DRIVE UNITS BY MANUFACTURER:
AIRMT-85
Categories: Monacor Tweeters Ribbon Tweeters
Air motion transformers (AMT) are a unique type of high-end ribbon tweeter which were developed by German physicist Oskar Heil during his research into the characteristics of the human ear.
Although AMTs are members of the ribbon family, they have a radically different mode of operation: these tweeters feature a specially folded / pleated diaphragm that expands and contracts along its length like a bellows, transforming an electrical signal into air waves and can therefore technically be viewed as a type of sound modulated air pump.The folding of the AMT diaphragm offers a larger active radiating area in the minimum of space.
AMT tweeters have a highly dynamic sound with an excellent transient response, high efficiency and low harmonic distortion.
We recommend a minimum crossover frequency of 2.5kHz / 18db octave.
Frequency range | 2kHz-30kHz | Nominal impedance (Zn) | 4 Ω |
Ribbon dimensions | - | DC resistance (Ribbon) | 3.8 Ω |
Effective area (squared) | - | RMS power handling | 20 W |
Crossover frequency | 2.5kHz 18db | Peak power | 40W |
Sensitivity (2.83V/1m) | 92dB | Faceplate (diameter) | 85mm |
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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)!