Giussani Research Delta Butterfly One

 The very Hi-End loudspeakers system of reduced dimensions, they are able to offer a true highly dynamic sound in every listening environment.

To facilitate their use in smaller rooms their emission has been optimized both for near rear wall installation and free space.

30° toeing in toward the listening position also facilitates Horizontal NPS© emission.

 Among the exclusive Butterfly characteristics we can point out:

 The proprietary Butterfly© anti-diffraction system.

The front and rear panels professional damping finish.

The exclusive Giussani Research DDELS© (Dual Driver Extended Loading System)

The internal division of the loading volume into two connected triangular sub-volumes Delta System©.

The cabinet totally resonance free, due to Delta System©, lead plates complete internal lining and damping finish.

The total exclusion of any added elements that might introduce a negative effect on acoustic performance (as, among others, a front grille).

The crossover network, electrolytic capacitor free.

The 24 kt gold plated input connectors that allow for both bi-wiring and bi-amping.

Specifications

System:  3-Ways, bookshelf type

Speakers:

Low-range:  1 Woofer,  8″diameter  rubber surround,

Mid-range:  1 Mid-woofer,   8″ diameter  rubber surround,

High-range:  1 planar tweeter push-pull neodymium

Crossover:  Linkwitz-Riley/GR (electrolytic capacitors free)

Woofer Loading:  Dual Driver Extended Loading System (DDELS©)

Sensitivity:  87 dB SPL (standard listening conditions)

Nominal Impedance:  4 Ω

Amplifier Maximum Suggested Power:  50 to 250 watt RMS (no clipping) bi-amping

Wiring:  Mono/Bi-Wiring

Dimensions (Wx H x D):  9 ½" x 16" x 13"

Weight:  40 lb

Finish:  Cherry wood (or on demand) and Nextel graphite

Suggested Listening Distance:  >= 5 ft

Rear wall Min/Max distance:  Min = 0 in / Max = according to listening room acoustics

AUDIOLAB DELTA 4

Presentato per la prima volta al pubblico nel settembre 1977, il diffusore Audiolab Delta 4 si affianca al noto modello Delta Tre. Alla sezione bassi totalmente esente da onde stazionarie interne, fa riscontro una sezione medi-alti unica al mondo. L'elemento verticale contiene quattro altoparlanti a cupola morbida, specializzati per ricostruire con la massima precisione le caratteristiche spazio-temporali del segnale acustico contenute nell'informazione elettrica. Il panello portante e' stato sostituito da un montagio elastico su struttura a traliccio evitando l'insorgere di multipath acustico, importante causa di perdita di definizione. Il posizionamento dei trasduttori rispetto alpiano del pavimento e la frequenza di incrocio con la sezione bassi consentono una corretta estensione del fronte sonoro anche in senso verticale, aumentando sostanzialmente la realta' di ascolto. La Delta 4 rappresenta la soluzione di un numero impressionante di problemi elettroacustici e viene proposta come espressione del
massimo livello di qualita' sonora raggingibile da un prodotto hi-fi.

Diffusore acustico a quattro vie; frequenze di crossover: 320/2000/7000 Hz.

Woofer in sospensione acustica, midrange e tweeter a cupola morbida.

Mobile bassi prismatico a basi triangolari.

Gruppo medi-alti a linea acustica sospesa.

Protezione individuale di ogni componente.

Livello acustico massimo: 113 dB SPL/m (campo libero).

Potenza nominale: 100 watt RMSImpedenza nominale: 6 ohm.

A sinistra: Audiolab Delta 4 "1978" (Mid-basso ITT LPKM/130/50/ 120 T, Mid-alto ITT LPKM/105/37/120, Tweeter Dynaudio D28-AF in sostituzione dell'originale TW-11 e Woofer Audiolab in un volume maggiorato di circa 5 litri, per circa 50 litri lordi)

A destra: Audiolab Delta 4 "2003" (GR Delta 4 R3)
(Mid-basso ITT LPKM/130/50/ 120 T, Mid-alto ScanSpeak D3806/820000, Tweeter Dynaudio D28-AF e Woofer RCF L12P48 da 8 ohm in un volume di 31 litri)

Giussani Research GR DELTA 4 R9

The Hi-Fi Speaker GR Delta 4 R9 is a hi-end system perfectly able todeliver at the highest level all the positive values of the "Delta 4 Systems", already proven and widely appreciated in many installations in a timeframe that, ranging from 1977 to current days, is now over 30 years long.

