I thought B&W used Mundorf caps? Or was that just for the new/posh speakers?

http://singaporehifi.blo...capacitor-shoot-out.html

Just found some measurements of you speakers:
http://www.stereophile.c...loudspeaker-measurements

Some advices before you doing upgrade:
- first what you need to understand is WHY you want upgrade - you need know what you dislike in your speakes.
- second and last - is measurements: you need to get real picture, what is really weak in you speakers and what exactly the problem which you do not like.
- every capacitor have it's own character and own place in crossover: just replacing caps to "better specs/prices" could spoil overall sound (it depends on drivers, cabinet construction, crossover schematics)
- crossover schematics: before replacing you should understand what is each cap is doing.
- most of the improvemens you usually get with remodelling crossover (you need to repeat design process of the engineers who made your speaker - measure drivers in cabinet with microphone, put the data in CAD and design crossover.
- many, many, many listening tests, as if you replace one cap with another overall picture changes and probably to get most you need to rebuild crossover and listen agian and again until you will find right combination of values and types of components.
- take the speakers which sound really good and much better that yours and use them as "reference" for comaprison of changes. Compare them 1:1 to your at your location and your equipment.
- connectors to drivers/crossover: my personal preference - to solder it with a good solder.

About upgrading:
Add the picture and schematics of your crossovers - it will give more info and ideas for upgrade.

Bennic electrolytics are better than average but have significant loss as all these electrolytics do , (ESR) which is accounted for in the crossover

you are likely to have changed the Q of the networks concerned , and if nothing else this will alter the timbre.

After a decade most are still close to their production characteristics.

As bi-polars with extra thick foil and subject to an easy duty cycle they can last very well and hold tolerance .

MartinC

Would using solid core wire on the woofer and multistrand on the tweeter improve the sound?

Solid core wire has lots of metal to carry the low frequencies and multistrand wire has lots of surface area to carry high frequencies.

your result agrees with my experience

single strand , down to 0.6mm if applicable, for the treble

but multi , low resistance for the bass

Martin C

My friend the "mad modifier" also likes Dueland very much. However, due to his propensity to alter values I haven't been able to really appreciate to degree of improvement he is getting.

As an example of this two of the inductors in my S 100s had started to physically come apart; when my friend Darrel rewired them for me he epoxied them back together and added cable ties fastening them to the circuit board. Easy to do in this case as the board is easily removable. I just received word that my Mundorf 5 watt resistors had been shipped, I am going to install them before changing any caps.

This is normal, as electrolytics have usually +-20% tolerance.
Many manufacturers use Bennic as OE supplier, but theis sound is not good. I've upgraded Magnat Quantum 709 - caps were all Bennic (electrolytics, MKT and MKP) replaced to standart Mundorf MCap 400V (3%) and it was really big improvement, as the speakers were flat enough with slight lower responce at 3...6KHz - that is what our ears like. But also upgraded Technics SB-M20, but after electrolytics were replaced the sound becabe unpleasant and dry: the reason was that speaker responce was not flat and electrolics were hiding it - with new caps highs were "higlited" while soundstage became better, but after some crossover changes (just simple attenuator to tweeter) it became much better than before upgrade.