Spikes = to much bass???

My speakers have been sat on concrete slabs, with brass cones between speaker and slab.
Yesterday i decided to put some aluminium cones between slab and floor.
The effect was not what i expected at all, in the same position as before but with the added cones, there is now to much bass resonance. There is much less feeling of bass in the floor tho.
I moved the speakers out a few inches and that helped, but it was late and i didnt play anymore.

So why has this happened? I thought that extra isolation would help, presumably the removal of floor vibration means they are better isolated?

 

perhaps you lost some isolation instead?
sounds like the spikes could be causing more resonanse , less damponing.

 

Ill try and get some sort of rubber and play with it (did that sound bad?)

Ill play withg positioning tonight aswell.
Just surprised me as it realy wasnt what i expected to happen.

 

The speakers now have a higher centre of gravity and are more compliant to rocking back-forth. Spikes or whatever will always have compliance. Now you have

compliance+compliance=2 compliance.

The best stability I have achieved with tall floorstanders is a very heavy flat slab and some way of sitting speakers firmly on it. I use those low profile stick-on rubber feet 'one' nicks from comms equipment [about 15mm dia 2mm thick]. My DIY 3 ways just sit on the carpet [concrete floor] but they are big-deep-n-heavy

 

Oh dear, my first thoughts disagree with two wiser heads above, but I'll post them so I can learn...

Could it simply be a question of how much energy is being directly coupled to the floor? With the old arrangement more energy was being lost that way than now, hence now you get more bass in the room rather than the floor, and this excites a room mode more giving unpleasant resonance?

Alternatively I'd have thought it might be a case of greater stability now, not less, meaning less bass energy is lost in moving the cabinet back and forwards and more is entering the room as sound.

 

martin, that was the way i was thinking aswell.

 

You think you've got bass problems? Pah!

I've got both no bass, and far too much bass at the same time.

Too many spikes, I reckon.

 

.

 

Had to quote this for penance, It was actually quite funny.

ps I really mean it deffinately no sarcasm intended.

 

cheers paul, i just assumed it would be about you know what
Maybe he should post me some of the excess spikes

 

I,m with Martin on this , sounds like the speakers are putting out more bass which is exciting a mode .
Or it,s to do with something merlin mentioned in a thread a while back .
the extra height has moved the bass cone into an area that is setting the resonance off .
If you get my drift ,

 

So, you're saying that there's a possibility that the floor was acting as some kind of a filter, damping device or bass sink. That's interesting.

I've been surprised so many times when trying to set up speaker systems that I wouldn't rule out any possibility - and that's about as 'wise' as this head gets at the moment.

 

usually when you lift speakers you get less bass and not vice versa.

 

I thought the idea of particularly a wooden floor being a bass sink was a common one? It's not my idea that's for sure; I've never tried to think through if it makes any sense to be honest!

What do you mean by 'lift'? What two situations are you comparing?

 

One way is to think of speakers like those old-fashioned musical boxes where you turned the handle and a cogged wheel flicks metal strands of different lengths to make a simple tune. Do you know what I mean?

Anyway, if you get one of these devices without the box you can place it against different surfaces - wooden or concrete floor, etc. to get different effects.

Come to think of it, just think of a tuning fork. You strike it and it doesn't make much noise at all until you place it against an object (like the floor).

 

The trouble with the "Ignore List" feature is that it's just too tempting to click the "View this post" button all the time so he probably read it anyway

Michael.

 

did I?

 

Im going to play with positioning tonight, tho ive not got much room to play with in regard moving them into the room.

I couldnt find any suitable soft type things to try instead of spikes.

Any other ideas?

 

I don't know, but I'm guessing you did.

Michael.