I am using Star Sound's Audio Points which I had them tap for me at 5/8-11. I have a set of three I could sell you if you need any.
Drill 5/8" holes where you want the points to go, purchase a 1 ft. long 5/8-11" threaded rod from Home Depot for about $3 and cut it to smaller appropriate lengths, then use on the top 5/8-11 nuts with a 5/8" washers thru the wood with the point fastened on the underside of the heartwood.
If you were to go this route, you might also consider purchasing some smaller Audio Points to go underneath your amps as well. That is the only way I know to obtain the full affects of coupling.
Heartwood is an interesting wood and it would be interesting to know how you think it may affect your sonics.
Following up on Stehno's suggestion... it would be cleaner look if you counterbored down from the top to recess the fastening nut to give a flush "finished" appearance from the top. Another option would be to do all the work from the bottom by drilling an appropriate size counterbore from the bottom, epoxy your fastening nut in the counterbore, then buy Audiopoints with a threaded stud and screw them in. A third option would be to to buy what are called threaded inserts which are fastening hardware that have wood threads on the outside and machine threads on the inside. Drill your three holes from the bottom, screw in these threaded inserts, then screw your audiopoints into those. You have many options. E-mail me for specific sources of hardware.
I second Stehno's post. A friend made a heartwood stand for his stereo and it looked and sounded excellent. I believe Audiopoint has a kit with prethreaded spikes and with threaded sleeves made up just for this purpose. I used some on my Maggies and they were simple to install and sounded great. You could follow their directions and do it yourself if you have a drill press.
I don't believe securing the cones to the hardwood shelf would produce any sonic benefit. If you can find 4 pieces of the wood consider configuring them like a Machina Dynamica Promethean Base. I use these under my M-60's, the resolution increase is immediately apparent. I highly recommend them as amp stands for the M-60.Machina Dynamica Website
BTW, the Promethean's use DH Cones, all of which are unthreaded.
I'd go with threaded spikes if for no other reason than the ability to level your stand. Being concerned about splitting, I would think you would want a small diameter tap, like 1/4".
Use the threaded inserts. They are usually made of brass. I'd use 1/4-20, it's a common size, many spikes are threaded to that size.
I presume you are talking about Purpleheart here? (never heard it referred to as purple heartwood but I guess that is what it is being discussed.)
I hate working with purpleheart.
It is a stunning stock when done correctly though
With equipment like yours, you should audition the Sistrum stands with your amps. When you hear how they will open the soundstage you will be blown away. They have a 100% money back guarantee and it is worth a listen. Talk to Robert at Sistrum and he will explain the technology behind them.
Before you start drilling holes at random, try reading the Stereophile article entitled "Bad Vibes" by Shannon Dickson
. From what i can remember, it mentions a formula that supposedly tells you the optimum or near optimum place to locate spikes / cones under a component or shelf. Sean
I suggest forgo the drilling and use Walker Audio Valid Points. These are massive and can handle anything. They can be delivered drilled and tapped as well, but I really do not think it is needed in your situation. They are a bit pricey but the best cone available, in my opinion.
Great article - I feel armed with concrete beginner information that I will have to refer to in the future. A formula is included which locates nodes within a platform. Why a node is interesting but is counter to some people's beliefs.
I've recommended this method earlier, but it bears repeating, you would really be doing yourself a favor by going the Promethean route.
The resolution gains available with the Promethean are absolutely stunning. I would not bother repeating myself if this isolation solution were not truly "crazy" good. Here are some specifics.
I was tweaking my digital platform tonight and it just reinforced how good these Promethean Bases actually are.
Components pieces listed from floor upward:
(deviations from standard Promethean configuration are noted in parentheses)
1) Ganymede VCS roller bearings on hardwood floor (Machina Dynamica recommends Super DH Cones/DH Squares in this position)
2) 1" Maple shelf
3) Machina Dynamica springs
4) 1" Maple shelf with Tekna-Sonic C-5 damper on bottom side
5) Super DH Cones/DH Squares
6) DAC - good performance was had without DH Cones/DH Squares as well
7) Mapleshade IsoBlocks (Machina Dynamica recommends DH Cones/DH Squares in this position)
I was impressed with the Prometheans in standard configuration, but I am floored by the modified version I tried this evening. It was hard to believe that there was that much more information available inside my digital discs.
I didn't have enough roller bearings to try this on my amp stands, but after my experience this evening I will acquire more and give it a try.
BTW, I realize your application is on carpet. You could try these atop your Symposium or some other shelf placed on the carpet. FYI, my platforms are the 16"X19" model.
Thanks to all for your valuable help! I've actually decided to use a set of speaker cones (brass) that I'm not currently using. My speakers are sitting on top of Aurios, placed on top of a carbon fiber board. I am also waiting to perhaps purchase the new State Technologies amp stands, which are supposed to cancel out stray magnetic fields and eddy currents which are produced by all amps. Preliminary indications are that these stands, which are the first attempt to solve a previously ignored fidelity problem, are spectacular!
Slappy, why do you hate working with purple heartwood? What type of sandpaper do you recommend?
Interesting. What are the gains expected by using the State Technology amp stands?