General question about floors and speakers

[Sal1950]

A basic question, because I've heard contradictory things here.

There are contradictory opinions. LOL
My personal feelings, I believe the speaker should somehow be restricted from a fore-aft movement.
With heavy towers maybe not much of an issue but with lighter stand mounts, etc., Newtons third law states that for every action (force) in nature there is an equal and opposite reaction. As the speaker (woofer) cone moves forward and attempts to pressurize the room, it is also attempting to push the speaker backwards. Enough of this movement could modulate the FR and is not something to be desired. Opposing this undesirable movement can be controlled by weight (mass loading) or spikes, whatever.
Just my thoughts.
YMMV

 

[Kal Rubinson]

Lets say brand new speakers out of the box, you dont have any spikes or feet. What floor is better?

Do you have an option?

 

[Justdafactsmaam]

All right, what did you do if I may ask?

Townshend isobars

 

[Justdafactsmaam]

So there has to be enough vibration transmitted to create an audible resonance…in a concrete floor?
Secondly even you effectively decouple the structural borne transmission there is still the airborne transmission.
Keith

I’d say it’s more of an issue for owners of turntables. I can’t say for sure it would not rattle the walls though. If the air can rattle the walls I would speculate that maybe the floor could too.

Mostly, because I do own a TT the idea that concrete doesn’t vibrate raised a red flag for me

 

[Mart68]

I’d say it’s more of an issue for owners of turntables. I can’t say for sure it would not rattle the walls though. If the air can rattle the walls I would speculate that maybe the floor could too.

Mostly, because I do own a TT the idea that concrete doesn’t vibrate raised a red flag for me

On a concrete floor I could jump up and down right next to the TT with no effect, I could not do that on suspended wooden floor without the needle bouncing.

Concrete does transmit vibration ofc but not like wooded planks, or a chipboard sheet, it's many orders of magnitude less.

None of that is any help to airborne vibration but it is speculated that the feedback from airborne vibration adds reverb and makes vinyl sound better.

The only solution to airborne vibration is have TT in different room than speakers. Or just get rid of the thing and use digital which solves the many problems of turntables in one stroke

 

[Justdafactsmaam]

On a concrete floor I could jump up and down right next to the TT with no effect, I could not do that on suspended wooden floor without the needle bouncing.

Concrete does transmit vibration ofc but not like wooded planks, or a chipboard sheet, it's many orders of magnitude less.

None of that is any help to airborne vibration but it is speculated that the feedback from airborne vibration adds reverb and makes vinyl sound better.

The only solution to airborne vibration is have TT in different room than speakers. Or just get rid of the thing and use digital which solves the many problems of turntables in one stroke

Unless you have outstanding isolation you would definitely get an effect. Feedback from speakers through a concrete slab is easy to demonstrate.

Likewise if you do have excellent isolation acoustic feedback through a suspended wooden floor can be audibly eliminated.

 

[Purité Audio]

As you have the Townsend isolation bars could you acoustically measure with one in place and again without, you may have to lower the microphone slightly, and mark the exact position of the speaker.
Thanks,
Keith

 

[Justdafactsmaam]

As you have the Townsend isolation bars could you acoustically measure with one in place and again without, you may have to lower the microphone slightly, and mark the exact position of the speaker.
Thanks,
Keith

Alas I am in China and will not be back until March. I never measured anything. The issue was he speakers were rattling the floor and walls. The isolation completely fixed the rattling floor.

 

[sigbergaudio]

Some speakers are designed to couple with the floor to extend bass output - like my lx521. I lose about 10Hz bass extension if I place on an isolation platform rather than direct floor placement.

The LX521 is a very specific design, and different from most.

For normal speakers the difference will typically not be measurable in the listening position if you add/remove spikes etc.

That being said, I subscribe to absorption, so soft feet rather than spikes to decouple the speakers from the floor and reduce vibration transfer (some have suspended wooden floors that may have enough flex to transmit vibrations that get furniture etc to rattle when playing loud).

 

[Barry_Sound]

Townshend isobars

Pricey!

 

[Purité Audio]

And almost certainly won’t make the slightest difference.
Keith

 

[Justdafactsmaam]

Pricey!

