DRIVE UNITS BY MANUFACTURER:
SB21RDC-C000-4

UK STOCK ITEM - EXCELLENT REPLACEMENT FOR VIFA / PEERLESS XT19TD00-04.
The SB21RDC-C000-4 by SB Acoustics is a 21mm ring radiator tweeter. The centre of the diaphragm is inverted and bonded to an internal dimple on the pole piece, this innovation negates the need for a front phase plug and gives excellent extension to above 20kHz.
| Resonant frequency (fs) | 760 Hz | Nominal impedance (Zn) | 4 Ω |
| Effective diaphragm diameter | 21mm | DC resistance (Re) | 3.0 Ω |
| Ferrofluid ? Y/N | Yes |
Max power handling | 60 W |
| Recommended crossover | 2.6kHz/12dB | Faceplate diameter | 92mm |
| Sensitivity (2.83V/1m) | 90dB | Cutout hole diameter | 64mm |
Firstly, thank you for the excellent service!
I wanted to replace a pair of old 92mm faceplate Scan-speak D2008/8203 tweeters I've been using with KEF B100B bass driver for many years. The replacement D2008/8511(now discontinued) would 'drop in', although isn't a perfect replacement efficiency or sound wise (the 8203 was heavily doped). The wonderful Hiquphon OW1/92 would be first choice but sadly out of my price range!
The SB21RDC-C000-4 required a little modification to the cabinet, simply to accommodate the connectors, and has four screw holes rather than three - but fits flush with the baffle.
I've had to re-work the crossover somewhat (this is a 4ohm tweeter), but the results are very promising using a third-order high-pass with an l-pad (1.5/2.7 ohm based on the 3 ohm DCR). Currently using a 5.6 and 16 microfarad capacitors and a 0.125mH inductor, which seems to blend rather well. I'm sure I'll tinker more, but there's really nothing to dislike as it is.
Thankyou for your review Peter!
Will & Caroline
Friendly technical support
40+ years in the trade
UK family run business
Excellent customer service
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I tried this uprated capacitor through sheer curiosity and am pleasantly surprised with the results. So far, and not too many hours in, it’s giving a slightly smoother edge to the top end and has solved an issue I had regarding some hardness to the sound. I’m impressed enough that I’ll look to replace the mid range caps in the future.
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!
New Foam covers supplies by WHF have completely changed the appearance- they look brand new! Great quality foam, very reasonably priced and quick delivery. Delighted with they now look and sound - will hang on to them forever now.
Excellent upgrade, works perfectly with the speakers it's just soldier and play, they takeaway the over intensity of the original tweeters.
I've had my Mission 734s for about 30 years and for the last five or so the bass units have been falling to pieces. I was about to take the speakers to the tip, but didn't have the heart knowing how capable these used to be. I did a little internet research and these Monacor replacements appeared to do the job. Next day delivery from Willys was impressive, as was the killer sound once the replacements were fitted (which was a simple job). I'd forgotten how these speakers make the windows rattle. Very happy customer!
