Speaker Stands/Behaviour of speakers mounted on desktop

[Syncamorea]

Originally Posted by Northward

We are aiming at a natural frequency of 7Hz for now and looking at options to get it down to 6Hz.

Do you have any idea of the lifetime that can be expected for the elastomer (or whatever kind of material) you are using to decouple the monitor? Sub-10Hz systems are impressive.

[Northward]

Originally Posted by Syncamorea

Do you have any idea of the lifetime that can be expected for the elastomer (or whatever kind of material) you are using to decouple the monitor? Sub-10Hz systems are impressive.

The elastomers (BSW REGUFOAM or SYLOMER) are used in building foundations or rail track for example. Their lifetime will extend way beyond mine.

To get to 6Hz, we have to use a mix of springs and elastomer, since the elastomer alone will not go lower than 7Hz.

Springs will also last longer than the user.

[akebrake]

Originally Posted by Northward

Hey Akebrake,

We are currently working on a prototype of speaker stands with a very efficient decoupling system integrated - where you can even dial in the weight of your speakers to optimize the decoupling. We are aiming at a natural frequency of 7Hz for now and looking at options to get it down to 6Hz.

They should not be particularly heavy (well...) but we had to think out of the box to make it work and get rid of all the problems you describe and quite a few others. They are very stable. Basically no parasite movements. They meet your 1. and 2. points ........

Wow, interesting project and thanks for your comments.
And I like your ”in the window monitoring”!

Just for curiosity: I was involved in a project a number of years ago where we took the ” safe route” and used heavy ship plate for ballast…and steel springs (Vibrachoc)

From ground up: Concrete floor> Welded stand (sand filled)> Decoupling (steel springs) > Two layers of 30 mm ship plate (150 kg! 340 lb)> Thin rubber layer> Speaker cab.

The idea was borrowed from rotating machinery set up. Aim: ”Inertia 5 times the mass of the motor”.
OK, the Genelec 1038 is only 60 kg (130 lb) so we cut cornes there.
It worked well I believe when listened to the stand with a "stethoscope" (screwdriver) and hit on the plate by a sledgehammer.

And the neighbours loved it !

[akebrake]

This is the steelspring. (Vibrachoc)

[akebrake]

Originally Posted by DanDan

+1 ake, not simple, thus the confused and conflicting views.
e.g. By what stretch of the imagination does a spike decouple?
I have seen people add mass to the speaker cab. A brick on top....
Well maybe a lead mat or such. The Recoil stabilisers have a heavy layer.
I think it is pretty easy to detect if the decoupling is working or not, by touching the stand.
EDIT, not so easy to detect of the speakers a recoiling a tad with each Kick Drum hit.

Check out the hanging speakers at TBWA - FTB CONTROL ROOM A on the Northward Acoustics site. DD

Dan , you are welcome!

The spikes are interesting. Haven’t tested. Spkr will probably stand still. Claimed to work by "only small area in contact with the floor"? Hmmm…
Drive a nail into the floor and have a listen?

Recoil Stabilizer. I believe they work very good with nearfields on top of huge SSL or Neve consoles. Why shouldn’t they?
On a flimsy desk? I dont know...

Message is: Don’t forget the foundation.

[DanDan]

That's good news Thomas. I am sure that this will start a ball rolling. If one source has clearly done the maths/physics, it should help others to consider their offerings. I have been quoted a four figure sum, by a speaker manufacturer, for square steel tubing, painted black, with spikes to pierce my floor.

EDIT, akebrake, I am not a physician, but consider an upright steel rod, say 100mm, flat top and bottom. Speaker on top, bottom sitting on nice flat concrete. Lots of weight, pressure. Good vibration conduction.
Now, let's shape that down to a point. Surface area of contact is vastly diminished, but the pressure at the now very very intimate point of contact is vastly increased.
Less transmission of vibration? Intuitively, no IMO, but I am also interested, and am open to a physics lesson on this.
I note that my friend at Towersonics offers a pointed rubber cone as an (expensive) alternative to spikes. And rubber wheels.

