Decoulping vs Spiked

[rollo]

   Recently purchased decoulpers from Herbies to use with Rethm Saadhana speakers. Using four per speaker I was taken back as to the improvement.
  Bass lines are more focused and powerful. Sound stage size increased. Everything is more open and focused.
My floor is Karastan wool carpet on 7/8" marine ply over 2x3 wood sleepers [ layed sideways 12" OC]] resting on concrete slab. I thought that construction would act as a solid floor similar to concrete. WRONG.
  Spiking just mucked up the sound. Decoulping was the solution.
Now with more focus and resolution an more powerful tuneful bass I tried moving the speakers around. The final position was more toe in and 6" closer to front wall.
  I have never heard these speakers like this. Truly a world of difference. Yes I removed decoulpers after speaker repositioning and was disappointed.
  So give it a try you may well hear your speakers for the first time.

charles

[mdconnelly]

Did you go with Herbie's Decoupling Spikes or Decoupling Gliders?   I've been using the Gliders (on hardwood floor) for quite a few years now and have been quite pleased.

[rollo]

Did you go with Herbie's Decoupling Spikes or Decoupling Gliders?   I've been using the Gliders (on hardwood floor) for quite a few years now and have been quite pleased.

Gliders.

charles

[JBNY]

Yeah the gliders work great and in almost all cases decoupling is the way to go over spiking them to the floor and coupling. I had the Herbie Gliders on my speakers and I completely agree that they make a big difference for the better. More focus, better imaging, the bass might not be as strong but it has better definition due to being decoupled. 

[Nick B]

I'm using gliders, partly for the convenience of not having to mess with spikes on a new laminate floor, and am liking the result quite a bit.

[steve]

Quick question guys. I am gathering information, for myself; how high is your midrange driver, tweeter, or full range driver off the floor? Also, how high is your ceiling?

Cheers and thanks for your time and efforts.

steve

[Nick B]

30 1/2" from kef uni-q driver to floor and 10' ceilings.....but I don't like my stands only being 24" tall

[tmazz]

My Nola Boxers sit on 24" stands, which puts the tweeter aprox 36 inches off the floor in a room with 8' 3' ceilings.

[JBNY]

Midrange is 36 inches off the floor. Ceilings are normal 8 foot.

[gander]

Allow speaker movement or don't? Spike them down or allow some movement? Brace a speaker frame so it is stiff, or allow it to vibrate like the speaker itself is an instrument? 

I'm not a physicist, but I'll talk about Newton's 3rd law of motion in relation to speakers, as I understand it. This law states that for each action there is an equal and opposite reaction.  The action, or force would be a constant, and movement of the two bodies away or toward each other would be proportional to the mass of each body. Speaker cone and voice coil, vs the mass of the speaker basket plus cabinet in this case.

So, when a speaker cone VC magnetic field is pushed away from the speaker magnet this causes them both to push apart, not only the cone. And theoretically they should move apart in relation to their mass. The mass of the VC and cone is much less than that speaker basket and magnet, and the speaker cabinet itself. so the cone mass will try to move proportionally to basket / cabinet mass in free space. If the speaker basket plus cabinet mass is 1000 times that of the cone and voice coil, and if the cone moves 10mm, then the cabinet should be able to move .001mm away when the cone moves that 10mm.  While this doesn't seem very much, if that counter-movement isn't allowed to happen (by spiking the cabinets, for example), then the cone movement will be affected in such that it won't be able to move as freely as it should, which I believe will result in a poorer sound than with the speaker allowed to move along that axis.

I tried a set of speaker stands whose maker said it used this 3rd law of motion concept, and while I noticed that there was some improvement of sound, when the speaker was allowed to move forward and back, the way the speaker stand allowed that movement also forced the speaker to move a bit up and down at the same time, not along the main axis of motion, which to me seemed like trying to move a spinning gyroscope against its main axis. I set out to find a simple solution to this, so the only allowed motion of a speaker is along its cone-movement axis.

