This raises a few interesting points;
How to Quote on Speaker Repairs
When a customer comes into your store with a damaged speaker, you need to be able to assess the problem and give an accurate quote. This is a quick guide to assist you.
No 1, If the customer brings in one speaker, ask them to bring the other one in because in most cases it will be damaged also. It is also best to do the same job to the other speaker to keep the sound matched. If the customer brings in HI-Fi speakers, if economical to you, ask them to bring the boxes also. The idea of this is to give the customer a free check of the other components in their boxes, this includes, drivers x-overs and wiring. You would be surprised how many people do not know that other drivers do not work in their boxes.
No2, the next step involves identifying the problems with the speakers. If the speaker has worn or damaged surrounds you need to make sure that this is not the only problem. Typically once the surround has gone, the voice coil goes off center causing it to rub and get damaged also.
Another problem is that all of the cones weight has now been put on the bottom suspension.
This causes uneven up and down movement and causes it to become too soft which can make the speaker sound slow and muddy.
Logically the best option would be to re-cone the speaker. This replaces all the moving parts with high quality modern materials which not only make the speaker like new again, it also sounds much better than new and will give many years of trouble free operation.
This also applies to blown voice coils, damaged cones and other severe damage.
No3 Now if you get Hi-Fi speaker boxes you need to assess what needs to be repaired. Check the tweeters, midranges, x-overs and wiring. In most cases if the boxes are 15 years or older they will need attention
No4 Remember most customers would love for you to repair their old speakers. People usually grow quite attached to them and will do anything to get them repaired.