The designer of GR Delta 4 R9 is Eng. Renato Giussani, of whom we should at least remember thedesign of ‘Audiolab Delta 3’speaker system in 1975, ‘Audiolab Delta 4’in 1977,’ ESB Serie New LD’in 1980, ‘ESB Serie 7 DSR’ from 1981, ‘Aedon Audio Serie NPS’ from 1990 to 1994, plus of courseall the GR (Giussani Research) systems from 2003 to present days.

DESIGN PHILOSOPHY

While listening music with a pair of ‘good’ electrostatics, isodynamic, systems with separatemid-high head, omnidirectional or free-standing mini-speakers... the user may easily have thesensation to listen to music in front of the real stage: the physical presence of the speakers isdisappearing in a much more evident way than in any other experience involving speaker systemswith wide front panels (say wider than 8 inches, to set a reference) The reasons of this achievement are partly related to psychoacoustic reasons (also depending fromthe external appearance of the speaker), but for the most part they are related to specific andobjective acoustic properties, derived by some common emission modalities of this systems, even ifthey look quite different from each other. In the following chapter we will review four main aspects of sound emission, that will be put inrelation with the operation modalities of the listed systems, highlighting that, among them, only themini-speakers (even with their well known limits in dynamics and extension at lowest frequencies)can provide the best and most realistic "phantom scene". In order to enjoy this quality to “become invisible”of the best mini-speakers, without having to giveup in terms of extension of low frequencies, max dynamic of the reproduced program and apleasant and realistic "phantom vertical dimension" of the reproduced soundstage (as delivered, forinstance, by electrostratic and isodynamic systems with large vertical extension), an extremelyeffective solution is provided by systems Delta 4 like, characterized by a very small emission areafor mid-high frequencies, coupled with a floor-loaded woofer (not a "subwoofer") able to coherentlycomplete the full musical message.
THE GR DELTA 4 R9 SYSTEMS
One of the main features of the GR Delta 4 R9 is that the mid-high unit is mounted on a specificpanel 16,6 cm. wide (about 6”) with bevelled edges. The dimensions of this front panel are chosen to minimize the perception of its physical presence,since from 1.000 Hz. This means that the horizontal dispersion of the sound waves generated by the speakers mountedon this panel can spread to reach the value that it would have without any mounting panel for allfrequencies up to 1.000Hz, while above this value the behavior of horizontal dispersion will besimilar to the one it would have if the soundwaves would be generated by any natural source havingan horizontal dimension similar to the one of the panel itself. Such effect leads to have a dispersionsimilar to the one that we find around a human head… And this explains the very peculiar perceptionthat a listener experiences by walking around a Delta 4 while the speaker is reproducing an humanvoice. This perception is very similar to the one experienced walking around a real person standingin the loudspeaker position.Of course the rear emission should not find obstacles on their path, and this is why the system hasan acoustically transparent rear panel, exactly like the front one. Another acoustic phenomena that makes perceivable the presence of the ‘box’ in electroacousticsystems is the one defined ‘diffraction’, that in this case happens around the edges of the frontpanel.

TECHNICAL SPECIFICATIONS
Emission: monopolar full-range (Never dipolar)
Number of ways: 4
Nominal Crossover Frequencies: monopolar full-range (Never dipolar)
Resonance Frequency: 41,5 Hz
F -3 dB: 34,2 Hz
Sensitivity: 87dB/1W in normal enviromental conditions
Nominal Impedance: 8 ohm
Max amplifier power, per channel: between 50 and 500 watt RMS
Dimensions: 44 L x 38 P x 163 H cm
Recommended listening distance: 2,5 meters or higher ( 8” 6’)
Recommended listening height (at rec. distance): between 105 e 165 cm from floor (41 inch to 65 inch)
Min - Max distance from rear wall (internal corner): Min=10 cm (4 inch) – Max = depending on the room

Speaker Components:
woofer GR-W12/A;
low-mid planar BG Neo10;
mid-high planar BG Neo3 PDR;
tweeter Scan Speak D2010.