I have a pier home with wooden floors. I will have roughly 4" to build below the speakers to get them to the right height. I have been trying to get up to speed on the whole decouple issue and here is what I think I have learned and/or read:
1) You dont want the speaker to move or wobble, so you want them planted solidly. Using spikes whereby the tip if the spike goes through the carpet and contacts the actual floor actually couples it, not decouples it. For carpeted rooms, you may want this because a speaker sitting merely on the carpet surface allows it to float a bit.
2) Vibrations to the floor and walls are caused more by the waves of sound traveling through the air than actual vibration from the speaker grounding to the floor.
3) One site was making the point that you want the speaker coupled to allow the vibrations it does have to ground out somewhere. A decoupled speaker "clings" to its vibrations and has no way to transfer them anywhere causing the speaker cabinet to vibrate more. Bad.
4) Still another site contends that decoupling is preferred because a coupled speaker allows the vibrating floor to transfer its energy to the speaker, causing the speaker to vibrate more.
5) Some feel spikes are snake oil and have no noticable effect.
6) Some have said cement blocks are a good combination of a cheap, rigid and sturdy platform for speakers sit on and help some with uncoupling.
7) Some feel pricey absorbers are the way to go
8) Some get very technical (like the link below) and subscribe to different combinations of materials, sometimes sandwiched together depending on your floor makeup.
Overall, the actual science seems a bit thin. Most is opinion and speculation. I did find this http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/ir/ir802/ir802.pdf which is rather interesting.
1) You dont want the speaker to move or wobble, so you want them planted solidly. Using spikes whereby the tip if the spike goes through the carpet and contacts the actual floor actually couples it, not decouples it. For carpeted rooms, you may want this because a speaker sitting merely on the carpet surface allows it to float a bit.
2) Vibrations to the floor and walls are caused more by the waves of sound traveling through the air than actual vibration from the speaker grounding to the floor.
3) One site was making the point that you want the speaker coupled to allow the vibrations it does have to ground out somewhere. A decoupled speaker "clings" to its vibrations and has no way to transfer them anywhere causing the speaker cabinet to vibrate more. Bad.
4) Still another site contends that decoupling is preferred because a coupled speaker allows the vibrating floor to transfer its energy to the speaker, causing the speaker to vibrate more.
5) Some feel spikes are snake oil and have no noticable effect.
6) Some have said cement blocks are a good combination of a cheap, rigid and sturdy platform for speakers sit on and help some with uncoupling.
7) Some feel pricey absorbers are the way to go
8) Some get very technical (like the link below) and subscribe to different combinations of materials, sometimes sandwiched together depending on your floor makeup.
Overall, the actual science seems a bit thin. Most is opinion and speculation. I did find this http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/ir/ir802/ir802.pdf which is rather interesting.
To me, spikes look exactly like the bridge that couples the strings of a piano or guitar to the sound board.
I would say you like to have the sound emanate from your speaker, not from a floor that is acoustically well coupled to the enclosure. As you know from a tuning fork, not much vibration is needed to get a lot of sound from a well coupled sound board.
Therefore, I don't think spikes are just snake oil, they are poisenous snake oil.
vac
I would say you like to have the sound emanate from your speaker, not from a floor that is acoustically well coupled to the enclosure. As you know from a tuning fork, not much vibration is needed to get a lot of sound from a well coupled sound board.
Therefore, I don't think spikes are just snake oil, they are poisenous snake oil.
vac
😀Read also 'the parallel Thread '
http://www.diyaudio.com/forums/multi-way/212085-rigid-flexible.html
http://www.diyaudio.com/forums/multi-way/212085-rigid-flexible.html
I suppose the threads are different enough to allow them both. By title only, I didnt realize the real subject of the parallel one 🙂
...Parallel ...
Vibration is determined by forces , and those are represented by vectors ,
as most of the physics that regulate the movement of a membrane / cone of the speaker .
So the major force is the gravity
😱
The boundaries are not parallel !
Vibration is determined by forces , and those are represented by vectors ,
as most of the physics that regulate the movement of a membrane / cone of the speaker .
So the major force is the gravity
😱
The boundaries are not parallel !
Member
Joined 2009
I had large heavy floorstanders on thick carpet. They sounded kinda blurry until I installed spikes. It made a huge improvement. A reduction in vibration could be felt by feeling the cabinet wall with my hand.
My suggestion - experiment with different solutions and keep the best one.
My suggestion - experiment with different solutions and keep the best one.
