Hello,
I am looking for some diy solution or non audiophile price ( so general purpose) so isolate my Altec Vot cabinets they are above 100 kilogram( 220 pounds) . I have no way to check the weight. So it could be a bit higher. Maybe i will add a bag of sand on top lol but i need something to give a better isolation than the rubber wheels.
Something like a ''pile '' of 4 square inch of 3.5 mm 1/8 inch thickness cork ''sheets '' like the ones on my wall or get some thicker cork panels normally used for temperature/sound isolation? I can make a sandwich of cork and lead sheets.
Any ideas are welcome.
Greetings,Eduard
I am looking for some diy solution or non audiophile price ( so general purpose) so isolate my Altec Vot cabinets they are above 100 kilogram( 220 pounds) . I have no way to check the weight. So it could be a bit higher. Maybe i will add a bag of sand on top lol but i need something to give a better isolation than the rubber wheels.
Something like a ''pile '' of 4 square inch of 3.5 mm 1/8 inch thickness cork ''sheets '' like the ones on my wall or get some thicker cork panels normally used for temperature/sound isolation? I can make a sandwich of cork and lead sheets.
Any ideas are welcome.
Greetings,Eduard
Attachments
Hello.
I don't know what is your budget but i would try to contact sorbothane about their 'standard industrial line' and the isolation pad they have on offer.
Standard Industrial Products for Shock Solutions & Vibration
I don't know what is your budget but i would try to contact sorbothane about their 'standard industrial line' and the isolation pad they have on offer.
Standard Industrial Products for Shock Solutions & Vibration
Hello France,
The pads are kind of thin but they have other products that could be interesting like this one. I will just have to glue a wooden block to the bottom side of the Altec cabinet.
Silent Feet Anti-Vibration Riser for Beds - Superior All Surface Vibration Barrier - 4 Pack
Some of the industrial feet only start working with a much higher load.
Have to check if i can use 3 or 4 because the '' weight division '' bewteen left and right is identical but i think 75 % of the weight is on 50% of the depth. I mean the center of gravity will be not be in the middle . Let us say the depth of the speaker is 60 cm the center of gravity wont be at 30 cm from the front but at 40 cm from the front.
Maybe i will make a 20 30? kilo lead bar that i can locate under the wooden horn on top of the cabinet as close as possible to the front side of the speakers so the center of gravity will move in that direction too. Of course the further the feet are apart the better the stability will be and of course all the feet should have a similar load.
Greetings, eduard
The pads are kind of thin but they have other products that could be interesting like this one. I will just have to glue a wooden block to the bottom side of the Altec cabinet.
Silent Feet Anti-Vibration Riser for Beds - Superior All Surface Vibration Barrier - 4 Pack
Some of the industrial feet only start working with a much higher load.
Have to check if i can use 3 or 4 because the '' weight division '' bewteen left and right is identical but i think 75 % of the weight is on 50% of the depth. I mean the center of gravity will be not be in the middle . Let us say the depth of the speaker is 60 cm the center of gravity wont be at 30 cm from the front but at 40 cm from the front.
Maybe i will make a 20 30? kilo lead bar that i can locate under the wooden horn on top of the cabinet as close as possible to the front side of the speakers so the center of gravity will move in that direction too. Of course the further the feet are apart the better the stability will be and of course all the feet should have a similar load.
Greetings, eduard
Attachments
Something like this maybe: RS PRO M8 Zinc Plated Steel Stud Mount 23.65kg Compression Load 25mm dia. Natural Rubber | RS Components
Four of should get the resonant frequency below the working range of the speaker if it weighs around 100kg.
Four of should get the resonant frequency below the working range of the speaker if it weighs around 100kg.
Hello,
I know these products they were used at the company where i worked before and they were used for a small machine that we did assemble. But these were the ones that were designed for a much lighter load.
Probably i will melt some lead into a probably T shape mold where the upper part from the T will cross the entire cabinet from left to right side and being located in front of 515 loudspeaker cone and the lower part of the T will cover the area under the wooden horn that is placed on top.
Distributing the weight in such a way that the center of the weight will move to center of the 66 centimeter total depth of the cabinet will allow me to put the 3 or 4 feet further apart which will give a more balanced situation and for best results the load on each '' foot '' should be close to identical.