Yeah. But I tried cheaper solutions that did not get the job done

 

[Mart68]

Unless you have outstanding isolation you would definitely get an effect. Feedback from speakers through a concrete slab is easy to demonstrate.

Likewise if you do have excellent isolation acoustic feedback through a suspended wooden floor can be audibly eliminated.

you will get very low frequency vibration - if a big diesel is idling outside you feel that vibration transmitted. Not the same as a loudspeaker though.

Whatever isolation you employ I take the position from decades of experience, that it is better to start with a solid floor rather than a suspended one.

I find the having the speakers sitting on the supplied hard rubber feet, on top of carpet, on top of thick underlay is more than adequate on concrete. I would not change to suspended floor if you put a pistol to my head. (well, maybe if I thought you'd really use it I would. But it would have to come to that).

 

[Roland68]

A basic question, because I've heard contradictory things here.

What is generally the physically preferred floor to place speakers on? Is it rock-hard concrete that does not vibrate at all, or is it soft wooden floorboards that "swing" with the speakers and absorb any cabinet movement?

In general, it makes a big difference how and on what floor the loudspeaker is placed.
The better the speaker and the better it resolves, the bigger the difference.
This is where physics has a very strong impact. No material is infinitely hard, there are only approximations to it. Granite is harder than concrete, concrete is harder than screed, screed is still much harder than Aspfalt (but nobody will have Aspfalt in their apartment and the hardness is very dependent on temperature). For any other floors, such as wood, parquet, laminate, etc., it also depends heavily on the material underneath; this can also apply to floating screed.

In my experience, it is best if the speaker is extremely stable and with as little surface area as possible. Ideally only on 3 points. However, I'm not a fan of spikes these days either.

 

[StigErik]

Lets say brand new speakers out of the box, you dont have any spikes or feet. What floor is better?

It's like asking "I have a brand new car with no tyres. Asphalt or gravel roads?"

 

[Justdafactsmaam]

you will get very low frequency vibration - if a big diesel is idling outside you feel that vibration transmitted. Not the same as a loudspeaker though.

Whatever isolation you employ I take the position from decades of experience, that it is better to start with a solid floor rather than a suspended one.

I find the having the speakers sitting on the supplied hard rubber feet, on top of carpet, on top of thick underlay is more than adequate on concrete. I would not change to suspended floor if you put a pistol to my head. (well, maybe if I thought you'd really use it I would. But it would have to come to that).

It’s rarely an option. My point was concrete still transmits vibrations. Not that it was either inferior or superior to a suspended wood floor. They both present issues.

 

[Mart68]

It’s rarely an option. My point was concrete still transmits vibrations. Not that it was either inferior or superior to a suspended wood floor. They both present issues.

I asked two questions when I bought my house:

1) Is this a concrete floor?
2) Does the shower work?

Yes to both questions so made an offer on the spot. Would not have bought if floor was suspended.

All rooms have issues that need addressing but if you start with a suspended floor you are starting from behind.

 

[Roland68]

It’s rarely an option. My point was concrete still transmits vibrations. Not that it was either inferior or superior to a suspended wood floor. They both present issues.

Concrete transmits very little resonance. It's mostly a complete (-micro) movement of the building. If you feel vibrations in the floor, you will also feel them in the walls.
You notice this when you jump directly on a concrete floor (not floating/screed) next to a running record player. Any other soil is worse.

 

[Justdafactsmaam]

I asked two questions when I bought my house:

1) Is this a concrete floor?
2) Does the shower work?

Yes to both questions so made an offer on the spot. Would not have bought if floor was suspended.

All rooms have issues that need addressing but if you start with a suspended floor you are starting from behind.

Not sure entirely sure that’s true.

 

[Justdafactsmaam]

Concrete transmits very little resonance. It's mostly a complete (-micro) movement of the building. If you feel vibrations in the floor, you will also feel them in the walls.
You notice this when you jump directly on a concrete floor (not floating/screed) next to a running record player. Any other soil is worse.

As for turntables, concrete has a substantial advantage over suspended wood floors. But with the right isolation a well built suspended wood floor can be reduced to a non issue. As for room acoustics though, suspended wood floor is much better.