Speaker coupling & isolation

[buddyev 3,526]

Ok, I know coupling and isolation have been discussed before but I’m a bit dullwitted and need some clarification.

My speakers ( B&W 805 standmounts) are on spikes on hardwood floor boards with 5 ct coins protecting the timber - so they are coupled to the floor.

I’m getting quite a bit of resonance through the boards - it’s not bad, the floor is really solid and tbh the bass is pretty nice, but it has to be compromising the speakers and the component rack.  So a tweak is in order. 

 

I think I’m correct in assuming, in short, that

• coupling gives the speaker solidity and stability and therefore image precision
• isolation stops the vibes and resonance running amok.

So:

1. if I put the speakers on spikes on top of and therefore coupled to a slab which is in turn isolated from the floor with rubber pads will I get benefits of both coupling and isolation, or do they just compromise each other?

 

2. Supposing  this works, in theory which will give me the most benefit, a plinth with greater mass - ie a concrete paver - or will something relatively lightweight like a bamboo chopping board or piece of timber benchtop work as well. I’m assuming the more mass the better.

 

Thoughts?

 

 

 

[sakabatou 77]

I'm no expert, but I did see a video from Dynaudio that addresses this issue. They suggested all or nothing - that is, all isolation or all coupling

 

[Telecine 3,342]

Minds will differ on this. My view is to couple speakers to the floor and isolate and decouple stereo components.

[bzr 897]

17 minutes ago, Telecine said:

Minds will differ on this. My view is to couple speakers to the floor and isolate and decouple stereo components.

Can be good but if you have a floating floor on separate levels, well..., all hell breaks loose. I am thinking we might be at this stage..

 

[Telecine 3,342]

1 minute ago, bzr said:

Can be good but if you have a floating floor on separate levels, well..., all hell breaks loose. I am thinking we might be at this stage..

 

Different issue I suspect (marital harmony).

[Muon N' 1,746]

I found my best result was from coupling to bamboo boards via spiked stands (ML-1 standmount speakers) and those Bamboo boards isolated from the floor using the rubber anti-vibration blocks sold in Bunnings, improved clarity and imaging without any negatives i could perceive.

 

Different materials used will give different results... ymmv

Edited February 3 by Muon N'

[andyr 3,943]

40 minutes ago, buddyev said:

Ok, I know coupling and isolation have been discussed before but I’m a bit dullwitted and need some clarification.

 

Clarification, Russ - many people need!    (Not just oldies like you.  )

 

40 minutes ago, buddyev said:

My speakers ( B&W 805 standmounts) are on spikes on hardwood floor boards with 5 ct coins protecting the timber - so they are coupled to the floor.

 

With 5c coins under the points ... you're not 100% coupled (you'd need the spikes digging into the wood floor, for this).  But you're enough coupled to get resonance from the floorboards - 100% coupled would simply give you more resonance.  Which is not a good thang! 

 

40 minutes ago, buddyev said:

I’m getting quite a bit of resonance through the boards - it’s not bad, the floor is really solid and tbh the bass is pretty nice, but it has to be compromising the speakers and the component rack.  So a tweak is in order. 

 

I think I’m correct in assuming, in short, that

• coupling gives the speaker solidity and stability and therefore image precision
• isolation stops the vibes and resonance running amok.

 

Agreed! 

 

40 minutes ago, buddyev said:

So:

1. if I put the speakers on spikes on top of and therefore coupled to a slab which is in turn isolated from the floor with rubber pads will I get benefits of both coupling and isolation, or do they just compromise each other?

 

I agree with your thinking.  The biggest issue IMO is what to use for isolation?

• rubber pads - cheap, yes ... but not ideal, IMO.
• a UK spkr mfr makes some 'isolation stands'; I suspect these would work very well - but they are not cheap! 
• springs would probably be good - they'd need to be fairly stiff, so that they are, say, 50% compressed (to allow some more movement for the isolation effect).
• best of all, IMO, would be 'roller blocks' under the slab.  These are basically ball bearings sitting in a shallow bowl - various people make them ... out of either ceramic ... or stainless steel.

 

40 minutes ago, buddyev said:

2. Supposing  this works, in theory which will give me the most benefit, a plinth with greater mass - ie a concrete paver - or will something relatively lightweight like a bamboo chopping board or piece of timber benchtop work as well. I’m assuming the more mass the better.

 

Thoughts?

 

I suggest a plinth with more mass does a better job than one with less mass - so use a concrete slab from Bunnings ... rather than a bamboo chopping board from IKEA.    And if WAF is an issue - a nicely polished and oiled 30mm thick slate plinth rather than a concrete paver.

 

Andy

 

[davewantsmoore 6,409]

1 hour ago, buddyev said:

I think I’m correct in assuming, in short, that

 

1.  coupling gives the speaker solidity and stability and therefore image precision

2.  isolation stops the vibes and resonance running amok

Most people dramatically overestimate #1.    Forget #1 and apply #2 if you need to solve a problem.    Some people say apply #2 as it will always improve speaker performance.

 

1 hour ago, buddyev said:

So:

1. if I put the speakers on spikes on top of and therefore coupled to a slab which is in turn isolated from the floor with rubber pads will I get benefits of both coupling and isolation

No.

[Big Nads 10]

I have my R700s coupled to a piece of 20mm composite stone, that is issolated from the floorboards by bunnings pads.
I have also made spring issolators out of water auto pump seals and few other bits.
They go under my TT.

[buddyev 3,526]

There’s no doubt I’m getting a bit of energy draining into the floorboards - listening to some Charlie Haden bass playing today and it was very obvious - so I think isolation is going to be worth a go.

I’ll try the Bunnings rubber vibration pads first, then add some pavers. It’s cheap enough to try the various options to see what works and prove the concept.

Obviously I will have to have the brains trust (or is that the ears trust) to adjudicate. @andyr

Edited February 3 by buddyev