Spiked my speakers... and didn’t like

DarqueKnight

WLDock wrote: »

Whats interesting in the audio production / recording world, you see speaker decoupling / isolation more so than and coupling used.

Isolation/decoupling makes sense in a room with multiple pairs of speakers. I can see where having two or more pairs of speakers acoustically grounded to the same plane could cause some coloration issues, even if only one pair of speakers is active at a time.

RobbyKY

@DarqueKnight wrote:
The LSiM 707s in my home theater are spiked on a ceramic tile floor. The SDS SRS 1.2TLs in my two channel stereo system sit on their natural feet on a hardwood floor laid over cement slab, but are braced to the rear wall. Natural feet and wall brace sounded better than spikes alone.

Been wondering about this for some time. I've spiked both pairs of my 1.2TLs and liked the improvement over the OEM pads sitting on carpet. I know Polk included the "Bass Brace" threaded attachment point on the rear of these but always though it was just a cover story to prevent liability claims if they tipped over on a child.

Have you compared spiked vs braced results during any of your past experiments?

Spiked and braced?

I know many theories float around concerning how far off the back wall these should be for peak performance and found it does make a slight difference to the sound stage I get on one of my set-ups. Just curious how far offset you're running yours?

Thanks

steveinaz

DSkip wrote: »

Please explain to me exactly how a spike decouples. I’m not picking a fight here.

Spikes create pathways for energy to travel. This in effect is a coupling mechanism.

The small surface area of a spike is intended to not allow floor vibrations to creep up into the speaker, and they also serve to minimize speaker vibrations being transferred to the floor... John is correct.

Think of it this way...you could either set the speaker on the floor and have the entire surface area of the bottom of the speaker transferring (and receiving) vibration; OR, you could remove 99% of that "vibrating" surface area by channeling it via 4 tiny spike tips.

You all can debate the semantics of "coupling" and "de-coupling." I have found that "soft" floors (sub-floors) sound best "spiked" while hard subfloor (concrete/tile) sound best with "soft" isolation; ie, rubber feet.

nooshinjohn

jdjohn wrote: »

Spikes are tuning devices, just like cables and room treatments.

Cables are more than just tuning devices. They are the bedrock upon which a good system depends.

Clipdat

steveinaz wrote: »

The small surface area of a spike is intended to not allow floor vibrations to creep up into the speaker, and they also serve to minimize speaker vibrations being transferred to the floor... John is correct.

Think of it this way...you could either set the speaker on the floor and have the entire surface area of the bottom of the speaker transferring (and receiving) vibration; OR, you could remove 99% of that "vibrating" surface area by channeling it via 4 tiny spike tips.

"The basis of this idea seems to be that if the contact area was zero (i.e. no contact at all!) then no solid vibrations could pass. Hence if we make the contact area tiny, this approaches zero, so should only allow a small amount of vibration through. Unfortunately, although plausible, this idea may simply be incorrect.

We can understand how the above idea might be wrong by considering another example of the use of “spikes” – a running shoe. Here the purpose is to increase the grip between two objects (shoe and ground) and hence transmit forces more efficiently. This example instantly shows that a cone or spike might not reduce the amount of actual force transmission, but actually help ensure effective transmission. Hence spikes and cones – far from “isolating” – might sometimes give a more effective link for vibrations to pass though."

Clipdat

"Spikes are primarily designed to puncture through carpet to get a solid connection between the stand and the floor, essentially enhancing the connection or coupling.

The only time you would want decoupling is if there were a problem with sympathetic resonance from a subfloor or desk for example."

steveinaz

The spikes "couple" the speaker to the floor, however they de-couple the speaker from floor-borne vibration. That's why I don't like those terms. I think isolation is a better way to categorize spike vs rubber feet; or what I call hard or soft isolation.

joecoulson

Clipdat wrote: »

"Spikes are primarily designed to puncture through carpet to get a solid connection between the stand and the floor, essentially enhancing the connection or coupling.

The only time you would want decoupling is if there were a problem with sympathetic resonance from a subfloor or desk for example."

Which I have

VR3

Honestly, nothing in this hobby is a "truth". Everyones ears are different. If you like rubber feet versus spikes, it is what it is.

pitdogg2

VR3 wrote: »

Honestly, nothing in this hobby is a "truth". Everyones ears are different. If you like rubber feet versus spikes, it is what it is.

Truth!

DarqueKnight

RobbyKY wrote: »

I know Polk included the "Bass Brace" threaded attachment point on the rear of these but always though it was just a cover story to prevent liability claims if they tipped over on a child.

I don't think it had anything to do with accident liability. If so, they would have made it a safety requirement or safety recommendation. Tall, relatively shallow depth speakers with high bass output can't help but wobble a bit back and forth due to the push back from the drivers. Bracing to a drywall wall damps the wobble considerably. Bracing to a masonry wall (which is what Polk recommended) stops the wobble.

RobbyKY wrote: »

Have you compared spiked vs braced results during any of your past experiments?

I did listening tests and room response measurements between regular feet, braced and non-braced, here:

https://forum.polkaudio.com/discussion/123136/sda-driver-seals-original-foam-vs-mortite-vs-armaflex-foam/p2

I have done listening tests between spiked and non-spiked, but I didn't do any measurements. Spiked was better than non-spiked. Braced was better than non-braced.

RobbyKY wrote: »

Spiked and braced?

