Springs Under My Speakers: What's Happening?

[fineMen]

I wouldn't take it personally.
I tried to read your post 292 again, but as soon as I hit :
Another is the elasticity of a spike. Everything becomes soft,,,,,
I start giggling and can not read the rest, perhaps if you re-post it and put that clause right at the end.

I gave you the formula on how to calculate the spring of whatever kind. The indicator for a succesfull decoupling frequency, to put it a bit sloppy, is how much the spring(s) sinks in when loaded with the speaker. 1mm is way uber-sufficient given the current gravitation constant of mother earth. All other parameters cancel each other out (math).

In short: take a mousepad, upused if you wil, done! For very small speakers: support only the edges, right?

Don't you call it "spike" over there, but "cone"? Whatever, yes, the tip of that thing is weaker than you might think. And if it were not, the surface it contacts isn't material stolen from a neutron star. At least if they say so, it would be a relatively new lie.

I neglected rotational modes, but some qualitative and semi-quantative arguments relate the spring idea to rotation and shift also. The caveat with the analogy to piles / piers in cities doesn't count because it doen't take those arguments into account. It is empty, caveat emptor. I'm not so much convinced that even the most basic ideas of physics would help you all here.

Btw, you cannot decouple using a heavy concrete slab against a wobbly floor, and so on and on.

 

[MattHooper]

Further adventures:

I had the Joseph speakers (Isoacoustics Gaia on back, spikes hockey puck on front), on the MDF base, beneath that 1 1/2" thick Cedar caps. That was working really nice - huge sound, good bass control, pretty snappy sound, I liked the height.

I replaced the 1 1/2" Cedar caps with lower spikes (3/4" I think). So now the MDF shelf was spiked to the ground, nothing else underneath it, speakers were lowered slightly.

Result: Very nice! Super dense, snappy "live vivid" sound. Probably the most dense, punchy energetic sound so far. Lots of fun. Negatives: A little less suave tonally (slightly more coarse), a bit less spacious and rich, and slightly more prominent bass. Just a bit overrich. It was mostly quite well controlled though.

So today...I finally put the granite bass, which I had made for me last week, under the speakers. It's a dark (much darker than it looks in the photo) with nice golden speckles.
1 and 1/4" thick, so quite hefty. Basically what I did was go back to MDF base atop the Cedar caps again, but replace the MDF shelf with the Granite. Both the Granite and MDF are exactly the same thickness, so the position/height of the speaker remained exactly the same.

Result?

Awesome: Midrange on up to die for. Lush, soundscape is huge.

Not Awesome: The bass went insane! WTF? It's just gigantic and overblown now. Like I added subwoofers without dialing them down. This really surprised me
since the granite at least seems much more "dead" than the MDF base (it's and MDF 'sandwhich' with damping material in between). Why would the bass be so much
stronger just substituting the granite for the MDF? I dunno. Seems like chaotic sorcery at this point.

Anyway...gonna keep fiddling, because I really like the look of the granite bass. Looks much better in person vs this photo:

 

[Purité Audio]

REW plots to show the ‘insane’ bass ?
Keith

 

[Axo1989]

I had the Joseph speakers (Isoacoustics Gaia on back, spikes hockey puck on front), on the MDF base, beneath that 1 1/2" thick Cedar caps.

Clarification: are you saying that only some mounting points on the speakers are isolated, and some are essentially spiked? I understand Gaia gadgets but I've forgotten what 'hockey puck' was made of.

 

[Ken Tajalli]

Further adventures:

I had the Joseph speakers (Isoacoustics Gaia on back, spikes hockey puck on front), on the MDF base, beneath that 1 1/2" thick Cedar caps. That was working really nice - huge sound, good bass control, pretty snappy sound, I liked the height.

I replaced the 1 1/2" Cedar caps with lower spikes (3/4" I think). So now the MDF shelf was spiked to the ground, nothing else underneath it, speakers were lowered slightly.

Result: Very nice! Super dense, snappy "live vivid" sound. Probably the most dense, punchy energetic sound so far. Lots of fun. Negatives: A little less suave tonally (slightly more coarse), a bit less spacious and rich, and slightly more prominent bass. Just a bit overrich. It was mostly quite well controlled though.

So today...I finally put the granite bass, which I had made for me last week, under the speakers. It's a dark (much darker than it looks in the photo) with nice golden speckles.
1 and 1/4" thick, so quite hefty. Basically what I did was go back to MDF base atop the Cedar caps again, but replace the MDF shelf with the Granite. Both the Granite and MDF are exactly the same thickness, so the position/height of the speaker remained exactly the same.

