Good morning, (Google translations) That is a good question. As far as my information goes, for example, with the Tannoy HPD295 and the Dynaudio 24W100 speaker units series, the design remained completely the same at a time, and only the rubber surrounds was replaced. We have the rubber surrounds both, and they are very flexible, thin and light. Note: I don't have this information directly from an importer or manufacturer (I also wonder if they want to share this information.). Theoretically, you can expect such quality speaker units that the Thiele / Small parameters (see: en.wikipedia.org/wiki/Thiele/Small_parameters) have remained the same during the transition from foam surrounds to rubber surrounds. Unfortunately I have not had the opportunity to hear the difference. I expect that with the aforementioned, it is nil to the audience, so not audible .. Actually purely based on the long experience of both brands and that these brands have their name high, and should keep it. Now a non-original rubber surround to replace a foam surround. That will be different for each speaker. Some speakers are more sensitive to this than other speakers. I suggest that I limit myself to the bass speakers. At worst, the rubber surround is a lot heavier (less flexible comes later in this story). Due to the weight, which completely turns the calculation of the loudspeaker upside down, the resonance frequency Fs of the driver may become lower. That would not be a problem, but the efficiency is less of the woofer, which is different per woofer. The bass of the speaker cabinet can therefore decrease. If the new rubber rim is not flexible, the resonant frequency Fs increases, which is not desirable. Below the Fs frequency, usually not much happens in the low end. The result is that the bass becomes less deep. The efficiency of the woofer can increase, but usually on the more middle frequencies. If the above is the case, especially with a large woofer, you can turn a good woofer into a poor midrange speaker. That is undesirable. Finally, it is not to be underestimated what the damping of the vibrations of the cone, by changing the surround from foam to rubber, does for the final sound that the speaker produces. Thigh heavy thick rubber surrounds will have more influence than thin light surrounds. To come back to the question, this is different for each speaker. I dare even say it can be a gamble at times. The question is whether you are willing to take that gamble. Kind regards, Fred
since the rubber is stiffer i bet it will sound different, at least will need bit more power to produce the same volume. On the other hand the cone will move in a more controlled manner, giving tighter bass response
@@fabiuh991 Good evening, Thanks for your response. I must say the rubber version of the SR192/2 is very thin and very flexible. One could shoot the rubber surround like an elastic. Therefore, the rubber version is also somewhat difficult to assemble. For those who want to order a rubber SR192/2, I maybe have a tip. If you make a ring from cardboard on which the outer flange can rest, this is easier to do during assembly. Best regards, Fred
Yes. I replaced an original foam ring with a rubber one, and the bass didn't slap as it used to. The rubber is too stiff for what my speaker was designed for.
How to tell if you have a rubber or foam surround? I have a subwoofer that is easily 20+ years old and the surround still seems fine so I am thinking it has a rubber surround? (I am using the jvc hx-z30 btw)
Good morning, sorry for the late reply. I normally take a flashlight with the option on it to bundle the light to a strong small one. Then take a close look at the surround. Normally foam has a kind of structure on the roll, (it is pressed material from base material with an open structure) and the surface is not 100% flat and smooth. If you also shine a bit obliquely on the roll, it is easy to see whether the surface of the surround is completely flat (rubber), or with a small structure (foam). Best regards, Fred
Good morning, thanks for your reply. Maybe a strange answer, but if the moving parts of the new rubber surround are (at Hifi, not PA / power subs, disco-speakers, etc. ) light and flexible, some extra mm should be no problem. I by the way have seen in a matched pair of speakers, originally left and right rubber surrounds with and other code on it. Tracking the code gives just a small difference in sizes. This was by the way at a midrange, but it wouldn’t surprise met if it would had happened with some woofers. I have to say that in the past so called ‘batch-differences’ happened more as nowadays. Best regards, Fred
You really can't compare rubber with foam in terms of quality and durability. I replaced the foam surround of my Altecs about seven years ago and they are rotten again. The rubber surround of my Polks from 1989 are in absolute perfect condition, just like the day I purchased them. There's no comparison.
Good afternoon, you'r right. But also certain rubber surrounds can get inflexible. For a car for instance a surround of good lasting rubber would not be bad idea. Kind regards, Fred
I have speakers from ADS and the Butyl rubber surrounds from 1981 are still perfect. Not dry or stiff. Foam is inferior. Changes with time and gets worse and worse and then fails. It is the cheap surround that ends up costing more in the long run.
I purchased a audiobahn awt10x recently, and it has a massive rubber surround. It is hardened at the underside and feels crispy to the touch. Some small chips fall off. I build a box for it and at first it played so rigid it had no bass extension in the upper frequencies (+40hz). After 2 weeks its getting better. I hope it will hold.
There's only ONE reason companies use foam surrounds instead of rubber. FOAM FAILS, and that means you're a return customer - either to replace the surround (with a "correct"one that they'll sell you) or buy a new driver.
Well, maybe there's more to it than that. Advent must have been among the first to use foam. Their interest was getting a 2-way speaker to handle the midrange well, up to ~1000Hz. So, they wanted light weight in their nominally 10" (piston diameter) cone. There may have been production advantages too. My GUESS is that if you're dealing with a real woofer (no higher than 400 Hz) the rubber will be a good choice.
I see Kicker speakers are using a 'polypropylene foam' surround instead of rubber- I'm curious as to whether its cost-saving or improving the bass response. So far, while testing these Kicker CSC's I bought, I feel the bass is quite deep, punchy, and has a great deal of loudness, however, I feel the bass response may be muddled, and even 'farty', its barely noticable as its a booming speaker, its also only a 2 way, so definitely lacking the mids and highs, I came here for some info on whether it could be the material used or not... I wonder which costs more to use? that might answer the question on quality?
Good evening, Thanks for your message. I can say that making a mould for rubber surrounds is generally more expensive than for a mould for foam surrounds. But if thousands if not tens of thousands of speakers are made with the surrounds of this mould, this will not be a reason to choose foam. Same story for the material itself. When buying in bulk, the differences in price disappear so that, as far as I can see, there is no reason to choose foam because of the price. Although with full range speakers, for example, Lowther still uses foam surrounds. Given the price of GBP 830 for a single Lowther PM4A (or €1,449.00 at for instance www.audio-constructor.com), the choice of foam will certainly not be due to the possible lower price of a foam surround. (See also: lowtherloudspeakers.com/pricing). I would personally, if this is possible, for speakers in a car choose a speaker with a rubber surround. This is because the potentially high temperature in the car, etc. foam perishes faster. I hope to have answered your question, best regards, Fred
Polypropylene is heavy and was first introduced to combat paper cones that absorbed moisture in damp conditions and changed the sound. Ceramic is one of the finest materials. Less cone break up and still light like paper and stiff. Using laser vibrometers to measure cone break up shows Ceramic is extremely good. Newer materials are available now. Don't know if any manufacturers are using them though. Graphene sticks out. scitechdaily.com/scientists-toughening-graphene-by-integrating-carbon-nanotubes/
Hi guys, would you consider sending a foam surround repair kit for Dynaudio 15W75 to Australia? You have aproduct is stock but shipping to Australia not available, would you consider or point me in the direction of a someone who could supply this. Thanks.
Thanks for your reply, actually we don't sent glue to most country's. The reason is that NL=drugs-country + customs = problems. Most times surrounds are possible. Best is to e-mail to info@audiofriends.nl. With best regards, Fred
What would be recommended for a TRF2215 SPL sub? I have had the hardest time finding anyone with anything that would work. The speaker surround is coming apart but the rest of the speaker is in good shape.
Thanks for your reply. I have searched on Google. You need if I'm correct a 15 inch surround for Rockford with thee shape like this one (with a inflexible wide roll): www.repairyourspeakers.com/en/surrounds-by-size/9-12-inch/10-inch-foam-surround-for-repair-rockford-subwoofer/a-2705-10000071. I have searched a lot on Google, but can't seem to find a special made roll for this subwoofer, sorry. Maybe eBay gives an option. Not specially made for Rockford, but maybe with the right sizes, and wide inflexible roll for power subs: www.ebay.co.uk/sch/i.html?_nkw=15%20inch%20foam%20surround Sorry that I can't help you better! Best regards, Fred
Let's say I have one speaker with a Rubber surround and another with foam surround. Would they sound different from each other?
Good morning,
(Google translations)
That is a good question. As far as my information goes, for example, with the Tannoy HPD295 and the Dynaudio 24W100 speaker units series, the design remained completely the same at a time, and only the rubber surrounds was replaced. We have the rubber surrounds both, and they are very flexible, thin and light. Note: I don't have this information directly from an importer or manufacturer (I also wonder if they want to share this information.). Theoretically, you can expect such quality speaker units that the Thiele / Small parameters (see: en.wikipedia.org/wiki/Thiele/Small_parameters) have remained the same during the transition from foam surrounds to rubber surrounds. Unfortunately I have not had the opportunity to hear the difference. I expect that with the aforementioned, it is nil to the audience, so not audible .. Actually purely based on the long experience of both brands and that these brands have their name high, and should keep it.
Now a non-original rubber surround to replace a foam surround. That will be different for each speaker. Some speakers are more sensitive to this than other speakers. I suggest that I limit myself to the bass speakers.
At worst, the rubber surround is a lot heavier (less flexible comes later in this story). Due to the weight, which completely turns the calculation of the loudspeaker upside down, the resonance frequency Fs of the driver may become lower. That would not be a problem, but the efficiency is less of the woofer, which is different per woofer. The bass of the speaker cabinet can therefore decrease.
If the new rubber rim is not flexible, the resonant frequency Fs increases, which is not desirable. Below the Fs frequency, usually not much happens in the low end. The result is that the bass becomes less deep. The efficiency of the woofer can increase, but usually on the more middle frequencies. If the above is the case, especially with a large woofer, you can turn a good woofer into a poor midrange speaker. That is undesirable.
Finally, it is not to be underestimated what the damping of the vibrations of the cone, by changing the surround from foam to rubber, does for the final sound that the speaker produces. Thigh heavy thick rubber surrounds will have more influence than thin light surrounds.
To come back to the question, this is different for each speaker. I dare even say it can be a gamble at times. The question is whether you are willing to take that gamble.
Kind regards, Fred
since the rubber is stiffer i bet it will sound different, at least will need bit more power to produce the same volume. On the other hand the cone will move in a more controlled manner, giving tighter bass response
@@fabiuh991 Good evening,
Thanks for your response. I must say the rubber version of the SR192/2 is very thin and very flexible. One could shoot the rubber surround like an elastic. Therefore, the rubber version is also somewhat difficult to assemble. For those who want to order a rubber SR192/2, I maybe have a tip. If you make a ring from cardboard on which the outer flange can rest, this is easier to do during assembly.
Best regards, Fred
Yes. I replaced an original foam ring with a rubber one, and the bass didn't slap as it used to. The rubber is too stiff for what my speaker was designed for.
How to tell if you have a rubber or foam surround? I have a subwoofer that is easily 20+ years old and the surround still seems fine so I am thinking it has a rubber surround?
(I am using the jvc hx-z30 btw)
Good morning, sorry for the late reply. I normally take a flashlight with the option on it to bundle the light to a strong small one. Then take a close look at the surround. Normally foam has a kind of structure on the roll, (it is pressed material from base material with an open structure) and the surface is not 100% flat and smooth. If you also shine a bit obliquely on the roll, it is easy to see whether the surface of the surround is completely flat (rubber), or with a small structure (foam). Best regards, Fred
I have a Z30 as well. The speakers are great no damage after all these years. It's foam, not rubber.
Can you replace a surround with a taller one?
Good morning, thanks for your reply. Maybe a strange answer, but if the moving parts of the new rubber surround are (at Hifi, not PA / power subs, disco-speakers, etc. ) light and flexible, some extra mm should be no problem. I by the way have seen in a matched pair of speakers, originally left and right rubber surrounds with and other code on it. Tracking the code gives just a small difference in sizes. This was by the way at a midrange, but it wouldn’t surprise met if it would had happened with some woofers. I have to say that in the past so called ‘batch-differences’ happened more as nowadays. Best regards, Fred
You really can't compare rubber with foam in terms of quality and durability. I replaced the foam surround of my Altecs about seven years ago and they are rotten again. The rubber surround of my Polks from 1989 are in absolute perfect condition, just like the day I purchased them. There's no comparison.
Good afternoon, you'r right. But also certain rubber surrounds can get inflexible. For a car for instance a surround of good lasting rubber would not be bad idea. Kind regards, Fred
I have speakers from ADS and the Butyl rubber surrounds from 1981 are still perfect. Not dry or stiff. Foam is inferior. Changes with time and gets worse and worse and then fails. It is the cheap surround that ends up costing more in the long run.
I purchased a audiobahn awt10x recently, and it has a massive rubber surround. It is hardened at the underside and feels crispy to the touch. Some small chips fall off. I build a box for it and at first it played so rigid it had no bass extension in the upper frequencies (+40hz). After 2 weeks its getting better. I hope it will hold.
There's only ONE reason companies use foam surrounds instead of rubber.
FOAM FAILS, and that means you're a return customer - either to replace the surround (with a "correct"one that they'll sell you) or buy a new driver.
Well, maybe there's more to it than that. Advent must have been among the first to use foam. Their interest was getting a 2-way speaker to handle the midrange well, up to ~1000Hz. So, they wanted light weight in their nominally 10" (piston diameter) cone. There may have been production advantages too. My GUESS is that if you're dealing with a real woofer (no higher than 400 Hz) the rubber will be a good choice.
I see Kicker speakers are using a 'polypropylene foam' surround instead of rubber- I'm curious as to whether its cost-saving or improving the bass response. So far, while testing these Kicker CSC's I bought, I feel the bass is quite deep, punchy, and has a great deal of loudness, however, I feel the bass response may be muddled, and even 'farty', its barely noticable as its a booming speaker, its also only a 2 way, so definitely lacking the mids and highs, I came here for some info on whether it could be the material used or not... I wonder which costs more to use? that might answer the question on quality?
Good evening,
Thanks for your message. I can say that making a mould for rubber surrounds is generally more expensive than for a mould for foam surrounds. But if thousands if not tens of thousands of speakers are made with the surrounds of this mould, this will not be a reason to choose foam. Same story for the material itself. When buying in bulk, the differences in price disappear so that, as far as I can see, there is no reason to choose foam because of the price.
Although with full range speakers, for example, Lowther still uses foam surrounds. Given the price of GBP 830 for a single Lowther PM4A (or €1,449.00 at for instance www.audio-constructor.com), the choice of foam will certainly not be due to the possible lower price of a foam surround. (See also: lowtherloudspeakers.com/pricing).
I would personally, if this is possible, for speakers in a car choose a speaker with a rubber surround. This is because the potentially high temperature in the car, etc. foam perishes faster.
I hope to have answered your question, best regards, Fred
Polypropylene is heavy and was first introduced to combat paper cones that absorbed moisture in damp conditions and changed the sound. Ceramic is one of the finest materials. Less cone break up and still light like paper and stiff. Using laser vibrometers to measure cone break up shows Ceramic is extremely good. Newer materials are available now. Don't know if any manufacturers are using them though. Graphene sticks out.
scitechdaily.com/scientists-toughening-graphene-by-integrating-carbon-nanotubes/
Hi guys, would you consider sending a foam surround repair kit for Dynaudio 15W75 to Australia? You have aproduct is stock but shipping to Australia not available, would you consider or point me in the direction of a someone who could supply this. Thanks.
Thanks for your reply, actually we don't sent glue to most country's. The reason is that NL=drugs-country + customs = problems. Most times surrounds are possible. Best is to e-mail to info@audiofriends.nl. With best regards, Fred
What would be recommended for a TRF2215 SPL sub? I have had the hardest time finding anyone with anything that would work. The speaker surround is coming apart but the rest of the speaker is in good shape.
Thanks for your reply. I have searched on Google. You need if I'm correct a 15 inch surround for Rockford with thee shape like this one (with a inflexible wide roll): www.repairyourspeakers.com/en/surrounds-by-size/9-12-inch/10-inch-foam-surround-for-repair-rockford-subwoofer/a-2705-10000071. I have searched a lot on Google, but can't seem to find a special made roll for this subwoofer, sorry. Maybe eBay gives an option. Not specially made for Rockford, but maybe with the right sizes, and wide inflexible roll for power subs:
www.ebay.co.uk/sch/i.html?_nkw=15%20inch%20foam%20surround
Sorry that I can't help you better! Best regards, Fred
Also in English, German and Nederlands on www.repairyourspeakers.com (PayPal, creditcard, Sofort, iDeal, etc.).
You don't even know how to present