Shelf Material

My thoughts are that you want a shelf to be dead rather than resonant, but that it released its energy very quickly. Dead means the least effect on tonality - ie. no resonant peaks. Releasing its energy quickly means no perceived slowing of the music. I suspect that engineering-wise, getting these two things at the same time is very difficult, if not impossible, hence the difficulty I am having getting something that sounds right. I concur with all of the above posts to some degree, but think the most fruitful approach may be to get a shelf that releases its energy quickly - ie. is light and rigid - and use some form of damping that does not add weight, and hence energy storage. This aligns with the suggestions from Dekay and Vantageaudio. So I will work on that avenue I think. Perhaps two layers of 6mm perspex bonded together - but perpexes rigidity:weight ratio is not great. Perhaps Corian is worth investigating. Any ideas? Of course Dekay is right that the exact answer each time is equipment dependent, but the general strategy ought to have some consistency in my mind. Thanks for the ideas so far.

Wow, those last two posts sound on the right track to me - I will check them out. Many thanks to all that posted.

Thanks for your kind words and advice Cornfedboy. The sad reality is that the only racks/shelves that reach these shores are of the basic variety, with the exceptions being Mana Acoustics and Townshend (and I own examples of each - most of which are in "the closet"). There are importers of cones from BDR and Polycrystal, but noone brings in the shelves. And noone brings in Zoethecus so far as I know. For example, I wanted two amp stands for my monoblocks and called around all of the better dealers in New Zealand - or at least that was what I intended, but truthfully I gave up after the first six because I was sick of explaining what an amp stand was... if you get the picture. In the end I did what every other audiofile does here - got them made. I would indeed prefer to just try and buy, but I am much less keen on importing one, only for it to end up in "the closet" - I am sure we all have one of those. Having come to this point with shelves (ie. needing to splash out and hope), I posted here hoping optimistically that there might be a concensus as to the best shelf material/product so that the chances of success could be improved. I think Albert Porter has done a lot of experimenting with vibration control, but his posts indicate he agrees pretty much with Dekay ie. that there is no universal answer. Perhaps I am being too optimistic. Anyway, I will investigate Zoethecus from here, and perhaps that is what I may end up trying. I hope you do get to New Zealand one day. I have known many Americans who have come here - some stay, some get homesick and go back. The ones that stay are adamant there is no place better. Personally I don't think it is a place to spend all one's life, but it is a wonderful place when you are a kid, when you have kids, and when you want to live a quieter life later on. In between, most of us Kiwis travel a lot and I have been forunate to visit your lucky country a number of times - picking up audio gear every time of course.

Only the Townshend are available in this part of the world, and they are not light compared with a light rigid shelf. I hear them as slowing things up. I am not familiar with the 855 so it is difficult to comment further on the problem you are experiencing. Currently, I use a very light and rigid chip-board shelf under my transport - the sort that is small chips of wood glued together and which includes a lot of air. It is much lighter and more rigid than particle board. It is clad with a very hard surface of compressed wood and so cones and spikes make no impression on it. I then use BDR #4 cones under the transport. In general I find that the right cone depends on the shelf being used, and that this combination works quite well. However, the reason for this post is that, although the result is fine, it is still a trade-off. It is definitely still more resonant than using a bladder product, but I prefer its more accurate pacing.

I will look for some Maple butchers block Albert but I doubt I can get it here. I have seen such blocks made out of NZ native timbers, mainly in Rimu - how hard/soft is Maple? I have always heard good things about the Vibraplane, and the item at machinadynamica.com sounds like a similarly impressive product. Not only are they expensive, but the freight to NZ will add even more, and hence I need to take a biggish risk going down that path - but maybe a risk I will have to take. Suspending with string is novel (at least to me). That is something I can try very quickly and will have a go at it soon. I have also located some off-cuts of Corian, so will try those in the next week as well. Strangely I have never liked Vibrapods in any application, and similarly do not like the Sorbothane or Sorbogel stuff. A friend of mine says I am on the wrong track and insists that I have to damp the components directly first, and he may have a point. Are there any decent damping sheets available? I notice that the Sonic Frontiers stuff has damping pads inside, and I have found their gear to be relatively immune to the effects of cones, shelves etc.

