Tom,
I recommend you do this mod in stages because you can stop any time you are comfortable with the results.
Now, I also recommend you make changes to a cheap pair of headphones and not work on your regular ones.
Anyone who uses headphones for any period of time with their detector will agree a decent pair of coiled cord headphones are better than straight cord types. Personally, I like a set that have a longer coiled cord so I chose a set of Hamilton units. Their cord is 9' long which is the longest I have found in a regular set. The beauty of this brand is they can be found at very reasonable prices.
Because this brand is often sold to schools, the headphones have to have some durability.
Now, the two models I feel work well are the 5900's and the more common SC-7V models. The ear muffs are a little bigger in the 5900's but this model is a mono version. Both models can be purchased for about $20 or less even from ebay. Just be careful because some of the same models are being sold for a much higher amount. Just look for the bargains.
I recommend you check the headphones volume and speaker resistance before you begin. The reason is, on some of the 5900's you may be lucky enough to get a set of headphones with 300 ohm speakers already installed. Older units will have the higher resistance speakers. Newer ones will have 32 ohm speakers.
You have to be careful with the 5900's because they are a mono set and not stereo units and as such will not work on all detectors if the plug is fully installed. Some older detectors won't work right and at least one gold detector brand, the older FIsher Gold Bug 2 and mabe the earlier gold bug wont work right.
Once you have initially checked out the headphones, then the first mod is to simply change the speakers. Do nothing else at this time. The speakers should be pried out of the holders and the new ones installed. To get to the speakers is very easy. Remove the ear pad by simply pulling it off and then with a small screwdriver, pry each of the flat plates holding the speaker out of the earpiece. This will be obvious when you take the pad off as to what needs to be done.
Use a good glue to hold the new speakers in place. I prefer to use a good contact cement or I will make a paste of abs plastic using scrap abs plastic melted in MEK. This slurry actually bonds to the flat the speaker is attached so it will never come loose. When the glue is dry, simply pop the plastic flat with the new speaker attached back into place and reinstall the ear pads. One thing you can do before putting the headphones together is to find some cheap foam rubber maybe a half inch thick and cut a piece large enough to stuff in the ear housing before putting each side back together. This foam will had a little insulation from external noise. This foam isn't a necessity so don't worry if you don't have any foam at this time. The foam can always be added later if you feel it is needed.
Once the headphones are back together, you should find they are much louder.
Now, many people may find the headphones are more than loud enough with just this change so you might want to use them for a while this way before even considering making any more changes.
BTW, you should find these headphones now will come close to matching or even exceeding some of the much more expensive headphones people buy.
One final note, I do recommend you test the headphones as I mentioned before. This will eliminate a lot of problems should something not work right. BTW, I did find one set of headphones I received didn't work right. So, that is a possibility but it should be rare. On my set, the wire going between the left and right side was pinched and shorted by a screw holding things together. In my case, I removed the offending screw, wiggled the wire and reinstalled. Everything worked ok then.
Reg
