I’ve picked up some s/h Arivas for a good price, mainly because they came without the original platforms. Rather than try to track down some replacements, I’d rather have fun making my own but details of the originals are hard to come by.
The speakers have three hemispherical indentations on their bases, so I’m imagining some sort of ball bearings fitting into them which then couple with some similar indentations on the platform. The speakers’ indentations are about 18.5mm in diameter and I’m thinking that trying to get ball bearings to match the diameter exactly would be a fool’s errand so getting ball bearings a bit bigger (say, 20mm) would be easier and work better from a stability and coupling point of view. I was thinking of using a countersink drill bit to make suitable recesses in the platform to receive the ball bearings.
I’m planning on fitting three 8mm threaded spikes to each platform to site them on the carpeted floor where they’ll be used.
So, if someone with a full set of Arivas could post pictures of their platforms, including dimensions and how they couple to a) the speakers and b) the floor, that would be hugely helpful. Information (or speculation!) on the type of wood used for the platforms would also be great.
Any other thoughts or advice would be great too. Before anyone suggests, I’ve tried emailing Naim but had no reply - I think they might be keen not to get too involved in my DIY project and who can blame them?
Mark, making up some replacement plinths shouldn’t be too hard. Their dimensions are the same footprint as the base of the Ariva speakers and somewhere around 2.5-3cm thick. I’ll have to see whether I have any decent pictures, but in the meantime there’s this picture I found posted on the net which should give you some clues. As for material I think it was MDF. The recesses in the base of the speakers fitted the three domed metal “heads” you can see in the picture. You can also see the four holes at each corner which allowed you to adjust and level the spikes from above.
Thanks, Richard - similar to what I’m planning on making, but not exactly what I had anticipated!
I could drill eight whacking great holes in the platforms to match the originals, but it’d be quite a faff. Any thoughts on how desirable they are? I presume Naim did it for a reason - reducing the mass without too much loss of stiffness (a bit like Russ Andrews does with Torlyte)?
There is wood and wood, you only have to look at cupping and bowing of floor boards to get some idea of movement across a relatively short distance. That is down to seasoning and how the tree is milled in the first instance. In the case of this platform, Richard says he thinks it is made from MDF, which surely is engineered wood. One of the reasons MDF is popular is that it is effectively dimensionally stable. If there was a risk, just think how many warped speaker cabinets there might be.
It might be a faff to cut all those holes especially without equipment, depends if you have a drill press and forstner bit. I wouldn’t try it by hand.
I have Arivas, the MDF 25mm thick and is rather heavy so must be very dense. The holes are 60mm diameter and the spikes are adjustable through small holes from the top of the plinth, very handy. In place of the steel locating ball thingys you could maybe make wooden ones or use something like this . I have used similar on some DIY speakers when I stole the design for the plinths from Naim (now I’ll be in big trouble). The ones I used were more rounded and made of hard rubber and worked well.
Best of luck and enjoy!
Thanks, @anon85526005 , that’s really useful. I like the convenience of being able to adjust the levelling from above rather than scrabbling around underneath the platform.
Having been pleasantly surprised at the price of a 60mm Forstner bit, I’m feeling slightly less anti-holes, if you see what I mean. I’ll be pillar-drilling everything so it won’t be much physical effort, it’ll just take time.
I’ll try to remember to post pictures when I’m done. It’s got to fit around work, so don’t hold your breath.
Should be an interesting project recreating the Ariva bases - looking forward to seeing the results and would be great if you could post progress pics. Forstner bit definitely the best way to go with a pillar drill, but they can blunt quickly and rip if very cheap, but just fine for a few cuts.
At that thickness, eight 60mm holes in each platform is not going to be something I can be bothered to do (carpentry taking precedence over hifi, I’m afraid - it happens), but I don’t think I’ll get many strength or stiffness problems!
Loudspeakers, HiFi racks etc. are invariably made from composite material, not solid wood, because of the dimensional stability, acoustic properties and consistency they provide. By all means use a nice looking bit of wood instead, although once it’s had a loudspeaker plonked on top of it I don’t think it’s going to matter what it looks like underneath.
@garyi , the whole piece cost under £60. A bargain in my book, not least because I’ll only need half of it for the platforms, leaving me with enough for a nice shelf, small table or some such.
. I have used similar on some DIY speakers when I stole the design for the plinths from Naim (now I’ll be in big trouble). The ones I used were more rounded and made of hard rubber and worked well.