B&W 803D crossover caps


I am considering an upgrade of the crossover capacitors in by B&W 803Ds, particularly the mid and HF coupling caps.

I took out the top bass driver to find out what caps were installed. It looks like for the diamond tweeter B&W uses a Mundorf Supreme silver/gold, 4.7 mfd 1200V. For the mid driver there are two; a 47 mfd Mundorf MKP 400V series coupling cap (in series with the driver) and a 10 mfd Mundorf Supreme siver/gold bypassing cap (parallel to the driver).

I was thinking about changing out all three, but have a few concerns.

I was going to replace the 10 mfd, 4.7 mfd Supreme silver/gold with Supreme silver/gold/oil. Would there be enough of a difference in these two types to justify the cost? I also do not want to make the upper end any brighter.

I am also concerned about the long term reliability of oil filled caps, as some failures have been reported in warmer environments. I wonder if B&W did not use the silver/gold/oils for that reason.

The biggest impact I suspect will come from the replacement of that series 47 mfd MKP. I would probably use either the Mundorf MCap EVO (Al metalization), MCap EVO oil (Al/oil), or the MCap EVO silver/gold/oil. All three are the same size for 47 mfd, and will fit to replace the MKP. Barring the issues about oil, which might be the best sounding? Again, I want to avoid too much enhancement of the upper midrange.
dhl93449
Dhl: I have a bit of recent experience, although with a different speaker. This summer I threw caution to the wind and did some nice crossover upgrades to my Tyler Woodmere speakers. I wanted to share my results in a dedicated thread, but I wanted to give you my thoughts now, so that you could have a bit more information to help you.

I swapped out the SEAS Millennium tweeters for the new SEAS Beryllium tweeters (exact size and fastener swap). I already had the Mundorf Silver/Gold/Oil tweeter cap. I am very, very pleased with the result. I did, naturally, swap resistors also, to match sensitivity as required. I won't go into a long rant, but this is super nice now. Multiple high freq instruments now are played simultaneously with realistic separation and space of each. Nothing harsh or tinny. And the presence is superb.

The tweeter mod was so nice, it made me long for better-defined midrange, especially upper mids where they are approaching high frequencies, as the mids did not measure up to these great high freq notes. Midrange caps are 120 uF, and I bit the bullet and bought six Mundorf M-Cap Supremes which total that capacitance. Yep, they are a big bunch of caps that take a lot of space. Well....was it worth it?? Hell Yes! A good bit of break-in was required, and right off the bat I only noticed more separation in upper mids. But as they broke in, I am getting a ton more definition, air and bass. Much more lower midrange/upper bass coming through now. The midrange drivers are 7", and in the big Woodmere enclosure I get gobs of bass. That is the biggest adjustment for me. I keep asking myself- is it realistic, or just bigger? Those big midrange caps are nearly broken in now I reckon, and I think it is both bigger and more realistic. I accomplished exactly what I was hoping to do in keeping up with the new tweeters.

Best part is that these improvements, while significant, do not ruin the overall sonics of the Woodmere speakers. They have simply been woken up. I could not be happier. Hope this gives you a bit of confidence to try your luck.
DHL,

It's funny how these reviews go. I think at this level of capacitor it must come down to system synergy and personal preference.

I have experience only with the 630VDC version of the MR and that's the one with which I would stay. For my friend's crossover project a few weeks ago I ordered a set of MR's from PartsConnexion. They didn't have the ones we needed in stock but it only took them a couple of days to get them from their distributor. If PartsConnexion is indicating a longer delay for the values you need then you might give MadiSound a call. HifiCollective in the UK might be another source.

You mentioned the various conductive materials in your post. As I know you are aware, the MR is an aluminized polypropylene cap. I prefer the tone of the copper film caps more, but as you also mentioned in your note the cost of admission to those caps is high. To me, short of making the jump into those caps, the MR is the best out there.

I reread your original post and it looks like you need a 4.7mfd for your tweeter? I have a pair of MR 630VDC in that value that I don't use anymore since moving the crossover to Duelund CAST. I'll send you an email offline to discuss further.

Cheers,

John
Rtilden:

Based on your experience, did you find a material difference between the Mundorf M-Cap Supremes vs the SGO? I understand the "Supremes" do not contain oil, so my quandary is still SG only vs SGO vs silver oil vs "no oil". I still do not quite understand the use/impact of oil in the first place.

John:

I wanted to thank you publicly for generous offer. I will try those Carity caps when I get them.
Thanks DH for the link. I found it interesting but did not see any post mods pics?