DRIVE UNITS BY MANUFACTURER:
18M/4631T00
This new addition to the ground breaking Revelator series of dedicated midrange drivers features a larger 18cm sliced / glued pulp cone and a rigid titanium voice coil former. The low loss suspension and coated foam surround help this lovely unit yield a very useful sensitivity of 92 dB whilst still producing excellent midrange clarity and upper range extension. Highly recommended.
A full datasheet can be downloaded from this page.
Resonant frequency (fs) | 65 Hz | Nominal impedance (Zn) | 4 Ω |
Mechanical Q factor (Qms) | 5.65 | DC resistance (Re) | 3.5 Ω |
Electrical Q factor (Qes) | 0.67 | RMS power handling | 50 W |
Total Q factor (Qts) | 0.60 | Sensitivity (2.83V/1m) | 92 dB |
Equivalent volume (Vas) | 14L | Chassis diameter | 182 mm |
Friendly technical support
40+ years in the trade
UK family run business
Excellent customer service
Quick dispatch
Been looking for a supplier of replacement drivers for some years.
Willy's HiFi had just the parts at a good price and they arrived in a couple of days.
Excellent service. Even a personal thank you hand written on the invoice.
A quick delivery and the tweeters are perfect on my mission 753 freedom speakers. Easy to fit . Highly recommend.
I’m no expert when it comes to speakers, but after some research (and a strong recommendation from ChatGPT), I went with the SB Acoustics SB65WBAC25-4 as a reference full-range speaker in this size range.
Having now tested them, I can confidently say they’re probably the best speakers I’ve ever owned. The clarity is outstanding—every detail comes through with incredible precision. The bass is surprisingly full and punchy for a speaker this size, and they handle power impressively well. For anyone looking for a high-performance compact full-range driver, these are hard to beat.
Item as described and arrived quickly - and did the job. However, I suggested that anyone replacing speaker foam makes sure they have a very large pair of sharp dressmaking scissors as it was not easy cutting to size without producing a ragged edge (which I managed to hide short of a close inspection)!