Can we have a Doc Mods idiots guide

[Quarknosis]

I have been using the search facility to try and get some info on Doc Mods and there is so much info spread over the forum that it is difficult to get a handle on it and it's going to take hours to find it all. Would it be possible to get a guide or set of bullet points of which steps should be done in which order to make it easy for anyone considering this to get the info. Or is it already in place somewhere and I have missed it?

I've just got a pair of JPW AP1s that I'm hoping to mod when I can. The foams are shot as expected so rather than try and refoam them I'm going to switch in a pair of JPW Vifa drivers that have been repaired with rubber surrounds for now, then hopefully get some Doc Mod drivers when I can. Does every internal surface benefit from steel plate and are do some areas give better results than others with the plate? I'm looking at some 100mm x 150mm x 5mm plate on ebay to go inside will this be enough to do the job on what I estimate to be a 200mm internal depth? I also have a local metalworking company that should be able to supply some 150mm x150mm plate if that would be better, anything larger than this would be a problem getting into the cabinet.

[Dr Bunsen Honeydew]

1/ remove wadding and any panel damping and throw it away.
2/ line the inside of the cabinet with steel plate (as much as possible)
3/ throw away the crossover
4/ wire the bass driver direct to the terminals
5/ wire the tweeter with a series capacitor and resistor 3.3mfd and 12 ohm.
6/ dope the cone of the bass driver to ear
7/ or better buy Doc Mod already doped drivers from me.

Done.

[Quarknosis]

Excellent, thanks Doc.

Does step 5 work for all tweeters or is it dependant on the electrical characteristics if the particular model used? I would have thought that would only be a starting point to work from? Most of the smaller JPWs use a 3.3mfd cap where the lager ones use 4.7mfd

Step 1 is the reason why I have got some JPW P1s, the P3s already have (bitumen type?) damping on the internal walls and I would imagine that it will be difficult to remove efficiently.

[Dr Bunsen Honeydew]

Do as you wish if you want to experiment, the point of Doc Mods is the experiment has been done for you.

As much as possible damping needs to be removed if you want it to be true to type. Bitumen will ruin what the steel plate is doing if you just put it on top.

[Fretless]

Additional steps: Ensure that any reflex ports are securely sealed (airtight). Positive and negative internal wires must be separated and spaced apart.

Final step - enjoy the result of your work !

[Quarknosis]

Doc, I won't be modifying the already damped AP3s, if I do feel that I need something the same size as those I'll try and get hold of some AP2s which I believe DQ has. They are essentially the same as speakers just that one has damping panels and the other doesn't. When the time comes I will be getting Doc Mod drivers rather than attempting it myself

Fretless, the JPWs are infinite baffle speakers so no ports to block up and the internal cables have usually run separately an all of the JPWs that I have seen so far so all is good there

Can anyone recommend a good source for the steel plate as the ebay seller that I contacted wants me to pay £24 for shipping the pieces having given me some blather about the post office being around the corner but expensive and it's the only place he will use due to working 6 days a week. Well he just lost my business.

[Daniel Quinn]

I do use JPW AP2 with doc mod drivers . I was lazy when it came to mass loading , I used some rather heavy stone floor tiles . These had the advantage of being free , they were in my garage and I could get more % surface area covered as they were convientinaly sized .

[Quarknosis]

That reminds me that I also have some tiles in the garage, they are quite large so I'll have to see if they fit, they are probably about 150mm x 200 mm iirc. Could be just the job for a first attempt.

I've now got 2 sets of P1s, the cabinets on the pair that I have just received need some TLC, I was thinking of trying to strip off the vinyl wrap and veneer them. I might try the tiles in the other pair and if I am successful with the veneering go for steel in those.

[Dr Bunsen Honeydew]

The mistake going on here is to confuse damping which is absorbing and decoupling and the coupling effect of steel plate, They are opposites and do opposite thing to the music.

[Quarknosis]

Step 1 done. I'm liking what I hear now that I've had a few days to get used to them without the wadding.

I'm in the process of painting up some spare cabinets that I have. Steel plate has been ordered from a local fabrication company. Then I need to get some adhesive to stick the plates in place, Bison Kit or use the spray adhesive that I have in the garage?