Spiking Your Speakers: What’s the Point?

[sidvee]

Can we then safely conclude that the “coupled/decouoled” argument is a false dichotomy (as with many other absolute extreme expressions)?

The bottom of any speaker has to rest on something or other thanks to gravity.

Spikes, footers or whole base directly resting on floor or carpet etc all reflect the degree to which the coupling happens.

There can be no absolute decoupling unless “Maglev” tech is used (as in some bonkers turntable setups).

I think it has to be seen in the context of the construction of the surfaces on which the speakers will rest. A floor constructed with wooden joists and plywood surface will behave significantly different from a floor with poured concrete base, as will the floor of a basement vs a floor of a high rise apartment. And then what is the floor treatment on top of the sub floor - deep pile carpet, tiles, granite etc etc. At the end of the day, it will boil down to experimentation and there can be no definitive answer - and certainly buying thousands of $'s worth of isolating/coupling devices - which seems to have become the fashion now-a-days with dubious scientific/auditory claims - is no guarantee of a solution.
Cheers,
Sid

 

[arj]

Depending on your floor arj. On carpet floors you really need spikes to keep the speakers in place. Otherwise they won’t be stable

Yes , I was responding to Argho...he is on bare floor. I place directly on thin cotton carpet with no spikes..experimenting with wood discs now between speaker and carpet.

Idea is to balance the bass and microdetails..

 

[Analogous]

Idea is to balance the bass and microdetails..

In other words “tuning it to your favourite taste”!

 

[alpha1]

In my understanding of physics: the speaker driver is housed in a box/enclosure and since momentum is always conserved, the speaker enclosure has to move in opposite direction (this could also be known as Newton's 3rd law).
The best way to observe this would be suspend the speaker body via string and watch how the enclosure moves according to the driver movements.

This is how your speakers will perform in perfect "isolation". Is this the best? Not at all, since the opposite movement of the body will cause a net lesser movement transferred from driver to the air.

What happens if I make the enclosure body extremely massive? It will move only very little; thus the driver's movements ends up pushing/pulling the air: this is closer to how we desire it to perform. Taking this idea further, if we couple the body to "earth", we will encounter negligible motion of the enclosure (since it is enclosure + earth that will oppose the driver movement) and thus the entire driver's movements are now transferred to the air.

 

[arj]

In other words “tuning it to your favourite taste”!

how much salt, chilly and pepper !

 

[Analogous]

In my understanding of physics: the speaker driver is housed in a box/enclosure and since momentum is always conserved, the speaker enclosure has to move in opposite direction (this could also be known as Newton's 3rd law).
The best way to observe this would be suspend the speaker body via string and watch how the enclosure moves according to the driver movements.

This is how your speakers will perform in perfect "isolation". Is this the best? Not at all, since the opposite movement of the body will cause a net lesser movement transferred from driver to the air.

What happens if I make the enclosure body extremely massive? It will move only very little; thus the driver ends up pushing/pulling the air closer to how we desire it to perform. Taking this idea further, if we couple the body to "earth", we will encounter negligible motion of the enclosure (since it is enclosure + earth that will oppose the driver movement) and thus the entire driver's movements are now transferred to the air.

So spikes and footers and such would matter more with lighter speakers and less so with heavy ones?

 

[Analogous]

how much salt, chilly and pepper !

Don’t forget the important ingredient snake oil

 

[alpha1]

So spikes and footers and such would matter more with lighter speakers and less so with heavy ones?

The mass of drivers vs the mass of cabinet matters.
In case of tweeter the moving parts (dome + coil) is so light that few kg of cabinet could be enough to provide a stationary opposition.
But in case of woofer / subwoofer - the driver itself would weigh close to kilos.
So, you are right, it will matter more for larger speakers.

 

[Analogous]

If a bookshelf speaker (10kg) on a stand (20kg) with metal spikes on a smooth ceramic tiled floor and playing Massive attack continuously at 90db avg for a week, how far would the speaker move?
Advancing the frontiers of Audio science with such research questions is important work.