Right now i have to find out which durometer to go for. I general it seems sorbothane is working better than rubber. My diy cabinet is sand filled so it does not vibrate as much as the original VOT but getting rid of unwanted vibrations ( sure the lead will help) will also make the wooden horn on top better.
Not sure if i wanna attach those by 3 strong wires to the ceiling.
Greetings, eduard
I know these products they were used at the company where i worked before and they were used for a small machine that we did assemble. But these were the ones that were designed for a much lighter load.
Probably i will melt some lead into a probably T shape mold where the upper part from the T will cross the entire cabinet from left to right side and being located in front of 515 loudspeaker cone and the lower part of the T will cover the area under the wooden horn that is placed on top.
Distributing the weight in such a way that the center of the weight will move to center of the 66 centimeter total depth of the cabinet will allow me to put the 3 or 4 feet further apart which will give a more balanced situation and for best results the load on each '' foot '' should be close to identical.
Right now i have to find out which durometer to go for. I general it seems sorbothane is working better than rubber. My diy cabinet is sand filled so it does not vibrate as much as the original VOT but getting rid of unwanted vibrations ( sure the lead will help) will also make the wooden horn on top better.
Not sure if i wanna attach those by 3 strong wires to the ceiling.
Greetings, eduard
Hello Eduard,
The sorbothane pads are thin (and sag under load so if you want to elevate the cabinet at a defined height you'll need to prototype and wait for some days sorbothane stabilize it's sag.) but if calculated for the right load they are efficient with a good price/performance ratio imho.
There is a load of differents variation with different durometer and rated load: https://www.sorbothane.com/Data/Sites/31/pdfs/product-guides/sorbothane-spg-isolation-pads.pdf
The rated load range is from 1lbs to 200lbs per pad. I would take a look at 70 durometer with your own constraints.
You could even goes a step further and locate your horn on some other sorbothane pads too to even more decouple the a7 cabinet/horn.
Anyway if you have question about your application there is an application guide availlable in pdf or you can contact them directly. I had and got answers and help.
The sorbothane pads are thin (and sag under load so if you want to elevate the cabinet at a defined height you'll need to prototype and wait for some days sorbothane stabilize it's sag.) but if calculated for the right load they are efficient with a good price/performance ratio imho.
There is a load of differents variation with different durometer and rated load: https://www.sorbothane.com/Data/Sites/31/pdfs/product-guides/sorbothane-spg-isolation-pads.pdf
The rated load range is from 1lbs to 200lbs per pad. I would take a look at 70 durometer with your own constraints.
You could even goes a step further and locate your horn on some other sorbothane pads too to even more decouple the a7 cabinet/horn.
Anyway if you have question about your application there is an application guide availlable in pdf or you can contact them directly. I had and got answers and help.
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Hello France,
I will write them a message .
It seems like the feet are easier to use than the thin sheets.
I will ask them about the silentfeet that are used for supporting a bed. If they can handle the weight that would be nice. They are sold in packages of 4 or 6 pieces. I could always go for using 5 or 6 instead of 3 or 4.
I just checked the bottom side of my cabinets it wont be difficult to add a kind of lead bar underneath the box to have a more uniform spread of weight. The lower the position of the weight the bigger the effect will be on the stability. And then use a thinner thickness of lead on the top plate.
It wont be difficult to hang the TAD2001 PBS on 3 '' strings '' attached to the ceiling
Greetings, Eduard
I will write them a message .
It seems like the feet are easier to use than the thin sheets.
I will ask them about the silentfeet that are used for supporting a bed. If they can handle the weight that would be nice. They are sold in packages of 4 or 6 pieces. I could always go for using 5 or 6 instead of 3 or 4.
I just checked the bottom side of my cabinets it wont be difficult to add a kind of lead bar underneath the box to have a more uniform spread of weight. The lower the position of the weight the bigger the effect will be on the stability. And then use a thinner thickness of lead on the top plate.
It wont be difficult to hang the TAD2001 PBS on 3 '' strings '' attached to the ceiling
Greetings, Eduard
Hello GM,
I remember you told me not to use the stainless steel '' pinpoints ' i got made decades ago..
As i wrote in this thread i am planning to use some lead to create a more even distribution of mass in the cabinet and also introduce some lead on the top side because there the 515 is mounted and it is also the area where the wooden horn on top is supported..
