Vibration Control and the Townshend Audio Seismic Pods


Vibration control has been a big thing with me going back to the early 90's. Recently, over the last few months, I've been experimenting with various types of springs and comparing a number of them. The whole story, more or less, is laid out in Millercarbon's Mega Vibration Control Journey https://forum.audiogon.com/discussions/millercarbon-s-mega-vibration-control-journey  Spoiler Alert: Millercarbon has added springs to his Mass/Stiffness/Damping approach to vibration control. 

For more on the story of springs check out noromance's thread here: https://forum.audiogon.com/discussions/springs-under-turntable?highlight=springs%2Bunder%2Bturntable
Ordinary eBay springs were working great under my amp and speakers. The Nobsound springs were working great under my turntable. Especially good for the money, I thought. Until some kind of really bad feedback/resonance problem came up- a powerful rumbling that at first sounded like it might be turntable bearing failure.  

Eventually the problem was chased down to a lack of spring damping. Basically, once a certain frequency got going it would resonate, and quite loud. Even the slightest damping would eliminate it. But this got me thinking. Surely this was only the most obvious form of resonance. There's no damping on any of these springs. Its only just by coincidence this happened to be so obvious. Plenty of others using the same springs without any problems.  

Still, it got me thinking. There has to be some damping or the spring will just bounce, maybe even getting into a resonant mode like my turntable was doing. There has to be some damping. But not much, or it stops being a spring. The trick is to somehow get the isolating bounce of the spring combined with enough damping to eliminate resonant feedback. Kind of like on a car, you need damping for control in curves but not too much or you won't have a smooth ride. Townshend Seismic Pods are made with 0.16 damping factor. This finally convinced me to give them a try. 

Seismic Pods are a spring wrapped in a rubber bellows. As the springs compress it causes the bellows to force air through a small hole. The bellows and hole are engineered to allow free movement for isolation of very small vibrations, yet while still providing adequate damping for avoiding problems with resonance. Seismic pods are sized by component weight. In my case both my amp and turntable are right about 75lbs. 

The Townshend Pods are a good deal more user-friendly than Nobsound or my DIY springs. They are covered top and bottom with a thin felt that made them easy to slide around and adjust. The threaded top turns easily even under load, making leveling easy and precise. No more shims! My turntable was more level than ever before- and faster! 

The sound was at first listen just a wee bit underwhelming. Perhaps my expectations were set a bit too high? The longer I listened though the more apparent it became there was a whole lot more refinement now. Instrumental texture and tonality were rendered a lot more clearly- string guitar sounding more believably string guitar-like. Certain bass lines were now more smooth and natural than before. By before I mean before the other springs, before BDR as well. Smoother and more natural than ever. There was a noticeable improvement in low extension, particularly in terms of slam and at the lowest frequencies, but the top end, other than losing a bit of grain and becoming a bit more liquid, was little changed. 

All together a very nice improvement, if one that left me scratching my head a bit wondering why it wasn't even better still. This after all is a turntable. What one might think would be the best place to show off what the Pods can do. To be sure, there was real significant improvement in tone and texture, with a lot more detail coming through and in a lot more natural sounding way. Maybe I was just expecting too much? 

Next they went under the Melody. The turntable experience had reset expectations for the integrated amp, which may be why I was so blown away. Where the Pods under the turntable were all refinement, here they were all balls! Dynamics! Extension! Now you're talking! It was like the experience with the Tekton Moabs, suddenly the music just comes alive with incredible detail and yet in a very natural non-fatiguing way.  

The talk from Townshend is this is due to the "very sensitive tube grid" which does I guess make sense. Electrons stream across, its a physical flow that of course vibrations will affect. Everyone is familiar with tube microphonics. The same only different, as they say.  

Whatever the explanation the fact is the improvement is impressive. The sound was already good but now is even that much more alive. No downsides I have been able to identify, and the more I listen the more I like em.




128x128millercarbon
Yes goose that's what I did and forgot to mention so thanks for bringing it up. John Hannant helped me out a lot as they have a lot of experience with loading and using under a wide range of components. Springs are interesting because they are a lot more sensitive to tuning for mass than other things like a cone or shelf. Townshend Pods are a lot better designed and sound a lot more balanced than plain springs. They are also a lot easier to use especially in terms of leveling. 

Its been a while now and still I sometimes put a record on and am amazed how much better it sounds now. sokogear ordered a set for his Rega and he's impressed and happy. That table is very light and John helped set him up with the right Pods and a platform that adds mass and stability. He hasn't written it up but sent me a message, seems he is pretty happy.
Townshend Pods were so good under my turntable and amp that I decided to try them under my Herron phono stage. The Herron is on the bottom shelf of my solid concrete rack. The bottom shelf includes a bed of sand mixed in mineral oil and about 2" deep. MDF pads are on top of the sand with BDR Round Things and Cones on top of the MDF pads. This is the way it was run for many years with excellent results. 

Until last year experimenting with springs showed they are quite a bit better than even the much more expensive BDR. Springs have less of a hard glare edge and more of a natural ambient sort of sound. But I learned from experience they have resonance issues and are very sensitive to load. Too much compression and the sound is too bass heavy, too little and it is too lean. Get it just right and it can be quite good, except for the resonance issues that affect the tone balance. The problem almost certainly being the lack of damping.  

Townshend solves the damping problem by wrapping the spring in a flexible rubber bellows. The base at the bottom is sealed, while the top piece has a very small hole. Compression and expansion forces air through the hole. The result is a small and precision engineered shock absorber. Components on Townshend Pods will bounce, but not freely. They settle down pretty quickly. Easy to see. The same happens on a micro scale. This has to be why they are so darn beautifully neutral.  

This makes three times now I have gone from BDR to springs to Pods. Turntable, amp, and now phono stage. Was expecting big things from the turntable and was not disappointed. Was not expecting as much under the amp and was pleasantly surprised. Was again not expecting a lot under the phono stage and this time was really surprised.

It must be the combination of tubes and sensitive high gain. Tubes for some reason, apparently if the plate vibrates this directly impacts the signal, which makes sense. In any case, impressive improvement. 

The already excellent sound opened up even more. Vocal and instrumental timbre is a lot more individual and recognizable. Inner detail comes out now like crazy. Never thought the sound was veiled before but now it is like it was under a blanket and now with the Pods the blanket is gone. Really impressive. May be the best yet. For sure at least as good as under the amp.


Searched and can’t find online direct comparison of Townshend, Isoacoustics and Critical Mass

anyone tested and compared these for turntable isolation?
 

 

rawlit, I found some comparisons with people that tried the isoacoustics gaia's and after trying the Townsend podiums they said that the podiums were on a total different level, as good as the iso acoustics were the podiums were even better.