.8dB (right) boost at a higher 14kHz [see Graph 1, below]. The symmetry between lateral [L+R, black traces] and vertical [L–R, red traces] is also excellent while the stereo separation is improved by a huge 10dB (25dB to 35dB) – both clear benefits of the 3rd gen dual optics/shading plate mechanism. Finally, as we’ve seen before, bass output is also boosted, reaching +4dB and +2dB/20Hz via 30Hz and 50Hz settings (first-order roll-off selected). PM
Frequency response curves (–8dB re. 5cm/sec) lateral (L+R, black, 30Hz cut; dashed, 50Hz cut) versus vertical (L–R, red, 30Hz cut)
Lateral (L+R, black infill) and vertical (L–R, red) tracing and generator distortion (2nd-4th harmonics) vs. frequency from 20Hz-20kHz (–8dB re. 5cm/sec)
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That was what you originally posted, followed by
Hopefully you have only one warp per record, so it will have a fundamental frequency of roughly 0.55-Hz, which is in the wow range below 6-Hz. A bit higher up comes the flutter frequency range of 6-Hz to 100-Hz. Meanwhile rumble is usually below 30-Hz. Of course the Japanese measure these things differently. It is like me telling you it is 40-degrees and stinking hot, whereas you think that is near freezing. Unless you are a physicist, where it is a very, very deep freeze indeed.
Stethoscopes don't pump blood either, but they have become essential badges of honour for doctors. They are fantastic tools for tracking down the sources of vibration in a turntable. By moving the stethoscope to different parts, you can determine how much noise is transmitted throughout the structure. Hard to use on a rotating platter though! | ||||||||||||||||||
Explains in part why the Holbo has such a low noise floor. The 5-kg mass of the platter is supported on a 10-micron (I think) layer of air. The non-metallic spindle is made of engineering plastic (Delrin) and is only needed to centre the platter against the slight pull of the drive belt. With the drive belt removed, the platter takes about 3 minutes to stop from 33-rpm. Placing the 625-gram puck on the edge of the platter is enough to ground the 'hovercraft effect' even with the air on. It is used during final levelling of the tonearm support shaft to stop the platter rotating, while the arm bearing is still floating freely on a 10-micron cushion of air. In this thread, Holbo has claimed a 100-fold reduction in noise compared with 'normal' bearings. I am sure this contributes to me hearing low level recording artefacts that are masked on most systems. It also brings to the fore musical detail that is otherwise lost. | ||||||||||||||||||
Thanks for that review of the DS Audio DS003 optical cartridge. I had seen it before, but this detail escaped me:
@billstevenson This is great corroboration of the ’clearer sound’ effect I noticed when adding your 5-gram weight, which as a by-product increased tracking downforce by about 50% because the balance weight reached its limit.
This is the first time I have noticed vertical and horizontal compliance reported individually, but the frequency is not specified, and I didn’t know what cu meant |
. It is higher than the 7cu at 125-Hz I saw in another review, which I previously used for the Vinyl Engine calculations.