I think isolating the TAD2001 horn by hanging it from the ceiling wont be that difficult but not sure if it will be beneficial. The French have done test with '' coupling '' conventional loudspeaker to a an element having both mass ( so partly concrete) and vibration absorbing properties ( so using sand). Of course the '' good vibrations '' made by loudspeakers are much bigger than the ones made by a 109 db/1w/1meter efficiency. So maybe my sand filled wooden horn doesnt need to be kind of '' fixed '' to a bigger mass. And this mass does contain some vibrations because of the 515.
If i attach a kind of string on both extremes on the front side of the horn and one string around the TAD2001 driver unit. I must take a look again at the Japanese Onken based sets. If i remember well i remember seeing iron chains being used. Of course some of these Onken are BIG and are being used for lower frequencies. So hanging the TAD on some reliable string could work well.
I already send Sorbothane company a message about using some feet designed for supporting a bed could work. I asked what will be the optimum load per feet so i will know how many to use. If using the calculator i wouldnt know what to go for durometer of resonance. I think it should be a rather stiff construction . The cabinet should have less movement/vibration the only thing moving should be the 515 cone.IF i can get a kind of balanced weight distribution then 4 feet would be easy. Maybe use number 5 in the center of gravity area.
It is almost plain logic but normally you will see people going for a close to identical load on each feet.
Greetings, eduard
I remember you told me not to use the stainless steel '' pinpoints ' i got made decades ago..
As i wrote in this thread i am planning to use some lead to create a more even distribution of mass in the cabinet and also introduce some lead on the top side because there the 515 is mounted and it is also the area where the wooden horn on top is supported..
I think isolating the TAD2001 horn by hanging it from the ceiling wont be that difficult but not sure if it will be beneficial. The French have done test with '' coupling '' conventional loudspeaker to a an element having both mass ( so partly concrete) and vibration absorbing properties ( so using sand). Of course the '' good vibrations '' made by loudspeakers are much bigger than the ones made by a 109 db/1w/1meter efficiency. So maybe my sand filled wooden horn doesnt need to be kind of '' fixed '' to a bigger mass. And this mass does contain some vibrations because of the 515.
If i attach a kind of string on both extremes on the front side of the horn and one string around the TAD2001 driver unit. I must take a look again at the Japanese Onken based sets. If i remember well i remember seeing iron chains being used. Of course some of these Onken are BIG and are being used for lower frequencies. So hanging the TAD on some reliable string could work well.
I already send Sorbothane company a message about using some feet designed for supporting a bed could work. I asked what will be the optimum load per feet so i will know how many to use. If using the calculator i wouldnt know what to go for durometer of resonance. I think it should be a rather stiff construction . The cabinet should have less movement/vibration the only thing moving should be the 515 cone.IF i can get a kind of balanced weight distribution then 4 feet would be easy. Maybe use number 5 in the center of gravity area.
It is almost plain logic but normally you will see people going for a close to identical load on each feet.
Greetings, eduard
Hello,
I did not get an answer from Sorbothane so i also looked around for other solution.
I can across a rubber based feet to be used for all kind of noisy machines. With the following property.
,
Natural frequences of the anti-vibration elements between 5 and 11 Hz
Also came across a sylomer foot with a little different frequency range
Natural frequences of the anti-vibration elements between 11 and 24 Hz
When i constructed the cabinets i already installed 3 M10 threaded metal '' elements that i can reach from the outside so if i lift up the speakers it will be easy to insert a M10 bolt or threaded rod.
Like i wrote before i will use some lead to create a similar load to each foot
Will it be good to use a set of 3 feet let us 15% above the minimum load or 15 % under the maximum load?
I hope the properties of the sylomer ones are better for audio because i like the looks.
There are also the ones using combination of a spring kind of surrounded by rubber.
As usual any ideas are welcome.
Greetings, Eduard
I did not get an answer from Sorbothane so i also looked around for other solution.
I can across a rubber based feet to be used for all kind of noisy machines. With the following property.
,
Natural frequences of the anti-vibration elements between 5 and 11 Hz
Also came across a sylomer foot with a little different frequency range
Natural frequences of the anti-vibration elements between 11 and 24 Hz
When i constructed the cabinets i already installed 3 M10 threaded metal '' elements that i can reach from the outside so if i lift up the speakers it will be easy to insert a M10 bolt or threaded rod.