DD

[Ethan Winer]

Originally Posted by Syncamorea

Err, NO! That's not what you quoted and thus were responding to about your endpin. Here, I'll show your post and the quote of mine you were replying to:

I was replying to you dismissing what Dan wrote, so it's the same thing.

Move along folks, nothing to see here.

--Ethan

[drumzalicious]

Is it necessary to use additional isolation in combination with the stands? Reason I ask is because I'm in a similar situation and my monitors were on some DIY Primeacoustic style isolation pads and I just picked up a set of On Stage monitor stands and just wanted to know if they were still needed. Thanks for any help.

[DanDan]

Drum, as I said, I favour belt and braces, given the currently available products.
I decouple the heavy stand from the floor, however inefficiently, using rubber wheels, carpet. Anything other than spikes.
Then I decouple the speaker from the top of the stand using Sorbothane, thick felt, etc.

I can however see why there may be an advantage to coupling the speaker to the massive stand, say with spikes. It would stop the speaker from wobbling back on its rubber mounts, every kick drum hit. It would bleed some energy from the speaker box wall. Hopefully the latter would be beneficial.
The danger lies in the possiblility of a highly conductive stand participating with the cab vibration, possibly resonating, and radiating.

One might spike a light passive speaker and decouple a heavy active one.

What I cannot get my head around is spikes at the speaker AND spikes at the ground.

Unless your speakers are very light, I would go for the foam. Note the primacoustic product has a heavy metal base to remove the uncertainty. You could copy that.

DD

[drumzalicious]

Originally Posted by DanDan

Drum, as I said, I favour belt and braces, given the currently available products.
I decouple the heavy stand from the floor, however inefficiently, using rubber wheels, carpet. Anything other than spikes.
Then I decouple the speaker from the top of the stand using Sorbothane, thick felt, etc.

I can however see why there may be an advantage to coupling the speaker to the massive stand, say with spikes. It would stop the speaker from wobbling back on its rubber mounts, every kick drum hit. It would bleed some energy from the speaker box wall. Hopefully the latter would be beneficial.
The danger lies in the possiblility of a highly conductive stand participating with the cab vibration, possibly resonating, and radiating.

One might spike a light passive speaker and decouple a heavy active one.

What I cannot get my head around is spikes at the speaker AND spikes at the ground.

Unless your speakers are very light, I would go for the foam. Note the primacoustic product has a heavy metal base to remove the uncertainty. You could copy that.

DD

Well the speakers I currently have are the vxt6 and they have some good weight to them. My only concern is if I put them on the foam they then are a bit to high. The tweeters are already at about 2in above my ear. They would be 6-8in above if I use the foam.

Sent from my DROID RAZR HD using Tapatalk

[DanDan]

Looking at the specs I see rising HF from 10-20K on those speakers. The extra height might tame this a bit. IMO this would be good.
Rising HF can lead to dull mixes.
I suggest you have a listen with the foam.

DD

[Syncamorea]

Originally Posted by akebrake

Message is: Don’t forget the foundation.

You mean the pile of cardboard boxes?

[drumzalicious]

Originally Posted by DanDan

Looking at the specs I see rising HF from 10-20K on those speakers. The extra height might tame this a bit. IMO this would be good.
Rising HF can lead to dull mixes.
I suggest you have a listen with the foam.

DD

Thanks. I will give it a go tonight and see how it goes. Its hard to really judge as I'd gotten used to hearing them off the desk and closer to me.

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[UnderTow]

Originally Posted by Northward

Hey Akebrake,

We are currently working on a prototype of speaker stands with a very efficient decoupling system integrated - where you can even dial in the weight of your speakers to optimize the decoupling. We are aiming at a natural frequency of 7Hz for now and looking at options to get it down to 6Hz.

They should not be particularly heavy (well...) but we had to think out of the box to make it work and get rid of all the problems you describe and quite a few others. They are very stable. Basically no parasite movements. They meet your 1. and 2. points

This is low priority stuff and we have very little time to work on it lately, but hopefully somewhere in mid 2013 we will have the final version ready.

It may sound strange, but we're now struggling with... their safety. There's a few elements in there you don't want to see snap near your hands or face.

When the product is released we'll be happy to show how it functions.

Just bumped into this thread. Any news on this?

Cheers,

Alistair