Dekay, I tried using a very thin steel wire, coated in nylon, with a breaking strain of 90 lbs. I did this roughly first - as per my nylon experiment, and then used it to suspend a shelf properly. The results were fine except for the Transport, which needed a soft footer between it and the shelf or it sounded hideous - and I mean unlistenable. Finally I have found a use for the Vibrapods! I will have to experiment further, but I can tell you there really was a very significant difference between the nylon and the nylon coated steel. There is certainly an advantage in that the steel wire did not stretch at all, so I will try and make it work if I can. Garfield - I have found in the past that a welded steel rack is very important, and so employ one in both my systems. I find thick guage steel like 3mm is better than the flimsy store-bought racks. I also find that if you have a concrete floor (as in my beach house) then filling the stand with sand and lead shot (or something else) is a good thing, but if you have a floppy floor (as I have at home) then leaving the stand empty is preferable. So I have followed both of these in the present. It is in the area of shelves and footers that I don't feel I am getting it right. The best shelf I have come across is a low density board with a very hard veneer. It is very light and rigid and is fast and detailed, but sounds a bit crisp and crunchy - and it is not unlike how I remember the Torlyte shelf I owned many years ago. If using this board, I prefer using cones rather than soft footers, else the sound gets muddy. The other strategy I use is to put bladder products on the same board. This gets rid of the crisp and crunchy sound, but has a suck-out that tends to fall in the bass region somewhere, depending on the mass of the component and the bladder product used. Either way the suck-out tends to take away some of the propulsion that bass instruments provide to non-classical music, and therefore the rhythm suffers. There is also a slight impact on pace - probably due to the mass of the bladder products. Currently I use combinations of the board I refer to, Townshend Seismic Sinks and cones from Walker and BDR. I own soft footers but do not use any of them. Vantage audio, I have tried all kinds of ideas with MDF, including using a thick and hard lacquer, without success. One possibility is that our locally made MDF is just not the same as you use in the US. I once had a pommie rack and its MDF shelves were harder and denser than what is made in NZ. The Corian has finally arrived and I slipped a piece under each of my monoblocks - and I kind of liked it. It will take me a little longer to figure out what it does with the line level components given the gantry it is now all suspended from, but will report back soon. I have a feeling it will work better at the beach house sitting on a damped heavy rack, because this Corian stuff is very heavy indeed and has a ping a bit like marble and is more 'live' than perspex. Garfield - maybe it is the floppy floor at home that has caused me to suffer extreme structure borne vibration, and hence an obsession to deal with it.

The Corian hasn't arrived yet so a report on that will have to wait, and it sounds like I should go directly for the Maple rather than try a native NZ wood - thanks Albert. BUT - I bought some 100lb strain guage nylon from the local sports shop today and suspended my source and preamp components (three of them, but each suspended separately) by merely tying the nylon to the steel frame of my rack - ie. I removed the shelf above the component and tied the nylon to the frame that had supported that shelf and then looped the nylon under the component below and tied it to the other side. I used two pieces of nylon for each component, going side to side, and used a trusted fishing knot each end, rigged up a twist arrangement to deal with fine levelling and sat back to listen. I have only listened to two CDs so far, but I am excited. Resolution is better, soundstaging is remarkable, bass is more extended and more punchy, and the sound is slightly more forward, but with oodles of depth. The sound is definitely more natural - applause sounding much more like hands clapping than rice crispies. There is none of the swimminess that the bladder products have, and there is no part of the spectrum that has any apparent resonance or suck-out effect (all shelves seem to suffer the former and bladder products suffer the latter). Before I get carried away however, while listening I could objectively say it was better than before, but I had a slightly nagging doubt whether it was in fact more musical than before. I will have to get more acquainted with the sound, because the source of that feeling may reveal itself given more time - on the other hand it may have been because I had to turn the equipment off and on, and it needs to settle again. While it was quick and cheap to do, it was very fiddly and if I decide to follow this up further I will need to come to a better arrangement - perhaps involving shelves (that Corian and/or Maple may be useful after all) - taking components in and out of the rack at present would be quite painful and probably require three or four hands. I will report on this again when I have listened some more, and played around with some variations on the theme. Dekay and Sound_decisions, thanks for the idea and recommendations - the results are very intriguing at this point.