Like i wrote before i will use some lead to create a similar load to each foot
Will it be good to use a set of 3 feet let us 15% above the minimum load or 15 % under the maximum load?
I hope the properties of the sylomer ones are better for audio because i like the looks.
There are also the ones using combination of a spring kind of surrounded by rubber.
As usual any ideas are welcome.
Greetings, Eduard
Attachments
What about those mats that you can use to reduce vibration of your washing machine? Size wise they might already be perfect 😉
Hello,
I do know them but what i like to install is something that is kind of adjustable . This will allow me to keep using the 4 present wheels installed there decades ago. So i will use the new feet to get just a little clearance between wheels and floor. If the clearance will be diminished or cancelled be cause of the loaf i just have to give the M10 bolts an extra turn.
Greetings, eduard
I do know them but what i like to install is something that is kind of adjustable . This will allow me to keep using the 4 present wheels installed there decades ago. So i will use the new feet to get just a little clearance between wheels and floor. If the clearance will be diminished or cancelled be cause of the loaf i just have to give the M10 bolts an extra turn.
Greetings, eduard
Greets!
OK, finally got a chance to review your cab's construction: Altec VOT in a new position
TTBOMK, all Sprague paper caps were oil filled.
Re the poles as side baffles, it needs to be ~71% of the lowest WL area to be of any use, so pretty sure a waste of time for LF, but may help some filling in below the horn's gain BW if at least as tall as the speaker and preferably ~30" above the bass cab.
A pallet Altec A7-500 [825 cab] weighs ~200 lbs, so ~160 lbs and with sand filled walls, sand filled HF horn box, I imagine it will be >220 lbs, but may still have spurious resonances and of course, a VLF fundamental/harmonics.
If you use a cheap mechanic's stethoscope to find any spurious resonances and using a tone generator plus a clear cup/jar with just a little bit of water will give a good enough [Fbox] and any subharmonics for choosing the range of the isolation feet.
All this hassle is why I always recommend making bass cabs stiff/rigid enough to raise its resonance up to ~2x the XO point, which while definitely makes it heavier, not nearly as much as is required to lower it to ~below its LF corner and no isolation feet required unless the floor moves: Audio Asylum Thread Printer
Re 3-4 feet, isolators/whatever, an 825 [near] stock cab isn't stiff enough to 'make do' with either unless turned upside down, though there's plenty of folks that will swear it's fine. If yours is braced and sand filled [or is the pedestal sand filled?], then you can get by with three; no bracing, have to assume that at some point something will occur to slightly alter the dynamics of the situation, making the third leg a high pressure point.
OK, finally got a chance to review your cab's construction: Altec VOT in a new position
TTBOMK, all Sprague paper caps were oil filled.
Re the poles as side baffles, it needs to be ~71% of the lowest WL area to be of any use, so pretty sure a waste of time for LF, but may help some filling in below the horn's gain BW if at least as tall as the speaker and preferably ~30" above the bass cab.
A pallet Altec A7-500 [825 cab] weighs ~200 lbs, so ~160 lbs and with sand filled walls, sand filled HF horn box, I imagine it will be >220 lbs, but may still have spurious resonances and of course, a VLF fundamental/harmonics.
If you use a cheap mechanic's stethoscope to find any spurious resonances and using a tone generator plus a clear cup/jar with just a little bit of water will give a good enough [Fbox] and any subharmonics for choosing the range of the isolation feet.
All this hassle is why I always recommend making bass cabs stiff/rigid enough to raise its resonance up to ~2x the XO point, which while definitely makes it heavier, not nearly as much as is required to lower it to ~below its LF corner and no isolation feet required unless the floor moves: Audio Asylum Thread Printer
Re 3-4 feet, isolators/whatever, an 825 [near] stock cab isn't stiff enough to 'make do' with either unless turned upside down, though there's plenty of folks that will swear it's fine. If yours is braced and sand filled [or is the pedestal sand filled?], then you can get by with three; no bracing, have to assume that at some point something will occur to slightly alter the dynamics of the situation, making the third leg a high pressure point.
I can't see three feet being a good idea in this case. I generally like tables and stools with 3 feet, but this seems too big and too heavy for that.
My suggestion was going to be a honeycomb silicone rubber mat, but you want it adjustable for the casters. So a simple mat is out.
My suggestion was going to be a honeycomb silicone rubber mat, but you want it adjustable for the casters. So a simple mat is out.