Speaker isolation

[Clarkey_71]

This subject has come up plenty of times before but I just wondered what peoples opinion was on the use of granite chopping boards.

To give a bit of background, I have PMC OB1 speakers. They are pretty sturdy but I have a solid wood floor. I currently use the spikes and sit them in Blue Horizon cups. They were relatively cheap but seemed to get a good write up. At the time, I felt they did improve bass performance.

Recently I stayed at a house and they had a granite chopping board that was quite hefty. Naturally I wondered if this could improve the isolation even further but sitting the cups on the granite.

They are relatively cheap at approx £20 each but I don't want to waste my money if it is unlikely to improve anything.

Any thoughts at all?

Cheers.

 

[CnoEvil]

Is the wooden floor suspended or on solid concrete.

 

[Clarkey_71]

The wood sits on concrete, though when I layed the floor the bonding agent was slightly rubberised. The wood itself is approx half inch think, so pretty dense itself. I'm only really tinkering around and wondered if there was a quick, cheap improvement out there.

 

[Vladimir]

Spikes don't isolate speakers from the floor. They couple them together so all the vibration is spread to the floor instead of making speakers resonate.

If your speakers are already stable on the surface, only benefit from added granite slabs is more height where the tweeter comes closer to ear height and woofers further away from the floor. As a result you will hear more clarity, details, tighter bass etc. and think its due to better isolation.

 

[ellisdj]

Buy a set of these - they will isolate anything you put them under.

These are a bargain of the century priced product for their performance - they are excellent

There is a new design coming from the seller - same as the one linked to but with a better material than aluminium.

 

[Clarkey_71]

Thanks for your comments.

i checked out the link. An interesting product but would set me back £250. The granite would total about £40, which is much more in my tinkering budget!

 

[Clarkey_71]

Cno,

You mentioned the type of floor. I was interested where you might be going with that.

also, the comment about slightly lifting the speakers giving a different listening perspective was interesting. I guess I'm just looking for a bit of a steer. Is it a waste of time or a relatively cheap but effective tweak?

 

[RobinKidderminster]

Popular opinion is isolate from suspended floor and couple to a solid floor. Even experts seem to accept its black-art nature when different situations may or may not prduce good or bad results. I would always suggest cheap experimentation before any investment but take your time since expectation bias bites us all.

With some similarity of response, tweeters should be at ear hieght (generally) since its frequency is highly directional. Position of speakers from each other and from walls as well as toe-in can significantly effect response & soundstage but you w8ll only find general rules since these effects are room and equipment specific.

And then there is personal preference, bias & ones individual abilities to assess and determine perceived changes.

Good luck with all that & welcome to the madhouse

 

[Vladimir]

Link: Speaker Spikes and Cones – What’s the point?

 

[BigH]

Cno,

You mentioned the type of floor. I was interested where you might be going with that.

also, the comment about slightly lifting the speakers giving a different listening perspective was interesting. I guess I'm just looking for a bit of a steer. Is it a waste of time or a relatively cheap but effective tweak?

Sorry for the late reply but was away for a day.

The reason I asked, is that a suspended wooden floor can cause all sorts of acoustic problems, as it can act like a resonance chamber...or in my case, all the bass dissappeared into the 5' space below.

As Robin has said, it is usually better to isolate from a suspended floor and couple (spike) to a concrete one....though trial and error will confirm what sounds best.

But how do actually couple to a concrete floor, surely the spikes are just resting on the top, I suppos you could drill some holes and then embed the spikes in the concrete?

Yes wooden floors can cause problems, I had them at my last house, vibration from bass was the main issue. But sometimes they can add to the sound, like that concert hall they filled the void under the stage killed the sound, took it out again many years later.

http://www.nytimes.com/1995/09/14/us/a-phantom-exposed-concrete-at-carnegie.html

 

[CnoEvil]

But how do actually couple to a concrete floor, surely the spikes are just resting on the top, I suppos you could drill some holes and then embed the spikes in the concrete?

If there is carpet on concrete, I believe that pressing the spikes through the carpet until the spikes are "gripping" the concrete, is enough to sink the vibrations into it (and keep the speaker steady).

Where there is wood on concrete, all you can do is use spike shoes (or possibly Granite) to protect the wood, but I don't think it will be quite as effective.....though this is conjecture.

 

[bigfish786]

i have concrete floors, carpeted and thick underlay. i use granite "chopping boards" to protect the carpet from getting holes in it from the spikes. i also did this at my other house which had wooden floors. the granite protected the wood from the spikes, and made it easier to make minor adjustments, and the same applies on the carpet.

i didn't notice any difference in sq. there may be some, but like bi-wiring there may be a bit of owner bias involved there too.

shop around,if you want granite, you can get decent chopping boards for under a tenner. try asda/tesco/argos. for me, the money was well spent, purely for protection, as well as them looking quite nice too.

 

[CnoEvil]

Cno,

You mentioned the type of floor. I was interested where you might be going with that.

also, the comment about slightly lifting the speakers giving a different listening perspective was interesting. I guess I'm just looking for a bit of a steer. Is it a waste of time or a relatively cheap but effective tweak?

Sorry for the late reply but was away for a day.

The reason I asked, is that a suspended wooden floor can cause all sorts of acoustic problems, as it can act like a resonance chamber...or in my case, all the bass disappeared into the 5' space below.

As Robin has said, it is usually better to isolate from a suspended floor and couple (spike) to a concrete one....though trial and error will confirm what sounds best.

 

[BigH]

I never worried about holes in carpets as you never notice them anyway if you move the speakers unless you have fairly thin carpet (like some foam backs), if a mark shows then just rub the carpet fibre to remove.

But spikes on granite won't they slide around if they get knocked?

 

[CnoEvil]

But spikes on granite won't they slide around if they get knocked?

In my case, I used Blu-Tak to stick the bottom of the stands to the Granite (without the spikes).

 

[BigH]

But spikes on granite won't they slide around if they get knocked?

In my case, I used Blu-Tak to stick the bottom of the stands to the Granite (without the spikes).

Yes that makes sense. But I think Bigfish786 just has spikes on granite boards which I think are fairly polished?

 

[CnoEvil]

But spikes on granite won't they slide around if they get knocked?

In my case, I used Blu-Tak to stick the bottom of the stands to the Granite (without the spikes).

Yes that makes sense. But I think Bigfish786 just has spikes on granite boards which I think are fairly polished?

You can use a variety of spike shoes on Granite, from home made, to tacky, to isolating ones.