Townshend Seismic Podium

How To

Townshend Seismic Podium

A car’s suspension has a number of functions but one of them is to isolate the driver from bumps and irregularities in the road surface, to do this a suspension system consists of a spring and a damper (or shock absorber). The spring is selected on the basis of the weight it has to support and the damper stops it from bouncing up and down. Nowhere is there a car with steel spikes for suspension, some are very stiff but they still have the elements described above. This is because steel spikes offer no isolation whatsoever, in fact they do the opposite, they make a bond with the surface they are in contact with, like a nail in wood. Yet for decades we have been told that spikes provide isolation for loudspeakers, equipment racks, even pieces of equipment. While in fact what they do is block certain frequencies and enhance others, they ‘tune’ the energy that they transmit.

Stand and support makers try to tune them in such a way as to enhance the sound of equipment placed upon them. In the case of a loudspeaker energy travels both from the speaker into the floor that supports it and vice versa, from floor to speaker or stand. It’s a two way street in which certain modes within floor and speaker are excited, both the floor and the speaker cabinet vibrate and this vibration, while not obvious because it is at a lower level than the main signal, is being added to that signal and masks the quieter details. But because it’s similar in frequency to the signal you don’t notice it until it goes away. How do I know? Because I have been using Townshend Seismic Podiums under a variety of speakers for over a year now, and all of them have dramatically improved as a result.

Seismic Podiums are an evolution of the bases Townshend has been developing since the nineties, they isolate the speaker on damped springs. In this latest iteration those springs are adjustable for a range of weights and the platforms themselves come in variety of sizes to suit different loudspeakers. The isolation is provided by a spring inside rubber housing at each corner with the platform is supported so that it is as close to the floor as possible. The rubber housing has an air hole in it to provide gradual damping and the top cap turns to increase/decrease tension in the spring to suit different weights. The ability to keep the speaker base low differentiates the Podium from its forebears, as does the damped treadplate support surface, which makes it very easy to locate a speaker of any size. Prior to the arrival of the Podiums I used Seismic Speaker Bars which operate in much the same way but have to be carefully positioned because there is no adjustment available, and can’t be used with larger speakers unless you are very careful/have some assistance.

So what do Seismic Podiums do for sound quality? If I said “everything” you wouldn’t believe me, but the answer is not far off. They dramatically increase low level resolution so you can hear more detail, they clean up the bass like you wouldn’t believe and the improve dynamics and speed. So nearly everything, they won’t turn a budget box into a giant slayer but they will upgrade it to something that sounds twice as good. It’s not subtle. I particularly like the way it lets speakers ‘disappear’ from the soundstage, by which I mean that with your eyes closed it becomes very difficult to pinpoint where the speakers are. This works with almost any good stereo recording and means that you get a cohesive, solid image with depth, width and height that does not seem to be related to the positions of the speakers. This is because the Podium increases the speaker’s ability to project sound into the room, at least that’s what it sounds like.

They bring control to the bass that you would not imagine the particular amp/speaker combination was capable of. Bass times as well as the rest of the range, so bass notes stop and start precisely when they should but there is no sharpening of the sound. Instead the presentation becomes more natural and relaxed, effortless in fact. It’s as if all the strain in the speaker has been removed, strain caused by the way the floor reacts to the energy being driven into it via spikes, some of which is reflected, some absorbed and the rest transmitted into the structure of the building. This is true regardless of floor type, most of my listening was done on a carpeted wooden floor but as Townshend has demonstrated, concrete floors are equally capable of transmitting energy, it just has a different character because its resonant frequency is different.

One side effect is that far less energy gets through floors and walls, which, if you live in an apartment or have adjoining properties, means they hear less of the bass the system is producing.

Bass seems to extend more. This is counterintuitive because you’d expect the lack of a solid connection to the floor would mean the speaker rocks in reaction to cone movement. But cones have such low mass compared to speaker cabinets that they can only vibrate their enclosures, not move them. The perception of bass extension probably relates to the extra control, distortion drops across the band but because it is usually higher at low frequencies that’s where it becomes most noticeable.

