Townshend Audio Podiums: The Full Review


I’ve been fascinated with the importance of vibration control for more than three decades now. A lot of my experience is already covered in Millercarbon's Mega Vibration Control Journey https://forum.audiogon.com/discussions/millercarbon-s-mega-vibration-control-journey The Journey ended with springs. Then I got Pods, and wrote Vibration Control and the Townshend Audio Seismic Pods https://forum.audiogon.com/discussions/vibration-control-and-the-townshend-audio-seismic-pods Now as we continue our journey forward it is time to review the Townshend Audio Podiums.  

Podiums are based on the same basic engineering used in Pods. A spring is encased in a rubber sleeve that functions as a sort of bellows, trapping the air inside. At the top the spring is attached to a threaded metal plate with a single very precise small hole in it. The threads are for height adjustment and the hole is to allow air to pass through. A very small, precision-controlled amount of air. This tiny little hole allows the air to function as a damper.  

A fundamental challenge with springs is they bounce. We want them to bounce. But we do not want them to keep bouncing! When that happens we say it resonates, and resonance adds color. It is a form of distortion, and we don’t want it. Springs all by themselves are already very good at isolation. Please read the above threads to see just how good they are. But even as good as they are springs do have this problem of resonance.  

The problem with damping is figuring out how to achieve it, and how much to use? The air valve method Max Townshend invented uses only a couple percent damping ratio and does this with air alone and no moving parts. Genius!  

The four damped spring towers are attached to a very dense, massive and inert plinth. My traditional knuckle rap test yielded a very satisfactory ’thunk’. Stiff and highly damped, it is also covered in an extremely durable and beautiful finish. Sliding speakers on and off left zero marks on them, and they really are handsome to look at.  

The damped spring towers at each corner are threaded for two different leveling adjustments. The first is to level the unloaded Podium on the floor. This first step eliminates any problems or situations where the floor is not perfectly level. This adjustment (if necessary) is made with a special thin wrench that comes supplied with the Podiums.

The speakers are then placed on the Podiums and fine tuned for precision placement. At this point, loaded with 150lbs worth of Moabs, making fine positioning adjustments on my thick carpet proved a bit of a challenge. The solution I came up with was BDR Round Things under the footers. Furniture gliders would probably also work. If it is even a problem. My carpet and pad are very thick. They do look like they will work beautifully on hardwood flooring.  

Once perfectly positioned the speakers are raised by turning the knobs at each corner. There is a process to doing this. First all four are turned equally, until all four corners are floating free and clear. It is essential to allow freedom of motion in all planes. Once this is achieved then the speakers can be adjusted perfectly level by turning the knobs in pairs- the two on the left or right, or the two on the front or back. Adjusting in pairs this way avoids diagonal rocking.  

Describing this process in print is hard but doing it in practice is easy. In fact this was the coolest part of setting them up! With the Podiums I was able to place my level right on the Podium. Even fully loaded with about 150lbs of Moabs and BDR the knobs turn silky smooth, and precision leveling is super easy.

Okay, okay, so how do they sound? In a word: wonderful! This can’t come as much of a surprise. They are after all basically Pods attached to a plinth, and the Pods work wonderfully under everything I have tried. Still, the Podiums are pretty impressive.  

The first thing I noticed was improvement in the direction of what I would call a more natural sound. Natural sounds are almost never described as having glare or strain. Natural sounds can be quite loud. But there is a difference in nature between a loud natural sound and the same sound through a system. They may measure the same volume but we have no trouble hearing the difference.

At this point I have to agree with Max and say that the difference is ringing. Natural sounds start and stop very quickly. Sounds reproduced by our systems cause the system itself to vibrate, then the room, and the room feeds back into the system until the whole thing is ringing like a bell. This all happens very fast and can be seen demonstrated on a seismograph placed on a speaker. https://youtu.be/BOPXJDdwtk4?t=6

In any case, whatever the explanation it is clear there is a lot less glare and strain with speakers on the Townshend Podiums. This results for me in a lot less listener fatigue. Another thing I find is that while I don’t necessarily need to turn the volume up, when I do it is way more enjoyable! The combination of speakers like Moabs capable of playing very loud and strain-free with Podiums is intoxicating!

The next thing I’m hearing is a massive improvement in what I would call truth of timbre, or tone, or whatever you want to call it that makes each individual instrument sound more like itself and not any other. Not the big differences that distinguish a steel from a string guitar, but the little details that distinguish one wood-bodied gut-stringed guitar from another. Not hyped-up count the spittle hitting the mic details either but the sort of tonal shadings that distinguish the real vocal talent from the second-tier. Even now after more than a month on Podiums still I put on records that have me going Wow that wood block really is a wood block!  