OOPS - it was Onhwy61 that suggested the suspension idea - thanks Highway Man!

Caterham1700 - thanks for your generosity, if you will allow me to be a little generous in return. I will send you an email directly. Recres - I have heard similar comments about Corian, but am curious to try because I think it will ping less than perspex. On the other hand "slow" is what I fear most about it as a material, being so dense and heavy. Did you use up-turned spikes underneath the Corian? Great to hear confirmation of the butchers block idea, and given Albert's recommendation I have tried to source some locally. However, I have found that no one brings it in and that our native South Island Beach is used universally in this country. If I can get some I will try it - but I think I will now have to begin investigating bringing some Maple in from the US. Dekay, I definitely recommend you use up-turned spikes between lips and shelf for your plan B, over any compliant material. But so far plan A (ie. suspension) sounds better still. Apart from issues of stretching, is there any reason to believe that a taut wire like the piano wire you mention will sound better than a wire that has a little give, such as the nylon I have used? Oh yeah, Gthirteen, this really defines the freaks among us, but whether it is my room or my hearing, this area of vibration appears to me to be as utterly critical as room treatment, yet unlike room treatment in that there does not seem to be any conventional wisdom on the best strategy. As I indicated when starting this thread, this is the one area of this hobby where I feel I am still way off achieving decent results (let alone understanding). I did try plexiglass and found it to be better than glass but not as good as perspex, but I might try a thicker piece and see what happens.

I certainly don't like MDF in practise - a very muddy sound. I don't have the ability to try such things as the BDR or Polycrystal shelves before buying (since noone stocks them here), and hence this post. But I quite like the BDR cones and so bought some of the BDR pucks - and they sounded awful. If they represent the BDR shelf then no thanks. I have actually got a lot of good ideas from the above posts and am in the process of trying or acquiring some of the less expensive suggestions. I am happy to splash out on the expensive stuff, but would prefer to see a concensus of more than one before doing so. It looks like the Butchers block qualifies. I wonder if Kevin has a point. Caterham and I tend to concur that you want light and rigid, release the energy quickly but damp the main resonances. But Kevin is suggesting the light and rigid shelf, and then deal with the resonances with some form of compliance between shelf and component. This may very well be right, but I tended to think of the rack as doing the light and rigid task and that you would begin to damp the resonance with the shelf. I don't like two forms of compliance in a system and so I have tried to get "dead" sounding shelves and use cones. My theory may be right, but the practise is possibly too dificult to achieve - we will see. Kevin may have a more practical solution. Am I missing something Kevin?

It is a long time ago that I used the Torlyte shelf Ken and it was under a Linn Turntable, which was just an ideal match. By memory the Torlyte was great with light components - say under 15 lbs, but sagged with anything heavier. Also spikes pierced its surface. It sounded fast and agile, if a little light in the bass. There was a slight thunk to the middle of the midrange and a slight crispness to the top end. Not nearly as bad as the crispy crunchy stuff of my current board. That Torlyte board I had would have trouble with my heavy Theta gear. I have been listening to the Corian and hear none of the dynamics or other problems that Recres reports above - this may be due to either the racks being different or the footers used. The Corian is not perfect - there is a slight recession of the mid-range, a slight flattening of images and a bit of grain. But it has wonderful bass and hardly any smearing of highs. Selection of the right footer or damping of the Corian may give decent results. But right now I would say tantalisingly close, but without some improvement in harmonics in the midrange, it would be hard for me to live with. A bit like marble or perspex, it has something going on in the mids that lets it down, but it is definitely better than either marble or perspex.