The main benefit of the extra control is better timing, this seems to be more noticeable on bigger speakers presumably because they go lower in the bass, and the greater the extension the harder it is for an amplifier to control. But it can be heard on all manner of speakers, from monitors on stands to 80kg active designs. It has got to the point where traditionally spiked speakers sound distorted to me and I always put the speakers I review on the Podiums if they are heavy enough, the Bars come out for lighter models.

Max Townshend has a theory as to why they have so much effect and that’s that micro tremors in the ground are greater in amplitude than the amount of movement in a loudspeaker cone. I wrote about it here a couple of years ago but essentially there is a continuous movement in the ground produced by the earth itself and increased by factors like road traffic and even waves. This might seem far fetched but it’s difficult to establish why isolating a speaker should be quite as beneficial as it is. In my system the equipment is supported on a similar isolation system, so it’s not as if you are reducing the amount of vibration getting to the hardware. Townshend’s demonstrates this effect by putting tablet computers on two identical speakers, each device running an app that reveals vibration at different frequencies. One speaker is spiked the other on a Seismic Podium, all you have to do is tap the floor with your foot to see how much the spiked speaker moves, and conversely how still the isolated one stays. And if music is played through another system the spiked speaker vibrates but the isolated one doesn’t, so one reason why isolation helps is that the music itself vibrates the floor and creates a low level form of feedback.

I’ve heard Podiums transforming the sound quality of all manner of loudspeakers; Bowers & Wilkins 803 D3, PMC fact.8,  fact.12 and twenty.24, Wilson benesch Cardinal, Naim Ovator 600, ATC SCM 19A and SCM150 ASL, Vivid Giya G4 and B1 Decade, Dali Epicon 8, Dynaudio Emit 20, Penn Audio Sara… the list goes on. But in every case the benefits were clearcut and of a sort that cannot be achieved with other ancillaries. The message has got to some loudspeaker makers as well, PMC used Seismic Podiums under a pair of 88 kilo, MB2S XBD-A professional monitors at the recent Indulgence show. This wasn’t the most expensive speaker at the event but it was the best sounding, and the Podiums had a lot to do with it.

All in all good speaker isolation is a major contribution to sound quality, the Seismic Podiums might seem expensive for a stand but the benefits they bring to mid and high end systems can in no way be matched by any other means at the price. In the context of high end cables they are a positive bargain. The spike was an aberration, a diversion from the path to high fidelity, a diversion that will seem as antiquated as the cassette once you have heard what they do. If you want to hear right into the mix genuine speaker isolation is the way forward, but don’t take my word for it give them a try, you’ll be amazed at how good your speakers really are.
Jason Kennedy

Follow up from Réne van Es:
Following your review I ordered myself a pair of size 2 Seismic Podiums to put under my PMC fact.12 loudspeakers. Normally my speakers are on spikes, standing on a wooden floor, followed by a thick layer of damping material and finally concrete. The wood ‘floats’ so unfortunately it can resonate. On the street in front of our apartment there is often heavy traffic and railway activity. With the Podiums I no longer have a mechanical coupling between the loudspeakers and the floor, only an acoustical one to the room.

On spikes it was always necessary to reduce the bass output of the fact.12 with the switch on the back. On the Podiums the output is now flat and still I have less boom in the listening area and in adjacent rooms. Bass is tighter and the balance is better with the midrange and highs. Using a simple spectrum analyser shows this fine balance even when I play louder and louder. The stereo image is deeper, with improved definition and I have not experienced a loss of dynamics.

The Podiums do look rather overwhelming compared to the speakers, but that’s because the speakers are 42cm deep, so I need the Size 2, while they are only 17cm wide. Another small disadvantage is that the music was 100% free from the baffles and now a good 95%. So I have to do some more tuning with regard to placement.

Overall I consider the Podiums my number one upgrade for 2016 in my living room and will never return to spikes. Coupling my speakers only acoustically to the room is a blessing accompanied by the benefit of decoupling the speakers from each other and from any seismic activity caused by traffic or even by my neighbours.
René van Es

Price: from £1,400

Available for speakers weighing up to 240kg (528lbs)
Support area: five standard sizes from 270 x 200mm to 604 x 440mm
Custom sizes available

Townshend Audio
T +44 (0)208 979 2155
www.townshendaudio.com