I don't recall trying spiked in combination with braced. The SRS manuals state one or the other is sufficient.

RobbyKY wrote: »

I know many theories float around concerning how far off the back wall these should be for peak performance and found it does make a slight difference to the sound stage I get on one of my set-ups. Just curious how far offset you're running yours?

My 1.2TLs are 11.5" from the rear wall.

Toolfan66

I use the brace and spikes, keeps the speakers nice and tight...

DarqueKnight

@Toolfan66

What kind of floor?

BlueFox

nooshinjohn wrote: »

jdjohn wrote: »

Spikes are tuning devices, just like cables and room treatments.

Cables are more than just tuning devices. They are the bedrock upon which a good system depends.

Exactly. Their job is to get the signal between two pieces of gear with as little degradation as possible. With audio on a good system, even the smallest degradation is audible.

F1nut

I was told by Matt or Stu or Al (don't remember) that the bass brace was conceived as a way to prevent the speakers from falling in an earthquake, read California. During the development Polk discovered it helped with the bass response. The manual states to use the brace or the spikes, but not both. I found while using the brace I could wiggle the speakers on my hardwood floor, which seemed counterproductive, so I went back to the spikes.

Toolfan66

DarqueKnight wrote: »

@Toolfan66

What kind of floor?

Carpet..

Toolfan66

I see no reason why you can’t use both, spikes made a world of difference in sound from every angle, adding the brace didn’t affect it at all, if it did it’s not audible to my ears, and like I said I like how solid they feel with the brace, keep in mind I have added about 40-50lbs of weight to each speaker as well, they are solid and heavy..

Tony M

Clipdat wrote: »

"Spikes are primarily designed to puncture through carpet to get a solid connection between the stand and the floor, essentially enhancing the connection or coupling.

The only time you would want decoupling is if there were a problem with sympathetic resonance from a subfloor or desk for example."

BINGO!
I agree. They ( spikes) were promoted in the beginning of spike usage to keep speakers from rocking on padded carpet. That's what my old memory bank is telling me.

Now currant theories can be many as we're reading about them now.

Book shelf speakers sat on, well, book shelves. Not stands. Then came spiking the stand's base. Then came spiking the stand's top plate. Then came using spikes on the base of the stands and foam or rubber half round pads on the top plate.

I like who ever said "some spiking or rubber isolation pods works differently in different circumstances".

I do see where anchoring a tower speaker to the wall with an upper brace would help!

This topic is like wires/cables and power cords.

kharp1

Everything is a try it and see adventure. What works for one speaker/set up may not work for the next.

westmassguy

tophatjohnny wrote: »

I spiked my wife's drink last night and she sounded amazing. 🎩

You a funny guy

delkal

From the above linked article.

"At first appearance, it seems plausible that cones under a loudspeaker should reduce the amount of sound energy transmitted between speaker and stand because they reduce the area of contact between the speaker and the stand. In the same way, we might expect spikes at the base of the stand to provide isolation. The basis of this idea seems to be that if the contact area was zero (i.e. no contact at all!) then no solid vibrations could pass. Hence if we make the contact area tiny, this approaches zero, so should only allow a small amount of vibration through. Unfortunately, although plausible, this idea may simply be incorrect."





It is faulty logic to think if you reduce the contact area you reduce the amount of transmitted energy. What they don't understand is that as you reduce the amount of contact area the force pushing down on the contact points increase exponentially. Think of it this way. A 50 pound speaker on a 10x10 inch base (100 cubic inches) is only applying 0.5 psi pressure to the floor. Now if you put spikes on you reduce the contact area to a very small size. Depending on how sharp the spikes are you could be coupling to the floor with hundreds of pounds per square inch.

You can demonstrate this for yourself. Stick your little toe under a speaker without spikes. Then put the spikes on and stick your little toe under a spike. Trust me, you will feel a difference. Then have an assistant start playing music with a lot of bass. I bet you feel plenty of vibrations.

jdjohn

nooshinjohn wrote: »

jdjohn wrote: »

Spikes are tuning devices, just like cables and room treatments.

Cables are more than just tuning devices. They are the bedrock upon which a good system depends.

Some tune better than others.

HzTweaker

delkal wrote: »

You can demonstrate this for yourself. Stick your little toe under a speaker without spikes. Then put the spikes on and stick your little toe under a spike. Trust me, you will feel a difference. Then have an assistant start playing music with a lot of bass. I bet you feel plenty of vibrations.

Bondage in the stereo room?

audioluvr

DSkip wrote: »

I’ve never paid for sex

If you're married, you pay for sex every day....

Clipdat

audioluvr wrote: »

If you're married, you pay for sex every day....

No married man is having sex every day.

joecoulson

Its like a car Drew, you make consecutive payments regardless of use just so you can have it available as needed..
unlike most cars, its not always ready when you are.

mhardy6647

HzTweaker wrote: »

delkal wrote: »

You can demonstrate this for yourself. Stick your little toe under a speaker without spikes. Then put the spikes on and stick your little toe under a spike. Trust me, you will feel a difference. Then have an assistant start playing music with a lot of bass. I bet you feel plenty of vibrations.

Bondage in the stereo room?

codycatalist

joecoulson wrote: »

Its like a car Drew, you make consecutive payments regardless of use just so you can have it available as needed..
unlike most cars, its not always ready when you are.

True dat!