Playing around with the Corian yielded some good results. I have the Corian shelves sitting on up-pointed spikes, and don't have any plans to try any alternative means of support. But sitting the components directly on the Corian is not great, as previously indicated. Using BDR cones is better, but still not liveable. But using soft footers like Vibrapods gives very good results - something I have not experienced before - I almost wish I hadn't given away so many of the things in the past. Interestingly the Vibrapods were much better than using bladder products under the transport, but the bladder products were a bit better (very close call - perhaps it will change after a recount) under the other equipment. Currently the sound is pretty damn good, but with some small vestiges of whitening and grain in the midrange. The huge bonus is a very powerful, fast and articulate bass, regardless of which footer is used. This may be what I live with for a while until I get to try a Neuance shelf from Ken (Caterham1700 - is that the racing car engine Ken? I used to race Lotus Europas and a S2 Seven, some of which had Caterham engines.), and get a good freight deal on bringing some Maple butchers block into the country. I have also begun to design what I am deducing is an ideal rack for putting the "stereo on a string" concept into practise properly, but I expect that to take some weeks before I will have a result to report on. One of the advantages of living in NZ is the low cost of getting stuff like this made up.

I can report on experiments 131a and 131b. A friend who likes acrylic shelves told me they were best, not on spikes, but on a hardish damping sheet - some of which he lent to me. So if you recall I found the Corian to be OK on spikes if one used a soft footer or bladder product - experiment 131. So I tried the damping pads in place of the spikes and removed the soft footers and bladders - 131a. The result was better in this configuration 131a - and I was beginning to feel that this was a pretty good result. It was around about midnight, but I said "what the heck" and began experiment 131b. This time I used 300lb strain guage nylon (the 100lb stuff definitely stetched too much and the nylon coated steel rang like a steel string on a guitar) to suspend the Corian. Now it was getting late, and I was a bit tired, but first impressions were very favourable indeed. Experiment 131b rules at this point and the 300lb nylon cable showed absolutely no visible signs of stretch even when subjecting it to loads over 50lbs (after all I am suspending each shelf with four threads and so they can theoretically go up to 1200lbs). Resonance effects on the sound are now very low indeed, and I have some ideas of how to reduce them further. In conclusion, I think the suspension idea has considerable merit and that very thick nylon is better than steel. The Corian is a two edged sword however. It does ping, and I am sure there are still small vestiges of this in configuration 131b, but it otherwise has an excellent top end and bottom end, and the dynamics are very natural indeed. It may still very well be that if I find an ideal shelf material, that sitting on spikes may get closer to the results with suspension. This would get over the problem of the transport swaying after the CD has loaded, for example. But right now, suspension is sounding great - and believe it or not, my beautiful wife Sonia thinks it is "cute". For those of you that really love soundstaging - you have got to try this suspension thing - the depth of field is stunning.

Thanks for your kind thoughts on beaming me the slab Dekay. But 100lbs would normally cost about $US400 to get here, and that assumes they don't sting me for the awkward shape. I do actually have a cheaper way which is to get a NZ freight company to pick it up in the US. I am checking out the maple idea and seeing where the best prices are, but I am keen also to try the Neuance shelf which Caterham 1700 is kindly helping me with.

Caterham 1700. I have posted it off to you and it will get to you early next week - in fact the plane it is on arrives in the US today Saturday. The Caterham motors were lovely creatures. You may or may not know that when Lotus aborted the Lotus 7 Mark IV, it licensed it to various companies, including one here in New Zealand - Christchurch to be precise. With its light fibreglass body it was at the time the fifth fastest production car ever made for 0 to 60mph. Above that its poor aerodynamics slowed its acceleration and the front wheel arches - they were really just protruding pieces of plastic - waved alarmingly. They were not as graceful looking as the Europas, Elites, Elans and Esprits that I played around with, but they were one heck of an exciting (and occasionally wet) way to get to work in the morning.