This is why I spent so much time explaining Max’s damping mechanism. Before Podiums my Moabs were on springs. The load was the same, and the springs were properly sized for the load. However, the springs on my DIY platforms were not damped. Consequently, they had their characteristic resonance. This resonance colors everything played on them. Like viewing the world through rose-colored glasses- you may like what you see but that ain’t the world! Now on Podiums the world as presented by the Moabs is full blown Ultra Panavision 70! https://vashivisuals.com/the-hateful-eight-ultra-panavision-70/

Those who follow me know I am not just about sound quality, I am also about value. Because I am so passionate about sound quality, but have only limited resources, I have to be. No way I have enough money to go chasing the latest and greatest. One look at my system anyone can see how hard I will work if it will get the job done for less. https://systems.audiogon.com/systems/8367 

For sure springs will do a very fine job for very low cost. Just about any spring, properly tuned and used, will outperform an awful lot of stuff that costs a whole lot more. For sure anyone in the market for good vibration control solutions- and that should be everyone! - should consider springs. But Townshend Podiums are so much better than ordinary springs that I have to say that even at their price they are not just as good value, but even better. They are that good.


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Showing 14 responses by bluemoodriver

The magnet isn’t meant to move of course. The coil does - probably less than a 10th the mass of the magnet. So the vibration movement of the cabinet in the vertical plane is probably a 10th of that estimate. So that’s 0.00001 mm every 200th of a second. 
Just the thing for a steel spring and bellows to sort out!

must be why not a single speaker manufacture has this as part of their design. 
So say the driver mass of (say) 1kg moves 1mm at 200 times per second (reports of improved soundstage means it must be higher frequencies that are benefitting).
The cabinet moves the opposite way. If the cabinet is 100 times the mass of the driver, it will move 100th of the distance. (Newton). That’s 1/100th of a mm.

But, assuming that the driver is mounted horizontally, that’s 1/100th of a mm parallel to the floor. But the springs are perpendicular to the floor. So we need to know how much of that 0.01 of a mm is left when the cabinet rotates around its centre of gravity. Probably very little indeed. Beyond my maths skills. Say 100th? If so then vertical component is, say, 0.0001mm. 200 times a second.
That’s one hell of a spring and damper you’ve got there! I doubt very much that an engineer would use a steel spring and an air-damped bellows to cope with 0.0001mm of movement 200 times a second between a 100kg cabinet and a floor.

A blob of blu tack might be perfect though if you have a solid floor. After all, it’s what Synergistic Research recommended for those HFT devices...

if you have a carpet, well, I guess the carpet would be perfect.

So the sound we hear comes from the diaphragm, pushed back and forth by the voice coil within a magnetic field and restrained by a spider and a rubber surround. All the moving components are insulated brilliantly from the non-moving components. That’s how a driver works. Kenjit argues the cabinets should be the heaviest concrete possible and gets shouted down, but maybe his reasoning is good. Anyway, those diaphragms whiz in and out suspended from anything which shouldn’t. They push air. The air vibrates everting around - floor, walls, mug of tea, ear drums. And these vibrations are shared around, so the cabinets get some too either directly because the driver’s design has less than perfect isolation, or indirectly because they are inside a vibrating air mass. 
Question - does any of the secondary vibration imparted to the cabinet make it all the way back through the isolation of the diaphragm and voice coil in a way that affects the primary production of sound waves?  Very unlikely indeed at all, and in a measure able amount I’d say no. 
So if your cabinets are vibrating because the air in the room (and therefore the floor they sit on) is vibrating, what does it matter?  If the seismograph in the video was mounted on the driver cone and the chap jumped up and down, would you see a trace?  Any trace would be due to the direct effect of any air vibrations on the diaphragm itself. There is literally nothing you can do about that. Apart from scale everything down and use closed-back headphones. 
If you worry about your cabinets ringing due to them being vibrated by the air in the room, you could cover them in sound insulating materials - aka room treatment. Might spoil the look and obscure the signatures though. 

MC - I said the diaphram and voice coil are isolated from the cabinet. That’s how they move. 
And by the way, compared to what is going on inside those cabinets, these vibrations from external sources are so many orders of magnitude smaller (whether additionally damped or not) they are unlikely to have any non-psychoacoustic effect at all.