Result?

Awesome: Midrange on up to die for. Lush, soundscape is huge.

Not Awesome: The bass went insane! WTF? It's just gigantic and overblown now. Like I added subwoofers without dialing them down. This really surprised me
since the granite at least seems much more "dead" than the MDF base (it's and MDF 'sandwhich' with damping material in between). Why would the bass be so much
stronger just substituting the granite for the MDF? I dunno. Seems like chaotic sorcery at this point.

Anyway...gonna keep fiddling, because I really like the look of the granite bass. Looks much better in person vs this photo:



View attachment 283586

Put the speakers solidly on the slabs, and use the isoacoustics between the slabs and the floor.
The speakers need the mass of the slabs as vibration sink, but the slabs should be isolated from floor.
The more mass on the slab, the more it absorbs vibrations from the speakers. But it only works if the speakers are solidly coupled to the slabs.
An analogy:
Have you ever attached a heatsink-fan to a computer processor?
The cpu gets hot, to loose this heat, a thermal cream is applied to it, then a flat chunk of metal with fins (the heat-sink) is solidly attached to it. The heat from the cpu can Sink its excess heat to the heat-sink, the fan blows air to aid cooling.
- the CPU is speaker cabinet
- The heat, is cabinet vibrations, specially at Bass.
- The chunk of metal is slab's mass
- the thermal cream can be the spikes or bolts, or anything that couples the cabinet to the mass of the slab.
- If the slab is not isolated from floor, some of the vibrations can leak into your floor, if solid floor, no problems, if suspended floor! problems . .

 

[MattHooper]

REW plots to show the ‘insane’ bass ?
Keith

Yet again: please revisit the caveat that begins this thread. You won't be satisfied, sorry, probably not the thread for you.

 

[MattHooper]

Clarification: are you saying that only some mounting points on the speakers are isolated, and some are essentially spiked? I understand Gaia gadgets but I've forgotten what 'hockey puck' was made of.

I have a set of Gaia on the back of the speakers, and spikes going in to actual hockey pucks (vulcanized rubber) on the front. (There were some issues that prevented my getting Gaia on the front of the speaker).

 

[Thomas_A]

Sometimes bass is percieved as vibrations in the floor. If you have a flexible wood floor you probably have losses at standing waves. Loading the floor at varoius points can change those modes. Audible? Don’t know. Can you feel the vibrations changing? Perhaps.

 

[OldHvyMec]

since the granite at least seems much more "dead" than the MDF base

It is denser so it rings. I think you're feeling the bass because you coupled the bass from the cabinet to the floor. You want to do the opposite.
You are getting two bass signals at two different times. Which is correct? The pressure from the room or the vibration through your feet and bottom?

Springs, pods, or air ride.

I don't use the bass in the main cabinets at all. Then I isolate ALL the cabinet(S) from the floor.
I use a 300sf room with 8ft lids. 4 12" servo sub drivers 80hz < and 6-12 8" bass drivers 80-300hz (band pass). There is no bass bloat because
everything is decoupled. Couple the same cabinets to the floor it's the worst mess you've ever felt/heard, unless you're already deaf. A TT nightmare!
Servos mitigate the vibration to a point, but 20 hz @ a given pressure will ring my bell. Feeling the bass, that's kid stuff. I CAN loosen every
screw in the house by using spikes. LOL

The whole house vibrates with spikes. Slabs can be the worst of all if they aren't anchored to friction piers. Reminds me of huge log drums.
Think of a 20 year old 4" (3.5") thick construction slab that the soil underneath hasn't seen water in 20 years.
There are air gaps all over the place under the slab. The older the slab, the worse it gets. DECOUPLE!!! Quite an eye opener for a vinyl user.
If you want to try it and not spend a fortune, use an inner tube and encase the top and sides with wood and leave the bottom open. Air the tube.
It reduced the waves in my neighbors pool to a dinosaur thump, we still had to tape the window in the shop. 25 x 35 x 12.

BTW My home is on stem walls the floor jacks have an adjustment nut. The funny part is everything SITS on the jacks, they aren't anchored either.
I should have thought of that when I built it 39(?) years ago. I sure learned.

