Michael Weidlich AUDIO
Michael Weidlich AUDIO | info@weidlich-audio.de
AMUR Series

The AMUR Series

AMUR C

AMUR D

AMUR D/8 

AMUR RSD

 

 

 AMUR C

 

 


Modern loudspeaker technology and the unique analog equalisation in every detail make AMURs the "State of the Art" sound transformers. Every loudspeaker will be fine-tuned to its optimal performance, metrologically and aurally, by our developer Michael Weidlich personally. The highly complex filter circuits of the crossovers are truly a masterpiece.


The loudspeaker chassis all come from the newest Cell-series of Accuton. Every chassis opens up a new chapter in the history of technology. The accustic centres of the Cell-series synchronise perfectly with each other. The AMURs can therefore achieve time-coherent music reproduction even with vertical baffle, which until now has been impossible.


The level of distortion of the Accuton Cell-chassis is extremely low. Together with the time-coherent tuning, the otherwise common distortion by signal-/transient-reproduction can be reduced to the lowest level possible.


In the case of AMUR, much emphasis was placed on minimal time-drift on end of transmission, which brings signal reproduction and room imaging to a whole new level.

 

The closed box configuration with a low Q-value and the additional circuit design of both woofers allow for a flat descent near the lower end of the frequency range.

 

The bass is impulsively strong and comes from the spot in the room when it's recorded. It belongs to the instrument played and not the loudspeaker!


Our developer Michael Weidlich has so painstakingly equalised the menbrane resonance of the Cell C25 tweeter in order to eliminate the distinctive sound of its material. The transmission range goes into highes way above the audible range with very little time shift.


These measures ensure a superb allocation of high frequency sounds, particularly of the overtones of the respective instruments and of their spacial representation.


Keen music lovers can now immerse themselves in the wonderful world of music in roundbreaking intensity. The solid imaging of the recording space in all dimensions is phenomenal. Details that were hidden are made "visible". In order to achieve that, good quality in the recording and the rest of the transmission chain are naturally indispensible.

 

The AMURs reveal immediately and unmistakenly all the characteristics in the transmission path and thus qualify as perfect control loudspeakers for mastering and for test purposes as well. With the help of an AMUR one can configure without fail a supurb audio equipment in little time. 

 

The eternal search for your dream loudspeakers will now come to an end.

 

The basic form of the enclosure is a pentagon with a multilayered wall mounting.

Wall thickness: 2,5 cm

Enclosure measurements (lacquered finish)

Height: 117 cm

Width: 35,8 cm

Depth: 34 cm


Surface finishes: natural bamboo, bamboo caramel, black bamboo, or lacquered in high gloss or matt in any colour. The membranes for Accuton chassis are available in white or anthracite.

 

 

 


Enclosure surface: Bamboo Caramel

                        

                                           

Bamboo gets the brownish tone from heat that caramellised the sugar contained in it.

 


 

Step Response

 

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 AMUR D

 

 

Accuton Diamond Tweeter 

 

The Accuton Diamond Tweeter BD25-6-258 is used in the AMUR D. Its frequency range goes beyond 50,000 Hz. The lineal swing of the system is +- 1.2mm, which shows the dynamic potential of this exceptional driver.

                                   

The basic form of the enclosure ist a pentagon with a multilayered wall mounting.

Wall thickness: 3,2 cm

 

Enclosure measurements:

Height: 118,4 cm

Width: 40,5 cm

Depth: 38,5 cm


The crossovers are housed in a separate chamber. They sit mirror-inverted behind one of the rear enclosure walls. The chambers are closed off with a 6mm-thick printed and/or lacquered glass plate. The print motif is individually configurable.


Because the crossovers are housed in separate chambers they become independent of the internal capacity of the enclosure. Microphonic effects are therefore effectively minimised. Further measures to reduce mechanical vibration result in an impressively stable, crystal clear sound.


The Accuton midrange and woofer membranes for AMUR D are available in white or anthracite. The diamond tweeter has a black diamond membrane.


Front view with anthracite membrane 

 

                                    

Rear view with glass plate   

 

                             

Test Result

 

 

Rectangular Playback 1 kHz

The AMUR D is exemplarily time-coherent and linear

 

 

 

Dynamic Measurement 3D Response

Test signal: Sine half-wave in the range of 100-10.000 Hz

This test method aims to interpret step response and shows the "dynamic frequence response" of the transformer. The dynamic performance of the AMUR D is sensational.

 

 

 

The top graph shows the impedance of the AMUR D in the range of 10-50.000 Hz. The bottom graph illustrates the electric phase. 

 

The resistance of a loudspeaker is frequency-dependent. In addition, it causes time shift (electrical phase) between electric current and voltage. Here the AMUR D also works examplarily and is therefore no heavy "burden" on the attached amp.

 

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  AMUR D/8

 

 

The AMUR D is alternatively available in a 8-sided enclosure.

 

Both the slim side plates adjacent to the baffle resemble roughly a parabolic curve. This results in good radiation performance. 