Two things relevant to this are "action is reaction" and "mass inertia".
To make a speaker seem heavier for the moving parts and soundwaves, a good contact to the floor will be needed.
But since the mass of the floor is much bigger than that of the speaker, these will have no problem feeding back into the speaker.
It's more the mass inertia thing than "bleeding off" vibrations. "Grounding out" is IMHO similar to trying to push away a truck with one finger.
What do you mean by "clinging"? Other than the resonance frequency, I can't imagine how it could "cling" to anything.
Same remark as 2).
At low to normal listening levels I wouldn't be surprised. Play loud and things may be different.
Here's the mass inertia playing its role again.
No doubt those that sell them. But maybe there is merit to them, I haven't tried them.
More aimed at preventing disturbing the neighbours than at sound reproduction.
Yep, but I did experiment when I still had carpet. I put the speakers on spikes right through the carpet, played some music very loud and had a listen downstairs. Then I repeated the same with cups under the spikes. The latter produced appreciably less noise downstairs so I kept them under the spikes as I couldn't hear any difference with or without the cups anyway.
But it would suggest that spikes help to make a better coupling to the floor, at least when carpet is on it.
P.S.
It's similar indeed.
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Thanks for the response jitter. But could you help me summarize your thoughts.
1) Good grounding is needed. By this are you saying that you are a proponent of Coupling?
2) But since the mass of the floor is much bigger than that of the speaker, these will have no problem feeding back into the speaker. So here are you saying to decouple?
3) It's more the mass inertia thing than "bleeding off" vibrations. "Grounding out" is IMHO similar to trying to push away a truck with one finger.
What do you mean by "clinging"? Other than the resonance frequency, I can't imagine how it could "cling" to anything. By clinging I meant any vibration the speaker produces itself. I dont really understand what you are saying here.
6) Here's the mass inertia playing its role again. Could you clarify whether your saying cement blocks are helpful or not. And could you elaborate on your view as to how well they decouple.
1) Good grounding is needed. By this are you saying that you are a proponent of Coupling?
2) But since the mass of the floor is much bigger than that of the speaker, these will have no problem feeding back into the speaker. So here are you saying to decouple?
3) It's more the mass inertia thing than "bleeding off" vibrations. "Grounding out" is IMHO similar to trying to push away a truck with one finger.
What do you mean by "clinging"? Other than the resonance frequency, I can't imagine how it could "cling" to anything. By clinging I meant any vibration the speaker produces itself. I dont really understand what you are saying here.
6) Here's the mass inertia playing its role again. Could you clarify whether your saying cement blocks are helpful or not. And could you elaborate on your view as to how well they decouple.
When I was writing down my previous reply, I noticed there were some inevitable contradictions there.
1) and 2):
I just thought of an analogy for explaining this:
Imagine trying to rock a small row-boat with your body weight. It shouldn't be hard as the boat is light. But, the boat is also easily rocked by the waves on the water.
Imagine trying to do the same to a big cargo ship and how little effect waves have on it.
By coupling the speaker to the floor it appears to its own vibrations as unresponsive as a cargo ship to the waves. Yet, the speaker itself is comparable to the row-boat with respect to the floor, so vibrations coming from the floor are like the waves of the ocean toying with the row-boat. That's the contradiction.
Vibrations in the floor caused by the sound from the speaker (when playing loud) are fed back to the speaker.
But IMHO, coupling to the floor would be best because I can't imagine a floor being as turbulent as the ocean (relatively speaking) at normal listening levels. So yes, I'm a proponent of coupling, but I'm not sure spikes provide enough coupling, though.
3) I meant that vibrations from the speaker are not absorbed by the floor but rather prevented from happening by appearing heavier. Concrete is actually pretty good at propagating sound, ask any building designer.
6) Mass inertia helps in reducing vibrations, so yes, it's helpful.
I added bitumen to a resonating computer case once to increase the mass. This case was resonating as a result of vibrations coming from the hard drive. The higher mass slowed down the resonance frequency of the case to below audible frequency and level.
1) and 2):
I just thought of an analogy for explaining this:
Imagine trying to rock a small row-boat with your body weight. It shouldn't be hard as the boat is light. But, the boat is also easily rocked by the waves on the water.
Imagine trying to do the same to a big cargo ship and how little effect waves have on it.
By coupling the speaker to the floor it appears to its own vibrations as unresponsive as a cargo ship to the waves. Yet, the speaker itself is comparable to the row-boat with respect to the floor, so vibrations coming from the floor are like the waves of the ocean toying with the row-boat. That's the contradiction.