 

[MattHooper]

Put the speakers solidly on the slabs, and use the isoacoustics between the slabs and the floor.
The speakers need the mass of the slabs as vibration sink, but the slabs should be isolated from floor.
The more mass on the slab, the more it absorbs vibrations from the speakers. But it only works if the speakers are solidly coupled to the slabs.
An analogy:
Have you ever attached a heatsink-fan to a computer processor?
The cpu gets hot, to loose this heat, a thermal cream is applied to it, then a flat chunk of metal with fins (the heat-sink) is solidly attached to it. The heat from the cpu can Sink its excess heat to the heat-sink, the fan blows air to aid cooling.
- the CPU is speaker cabinet
- The heat, is cabinet vibrations, specially at Bass.
- The chunk of metal is slab's mass
- the thermal cream can be the spikes or bolts, or anything that couples the cabinet to the mass of the slab.
- If the slab is not isolated from floor, some of the vibrations can leak into your floor, if solid floor, no problems, if suspended floor! problems . .

Yes understood.

As detailed earlier in the thread I've tried something similar. I put springs underneath the MDF base (and the speakers atop the base). It did indeed tighten things up, though ultimately I felt it tended to a more weightless presentation. What I keep finding is that I seem to prefer some level of contact, that is vibration transmission, which makes the sound a bit more dense and punchy. I'm trying to find that sweet spot. Though I'll likely try springs under the granite base as well.

Also: making it tougher on myself, I'm simultaneously trying to achieve another somewhat-at-odds goal: I want the speaker position to be easily shifted, because I like experimenting with different speaker positions, and also it can help in moving speakers out of the way so as not to block the image on the projection screen behind them.
So the flexibility would be a real bonus.

The most promising way to do this so far would have been the granite base. For one thing, when placed on the Cedar wood caps, it has just enough grip to stay very steady, but also due to the polished bottom of the granite, it can be slid around easily on top of those wood caps. Also, if I remove the wood from under the granite, it will slide very easily on the rug, so speakers atop that granite base would be easily re-positioned.

So, I think it's probably likely the best sound might come from something under the granite - e.g. spikes (or possibly springs) or even the Gaia, but that will make it harder to reposition the speakers easily. Which is why I've been trying to keep most of the isolation between the speakers and the base the sit upon, rather than between the base and the floor.

 

[MattHooper]

Sometimes bass is percieved as vibrations in the floor. If you have a flexible wood floor you probably have losses at standing waves. Loading the floor at varoius points can change those modes. Audible? Don’t know. Can you feel the vibrations changing? Perhaps.

Yes, it's been impressed upon me that this is going to be pretty unpredictable - different materials will vibrate differently, different combos will be different, where the speakers are placed on the sprung wood floor would change transmission/vibration consequences, etc.

One thing I have to experiment with still is tilt of the speakers. That might influence the perception of the bass balance.

 

[Ken Tajalli]

Yes understood.

As detailed earlier in the thread I've tried something similar. I put springs underneath the MDF base (and the speakers atop the base). It did indeed tighten things up, though ultimately I felt it tended to a more weightless presentation.

I can not get my message across, can I?
an MDF base has no mass worth mentioning. so yeh, what you did, I would not have expected any positive results.
Also, there is nothing magic about Granite, safe for the fact that it is made of compressed particles, so it should not ring.
It is the MASS of the slab that does the trick.
MDF is lightweight .
This mine:

I used to have monoblocks next to speakers, hence the size of the slabs.
But the heavier, the better.
Suspension underneath, full bond above.

 

[Purité Audio]

Yet again: please revisit the caveat that begins this thread. You won't be satisfied, sorry, probably not the thread for you.

You should really know better than just posting subjective twaddle, if there has been that ‘insane’ change then it will be measurable.
Show me the measurements or just post this stuff on other forums with gullible members.
Keith

 

[Thomas_A]

You should really know better than just posting subjective twaddle, if there has been that ‘insane’ change then it will be measurable.
Show me the measurements or just post this stuff on other forums with gullible members.
Keith

There are no big things happening here. What happens, happens for known reasons. Either transfer of vibrations that cause distortion, or sensing bass trough structure. I've not seen any audibility of speaker movement due to resonance - it is just a theoretical argument saying that spikes does not make the speakers more stable. Soft feet are better.

 

[Ken Tajalli]

There are no big things happening here. What happens, happens for known reasons. Either transfer of vibrations that cause distortion, or sensing bass trough structure. I've not seen any audibility of speaker movement due to resonance - it is just a theoretical argument saying that spikes does not make the speakers more stable. Soft feet are better.

