All systems go ! Black Friday free zone !!
All systems go ! Black Friday free zone !!
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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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!
