Wilson Watt Puppy 5.1 diffraction pads and resistors

I bought a used set of Wilson Watt Puppy 5.1s and they need some work.  Looking for thoughts and advice..

1. Midrange drivers don't work.  I've ordered new resistors hoping that fixes the problem. Wilson gave me some instructions but any other advice is welcomed on how to replace and what issues I might run into.

2. Diffraction pads were removed and left a sticky residue. Removal seems easy but makes me nervous.  Any advice here?

3. Some have said they prefer the to leave the diffraction pads off, others prefer the diffraction pads on claiming they sound bright without them.  Thought here?

Remove the midrange driver and put a meter on it for continuity.  If it tests good problem is in the crossover.  Goo Gone will take care of all sticky residue with no problems.  Did you know the speaker had a non working midrange when you bought it?
Goo gone for the resideue.  Since  I hope you replace the pads, you don't have to worry about messing up the look.

Personally, with those inverted Focal tweets, put the pads in.  It's a much smoother and more natural presentation.  If you are always chasing "revealing" leave them off.

You can always test the midrange by hooking them up directly to your amp at LOW volume first. 

Thanks erik.  When I touched the speaker wire to the actual mid driver terminals, the amp shut off.  Probably a stupid thing to do.
OK, sounds like the driver is shorted.

That's your answer.  If you want a final answer, get a multi meter and measure the resistance. 
Thanks erik. When I touched the speaker wire to the actual mid driver terminals, the amp shut off. Probably a stupid thing to do.


Only if you keep doing it.. And then NOT to smart fits better.. :-)

Digital multi meter (DMM), 8.00 - 45.00 dollars. Nothing fancy.. but the 8.00 dollar model might just impress you.. Pretty good ones at Parts Express, or Amazon... overnight from either..

The meter will arrive today. Not sure what setting to use or what to even look for when i connect the terminals

If you gently press the cone through its travel and feel rough friction, that’s a reliable indicator of a fried voice coil.

If the mid woofers are bad, I believe they are Scanspeak 8545-- possibly modified for Wilson.  But you can likely get close to the OEM performance with stock 8545 replacements.
@dgarretson yep, if you peel back the Wilson sticker on the woofer, it says Scanspeak.  I would doubt there's any modification to the driver.  That's a heck of alot cheaper than the $400 Wilson replacement.
I don't know how the damage was done, but it's not uncommon for a DC pulse from an amp to take out a woofer without affecting the tweeter.  With any luck, you should be fine with a fresh driver.
If you want an upgrade from the 8545, consider the new Purifi 6.5" driver.  It has very similar specs, but sounds much better at twice the price.  I've made that substitution in a Merlin VSM speaker without modifying the crossover.
Do they make a 7.5 inch driver?  Im not too crazy about changing these to make them aftermarket products.  Feels like putting new rims on a Bentley or something.  idk.
If it's the midwoofer in the Watt head unit that you're replacing, that should be 6.5".
Pretty sure it's 7 or 7.5 inch driver.  

Either way, I ordered new resistors..  Let's see if this works or if I blow the speaker up completely.  

I successfully took off all the old diffraction pad residue today so they look awesome.  Whether or not I add new diffraction pads will be determined later.


The original 7" W/P 5-8 mid drivers are 18W/4545-01 or -00. They are 4 Ohm impedance, so the 18W/8545-01 wouldn’t work as it has 8ohm voice coil and much lover efficiency. ScanSpeak doesn’t make than anymore. Got the last NOS pair from eBay in October 2022. You can search for 18W/4545-03 which has Aluminium frame, updated spider and 4 Ohm impedance coil. Old ones had a magnesium frame. I have original W/P drivers and the new ones, both are sounding the same. Quality stuff.