réactions à la news [AES] Le Neumann U 47 FET est de retour

J'ai pas compris du tout ce que tu voulais dire.
Sinon j'ai lu ça (comprendre : l'abscence de différences audibles entre capsules mylar et PVC) sur le site officiel Microtech.

Wir gestehen Klangunterschiede zwischen unseren beiden Schallwandlern bezüglich unterschiedlichem Membranmaterial, STW7 red (Polyester PET auch als Mylar bekannt bzw. Polycarbonat – Macrofol MCF) und STW7 blue (Polyvinylchlorid PVC) mit unseren Messmöglichkeiten nicht nachweisen zu können.

Due to our repair and reskin service we made the experience that the tension of diaphragms (e. g. red line) reduces a little bit over a long time whereas the tension of old PVC diaphragms could have increased. One can assume that the aging of PVC is the reason for small differences in sound like less bass, strengthened high frequencies, loss of sensitivity and reverse attenuation caused by a tauter tension of diaphragm. So differences in sound are caused by alterations in tension of diaphragm due to aging process and not directly by chemical composition of diaphragm's material. This small alteration is possibly accepted because these old sound transducers with PVC diaphragms were sometimes attested having the best sound.

Mylar is a little bit more porous than PVC in respect of the absorption of water and also the absorption of dust. Especially on non-vaporized spots of diaphragm this can cause problems over time. Due to the humidity of close vocal use noise occurs earlier and makes it necessary to reskin the sound transducer. We like to use MCF instead of Mylar. This material is has got better properties regarding the absorption of water.

Mylar respectively MCF diaphragms. Many years before Neumann Berlin modified the M7 sound transducer for U47 (K47) to make it possible to screw a Mylar diaphragm to the backplate. In contrary to Microtech Gefell they ceased the production of M7 sound transducer. Apart from another diameter (34mm instead of 32mm) the K47 sound transducer is identical with M7. That's why the question of differences in sound between M7/PVC and K47/MCF and also regarding a larger diameter can be interesting particularly because the U47/48 was produced with M7 as well as with K47. With the help of our ring STR32/34 the outer diameter of M7 style sound transducer can be adapted to K47 assembly. Acoustically the increasing of outer diameter hasn't a positive influence on sound. That's why holders should be as thin as possible or segment holders should be used (e.g. our offer STS7.1). As a result the sound transducer isn't completely enclosed and not thickened and a short way for sound around the sound transducer is maintained. Our sound transducer STW7.1 in combination with the holder STS7.1 complies with this requirements because segment holder STS7.1 thickens only a small part of the sound transducers and allows that the main part can free. Consequently the frequency response is hardly influenced by the holder.