JPW AP2

[floydfan]

Didn't mention it but on the JPW and Goodmans speakers I did put new caps and put a resistor on the tweeter. I used a variable resistor and changed the resistance on the high frequency until I thought the balance was correct.

[Alfi]

Step by step, take out BAF and listen.

Done Doc!

I wasn't expecting to hear much difference, I give it try with ZZ top's Head's in Mississippi. What a revelation, first impression is that I feel the speakers improved by a fair margin, far more realism. Is this perhaps because there's more free air volume behind the mid-bass driver? I don't know?

Next up, 5mm steel plates -I'll get some cut by a local eng. firm next week. Questions....

Do I glue these over the bitumen like material that's neatly placed in there now, as it looks as if this will be a right b'stard to remove? Also, do I make the steel plate the same size as the bitumen material or smaller? There's three slabs of bitumen approx 180mm x 150mm (these should be pretty easy to fit) and two 360mm x 150 in each. I think I'll be able to tease in the two long ones through the 8" diameter cut out. My AP2's will be bloody heavy when that lot's done in 5mm steel.

I'm going to enjoy this project immensely. Thanks Richard, everything you've helped with so far has improved my enjoyment of music.

Alfi.

[Alfi]

Didn't mention it but on the JPW and Goodmans speakers I did put new caps and put a resistor on the tweeter. I used a variable resistor and changed the resistance on the high frequency until I thought the balance was correct.

Thank's floydfan. I put a Monacor MKP in place of the bipolar electrolytic but left the original resistor in place on the crossover. Is there much to be gained in changing the resistor?

Alfi.

[Dr Bunsen Honeydew]

It would be better if you can get the bitumen out, but if you can't then put over it.

As much as you can get in, Plate size depends on what goes through the speaker hole. Fit everywhere you can, on top of the bitumen or fixed direct to the wood. Most glues do the job (don't use Superglue), I use a synthetic rubber based glue like UHU for these sorts of jobs. If you think the speaker will be too heavy then use 3mm steel plate, but the weight is your asset musically

[Alfi]

Thanks Doc. I agree that removing the bitumen would be ideal, but I don't want to start making a mess of it if it won't come out clean. 5mm mild steel plate will add approximately 7kg to each cabinet, so that sounds OK to me and a good quality rubber/solvent based contact adhesive should do the job quickly neatly and hopefully will prove to be effective long term.

So once this is done, I should then remove the mid/bass inductor from the crossover and dope the cone as required after listening tests - or should I install a better quality 8 Ohm driver?

The AP2's owe me £50 thus far, they are performing really well as they are right now, so it appears I'm in for a real treat when all the mods have been completed.

[Dr Bunsen Honeydew]

The driver is a pretty good one. I sold DQ a pair of the drivers I use. I am not sure if they fit easily, you will have to check with him.

One step at a time

[Alfi]

One step at a time

Indeed!

The driver is a pretty good one. I sold DQ a pair of the drivers I use. I am not sure if they fit easily, you will have to check with him.

I may just do that Doc but I think I'll be patient and wait to see what the further mods bring first.

[Alfi]

Hi Doc.

What's your advice for most appropriate stands for the AP2's, open frame or mass loaded central pillar?

Going by what you've advised so far regarding mass, my assumption would be the latter.

Thanks.
Alfi

[Dr Bunsen Honeydew]

Try both and tell us. I use these but I am sure there is better. I just like them and they sound good.

http://www.ebay.co.uk/itm/rcs-solid-oak ... 3cf15e3e9d

[Alfi]

They look gorgeous Doc.

I will experiment as a I have a few steel option here.