 

[aeroash]

If a bookshelf speaker (10kg) on a stand (20kg) with metal spikes on a smooth ceramic tiled floor and playing Massive attack continuously at 90db avg for a week, how far would the speaker move?

Unsure of the speaker, but the Family for sure.

 

[Analogous]

Unsure of the speaker, but the Family for sure.

What’s a little sacrifice to advance scientific knowledge that will benefit all mankind and womankind?
Besides keeping the door locked will prevent wind and human error

 

[keith_correa]

In my understanding of physics: the speaker driver is housed in a box/enclosure and since momentum is always conserved, the speaker enclosure has to move in opposite direction (this could also be known as Newton's 3rd law).

Momentum of what? Conserved?
Opposite to what direction?
Can you explain or elaborate more?

 

[drkrack]

I Moved from Default Spikes to DIY Steel Platform plus Spikes to Isoacoustics Gaia 2s/3s and Recently to Townshend Seismic Podiums for my floorstanders, on thin carpeted floor.

The Bass became more well defined or in other words less bleeding of bass to overshadow other frequencies helped a lot in improving overall detailed presentation and a balanced SQ.
Isoacoustics Gaia were allowing slight free movement of Speakers themselves, but the Townshend seismic Podiums allow very free movement of Speakers (Maximum decoupling from floor) to the extent that you wonder whether speakers will fall off the Podiums with a small push. But they sound the best with them.

That makes me wonder can we suspend the speakers from ceiling using steel wires and achieve much better results?
@Yelamanchili manohar

 

[Analogous]

I Moved from Default Spikes to DIY Steel Platform plus Spikes to Isoacoustics Gaia 2s/3s and Recently to Townshend Seismic Podiums for my floorstanders, on thin carpeted floor.

The Bass became more well defined or in other words less bleeding of bass to overshadow other frequencies helped a lot in improving overall detailed presentation and a balanced SQ.
Isoacoustics Gaia were allowing slight free movement of Speakers themselves, but the Townshend seismic Podiums allow very free movement of Speakers (Maximum decoupling from floor) to the extent that you wonder whether speakers will fall off the Podiums with a small push. But they sound the best with them.

That makes me wonder can we suspend the speakers from ceiling using steel wires and achieve much better results?
@Yelamanchili manohar

Good you brought us back on topic @drkrack . Curious why you signed the post as @Yelamanchili manohar though?

 

[mbhangui]

In my understanding of physics: the speaker driver is housed in a box/enclosure and since momentum is always conserved, the speaker enclosure has to move in opposite direction (this could also be known as Newton's 3rd law).
The best way to observe this would be suspend the speaker body via string and watch how the enclosure moves according to the driver movements.

This is how your speakers will perform in perfect "isolation". Is this the best? Not at all, since the opposite movement of the body will cause a net lesser movement transferred from driver to the air.

What happens if I make the enclosure body extremely massive? It will move only very little; thus the driver's movements ends up pushing/pulling the air: this is closer to how we desire it to perform. Taking this idea further, if we couple the body to "earth", we will encounter negligible motion of the enclosure (since it is enclosure + earth that will oppose the driver movement) and thus the entire driver's movements are now transferred to the air.

I was just waiting for someone to say this. You have Newtonian mechanics and the fundamental laws of thermodynamics in play here. This is absolutely correct what you have stated above. If the speaker moves, less of the energy of the drivers will get get converted to sound. It is exactly because of 'Energy cannot be created or destroyed'. So whether you use spikes or no spikes, energy will get transmitted to the floor, spikes or no spikes. With spikes, the engery will be transmitted over a very small area and hence the force on the small area will be small. Since the force is high, it will try to dig in into the floor. On our ceramic tiled floor (Ceramic is very hard), the spikes will have no effect. It won't dig in and the speaker will move. Since the point of contact is small, friction too will be small. On a wooden floor the spikes will definitely make a minor dent and thus the speaker will be held firmly to the floor. All energy will get dissipated in the form of heat or vibration in trying to transmit the energy to the floor. If you put coins or rubber below the feet or use rubber feet, again the extra energy will all be dissipated as friction. The extra area of contact with the floor will increase the friction and make it more difficult for the speaker to move in the opposite direction of the driver. Those fancy feets with spings will work differently (those iso something products). The springs will absorb the energy and release it in the opposite direction when the speaker moves in the opposite direction. I guess springs kind of feet will alter the sound wave and some may actually like the distortion caused by those springy feets.