 

A great deal of steps have been taken to reduce vibration. For example, the enclosure has a 32mm-thick trilayer wall mounting. The crossover chamber, independent of the internal capacity of the loudspeakers, is located in the rear of the enclosure. A 5mm-thick cork layer serves as vibration-absorbing mounting underlay for the crossovers. The over 70 crossover components are secured with a special accoustic putty. That way microphonic effects are effectively eliminated.

 

Special Vovox-Klangleiter cables are used for the internal wiring. Care is also taken to avoid unwanted vibration transmission in the wiring. The cables are run, embedded and fixed with vibration absorption.

 

Tweeter and midrange of the Accuton Cell-series are not screwed to the enclosure but rather held to place in the baffle opening by an expandable rubber band. With this technique the two-way vibration transmission with the baffle is reduced. The midrange grill's otherwise audible resonance is hindered by a transparent silencer.

 

Every AMUR is individually calibrated. The factory-selected loudspeaker drivers are already metrologically tested and paired. The filters of the crossovers are customised to the individual chassis. The almost complete elimination of membrane resonance by the use of filters may be unique.

 

The effort pays off. Every chassis' own inherent resonance is practically eradicated. Most crossover components smooth out the narrow-band resonance spikes as well as correcting the impendace, in order to ensure optimal working conditions for the resonance filters. The influence of the components in the signal path of the loudspeaker is to some extent smaller than with the simplest filters (Filter 1. Ordnung / 6 dB/Okt ).


 

TIME-COHERENT LOUDSPEAKERS


The myro AMURs belong to the category of the so-called "time-correct" tramsformers that one rarely comes across.


The time-precise conversion makes it possible for the loudspeakers to follow music signals very accurately. Music is a dynamic act with numerous transient effects. These so-called transients describe the initial noises that come with every strike, tap, blow, or brush of an instrument, practically with every played note.


Dynamically time-correct means that a loudspeaker tunes concurrently with all loudspeakersystems and sends transient effects largely true to their characteristics in the direction of the audience. The time references included in the recording, the corresponding room positioning, and the impulse dynamic are played back in their total intensity.


The difference to ordinary loudspeakers can be distinctly heard.


The highly precise, impulse-true signal conversion of the myro AMURs lead to an unrivalled, genuinely clear sound with breathtakingly realistic spacial reproduction.


DESIGN


The pictured myro AMUR D/8 shows the finish in piano lacquer with the NCS-Farbton S 8505-Y80R GL. Depending on its exposure to light, the lacquered surface can be reminiscent of the colour diversity of a good Bordeaux wine.


The vibration-absorbing glass plate is gummed up to the crossover chamber and makes up the rear wall of the enclosure. It's rear-printed with the myro Logo and label and lacquered in the same colour as the enclosure itself to deliver optical uniformity.


The enclosure can be finished in basically every colour.


The digital print on the rear glass plate offers a creative design option. The classy appearance can add, optically, to the pleasant surprise the AMURs will bring to their listeners.


The midrange and woofer are also available in anthracite. The Black-Diamond tweeter has a black gleaning membrane.


Enclosure measurements:

Height 118,4 cm

Width max. 34 cm

Depth 43 cm

Weight 61 kg

 

 

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 AMUR RSD

 

 

The AMUR RSD is designed as a rear speaker in a surround system together with AMUR D/8.

The sensational Accuton high-frequency woofer C168-6-990 is used in addition to the Accuton diamond tweeter BD25-6-258.

 

 

The nail-down accurate filtering of the transmission behaviour of the drivers in the enclosure leads to a very precise reproduction of the sounds and makes the AMUR RSD accoustically invisible. Its integration into the surround system is perfect. 


The following picture shows the crossovers in the rear and bottom chambers.

 

 

Enclosure measurements:

Height: 42 cm

Width: max 29,7 cm

Depth: 39,5 cm

 
The metrological review speaks for itself.

Step response (time axis 2 ms)

 

 

Dynamic Measurement 3-D Response 0,5 sine wave front view

(testing range 100 - 10.000 Hz)

 

 

Dynamic Measurement 3-D Response 0,5 sine wave rear view

(testing range 100 - 10.000 Hz)

 

 

The following test shows the signal reproduction of the AMUR RSD in the otherwise very critical transient zone between tweeter and midrange woofer.

Oscilloscope testing sine wave 2 kHz

 

 

oscilloscope testing sine wave 3 KHz 

 

 

oscilloscope testing sine wave 4 KHz  

 

 

The AMUR RSD works according to the closed-box principle. Due to the very low performance of the basic resonance it results in a most flat progression of the low-frequency edge. Therefore the AMUR RSD as a rear speaker doesn't disturb the bass behaviour of the main speakers AMUR D/8.


The high-pass filter response tested in near field (20 - 300 Hz)

 

 

frequency response and accoustic phase in the listening room

testing range 200 - 20.000 Hz / unpolished) 

 

 

Impedance (testing range 10 - 50.000 Hz) 

 

 

The minimum is 5,6 Ohm just above 10 kHz.

Nominal impedance: 7 Ohm

 

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Accuton C30-6-358, Accuton Cell C168-6-990, Accuton Cell AS250-4-552