Next time you strike a case of “Woofer Pumping” take a close look at the cartridge when it is playing and you can probably see it wobble up and down after the warped section has passed. It is a bit like a car with no shock absorbers on a bumpy road. This cartridge / arm combination or mismatch is easily excited into large scale un-damped low frequency oscillations when it encounters a warp or large scale vertical irregularities such as a bubble or a delamination in the vinyl pressing. It is typically caused by a cartridge / arm mismatch, usually a high compliance cartridge in a medium or high mass arm. The problem of “Woofer Pumping” as you describe it is not usually caused by a bit of extra dirt in the groove. Although the Cyrus one sounded brilliant on both Moving Magnet and Moving Coil I always thought it sounded “Bass Light”. Prior to that I used to own a Mission Cyrus One which had a permanently “ON” warp filter. Before that I used a pre-amp I that I built myself and its response was engineered to be flat down to 3 Hz. My curent phono stage is a Project PhonoBox SE and has its Warp filter turned off. It did make some difference, but didn't come close to eliminating the issue.Just my Two cents worth but I have never needed to use a Sub-sonic or Warp filter. I also added one of those 20Hz -12dB/Octave in-line RCA filters at the subwoofer. This shouldn't be a compliance issue with my Tonearm/Cartridge combo? I turned the volume up, and I could see the woofer flutter. I did an experiment where I turned the platter off and just rested the needed on an album. The entire bottom surface is resting directly on the floor. The new Martin Logan Grotto i did not come with any floor spikes. The entire thing is wrapped in very dark cloth. Also, it's VERY difficult to see the drivers with the Vandersteen sub. The first sub (Vandersteen V2W) never appeared to have issues, but that sub is decoupled (if that even matters) from the floor with spikes resting on brass disc. That really eliminated any audible rumble that I was having. I purchased a set of four Herbie's Tenderfeet, and used them in conjunction with a bamboo cutting board as a phono stand. My room has laminate flooring, and I was setting the Rega on a buffet which is where I store my albums). When I first got my TT, I had audible issues. I think the final solution is going to need to be a combination of isolation and subsonic filtering. I have 4 tenderfoots under a bamboo cutting board, and then 4 more tenderfoots under the turntable. My turntable is isolated with two sets (8) of Herbies tenderfoots. At $180 I would much rather spend the money on a better phono preamp.Īdditional info : My turntable is a modified Rega RP1 w/Ortofon 2M Blue cartridge. If this thing was $50 it would be a no brainer. I wonder why the new ones are different?ģ) KAB RF1 - Strictly a subsonic filter. I was looking at some of Pro-Jects older products such as the Phono Box II SE and they were 18Hz with a 24dB/Octave attenuation. It starts at 20Hz and attenuates 12db/octave. I can't seem to find this info anywhere.Ģ) Pro-Ject Phono Box DS - Has a built in subsonic filter. I also don't know how steep the filter slope is. So far I've been able to come up with three options.ġ) Cambridge Audio Azur 651P - Has a built in subsonic filter, but I have no idea what frequency it starts to filter. My current Phono preamp is a Rega fono mini so my current line of thinking is to get an upgraded phono preamp that has a subsonic filter. I just picked up a second subwoofer for my system, and now I have the dreaded woofer pumping issue when playing Vinyl.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |