Refoam FAQ

REFOAM FAQ (20x):

1. Why best buy from Audiofriends?
Audiofriends has also a non-profit website, for and by hi-fi hobbyists.  We are not just any trading company that would sell underwear if we could make a better profit, but an organisation with deep roots in the hi-fi world.
With this background, we always make all possible efforts to provide our customers with the right surround edges (surrounds). Further we have made about 40 refoam video’s manuals to help our customers.
We have a great variety of foam (+rubber) surrounds. We have developed about 30 special surrounds in 3D.
--------
2. Is it worth it to have my speakers repaired?
Repairing a speaker with a surround from Audiofriends is almost always okay. Having brands such as Tannoy, KEF, JBL, etc. revised is almost always a worthy investment.
There may be different reasons for repairing a speaker:
  • more quality for less money
  • especially for speakers of 15 years and older, but even for newer models: they will retain their value
  • if your speakers can retain their value, they are more easily interchangeable
  • if a certain model is out of production; ‘old love never dies’
  • a passion for old reliability
  • with a repair instead of buying new you are environmentally friendly
If you are not sure, you can ask us for an estimate. We have a lot of experience with loudspeakers.
--------
3. How does Audiofriends ship?
Audiofriends usually ships with self-sealing plastic bags till 40 x 40 cm in sturdy cardboard boxes or letterbox boxes. The ordered items, for example two 8 inch foam edges, easily come under great pressure in a heavy mail bag. After that, the shipment is regularly pushed through your letterbox opening with force. We sell and make excellent items, and want them to reach you safely. That means we ship in sturdy packaging, not cheap letterbox envelopes in which your items arrive crumpled..
--------
4. I prefer rubber surrounds while original foam surrounds were mounted(?).
See the menu on our homepage.
--------
5. Will I be able to carry out the revision?
Everybody should be able to revise a solid 8, 10 or 12 inch woofer. Some people can do a more precise job than others, but they should all pass the test with the test signals. We have exclusive manuals for virtually every problem.
The Tannoy Dual Concentric units are for instance a bit more complicated, so we have prepared special manuals for speakers. With our manuals or videos, everyone should be able to do it. However, a bit of skill and patience will help make things easier.
--------
6. What can I expect from the sound after the revision?
Please take care of the fact that in the past 5 years, your speakers played with surrounds that were much more flexible than the original design. Additionally, the new surrounds need to be run in (see other frequently asked question). Particularly in the beginning, your loudspeakers may sound different. After a run-in period the surrounds will have become more flexible. Especially with woofers the sound difference wil be hearable.
--------
7. How can I test the repair?
We have a series of test signals for you. You should bear in mind that test signals at a higher volume, especially if you do not hear anything, but the speaker is active, can cause damage. So be careful with test signals. The use of test signals is entirely at your own risk.
Picture A, performance (the volume under certain circumstances) may be reduced. In a multi-way speaker system (a loudspeaker casing with, for instance, a high tone and a low tone loudspeaker), the balance between the speakers can get distorted.
Picture B indicates what could be considered correct.
Picture C is the ideal situation.
Picture D is also excellent.
Picture E is correct from a technical standpoint, but it looks clunky.
Picture F is the correct situation.
--------
8. How much time takes a refoam?
That can vary quite a bit. A 15 inch Tannoy 385HPD speaker or a standard 6,5 inch speaker, if you’re handy, etc. We charge about 30 – 60 minutes for a standard 8 inch speaker unit. We do advise you to take your time for the repair.
--------
9. What about payment?
We will start the shipment after we have received the payment. On our homepage you can see with what possibilities you can transfer.
--------
10. Can I repair only one side of my speakers?
The other speaker will soon be worn out as well.
  • If one side has a new surround, and the old surrounds on the other side is more or
  • less decomposed, the sound will be uneven, which may be audible.
However, in special circumstances, it is possible that one side of the loudspeaker pair has always been exposed to the sun, while the other side was placed in a dark corner of the room.
--------
11. You want to know more about the dust cap story.
If you remove the dust cap please keep in mind:A part of the old cap remains in place, which renders the cone heavier and slower. It also reduces the performance. The cap plays an important role, especially in case of smaller units, for the production of higher frequencies. Installing a larger cap (which has to be larger in order to cover the remainders of the old cap) affects the production of these higher frequencies. The following is a direct quote from the Dutch edition of the book ‘The Loudspeaker Design Cookbook’ by Vance Dickason. This is not just any book, but a Bible among books used by loudspeaker designers: 'A dust cap has also influence on the of the high frequencies.'
The new cap is not an original one and will, in most cases, be made of a standard material, from which the whole product line of dust caps has been produced. This may also affect sound production. (see above).
You can probably imagine why, both from a visual and a sound-technical point of view, it is better to leave the dust cap in place and to use our way of refoaming. There are various types of dust caps:
  • plastic
  • paper
  • felt
  • fine meshed fabric
  • aluminium
  • air permeable fabric
For the last type, the air-permeable fabric, construction plays an important role. If left uncorrected, there may be an accumulation of compressed air behind the cap. This results in a distortion of the sound. Different manufacturers have found different solutions to this problem. For instance, by making ventilation holes in the voice coil holder, in the pole core, or simply by making the dust cap air-permeable. The installation of just any cap ‘that fits’ can cause unexpected problems. In a case like this, Audiofriends tries to deliver a dust cap that is most similar to the original one.
--------
12. Does Audiofriends also have special sizes?
--------
13. The surrounds size varies.
A somewhat different size doesn’t have to be a failure. If, although we’re very accurate, you got a different surround, you can of course trade them in at no costs..
--------
14. You want to know more about the type of glue we use.
(Click on this text for more information.) The glue is a part of the revision.
--------
15. Does Audiofriends guarantee the repair?
‘Do you guarantee that I will be able to perform the repair?’ Unfortunately, we can’t guarantee this. After a day of overtime until 21:00h, ‘quickly repairing the speakers’ would be unwise. Take your time, and if you encounter something you are not sure about, please do not hesitate to contact us. Watch the manuals carefully. Repairs are at your own risk.
--------
16. Do you also refoam for others?
We revised many speakers, of all types and sizes. Due to our website’s success, we no longer have the time to do this and we completely committed ourselves to the supply of loudspeaker parts, including foam surrounds.
--------
17. Running in your speakers?
New store-bought speakers need to be run in. The same is true in case the hanging surrounds have been replaced. It is best to let the loudspeakers only play normally (not to loud) for a week. You will notice that, over time, the surrounds become more flexible, the low spectrum deepens at woofers. Because of this speakers will naturally be run in through use. We recommend not taxing the loudspeakers too heavily during the first 48 hours.
--------
18. The sizes of Audiofriends (?).
> The sizes are different from other manufacturers. How did that happen?
Audiofriends started with hobby revision even before the internet era became active (from around 1993). Audiofriends then involved the surrounds in an old-fashioned way via a drawing sent in by post in which the measurements had to be filled. You already understand, that was the same according to the drawing above. Later, various suppliers of speaker surrounds came online. The sizes were slightly different. For example, where Audiofriends put size "C", most put "A" on the outer size of the speaker diameter.
Audiofriends had been around for a while, and it already had a range of surrounds. After consultation with various people, it was therefore decided, in order to avoid great confusion, to keep the measurements as used by Audiofriends from the beginning.
> Why is D (roll width) not equal to size B - A?
That's because measure D is measured from above, and sizes A and B from below. That's done, because only D on a speaker is only measured from above, and can be compared to the original.
Size D is B-A plus double the material thickness on site. In addition to the role, rounding also plays a role.
> Are the sizes actually 100% correct? Audiofriends often have a "±" sign on the bars!
Edge measurements are never 100% exact. This is because the surrounds are flexible. This makes correct measurement difficult anyway, also because the size can change slightly when mounting the speaker surround on the speaker unit. We usually offer flexible surrounds, where this certainly applies.
> Don't I get two different surrounds?
The surrounds are matched as much as possible per pair. This means that, if necessary, we send the edges as much as possible in pairs with equal dimensions. The edges, of course, come from the same mold.
--------
19. You think you have got too few surrounds!
A message is sometimes sent to us that too few surrounds have been sent. Would you be so kind to check the following for us?
1. Please do not count the wrapping plastic bags. You have not bought bags. Sometimes we find it important to preserve the surround to send it individually, per two or more in one bag.
2. If there seem to be too few edges in one pocket or bag, it may be that they are stuck together. We received the four 3,5”LAB surrounds in the image below from a customer as if it were only one piece. This optical illusion is often with both rubber and foam surrounds.

--------
20. Telephone contact with Audiofriends?
Calling Audiofriends is usually very inconvenient, for you and for Audiofriends. An e-mail is usually the medium to ask something, to pass on something, etc. We might like to give you some examples:
  • With a question or message by e-mail, things can be searched via the internet, images, hyperlinks, etc. can be sent along, or be referred to another entrepreneur.
  • If the customer does not speak fluent Dutch, English or German, it is inconvenient anyway. Dutch is the native language for Audiofriends, so fluently telling a technical story in another language can be very confusing.
  • Communicating by telephone takes a lot of time, is clumsy and often unclear.
That is why we prefer e-mail to telephone.

Sorry for the inconvenience.
--------