I have played around with the hard rubber footers and Vibrapods a bit more now and my vote is now with the Vibrapods. The hard rubber footers are a bit dark sounding, and may explain Recres not liking Corian. Corian is definitely not perfect - there are probably better shelves, such as from Neuance or the Maple butchers block. I am just saying that if decoupled from the rack (in my case by nylon fishing line) and if decoupled from the component with Vibrapods, I get a good result. The most positive aspect of Corian is a thumping and deep bass, that is fast and agile, but the tendency to mid-range grain rules out spikes or cones.

Sorry Craig (Garfish) - slip of the tongue. I have indeed come across and experimented with the single spike idea as Theta have used it in their transports, and I have owned a few of those. I have found that the best footer for an application is very dependent on the shelf used. With something like MDF you can be best to use damped cones like BDR, but spike and soft footers together is also good as you say. But I still don't rate MDF highly. Since my last post I have persevered with the suspending of Corian shelves from a steel rack using thick nylon wire, and tried various footers. (The biggest pain is designing a means of levelling the shelves without introducing vibrations.) The best (after trying several different types) is to use a very hard rubber footer, and Vibrapods work quite well too. Cones are too hard with the Corian, and spikes are definitely out of the question. The use of either (including up-pointed spikes under the shelf) result in a severe resonance adding grain and edge to the midband. The results I am getting are now very very good indeed and much better than MDF or the particle board I had been using which was only a bit better than MDF. While I am very happy with the results, I will not be able to rest until I have tried some of the other ideas posted here, especially the Neuance shelf and the maple butchers block. Ernie (Subaruguru), I am sure there must be microdisplacement, but in any vibrating system there will be microdisplacement. In a suspended system the displacement is larger, but slower moving - whether this is better or worse is for the ears to decide. I hear suspension as sounding very different from the bladder products. To put it in a nut-shell. A shelf sitting on a rack tends to add resonant peaks to the music, damage harmonic structure and reduce depth. Using different compounds just moves the resonance around and some are better than others, but none that I have heard reduce the resonances down even close to inaudibility. Placing a bladder product between shelf and component tends to fix each of these problems pretty well, but adds a new one in that it tends to cause a suck-out somewhere, usually in the mid-bass or upper-bass, destroying rhythm. Suspending a shelf can have various results depending on the wire used, but with thick nylon wire resonances are much reduced compared with sitting the shelf on the rack, with none of the suck-out problems of bladder products. Resonance is not totally eliminated and you can still hear the differences between shelves and footers. In addition to this I have discovered that Corian shelves, used with soft footers, can give terrific results, particularly if you want more power (and I mean a lot more) and articulation in the bass.

Megasam, you are right that the range of footers have a wide range of effects on the sound, but if significant vibration is getting to them then all they do is move the problem around the spectrum. But as my quest continues and I am reducing audible resonance through rack/shelf strategy, it is noticeable that different footers begin to sound more and more similar. Footers are an important part in the equation, but to obtin high resolution through concentrating mainly on footers, is not the best way to go IMO. Kdmeyer - I will follow that one up, it sounds very interesting indeed.

My understanding is that Corian is made of very dense acrylic polymer. It is a good deal heavier, harder and more rigid than perspex, and comes standard in 12mm thick sheets. I am spanning about 19 inches supporting a 40 lb CD Transport and there is NO sign of any bend in it whatsover - and this includes when I support the front of the Transport with a centrally located footer. I have played some more and tried damping the Corian. This means using cones is now best for footers. But I am not sure the sound is significantly better, just different. I do not want to hype Corian, but I probably have. It is certainly not ideal, I am just having fun exploring its capabilities and I am getting some good results. I am beginning to feel it has some of the characteristics of sand boxes - terrific firmness, extension and articulation in the bass, but a slight deadness creeps into the mids and highs - a slight absence of presence - hence whay I am feeling the need to play around with ways to remove the mid-band resonance with damping, either direct or by way of footer. Corian is used as a CD puck in CEC belt-drive turntables, and also as part of the cabinets in some very expensive speaker systems (eg. Pipedreams). I would only rate it 7 out of 10 for a shelf material, but better than anything I have yet tried. I would rate the suspension idea as more like 9 out of 10 so far.

