Shelf Material

Redkiwi, Caterham Motors ,the factory authorized service arm for Lotus Components that supplied your motors purchased the manufacturing rights and tooling of the Lotus Seven after Colin Chapman bored of it.They produce to this day a highly refined but direct descendant to the Series III Super Seven. The lightweight 250hp Jonathan Palmer Evolution(JPE) is capable of 0-6omph times of 3.5sec,0-1oomph in 8.3sec,0-100 to 0 in 12.5sec and roadholding of 1.1 lateral G without benefit of ground effects.Way cool.Still saving my pennies for the more streetable Caterham Seven SuperSprint 1700(135hp). I still do some autocrossing(gymkhana) with a B-Stock Mazda Miata MX-5R when time allows and formerly road raced a Crossle Formula Ford, Lotus Cortina and karts. I actually was pretty good at it but gave it up after an incident at Sears Point Raceway,CA. in the 80's when I managed to cut my F-Ford in half with an aerial summersault atop a long stretch of steel barrier at a pretty good rate of speed. :^) Best, Ken

Caterham: I finished the MDF shelving yesterday and had two shelves cut. One with an off center hole and one solid. I could not hear a difference between the two though neither sounded very good with my Musical Fidelity amp resting on them with its stock "integral" feet. I am not very articulate at describing sound so I will just say that I lost HF shimmer and a little LF definition as well. The amp was previously resting on the Persimmon wood of the cabinet and this combo sounded much better. I tried mystery adjustable speaker spikes (free from a friend) between the lips and the shelving which also made very little difference. I suspect that the problem is that the 3/4" shelf is 24" in width and I will try 1" thick high density board next. My lumber yard did not charge me for the MDF or the cuts which means that I am probably due for a shave and haircut. I will keep my ten year old T-shirt and shorts though. The CD player is still resting on its original layering system below so it is just the amp shelf that muddled up the sound. I may try terra cotta and other ceramic tiles under the amp(s) (my second one arrives this morning) as I have never used these materials and they are dirt/clay cheap. I was also able to free up 2" of space below the source to try the Mapleshade cones which I will order today. Since I will be burning in a new amp and cable I will not be able to experiment for a while as there are too many variables to account for. If tiles or other thin layers do not work with the MDF the amps will be going back into kitty territory for the time being until I try a 1" shelf of MDF or another material. I only have a 12" height to work with in the cabinet which severely limits my options. I will save the good materials (2 1/2" maple and marble) for a freestanding rack that I will build when I am more active. The freestanding rack will allow me to have normal cable runs and better speaker placement but will have to wait until the spring/summer at the earliest. I can barely move after putting together this simple shelf and my wife is not very supportive of any more construction projects for the time being. I will be certain to copy this thread for future use and will add comments in regard to the Mapleshade cones, etc., when the accessories arrive and settle into the system. I wish that I had a way to "beam" my maple slab to Redkiwi, it must weigh at least 100 pounds.

Dekay, just to add that we have utilized MDF and found that anything less than 1" don't work so well. As you have two MDF sheets cut already, try mounting them with the off-center hole cut one on top of the solid sheet with a space between the two of approx 1" (use whatever solid footers you have to seperate them). Mount this arrangement on more footers or spikes and place a selected component on top. Listen and trial by varying the "air gap" between the two MDF shelves. If you find that it works for you, then you can start to experiment and fine tune by filling the "air gap" with different materials. BTW, applying a finish coat to the MDF will drastically alter the "sound" of this arrangement. If any of this makes sense and you try it, let me know what you find...?? Richard. www.vantageaudio.com

Dekay, My intent was a semi-controlled experiment to note the effects of reduced mass of shelving of the same materials, and not a comparison of hardwoods vs. mdf. I was expecting that your response would take a minimum of week or more because of the time it takes just to familiarise oneself with the character of different materials. I am not a proponent of mdf,btw and have intentionally stayed away from specific recommendations in materials in this most interesting thread. Best, Ken

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.