Vinyl and subwoofers


I have a pair of Thiel 3.6 and a Thiel ss1 sub with the prescribed Thiel crossover. I have a pretty good vinyl rig with a Clearaudio performance se, Stradivari cartridge and a ARC PH8 phonostage. Although the Thiels go down to 20hz, an audiogon member  persuaded me that I was missing something without a subwoofer. What I have heard with the Thiel SS1 sub and prescribed crossover is an amplification of record imperfections I was not aware of without the sub. As well, the overall sound seems often muddied. Has anyone else had this problem with vinyl? Is this a problem with my setup? Any insights are very appreciated.
golferboy
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just a quick thought here.  Not being familiar with ARC phono stages, I am wondering IF the phono stage is inverting phase, which might account for the subwoofer's odd performance when playing vinyl vs the same sub working fine when playing other sources.  Not saying that it does, just something to consider....  good luck!
I use the Hsu Research ULS-15 Mk II with my system (look it up if you like) and my experience has been that with proper placement, volume and crossover settings, it enhances everything -- including good vinyl recordings.

Good luck!
If the sub is working OK with other sources, I suspect the problem is most likely a less than optimum TT set-up.  Might not be well-isolated.  Might have motor noise breaking through.  Belt tension off. 

Though the ARC PH8 is a pretty good phono stage, you might be getting noise from that unit.  Bad tubes, power supply problems, other issues? 

It could also be that the phono stage is picking up noise from your DAC, computer or digital player.  There's a lot of gain in your phono stage.  Wouldn't take much to introduce noise into the signal.  Might be breaking through inadequately shielded cables.  Try playing vinyl without any digital devices operating. 

Possibly try testing the phono stage with the arm park on the arm rest.  Try unplugging the table and seeing if there is noise coming from the phono stage.  (it's loaded so that shouldn't be an issue.)
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