Sol322, I am in two minds over the suspension thing. It isolates a shelf from a rack pretty well, but whatever you use to suspend the shelf has a sound of its own, a bit like a plucked string. I did have success with the Neuance shelf as well as damped Corian. The Neuance shelf is very promising, but with just one in the system, it is competing with the sound of four other shelves and so it is a little difficult to tell. So I am going to jump in the deep end and buy a set of Neuance shelves and play around with how best to support them. The Neuance is very light and rigid, yet damped and WAY outperforms MDF. You can get details at www.neuanceaudio.com.

OK - I know I have gone around in circles on this, but can now conclude my findings until some of the stuff I have ordered from the US arrives - probably two weeks time. Suspension - much less resonance than conventional supports, but need to use a non-resonant wire for best effect, heavy guage nylon fishing line is good - forward images are more forward, plus greater depth and 3D images, bass region is very clean allowing mid-bass to propel the music, everything is a bit more present, and resolution is enhanced. Corian - is a bit like other heavy supports like marble, perspex etc in that its bass is very strong, but that there is resonance across a wide band (ie. not peaky) throughout the midband which sounds like grain - this can be reduced by using pads instead of spikes to support the Corian, but is even better if suspended on wire - this resonance effect can be almost totally eliminated by selecting the right footer. After much experimentation I have concluded that Vibrapods are the best with Corian. I found that the use of soft rubber footers was plain muddy. I found that using cones or hard rubber footers was OK but had a slightly dead quality (referred to by Recres above), shades of what I hear in spades with sand boxes. Last night I got a bucket of Vibrapods and painstakingly selected the best model and placement until I had optimised the sound. The result was fantastic, and much better than my first attempts with Vibrapods when I was using higher model numbers than I wound up using last night. There is NO vestige of the dead quality now and the music is highly involving - that bass just propels things along beautifully. I have performed some more experiments with the Corian in terms of its ability to support heavy equipment and find I cannot agree at all with Kitch29 above, but my Corian shelves span 19 inches, not 24 inches of course. My shelves have no trouble supporting my 130W valve monoblocks and do not sag at all. For very heavy amps I guess you could be better to bond two pieces together. I am not saying Corian is ideal, but the combination of suspension, Corian and careful selection of Vibrapods is giving a result that is light years ahead of conventional glass or MDF shelves. I expect that the Neuance shelves, Polycrystal shelves, and Maple butchers are capable of even better results - but right now my shelf obsession has abated somewhat. I will report on these other shelves in a few weeks time when they arrive.

Dekay, right now they are still suspended and I prefer them that way. Yes the Vibrapods are sandwiched between the Corian and the component. Ghthirteen, I have tried the Vibrapods with other shelves made of glass, marble, perspex and mdf and found them to be inferior to using Townshend Seismic Sinks every time, and even when not using the sinks I have preferred BDR cones over Vibrapods with mdf. But BDR cones do not work so well with shelves like marble, perspex or Corian. [I actually have other cones from Walker, Golden Sound and others but these posts are long enough without describing them as well.] This is the first time I have liked the Vibrapods over everything else. In other applications I have considered them good value for money only. You may be right in suggesting massive and dead and then use the Vibrapods. I think massive and dead works best with a concrete floor, but that light and rigid is best with a floppy floor ie. wood. Kitch29 - I hope my offence isn't extraditable. I actually had no problem drilling holes in the Corian (for the suspension trick), but cutting is probably a whole other matter. I got mine by making it plain my application was an engineering one, not to make my own bench tops, and enquired about off-cuts - but I know what you mean about licensed fabricators. Garfish, I have tried mdf with a veneer that is half way between melamine and formica. It was not bad and worked well with cones. But in anyguise I have never been thrilled by the muddiness of mdf.