So all methods will ultimately dissipate the extra energy in some way or the other. The less the speaker moves, more of the energy will be converted to sound. Heaver and firmer the speaker more energy will be converted to sound. This was all in the head and it had to get out and hence my rant.

NOTE: On our indian floors which have ceramic tiles, it becomes very easy to move the speakers with spikes on (with the side effect of scratching the floor).

 

[mbhangui]

Looks like @alpha1 loved physics or took his physics lesson's seriously in school

I do have a thermocouple lying somewhere. I will dig it out and put it under the spike and blast some song at high volume. The multimeter will tell if the temperature increases. Let me try and come back later with the result.

For those who don't know, A thermocouple is a device for measuring temperature. It comprises two dissimilar metallic wires joined together to form a junction. When the junction is heated or cooled, a small voltage is generated in the electrical circuit of the thermocouple which can be measured, and this corresponds to temperature.

EDIT: located my thermocouple. Two different metal wires are fused at one end (if you can see the fused bulb at the end of blue sheath below)

 

[keith_correa]

I really don't understand the concept of the speaker moving in the opposite direction of the driver. It really doesn't make sense to me. Firstly where is the driver moving and why?

 

[Analogous]

I do have a thermocouple lying somewhere. I will dig it out and put it under the spike and blast some song at high volume. The multimeter will tell if the temperature increases. Let me try and come back later with the result.

For those who don't know, A thermocouple is a device for measuring temperature. It comprises two dissimilar metallic wires joined together to form a junction. When the junction is heated or cooled, a small voltage is generated in the electrical circuit of the thermocouple which can be measured, and this corresponds to temperature.

Now that’s a pure scientific inquiry! Love it and look forward to the findings

 

[mbhangui]

I really don't understand the concept of the speaker moving in the opposite direction of the driver. It really doesn't make sense to me. Firstly where is the driver moving and why?

Come to think of it, it is exactly the same reason why planes fly. When the speaker cone moves forward, it compresses the air in front of it. The compressed air then exerts a force in the opposite direction.

Same thing helps planes fly. The Jet turbine burns fuel and the compressed burnt fuel comes out from the back causing the compressed burnt fuel exert force on the plane in the opposite direction. The plane moves forward because it is not resting on spiked feets. The wings are tilted upwards. This cause air to get compressed in the downward direction. The compressed air the exerts force on the wings in the opposite direction and thus lifts the wings up and voila the aeroplane gets lifted into the air.

This is all Bernoulli ka Kamal who was the first to study fluid dynamics and explain it. https://en.wikipedia.org/wiki/Bernoulli's_principle

 

[Analogous]

I really don't understand the concept of the speaker moving in the opposite direction of the driver. It really doesn't make sense to me. Firstly where is the driver moving and why?

Like a piston? My simplistic understanding is:
The magnet moves the diaphragm (fast or slower vibrations depending on the frequency I think.)

The cones suspended/held by the rubber (or similar) surrounds move back and forth- more noticeable in woofer and subwoofers.
With larger ones we can easily feel the air move and room getting pressurised. So plenty of movement and Newton’s third law applies.

As the entire driver units are bolted in place to the baffle by iron frames vibration is transmitted to the baffle and the rest of the structure. And then to the floor (through the stands in case of stand mounted speakers.

A crude understanding, please correct me if I am mistaken.

I have noticed subs moving a bit on a smooth ceramic floor.