Hence why no reputable speaker manufacturer floats their engineered-to-death products on springs and bellows, or coats them on the outside with wool and foam like they do on the inside.  If there was an effect, they’d know. Given the willingness of some in the market to pay for even the tiniest (or even imaginary) gains, they’d sell it I’m sure. None do, so I’m guessing they realise that the reputational harm caused to their brand by quackery would be too great. 
A little startup though, with massive margins on their pretty-looking kit sold to the unquestioning part of the audiophile market?  Worth a punt. 
Oldhvymec - you build you own too?  I get the philosophy of no cabinets. I went the other way and made the cabinet part of the instrument; back loaded horns. The middle way (box cabinet, sealed, cube not spherical, loads of crossovers, and still hope it “disappears” when the music starts) always looked a compromise too far for me. Hence the looking for alternatives.
Coincidentally my dog just barked really loud. The room I’m in rang with a slower decay than her bark in the air. The dog has nature’s isolation pads on her feet but hey, the ringing still happened.  If she stood on her claws when she barked, you think the ringing would be noticeably worse?  Or if she jumped in the air to bark, noticeably better?  Doubt it. 
I need some help with the scales on the charts in that video. 
The left scale is labelled dBv. And the peak with spikes is about -105 on that scale. 
Am I right, that -105 dBv converts to -101 db?

and when the isolation pads were used, the peak reduced to -115 on the dBv scale.  Does that convert to -110 db?

Aren’t all these very substantially below the level of our hearing?  Does a change from -101 to -110 mean anything?
I can’t imagine this manufacturer would make an argument based on such numbers so my maths must be wrong. Can someone put me right?



I’ll leave you to your belief that a difference between -115 and -105 dB in a small part of the frequency spectrum of some music is noticeable. 
My question is whether the graphs in the video show -115 to -105 dB changes between spikes or no spikes. 
It kind of matters, because in the final graphs - the green and blue ones showing the change in decay, etc, also have an axis, this time in dB, and the entire scale is again in the negative. I.e. the inaudible range to human hearing. 
Unless I am mistaken (and I am asking someone to tell me I am) this entire video by the manufacturer of the isolation feet is showing sound problems and sound change outcomes which are all below the volume range of human hearing. 
Maybe you think that’s not the issue. But I’m just looking for someone to say whether I’m reading the graphs wrong. 
Mahgister - I thought negative dB was below our audible range. By definition. 
That’s what I can’t work out with the graphs on that video. It seems the differences caused by spikes or no spikes are all far, far below what humans can hear. 
But why would a manufacturer put that on their marketing video. Doesn’t make sense hence my request for help. 
Right - no help was forthcoming, so I've been reading into the meaning of a change from -105 to -115 dBV in a before and after measurement of the effect of these isolation stands.  

I think - and I remain very happy to be corrected in any of this - that:

dBV (capital V) is a ratio, expressed logarithmically, of a measured value relative to 1 volt.  1 volt is therefore zero, and smaller values are negative.  So your Credo chap excited the speakers with 1 volt RMS of energy (0dBV) in the form of that sound sample, and measured the amount of energy in the vibrations following that excitement - or at least expressed the ratio between them in that form.  Without the isolation, the amount of energy relative to that 1volt in the resulting vibrations was -105dBV.  This means of the 1 volt of energy inputted, 0.00000562 volt of energy was measured in the vibration.  Not a lot...  With the isolation, -115 dBV was measured, which means 0.00000177v of energy in the vibrations.  In absolutes rather than relatives, this means the effect of the isolation was a reduction of 0.00000385v in vibration energy when the excitement is 1volt.

This is useful if, as Credo suggests, this degree of suppression relates to what we hear.  Back to dB ratios.  The ratio of excitement to vibration with spikes is smaller than the ratio of the noise 1m from a ticking watch to the noise 1m from a petrol-powered chainsaw.  (10db vs 100db respectively).  So if the sound of the lumberjack's watch while he runs his chainsaw is something you can hear and you want to address, get some isolation stands.

Because if you do, the sound of the lumberjack's watch will be muffled a bit  - maybe he pulls his sleeve over his watch.  I'm sure this will make all the difference to your enjoyment of the sound of his chainsaw.

Anyway, that's the result of what I insist is a conclusion which is up for correction.  
Those are (I think!) supportive comments and if so, thanks!

There is so much that can be done to make a real difference to how we enjoy music, and money can be a bit scarce; and science is there to help us make the best use of it.
So I do get a bit annoyed when manufacturers, especially, try to part us from our money for stuff that makes no meaningful difference.
  
I also get annoyed when certain people spout utter nonsense and then get all defensive - or worse, offensive - when it is pointed out to them.  One of them called me a ‘pervert’, which I won’t forget.  
I won’t make friends with some of these folks, but I hope I make plenty of others.