Vibrations in the floor caused by the sound from the speaker (when playing loud) are fed back to the speaker.
But IMHO, coupling to the floor would be best because I can't imagine a floor being as turbulent as the ocean (relatively speaking) at normal listening levels. So yes, I'm a proponent of coupling, but I'm not sure spikes provide enough coupling, though.
3) I meant that vibrations from the speaker are not absorbed by the floor but rather prevented from happening by appearing heavier. Concrete is actually pretty good at propagating sound, ask any building designer.
6) Mass inertia helps in reducing vibrations, so yes, it's helpful.
I added bitumen to a resonating computer case once to increase the mass. This case was resonating as a result of vibrations coming from the hard drive. The higher mass slowed down the resonance frequency of the case to below audible frequency and level.
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More specifically, my situation is this. My speakers are about 100lbs a piece, no small rowboat, but I get your analogy.
I could put a 16x16x4 solid cement block underneath it (maybe 35 lbs?). But my place is carpeted, so 135lbs displaced over 16x16 inches isnt going to really give substantial coupling. On the other hand, all that mass shouldnt vibrate, shake or lend itself to much movement either.
So what I am wondering is if there is a better route than the 16x16x4 cement block.
I could put a 16x16x4 solid cement block underneath it (maybe 35 lbs?). But my place is carpeted, so 135lbs displaced over 16x16 inches isnt going to really give substantial coupling. On the other hand, all that mass shouldnt vibrate, shake or lend itself to much movement either.
So what I am wondering is if there is a better route than the 16x16x4 cement block.
Your speakers are more like ferries, then.
With that weight I think they're probably fine as-is, but I guess you'll have to experiment to find out...
With that weight I think they're probably fine as-is, but I guess you'll have to experiment to find out...
speaker decoupling
I found decoupling, if what i did = decoupling, works great for me.
Using a 1” hole punch, and 1/2" thick grade 3 felt, I made 8 1" diameter felt discs. 3/4" diameter x 1/16th thick stainless steel washers were adhered to one side of each disc with, 2 sided adhesive, rubber which is about 1/32" thick. The original, spike type, height adjusting screws, where replaced with flat head screws. The screw head diameter is larger than the washer hole. The same 2 sided adhesive rubber was used to secure the screw heads to the washers. These speakers have 4 leveling screws, and are fairly heavy, so I let things settle for a few days, then leveled them. IMHO, this setup improved the sound, from top to bottom, of my b&w 803n speakers.
I have since designed and machined stands for a pair of stand mounted speakers. No leveling screws or washers were used in this design. Four felt discs were adhered to the corners of the stand base and four to the corners of the stand surfaces, where the speakers rest, with the same 2 sided adhesive rubber. I designed the stands, so they could be leveled during assembly, from heavy aluminum components. I feel the improvement, for the stand mounted speakers, exceeded the level of improvement of the 803n.
Thanks,
henrylr
I found decoupling, if what i did = decoupling, works great for me.
Using a 1” hole punch, and 1/2" thick grade 3 felt, I made 8 1" diameter felt discs. 3/4" diameter x 1/16th thick stainless steel washers were adhered to one side of each disc with, 2 sided adhesive, rubber which is about 1/32" thick. The original, spike type, height adjusting screws, where replaced with flat head screws. The screw head diameter is larger than the washer hole. The same 2 sided adhesive rubber was used to secure the screw heads to the washers. These speakers have 4 leveling screws, and are fairly heavy, so I let things settle for a few days, then leveled them. IMHO, this setup improved the sound, from top to bottom, of my b&w 803n speakers.
I have since designed and machined stands for a pair of stand mounted speakers. No leveling screws or washers were used in this design. Four felt discs were adhered to the corners of the stand base and four to the corners of the stand surfaces, where the speakers rest, with the same 2 sided adhesive rubber. I designed the stands, so they could be leveled during assembly, from heavy aluminum components. I feel the improvement, for the stand mounted speakers, exceeded the level of improvement of the 803n.
Thanks,
henrylr
Hi Henry, a picture would be nice. Some of us with English not beeing the first language, can get lost in the description 🙂
Sure it sound interesting...
Danny
Sure it sound interesting...
Danny
I use Soundcare superspikes Jupiter,
a clever and simple design.
You can still move your speakers and your floor doesn't get punctured.
a clever and simple design.
You can still move your speakers and your floor doesn't get punctured.
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