This is why I talked about using rollers under speakers in my Gary's DIY and Tweaks section.
http://www.audionervosa.com/index.php?topic=6615.msg83674#msg83674
This is a very inexpensive and effective way to allow the speaker to move forward and back along the axis of cone movement.  And I did get feedback that it tightens up bass and allows an overall better sound.  However, it is possible that the speakers could slide off the rollers, so an improved approach to this could be done. I have a few ideas on that.

Another way would be to mount fixed wheels under the cabinets allowing movement along that same axis - not that expensive to do. And I'm trying that approach right now, with 3 wheels per speaker - two in the back and one in the front; not sure if this is better than rollers but it is more convenient.  I do notice a positive sound difference with this approach also.  And of course there are varying qualities of wheels. But I'm not completely sold on this yet - time will tell.

And now sliders.  The basic idea of allowing speaker movement I think can be good.  Basic sliders can be found at Home Depot, but I'm sure that Herbie's or others can be better. However, sliders allow movement of the speaker along all axes along the horizontal plane, possibly against the movement of the cone, and not just along the long axis of cone movement. I think that allowing speaker movement only along the axis of cone movement is important.

With all this being said, anything that you think improves the sound is a good thing for you.

Really glad to see that people are trying different things!

Gary

[steve]

Thank you for your input Gentlemen. Much appreciated. My mid/tweeter, at this time, is 43.5 inches, ceiling is A frame with ceiling tile 7.4 feet. I rent, the apt. came this way.

I have the speakers on multiple 6" x 4", I am on the second floor, all wood floor. So I can lower the speakers 4" at a time if I need to. I don't know how much I am coupled to the floor, but the floor doesn't seem to vibrate, but who knows for sure.

A fellow music lover and friend worked with me and we found that by raising the speaker, the sound stage lifted up to cover most of the front of the room. I don't know if the images are unrealistic size, but the sound stage definitely lifted vertical wise. Maybe a more realistic size of the orchestra? Maybe a better midrange?

If I lower the speakers, removing the 6 x 4, I suppose I am coupling to the floor a little more, but I don't know how much more. Any thoughts/findings?

One thing I can definitely state is that even a 1/16" or less movement side to side, or rotation affects the sound stage, tonal balance etc. Up and down not quite as sensitive, I think.

Any thoughts/findings appreciated.

cheers

steve

[steve]

Thank you for your input Gentlemen. Much appreciated. My mid/tweeter, at this time, is 43.5 inches, ceiling is A frame with ceiling tile 7.4 feet. I rent, the apt. came this way.

I have the speakers on multiple 6" x 4", I am on the second floor, all wood floor. So I can lower the speakers 4" at a time if I need to. I don't know how much I am coupled to the floor, but the floor doesn't seem to vibrate, but who knows for sure.

A fellow music lover and friend worked with me and we found that by raising the speaker, the sound stage lifted up to cover most of the front of the room. I don't know if the images are unrealistic size, but the sound stage definitely lifted vertical wise. Maybe a more realistic size of the orchestra? Maybe a better midrange?

If I lower the speakers, removing the 6 x 4, I suppose I am coupling to the floor a little more, but I don't know how much more. Any thoughts/findings?

One thing I can definitely state is that even a 1/16" or less movement side to side, or rotation affects the sound stage, tonal balance etc. Up and down not quite as sensitive, I think.

Any thoughts/findings appreciated.

cheers

steve

One other point I forgot. I use 20-25 lbs of lead shot on speaker tops to absorb energy. Coupling to 2nd floor is lessened by two 4' x 6" wood pieces with cloth sandwiched between. Checked again and the floor is pretty quiet but then I have not noticed any "overhang". Bass is very very taught but extremely dynamic/ punchy, but almost too tight to my liking.

cheers

steve

[Barry (NJ)]

Anthony Gallo started doing this with his Reference 3.5 series, using a silicone gel pad under them. It, along with other changes, made for a nice improvement in the sound.