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Inmates' comments on different materials in commercial or homemade racks appreciated.
How about using softboard?
I've tried MDF and glass and neither were ideal with my system; the MDF warped under the weight of the power amplifier and PSU and the glass rang, giving the bright, overly forward sound described in other posts.I've ended up using carbon fibre composite shelves - two layers of carbon fibre sheet with an aluminium honeycomb in the middle.
It's non-resonant, very very strong and provides excellent isolation for valve equipment and (of course) source components.
The only problem is that it's not cheap, but the results certainly satisfied me enough to suggest to the developers that they made it into isolation platforms rather than experimental valve amp chassis and kit bits.
This unfortunately means that you can't get shelves any more; though I suppose they might make some up to order...
Simon,
Just curious since you brought up the subject of construction.How were you able to prevent the hollow vertical chambers from resonating?I tried a number of carbon graphite and gfk laminates with everything from aluminum to cellulose to nomex honeycombs and had very mixed tho promising results some 12 years ago(I've friends that do sub work for Boeing out here with a decent sized autoclave).Did you use a buffer layer between the core and outer lam's?I'm not asking for proprietary info,btw.so you need not respond.I did notice that you did a nice edge decouple arrangement that looks effective.Someday,i'd like to chat in private about your thoughts and philosophies.
Best,
Ken
GeaterRanges/Neuance
No, Ken we didn't stop the internal sections from resonating, because we'd have had to fill them with something denser than air, and that filling would have a resonant mode anyway.But the hollow chambers are closed cells of varying sizes due to the random nature of the aluminium honeycomb we use - and by the way we tried Nomex and cellulose-type cores and they sounded dire - so the resonances are tiny and vary, resulting in a complete unit that has no significant resonant frequency.
I'm glad you noticed the edge decoupling - that was a real headache since we didn't want a platform that showed the honeycomb, but if we bridged the top and bottom carbon fibre sheets with anything apart from the honeycomb, it mucked up the isolation.
Eventually, we mounted a frame on the bottom plate, "floating" clear of the top plate; since the platform is supported on cones stuck to the bottom plate, the edge is purely decorative and sonically irrelevant.
I'm afraid the actual construction of the carbon fibre sheets is a critical factor and something we'd rather keep to ourselves, though of course the total construction is apparent straightaway as you saw.
I think it's the developer's experience in carbon fibre that's allowed us to succeed where others have not; that and the fact he's a hi-fi nut as well as an engineer!
Hi Simon,
Thanks for the insights.
Looking over the website, I couldn't help but notice many philosophical and conceptual commonalities with my own designs yet using entirely different approaches and material choices for the execution. Musical truths seem to provide many paths to explore on the way to a common destination.
Interesting too, that you should bring up the edging as that was also a challenge to properly execute.
I did notice that the site mentions an increased perceived loudness effect that I assume to operate in a manner functionally similar to that of the Mana Acoustics kit.
Once again, thank you for you most courteous, gracious and open remarks.
Best,
Ken
You can try Corian as a substitue for MDF or granite. Very stiff with excellent vibration damping properties. You can have Corian shelves custom cut in a variety sizes and colors at any kitchen countertop retailer/manufacturer.RAY
I've tried .5" glass, 2" granite, some composite commercial shelves and .75" MDF and keep coming back to MDF....I have not tried the Mana stands and understand they damp out the ringing, but even with the .5" glass on top of the .75" MDF the undamped glass (other than by the MDF) rang like a bell.....I have heard from someone that the way to go is plexiglas, but haven't taken the plunge yet.....
that it seems to work the best, saying that may be why several high end turntables (SpJ La Luce, Clearaudio, etc) are built of it.
On the other hand, Rockport, Walker, and Forsell aren't.What do you think?
rc,
the mana effect is a tuning of the resonant sig into primarily even order harmonics.the "ring" is essential to it's function.
Ken, now how did they accomplish that as I have this nice .5" piece of glass just sitting here that has some of the oddest harmonics I have ever heard in the upper midrange.....The only place it really worked well was on a sandbox where it was fully in contact and damped by the sand.....I moved on to 2" damped (Linoleum glued to bottom trick) granite for amps, but like MDF for line level components and an active air suspension for the turntable....I assume that Mana uses something glued to the glass to trick it into working. I guess they are just showing off as it must be rough to make glass behave....Do they sell the damping panels separately as I'm about to put the 18" x 25" piece of glass in the recycling bin?
rc,
They use 2 strips of a firm ceramic-like damping material about 8" in length and approx 1/2" in width.These are placed on the underside of the glass in 1/3 spacings.It's my belief that their primary function is not so much to tune as to reduce the amplitude of the released energy when the glass is finally excited at the target frequency(s) by ambient sonic charge. I am also of the opinion that the process of "phasing"(stacking additional levels with lam'd mdf) is an attempt to further exclude the floor/stand contributions for a more refined "effect".At some point, the primary energizing mechanism becomes almost exclusively those of airbourne charges.The results are of enhanced refinement of the "effect".Quite nice,really, esp once phase 4 is reached.Clever fellow, this Watson.:-)
Ken, are you speaking of aluminum oxide ceramic or aluminum borosilicate or some other ceramic? It appears we are both doing too much speculation and need to make some perspiration trying this....I'm really skeptical and should be open minded about this sort of thing, but have played with glass which only worked here on sand....Maybe that is where I need to put my head, give up and call EAR for a solution as I don't think anyone but Watson will be able to make it work as a DIY project....
rc,
I haven't attempted to unlock John's baby.I don't see the point.To do what he's done would take so many trials and protos that it would be a waste of time and energy.By the time you got something nearly as good but not quite,I'll bet you could have bought a full on phase 7 setup and have enuf for a new amp.
My opinions on the conceptual mechanisms are just based on what I've discovered with my own pets and extrapolating from there.The results are consistant with the model.
As a matter of fact, I own (and recommend) his stands, phasing,stages and all and then top it off with my own devices.'Saves me the logistic nightmare of stocking and warehousing stands(been there,done that) not to mention tooling up for ironmongering.
Wattie's stuff and apparent concepts are quite complimentary.He's done a few clever and original things that I'm very impressed by.Very simple and elegant.Besides, it's just interesting to see how someone else approaches the same problems and to discover that there's someone else as whacked out as yourself.
;^)Best,
Ken
Thanks Ken! Making glass shelves work must be a lot like herding cats and the shelf is in the recycling bin....Moving shortly....Once settled I will give plexiglas a try on my Fredericksen stands and report back...
nt
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nt
nt
otherwise the glass will resonate. This would be expensive. If you got the dough, this would be avry good sounding and attractive looking shelf.
giving your gear an unnatural "peak" in the high frequency region.Hint: materials used for Hi-Fi shelving: resonance control properties.
Jacques.
Mana uses 11mm glass for a particular reason, also it applies damping control, and the way the glass couples to the steel rack is specific for a reason.Just dropping a piece of glass to be a shelf does not sound good at all. Also, custom cutting of glass with edge polishing is not cheaper, and quotes range from $40 to $80 for a single piece of bevel-cut glass shelf.
nt
.
> > Hint: materials used for Hi-Fi shelving: resonance control properties. < <
That is not true. The very popular Mana equipment racks (used by a lot of reviewers) use glass shelves.
nt
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