Actually soft feet are worse. a simple google search should bring up why.
Spikes AFAIK were invented as a means to bypass carpets under speakers (i.e. soft feet). Spikes punched through carpets and coupled the speakers to the harder more solid flooring.
Then the hype took over, spikes were marketed as some kind of magical device (snake oil), and they started using them on DAC, amps etc.
then we got cones, wooden ones . . .

 

[Thomas_A]

Actually soft feet are worse. a simple google search should bring up why.
Spikes AFAIK were invented as a means to bypass carpets under speakers (i.e. soft feet). Spikes punched through carpets and coupled the speakers to the harder more solid flooring.
Then the hype took over, spikes were marketed as some kind of magical device (snake oil), and they started using them on DAC, amps etc.
then we got cones, wooden ones . . .

Both physic calculation and measurements show that soft feet are better in terms of speakers being more stable, as long as the interface of the speaker-floor (feet) have a resonance below the speakers lowest f.

Speaker enclosure vibrations - a few measurements with accelerometer

There are been quite a number of threads dealing with vibrations in speaker cabinets, both in relation to "speaker feet" and vibrations in enclosures themselves. I recently took out my ACH01 accelerometer to do some measurements, both speaker feet and enclosures. There was some initial...

www.audiosciencereview.com

 

[Ken Tajalli]

Both physic calculation and measurements show that soft feet are better in terms of speakers being more stable, as long as the interface of the speaker-floor (feet) have a resonance below the speakers lowest f.

Speaker enclosure vibrations - a few measurements with accelerometer

There are been quite a number of threads dealing with vibrations in speaker cabinets, both in relation to "speaker feet" and vibrations in enclosures themselves. I recently took out my ACH01 accelerometer to do some measurements, both speaker feet and enclosures. There was some initial...

www.audiosciencereview.com

Obviously you have put some effort and thought for your experiment and measurements.
I applaud you for that. But your experiment and results can not be gospel that one could apply to every speaker, every situation.
Commonsense dictates that in a properly designed and made speaker, only the diaphragms should move. Any movement (vibration) of the baffle or the enclosure would colour the sound. That's why most quality speakers employ solid, damped enclosures with hefty solid feet or stand.
Any compliance on mounting allows the cabinet to move (vibrate) as a reaction to movement of the diaphragm.
The heavier and the more solid the enclosure, the less of an effect we experience.
A solidly built speaker, on a heavy solid floor is best.
If we don't have a solid floor, then a virtual one is best compromise .i.e. a massive solid slab.
That's the physics of it, according to me.

 

[MattHooper]

You should really know better than just posting subjective twaddle, if there has been that ‘insane’ change then it will be measurable.
Show me the measurements or just post this stuff on other forums with gullible members.
Keith

You were given fair warning at the head of this thread. If you continue to be triggered by "subjective twaddle," again...best to avoid this thread for your blood pressure. Unless you get that much pleasure out of complaining.

The purpose was to both share my impressions and inspire input on the subject of speaker isolation etc. As I made explicit: nobody has to presume all or any of my impressions are accurate, but it is still of value to ask what type of sonic changes are plausible, given my experiments or anyone else's, and why. (And I did at least post measurable changes in vibration/isolation effects using a vibration measuring app).

It has been a very rich thread with lots of interesting input.

 

[pablolie]

How much do they cost? I have the same problem. Elevated pole home, timber floor and my speakers actually sound better when I remove the spikes and decouple them through thick carpet pieces.

I am not a believer in spikes for that reason. Every speaker I ever owned sounded better with some isolation. Even in the old house with a carpeted floor in the listening room and a concrete slab underneath.

 

[MattHooper]

I can not get my message across, can I?

No, I understand your message. I don't think mine is getting across though. (You and I may not be after precisely the same outcome).

an MDF base has no mass worth mentioning. so yeh, what you did, I would not have expected any positive results.

But I did have positive results. I said that springs under the platform tightened up the bass.

Also, there is nothing magic about Granite, safe for the fact that it is made of compressed particles, so it should not ring.
It is the MASS of the slab that does the trick.
MDF is lightweight .
This mine:
View attachment 283726

I used to have monoblocks next to speakers, hence the size of the slabs.
But the heavier, the better.
Suspension underneath, full bond above.

Right. As I mentioned I'll probably try springs or another isolation material under the granite, just to see. But...for reasons already stated I'm skeptical it will
be a final solution for my use case.