Rack shelves: aluminium or wood?

Just wondering if the material of shelves may affect sound. Pre BHK, DS DAC, PW SACD, Pre Phono and TT Techincs MC on 3 upper shelves while M1200 and 2 P12 power plants on other 2 shelves under.
Is aluminium shelf a good solution or this metal can cause resonance or something else unwanted. I found a way to cover aluminium plate shelf with a thin layer of wood MDF. So they are rigid and solid metal inside {reducing thickness for saving space) while the surface id wooden.

Each component is separated from each other (no stack) and decoupled with 4 IsoAcoustic feet Orea.

Do you experienced problem with metal?

Metal resonates much more so than wood. Rap your knuckles on anything metal and listen for how long it rings. If isolated with weight (the weight of the components) it can be fine. I like to isolate any shelves from the structure with something like this:

Cut pieces to fit as needed.

IMO you can’t generalize things. Damping of a material can play a role as well as deduction speed. The best solution usually is the combination of both (e.g. damped, fast metal). Fast metal is e.g. titanium, but alloy is also quite fast. It can be damped by fluid or sand etc. and still has its fast deduction ability.

Depending on the concept (in this case of a rack) damping ones or deducing ones can be good. It’s important that a thought out concept is observable and not just a shallow story behind just another rack offer. It all also has to fit to your situation (floor, equipment feet etc.). If deduction is the concept of the rack, the interface to the floor and the characteristic of the floor should support it (similar with the choice of equipment feet).

People always one easy rules, but what you need is either know how or someone with experience and good advice for the individual situation.

One thing you can be quite sure about: anything out of glass (no matter if a turntable platter or a rack shelf should be strongly avoided.

And maybe the most important:
Don’t be anal about things that make no difference for your setup. Do the cross check (but listen at louder levels as this will reveal more differences). Put your stuff shortly on a chair or floor and on a good rack. If you hear hardly any difference, buy a good Scotch Whisky and some records instead :wink:


Glass can be damped like anything else but I too would avoid it for the same reasons I’d avoid metal. Both are far more difficult to damp than wood as many species of wood are naturally damped.

Thank you. I prefer wine (good wine) here in Italy. My question about aluminium, in general, is strictly connected to a choice: the rack I’m building is handmade. I can design the size, the composition, the shelves with a local artisan carpenter, the man who solves any problem!

The idea was to use aluminium in every single shelf to be solid, resistant, rigid, plane, robust but… thin, so much more thin. It means more space, then. Then applying above and under every aluminium shelf a foil of wood, to reduce resonance, to feel it more warm and good looking.

Resonance, magnetism, waves, noise or disturb due to electricity gears so close to each other…
This is why I posted my doubt here into the Forum: to avoid a big error if my idea was wrong. You know: first ask, then decide and act!

Thank you again, I return listening to my ‘70s vinyls some rock at midnight. not on a chair, on comfortable sofa! Cheers…

But danping is not always wanted. Damping without deduction means the vibration stays in the circuit at an early position for too long in case it’s not wiped out directly (which it usually can’t be snide wood only).

As I said, imo it depends in the concept.

And imo you can’t compare glass with metal…from its resonance and as metal is usually not used for a base and glass not for bracing (but vice versa). The evil thing is glass as a base (which unfortunately is quite usual). The evil thing (especially if additionally damped) is not metal as bracing or pillars (which is quite usual, too). Undankes Metal as bracing with glass as bases is probably worst.

I would then go for what you think is good looking and what’s robust, too. Without deeper knowledge you have no real resonance concept (which may just sound fine enough anyway), so it’s pot luck how it exactly sounds at the end. Wood is easy, looks solid and doesn’t sound false as glass can, even if probably not as good as a sophisticated individual concept (which no one can deliver here probably).