Budget Spikes. Spike your SDAs for under $3!

1. I chose to grind Grade 8 (hardened steel) hardware to a point. A few minutes with a bench grinder or perhaps even an angle-grinder is all it takes once the bolt head is cut off.
2. Don't forget jam nuts, (and perhaps washers) so the adjustment isn't lost due to vibration. This also prevents the threads of the insert from bearing the weight.

I have absolutely no idea how the "cone shape" makes a bit of difference,except for the obvious--as the cone gets wider, there's more of the speaker cabinet that is directly supported. If the point will pierce the carpet and pad, and the weight isn't supported on the thread insert...you're set.

To me, the big question is whether three or four spikes per speaker is best. I like the three-legged stool concept: Inherently stable. Problem is that the speakers came with four feet.

I will pay extra to get a better looking spikes & they can be installed easily. Seriously you can save money by going cheap & sure it will work & probably work/sound outstanding (no arguements here) but when it comes to the better made quality spike they can be installed by people like me & they look much cleaner & they make the bass sound much better & seems to get better control of the tone

Here is some heavy duty spikes for dirt cheap that work well. Im using them on 1c's & 15tl's. Adding spikes is cheap & rewarding sonically.

I've tapped a set of conical stainless wine bottle stoppers before. The head of the setscrew was inside the cabinet.

When I find a set of those SDA's like Lawdog's here, I will design billet end caps for them with pre-tapped positions since they are heavy.

Depending on static load, the only limiting factor in a small continuous diameter material/part is Euler's law. More sound energy will transfer, but how much is up to your ears/taste.

Even intelligent life forms are cone shaped. I tried the pointed spikes, changed to cones.

How much money will you have saved when an insert or 2 gets pushed into the cabinet from bearing all that weight? Worse yet what if the speaker topples over and ruins more than just the cabinet base? I admire your resourcefulness but in this case spending an extra $20 might be a better idea.

As long as you're happy is all that matters. Necessity's the mother of invention... but if mom finds out about that kind of invention on her new carpet....hehe.

Joking aside, What is the weight of each speaker?

Schurkey wrote: »

Don't forget jam nuts, (and perhaps washers) so the adjustment isn't lost due to vibration. This also prevents the threads of the insert from bearing the weight.

as the cone gets wider, there's more of the speaker cabinet that is directly supported.

pitdogg2 wrote: »

The obvious is that the insert now bears all the weight instead of the base of the cone. It is now also much easier to torque the insert enough to ruin it if you are adjusting the speaker. The insert or base of the speaker still needs something solid to sit on not just threads. I have used the cheap version of spikes but would never on something that heavy, something smaller that I could pick up and down without having to lean one way or the other.

Schurkey wrote: »

It's not the cone that works the magic, it's the fact that the speaker is no longer "floating" on a thick, squishy carpet.

I would strongly recommend the washers unless the tapped portion was designed to support the load, and the spikes and base have enough lateral load capability. Otherwise they are doing most of what spikes are designed to do.

The majority of the science is from mechanics and practicality - simplicity. The wide top is for a large base to support the load. If the cabinet already has a tapped base then the spike or threaded insert only needs to support the cabinet laterally. A point increases the pressure at the contact area and can help focus and concentrate vibrations for better transmission across the contact area. The smaller the contact area for a fixed load, the higher the pressure. Ideally there are only 3 spikes for proper load distribution.

The cone shape, a straight taper, is the easiest to machine from a larger diameter to a smaller one. The lateral load capability may have an impact on the taper angle.

There is some longer sonic theory of transmitting cabinet vibrations to the floor for more bass presence, however some people to not care for the differences in the speed of the sound transmission. The type of floor can have an impact on this, along with the frequencies transmitted. If I recall the main uses for spikes was for tall bookshelf speaker stands. People removed the speakers from the solid "bookshelf" to tall stands and they sounded "airy" and lacked bass. A stand with a heavy base helped keep it stable, but was difficult to move and often provided too much dampening. The stands with spikes gave the speakers a more solid base, especially on carpet. If the stand was designed right, bass frequencies were transmitted to the floor to aid in the bass response from a small speaker.

Larry, I think Rambo threaded those onto the end of his arrows to blow up helicopters and bad guys.

yeah, I was just thinking earlier - good info in this discussion re: spikes in general.

Thanks PQ, that falls in line with what I was thinking that a harder rubber would be better if it were to be used. Ill be using 60A polyurethane when I make the bases for the harwood floors.

4ea at 1" diameter interface of the floor, the 60A Poly will not compress much at all but grip solidly. End the end, I think spikes are for people without 3 year olds.