DRIVE UNITS BY MANUFACTURER:
OC25SC65-04
REPLACES VIFA 0C25SC05-04.
This tweeter features a 25 mm 4 ohm voice coil, a damped fabric dome giving a smooth frequency response and ferrofluid in the gap of the neodymium magnet for enhanced cooling of the voice coil. Twist-lock bayonet mounting for easy installation into custom faceplates / baffles. A full datasheet can be downloaded from the bottom of this page.
Can be supplied specially modified and prepared for easy replacement in the following B&W models: P4, P5, CDM1, CDM7SE. Not suitable for P6 or NT models. Please select which type you require from the dropdown menu.
Excellent replacement for Mission M7, M71, M72, M73, and so many others.
| Resonant frequency (fs) | 1382 Hz | Nominal impedance (Zn) | 4 Ω |
| Effective diaphragm diameter | 25 mm | DC resistance (Re) | 3.0 Ω |
| Ferrofluid ? Y/N | Yes | RMS power handling | 25 W |
| Recommended crossover | 2.5 kHz 12dB | Faceplate diameter | - |
| Sensitivity (2.83V/1m) | 93.1 dB | Cutout hole diameter | - |
Peerless by Tymphany
I came across some info that after many years these old B&W P4's tweeters degrade. As I grew older, (with reduced hearing of course), I never noticed this gradually deterioration over the years. So I bought the replacement tweeters from Willy's which was picked up just a few days later in Norway. They were mounted in 30 minutes,.. and what a change! My HiFi sounds as a new set. Thanks!
Thanks for the review Morten !
Will & Caroline
thx you so much for helping me geting the twiters for my speakers i hope all good for your bisnis in the futur and that it will never close i recemed you to the norwigen hifikluben its a store in norway for parts and hifi so you brobely will get order from ther now thx agine for the parts btw you need to put a bit of fome on the back side of the speakers for it to mount in the b&w cmd1 se to make them fit i will leave som pictur of the istalsjon
Thanks for the review Jeb !
Will & Caroline
Very good. A chance it does replace old inaudible tweeters
Thanks for the review Pascal !
Will & Caroline
Tweeter has been shipped very quickly and is working perfectly now. One point to mention is, that it did not fully fit mechanically as replacement as it was announced, had to rework mounting part slightly
Thanks for the review !
Will & Caroline
New tweeters bought as a replacement for B&W CDM1SE. Willy's fitted them in my existing housings and delivered promptly. Full marks!
Thanks for the review Jonathan!
Will & Caroline
Friendly technical support
40+ years in the trade
UK family run business
Excellent customer service
Quick dispatch
The crossover was constructed well, I just need to figure out the best way to attach it to my Kef Concertos as they are bigger than the ones supplied by Kef that are mounted on the front of the baffle board.
Very nice deep bass look amazing with my custom made speaker
Great speedy delivery and very easy to fit. The plastic in my drivers had perished and they had suffered one too many parties! No need to make any adjustments (someone above did suggest that). I just screwed them in and the foam compressed into place. Before and after below (before I changed speaker number 2). Thank you!
Thanks you very much for the kit. I found back my kelidh after nearly 27 years. The filter were really dead and one tweeter damaged. Very happy to decide to repair/ upgrade rather than change. I found back tone and stereo stage like in the old days probably even better.
I didn't know soldering material was so important thanks for providing some.
Quite easy to recap filter and change tweeters.
Also wanted to thank you for this little note hand writen in French just for me. Very nice attention to see.
Next step is the next question do I change first the drivers with the monacor as I ve lost dust caps but they still work properly or do I change my old arcam alpha 8. Is there really something to gain moving to an newer arcam sa10 or Radia a5? Are newer amplifier much better than the old days one?
In addition to my post from 17/11/2025, here is some information on the final status of the project: Saving the Mission 752 loudspeakers.
Once it was certain that it would be possible to revise the loudspeakers (thanks to Willy), the desire to also replace the low-midrange drivers and convert the crossover to a high-quality version quickly arose. I was fortunate enough to be able to purchase two Burmester 949 MKII midrange drivers from Audax to replace the existing low-midrange drivers (52LFHDA – still available and can be sold). They are practically identical in design, but significantly more refined and powerful. Revising the crossover proved somewhat more difficult because the values of the coils were not printed on them. However, they can be determined by measuring the originals. Mundorf resistors, coils and capacitors of the two highest quality grades were installed. These are not exactly cheap, but once the speaker is finished, the difference is clearly audible. The crossover was also modified slightly. A shunt was integrated into the high-frequency branch. Following a tip in a forum, the crossovers were also moved to the outside. They are currently still on the speaker without a housing. The metal housing provides perfect shielding. As the Willys tweeters are very efficient, they were ‘damped’ slightly. The final cost of the conversion was approximately £600. In return, the speakers now perform at a level that far exceeds their original condition. An exciting project that was only made possible by Willys – thanks to Caroline & Will ❣️
